SBI 3U Exam Review 2024 PDF

Bio Study Doc Exams Biochemistry 1. Characteristics of Life ​ 4 main elements are found in living things C (carbon), O (oxygen), N (nitrogen), and OH (Hydroxide) ​ These are the main elements needed for protein production for life Nutrients ​ Chemicals which are needed in order to mai...

Bio Study Doc Exams Biochemistry 1. Characteristics of Life ​ 4 main elements are found in living things C (carbon), O (oxygen), N (nitrogen), and OH (Hydroxide) ​ These are the main elements needed for protein production for life Nutrients ​ Chemicals which are needed in order to maintain life ​ Main types of nutrients are carbohydrates, proteins, lipids (fats), vitamins. Minerals and water ​ Organic nutrients: contains carbon from a living source (carbohydrates, lipids, proteins and vitamins ​ Inorganic nutrients: does not contain carbon, not from a living source, (from the earth) minerals and water ​ Macronutrients: are needed in large quantities during the day (more than 1g per day) like carbohydrates, proteins, lipids and water ​ Micronutrients: are needed in small quantities during the day (less than 1g usually in mg or u gram) like vitamins and minerals 2. Draw a table that shows the monomers and polymers of carbohydrates, proteins, fats and nucleic acids (DNA/RNA). Know the functions of each. Carbohydrates: ​ Provides Energy ​ Made up of C, OH and O in the ratio; 1C ; 2H ; 1O 1.​ Monosaccharides (simple sugar) ​ They contain 3 to 7 carbon atoms in them but the most common formula is C6H12O6 (glucose, fructose and galactose) - Structure ​ Taste very sweet ​ These sugars go directly to the blood, not digested 2.​ Disaccharides (double sugar) ​ Contains 2 monosaccharides that have been chemically bonded ​ These sugars have different properties from monosaccharides ​ Lactose, Sucrose and Maltose ​ They do need digestion as the bonds between the sugar molecules must be broken apart 3.​ Polysaccharides (Very complex-contains 100’s of sugars) ​ Chain of monosaccharides joined together, how the chains are joined determines the type of polysaccharide ​ 3 main types: ​ Starch - which is used to store energy in plants and is made up of a simple chain of monosaccharides - breads, rice, pasta.  ​ Glycogen - are highly branched chains of glucose that are used to store extra sugar in humans and animals ​ When blood sugar decreases, the extra glycogen is converted back to glucose ​ It is stored in the muscles and liver. Enough is stored for a normal day ​ Cellulose- highly branched chains of glucose that are twisted in a way to make them water-insoluble ​ Provide support to the cell wall of plants. Humans cannot digest it, it is digested by fiber for us. Protein ​ Proteins are most diverse nutrients and their structures determine their functions ​ Structure- each protein is made up of chains between 20-200 amino acids held together by peptide bonds created by hydration synthesis. ​ There are 20 different types of amino acids, all have a common central structure where a unique “radical” group is attached ​ Variety of proteins are made by different combinations of the 20 amino acids ​ The NH2 group is the amino acid ​ The COOH group is the carboxylic acid group ​ Every protein has a unique 3D structure which determines its function (shape is everything in proteins) ​ Functions: ​ Structural element (hair, teeth, nails, bones), tissue repair/ growth, cell walls, enzymes, messenger hormones (pheromones) Lipids ​ Lipids are fatty compounds which carry out a lot of functions in our body. They are not soluble in water and used for long term energy storage. It works as an insulation under the skin and this padding protects the organs (kidneys and brain). It is a messenger like testosterone. ​ Structure- formed when 1 molecule of glycerol and 3 molecules of fatty acids combine through dehydration synthesis. Water- Inorganic macronutrients ​ 68% of pur body mass and 90% in plants and animals ​ Functions: ​ Lubrication in joints ​ Shock absorber ​ Dissolves toxins ​ Helps regulate temperature ​ Solvent for body chemicals ​ Ensures proper cell communication ​ Water is a polar chemical(+charge on one side and -charge on the other side) ​ Water molecules stick to each other Vitamins:  ​ Micronutrients that act as important coenzymes (help enzymes to work) ​ Necessary for growth, disease resistance, maintain healthy intestines and blood clotting ​ Fat soluble vitamins: ​ Vitamins that will dissolve éaccumalate in the fat storage areas of the body. Can accumulate to toxic levels if not taken correctly ex A,D,E,K ​ Water soluble vitamins: ​ These dissolve in water an the body can excrete any excess of those ​ Lost when we cook them Ex: B1,B6, B12 Niacin and Folic acid and Vitamin C ​ A lack of certain vitamins = deficiency disease ​ Vitamin C deficiency - scurvy Minerals: ​ Your body uses minerals for many different jobs, including keeping your bones, muscles, heart, and brain working properly ​ Minerals are also important for making enzymes and hormones ​ Micronutrients that help chemical reactions to occur and structural components Ex: Calcium and iron 4. Know the levels of protein structure. 1.​ Primary structure - order of the amino acids in the polypeptide chain (glycine- asparagine-methionine) ​ Any changes here change the shape and function of proteins 2.​ Secondary structure- Past 30 amino acids, in length, chemical attraction among the NH2/COOH groups and cause the chains to become either a helix or a plated sheet 3.​ Tertiary structure- Attraction between the R group cause the chains to twist into a 3-D shape which is the functional form of the protein 4.​ Quaternary structure- proteins where 2 or more polypeptide chains are combined together to make the proteins work ​ Ex: Hemoglobin is made up of 4 protein chains Affecting the protein structure Denaturation- when a protein is exposed to changes in temperature pH which breaks the tertiary structure ​ 3D shape changes and it loses its function and structure ​ Heat causes protein loses it shape ​ Straightening or curling hair requires heat 5. What is the difference between saturated and unsaturated fat, and types of cholesterol? Saturated Fats- Have only single bonds between the carbons in the fatty acid chains. They are solid at room temperature (like butter) Unsaturated Fats- have double bonds between the carbons in the fatty acid chain. Tend to be liquids at room temperature (nut oil, olive oil) Cholesterol- A waxy - lipid necessary for making cell membrane rigid, to to insulate nerves so signals travel properly and to make bile (fat digestion)  ​ Our livers make the cholesterol we need, so excess in our diet gets turned into plaque in our arteries ​ Cholesterol in the blood binds to proteins to form lipo proteins High Density Lipoproteins- they are good for us cause move cholesterol out of the body. Low Density Lipoproteins- they are bad for us because they get collected in the walls of the blood vessels causing them to narrow. 6. Explain the induced fit model of enzyme action Cell Biology 1. Be able to sketch a cell membrane and know the key components. Know its function. ​ Cell membrane: ​ Controls what enters and leaves ​ Prevents the entry of unwanted particles and the escape of important nutrients ​ Composed of phospholipids - modified lipid molecules (have a PO4 group instead of fatty acids) ​ The head of the phospholipids - phosphate group. Its -3 charge makes it polar and attracts to the positive side of the water. (hydrophilic ) ​ The tails are the other 2 fatty acids- since are neutral (non polar) they do not attract to water AKA (hydrophobic) ​ Lipid Bi- layer ​ Phospholipids are arranged in a double layered membrane that has the tail regions touching while the heads are in the contact with the water ​ Within this membrane are the protein molecules which form pores for materials to pass through ​ Proteins which run through the membrane are intrinsic, integral while those that sit on the inner or outer surfaces are called extrinsic, peripheral. 2. Know diffusion and the three osmotic solutions and how they affect a cell. Diffusion ​ The movement of a substance from high concentration to low concentration ​ Does not require energy ​ Occurs when the molecules are moving ​ When the concentration is equal throughout the container (cell) then dynamic equilibrium has been met Hypotonic - more solute inside the cell ​ Water enters in large amount to balance it out ​ Cell swells, may burst Hypertonic - more solute outside the cell ​ Water leaves to balance it out ​ Cell shrinks may dehydrate and die Isotonic - equal amounts of solutes inside and outside the cell  ​ Water flows in and out at equal rates ​ Cell is engaged 3. Discuss the many and varied ways that substances enter and exit the cell. 1.​ Passive transport: The movement of materials from a high concentration to low concentration without the use of energy ​ Diffusion, osmosis, and facilitated diffusion 2.​ Facilitated diffusion: ​ Diffusion with a helper protein to carry large molecules into the cell ex glucose ​ Instrine proteins (pores) allow these in 3.​ Active transport: ​ A process that requires energy to move from a low to high concentration area ​ Uses energy in the form of (what glucose gets changed into) 4.​ Bulk transport: ​ Used for molecules too large or polar to pass through ​ Cell membrane folds itself inwards to form a membrane enclosed (vesicles) 5.​ Endocytosis ​ Cell membrane folds inwards to swallow the materials ​ Pinocytosis, phagocytosis and receptor mediated endocytosis 6.​ Pinocytosis ​ Cell drinking, intake of extracurricular fluid and small charged particles 7.​ Phagocytosis ​ Intake of large particles, involves the cell chasing downwards and engulfing particles ​ White blood cells in immune system 8.​ Receptor Mediated Endocytosis ​ Specific protein receptors in cell membrane bind to specific molecules and draw them into the cell ​ Ex adrenaline Genetics 1. Mitosis and meiosisMitosis is the type of cell division responsible for growth, repair, and asexual reproduction in multicellular organisms. It produces two genetically identical daughter cells, each with the same number of chromosomes as the parent cell (diploid number). Phases of Mitosis 1.​ Interphase (Preparation for division): ○​ The cell grows, replicates its DNA, and prepares for mitosis. ○​ Interphase is divided into three stages:  ​ G1 (Gap 1): Cell growth and normal function. ​ S (Synthesis): DNA replication. ​ G2 (Gap 2): Further growth and preparation for division. 2.​ Prophase: ○​ Chromosomes condense and become visible. ○​ The nuclear membrane begins to break down. ○​ The spindle fibers (microtubules) start to form and attach to chromosomes. 3.​ Metaphase: ○​ Chromosomes align at the cell's equator, known as the metaphase plate. ○​ Spindle fibers attach to the centromeres of each chromosome. 4.​ Anaphase: ○​ The sister chromatids are pulled apart toward opposite poles of the cell as the spindle fibers shorten. 5.​ Telophase: ○​ Chromatids reach the poles and start to de-condense back into chromatin. ○​ The nuclear membrane reforms around each set of chromosomes. 6.​ Cytokinesis: ○​ The cytoplasm divides, creating two separate daughter cells, each with a full set of chromosomes. Significance of Mitosis ​ Mitosis is crucial for asexual reproduction, growth, and tissue repair. ​ It ensures that each new cell has an identical set of chromosomes, preserving the genetic material. Meiosis Meiosis occurs in two stages: Meiosis I and Meiosis II. Meiosis I: Reduction Division 1.​ Prophase I: ○​ Chromosomes condense and become visible. ○​ Homologous chromosomes (chromosomes with the same genes, one from each parent) pair up and undergo crossing over, where sections of  chromatids are exchanged between homologous chromosomes, increasing genetic variation. ○​ The nuclear membrane breaks down and spindle fibers form. 2.​ Metaphase I: ○​ Homologous chromosome pairs align at the metaphase plate. 3.​ Anaphase I: ○​ Homologous chromosomes are pulled to opposite poles (this is different from mitosis, where sister chromatids separate). 4.​ Telophase I: ○​ The nuclear membrane reforms around each set of chromosomes, resulting in two haploid cells. Meiosis II: Similar to Mitosis Meiosis II is similar to mitosis but involves the division of haploid cells produced in Meiosis I. 1.​ Prophase II: ○​ Chromosomes condense again, and spindle fibers form in the two haploid cells. 2.​ Metaphase II: ○​ Chromosomes align at the equator in each haploid cell. 3.​ Anaphase II: ○​ Sister chromatids are pulled apart toward opposite poles. 4.​ Telophase II: ○​ Nuclear membranes reform, resulting in four non-identical haploid cells (gametes: sperm or eggs). Significance of Meiosis ​ Genetic diversity: Meiosis introduces genetic variation through processes like crossing over and independent assortment of chromosomes. ​ Reproduction: Meiosis produces gametes (sperm and eggs) for sexual reproduction, ensuring that offspring inherit a combination of genetic traits from both parents. Difference between Mitosis and Meiosis Mitosis results in two nuclei that are identical to the original nucleus. Meiosis, on the other hand, results in four nuclei, each having half the number of chromosomes of the original cell. In animals, meiosis only occurs in the cells that give rise to the sex cells (gametes), i.e., the egg and the sperm. Before mitosis occurs, a cell's DNA is replicated. This is necessary so that each daughter cell will have a complete copy of the genetic material from the parent cell.Mitosis occurs in somatic cells; this means that it takes place in all types of cells that are not involved in the production of gametes. 2. Understand the chromosome number in each process and how they differ. -​ chromosome number (diploid) in the daughter cells. -​ Meiosis involves two divisions and results in four different daughter cells. It reduces the chromosome number by half (haploid). 3. Know how the final stages in meiosis differ in each sex. -​ Spermatogenesis- sperm formation in males: 1. Start (46 Chromosomes): A starting cell has 46 chromosomes. Before meiosis, the chromosomes are copied, making 92 chromatids (still 46 chromosomes because they're paired). 2. Meiosis I (Split #1): The cell divides into two cells, each with 46 chromatids (or 23 chromosomes in pairs). 3. Meiosis II (Split #2): These two cells divide again. Now there are four cells, each with 23 chromosomes (no pairs). 4. Final Step: These four cells develop into four sperm, each with 23 chromosomes, ready to combine with an egg during fertilization. 1. Start (46 Chromosomes): 46 chromosomes start the process. The chromosomes are copied, making 92 chromatids. 2. Meiosis I: The cell splits into: A secondary. First polar body. Both have 23 chromosomes. 3. Meiosis II: The secondary splits into: A mature egg (big, functional cell with 23 chromosomes). Another polar body (small and dies). 4. End Result: One egg (ready for fertilization) and three polar bodies (waste cells). 4. Know the structure and function of DNA and RNA. Structure DNA (deoxyribonucleic Acid- responsible for growth and development of loving things) ​ Our Dna codes for 40- 60,000 traits in our body and is inherited through genetics ​ DNA is organized into 46 strands of information or chromosomes ​ Chromosomes are divided into segments called genes which provide instructions about everything. Gene (DNA) ​ Gene is a small segment of DNA which controls a single trait in our body (hair color, eye color, height) ​ Many traits at least require 2 traits to control them ​ Your DNA will contain a gene or trait from each of your parent ​ Genes are made up of smaller subunits called nucleotides ​ A nucleotide is a building block for DNA and RNA (DNA copy) ​ It is composed of a sugar molecule, phosphate group and a nitrogenous base ​ In DNA the sugar is deoxyribose in RNA it is ribose DNA (Deoxyribonucleic Acid) ​ Structure: DNA is a double-stranded molecule that forms a double helix. Each strand is made up of nucleotides, consisting of a sugar (deoxyribose), a phosphate group, and a nitrogenous base. ○​ Adenine (A) ○​ Thymine (T)  ○​ Cytosine (C) ○​ Guanine (G) ​ Function: DNA contains the genetic instructions for the development, functioning, growth, and reproduction of all living organisms. It is the blueprint for protein synthesis, which determines an organism’s traits. RNA (Ribonucleic Acid) - DNA is too important to leave the nucleus each time so it makes a copy of itself (RNA) which could leave ​ Structure: RNA is a single-stranded molecule composed of nucleotides (like DNA) but has ribose sugar instead of deoxyribose and uracil (U) instead of thymine. ​ Types of RNA: ○​ mRNA (messenger RNA): Carries the genetic code from DNA to the ribosome, where proteins are synthesized. ○​ tRNA (transfer RNA): Brings amino acids to the ribosome during protein synthesis. ○​ rRNA (ribosomal RNA): Makes up the ribosome, the site of protein synthesis. Key Difference Between DNA and RNA ​ DNA is used as a long-term storage of genetic information, while RNA plays a key role in the short-term transfer and use of that genetic information in the cell, specifically in the process of protein synthesis. 5. Know DNA replication. DNA Replication: The Process of Copying Genetic Material Before cell division (whether mitosis or meiosis), cells must first replicate their DNA to ensure that each new cell receives a complete copy of the organism’s genetic material. Steps of DNA Replication 1.​ Unwinding of the Double Helix: The enzyme helicase unwinds and separates the two strands of DNA. 2.​ Base Pairing: The enzyme DNA polymerase adds complementary nucleotides to each strand, following the base-pairing rules (A with T, C with G). 3.​ Formation of Two Identical Strands: The result is two identical strands of DNA, each containing one original strand and one newly synthesized strand. 6. Name the types of mutations and how they occur and their results. ​ Change in the nucleotide sequence of DNA ​ May occur in somatic cells ​ May occur in gametes (eggs and sperm) and be passed to offspring Mutagens : Anything that causes a change in the sequence of the DNA ​ Radiation- UV radiation (sunlight and tanning) and x rays (medical, dental, security) ​ Chemicals - cigarette smoke ​ Infectious agents - viruses and bacterias Chromosome Mutation:- ​ Deletion- the breakage of a piece in a chromosome ​ Inversion - chromosome segment breaks off and flips around backwards and reattaches ​ Duplication - occurs when gene sequence is repeated ​ Translocation - involves two chromosomes that are not homologous. Part of one chromosome transferred to another ​ Non- disjunction - Failures of chromosomes to separate during meiosis. Causes gametes to have too many or too few chromosomes 7. Know the terms – gene, allele, dominant, recessive, homozygous, heterozygous, hemizygous, carrier, genotype, phenotypes, Trait - is a specific characteristic of an individual. Traits can be determined by genes, environmental factors or by a combination of both. Allele - the alternative form or versions of a gene. People inherit one allele for each autosomal gene from each parent. Dominant - Individuals inherit two versions of each gene, known as alleles, from each parent. In the case of a dominant trait, only one copy of the dominant allele is required to express the trait. Recessive - A type of allele that when present on its own will not affect the individual. Two copies of the allele need to be present for the phenotype to be expressed. Homozygous - when two alleles are same (TT, tt) Heterozygous - when two allele are different (Tt) Genotype - the genetic makeup of the organisms, usually shown in a code Phenotype - the physical appearance of the organisms Incomplete dominance - occurs when a dominant trait blends with the recessive trait ( red + white = pink) Co- dominance - when 2 dominant traits are seen at the same time. No blend. Sex Linked Traits - traits located on the X and Y chromosomes are called sex linked traits, as these are the chromosomes that determines sex body (Ex: hair color, eye color, height). Many traits require at least 2 genes to control them. Chromatin - the genetic material of cells which normally exists in long thin strands Chromosomes- they get condensed into coils and become visible usually in preparation for cell division. (46 chromosomes in a human cell) Chromatid- one half of the chromosome joined by the centromere Centrioles - A centriole is an organelle that helps cells divide, or make copies of themselves. Centrioles are only found in animal cells Spindle fibers- is a network of filaments that are formed during the cell division process. They help in the movement of chromosomes during both mitosis and meiosis. Homologous - A pair of identical chromosomes Zygote - a diploid cell resulting from the fusion of two haploid gametes Gamete - A gamete is a reproductive cell of an animal or plant NONDisjunction - failure of chromosomes to separate during meiosis causes gametes too many or too less chromosomes Disjunction - The regular separating of the chromosomes to opposite sides of the cell (anaphase) 8. Be able to work through problems involving simple dominance, incomplete dominance, codominance, sex-linkage, and dihybrids. (define) 9. Be able to analyze a pedigree. 10. What is nondisjunction? How can chromosomes be analyzed? -​ Nondisjunction: failure of chromosomes to separate during meiosis, gamete to have too many or too few chromosomes. Chromosomes can be analyzed using Amniocentesis-  extracting amniotic fluid (the fluid surrounding a fetus in the uterus) which has fetal cells. Can determine the chromosome number, and sex (risky). -​ 15 weeks. Chorionic Villi Sampling: sample from the placenta (chorionic villi), contains fetal cells. -​ 10-13 weeks in pregnancy. 11. Know genetic disorders discussed. Down syndrome - Trisomy 21 ​ Individuals experiencing this will have an extra copy of chromosomes ​ Mild to moderate intellectual disability Turner's syndrome - XO ​ One of the parents sex cells does not contain a sex chromosome ​ Individuals have only 1 X chromosome ​ Phenotypically female underdeveloped Klinefelter's Syndrome - XXY ​ A gamete which contains 3 sex chromosomes Dominant Recessive traits: Phenylketonuria: ​ A homozygous recessive traits ​ Causes the lack of an important enzyme which breaks down the amino acid; phenylalanine ​ Phenylalanine builds up and can cause brain damage ​ Every baby is tested at birth for this ​ Requires a special diet until around age of 5 when they may start making the enzyme again Huntington disease: ​ Due to the presence of dominant gene (could be homozygous) ​ Symptoms present after age of 35 ​ Loss of muscle coordination, mental deterioration because nerves deteriorate ​ No treatments or cures Tay-sach disease: ​ Homozygous recessive disorder ​ Lacking an enzyme that prevents the build up of large fat molecules in the brain ​ Normal at birth, but fat deposits increase and cause damage ​ Intellectual disabilities, blindness, little vascular activities by age of 1 Mutated Gene Disorder Cystic Fibrosis  ​ Caused by the mutation in one gene in the cells that line the respiratory tract and digestive tract ​ Homozygous recessive disorder ​ No treatments or cures Sickle Cell Anemia ​ 50% of blood cells become sickle shaped which decreases oxygen supply to tissues The Respiratory System 1. Outline the path of an oxygen molecule as it travels from the atmosphere into the bloodstream. 1. Inhalation (Mouth/Nose) ​ The oxygen molecule enters the body through the mouth or nose. ​ In the nasal cavity, the air is filtered, moistened, and warmed. 2. Pharynx (Throat) ​ The oxygen passes through the pharynx, a shared passage for air and food. 3. Larynx (Voice Box) ​ The air travels through the larynx, where the vocal cords are located. Here, the airway is open for the air to pass into the trachea. 4. Trachea (Windpipe) ​ The oxygen molecule moves down the trachea, a tube that leads to the lungs. It is kept open by cartilage rings to prevent collapsing. 5. Bronchi and Bronchioles ​ The trachea branches into two bronchi (one for each lung). ​ Each bronchus further divides into smaller bronchioles within the lungs. 6. Alveoli ​ The oxygen molecule reaches the tiny air sacs called alveoli at the ends of the bronchioles. ​ In the alveoli, oxygen is exchanged for carbon dioxide in the capillaries (tiny blood vessels surrounding the alveoli). 7. Diffusion into Bloodstream ​ The oxygen diffuses from the alveoli across the thin walls into the capillaries. ​ It binds to hemoglobin in the red blood cells, which carry it through the bloodstream to tissues and organs throughout the body. Hemoglobin ​ Iron based protein made up of 4 polypeptide chains to come together ​ It is considered to be the main respiratory pigment in red blooded organisms ​ Fe atom is able to hold up 4 molecules of oxygen for transport of the cells ​ When O2 mixes with Fe, it creates oxy-hemoglobin which is bright red in color ​ When no O2 mixes with Fe, it creates deoxy-hemoglobin which is dark maroon red ​ Each RBC has 250 million of hemoglobin molecules which must be maintained at a pH of 7.2- 7.4 2. Make a chart of organ structure and function. Organ Structure Function Nose/Nasal Cavity Nasal passages lined with - Air intake: Filters, warms, mucous membranes and humidifies the air. - Protection: Traps dust, microbes, and foreign particles Contains cilia and mucus in mucus to prevent infection. for filtering air Pharynx (Throat) - Funnel-shaped muscular tube Directs air to the larynx and food to the esophagus Airflow regulation: Directs air from nasal cavity to the larynx Larynx (Voice Box) - Cartilage structure with vocal - Air passage: Directs air into cords the trachea. - Contains epiglottis to prevent - Voice production: Houses food from entering the airway the voice box Trachea (Windpipe) - Tube-like structure made of - Air passage: Conducts air cartilage rings from the larynx to the bronchi - Lined with cilia and mucus to and lungs trap and move foreign particles Bronchi - Branches of the trachea that - Air passage: Distributes air to lead into each lung the left and right lungs - Lined with cilia and mucus for - Branching structure: Divides filtering air into smaller bronchioles to  ensure air reaches all parts of the lungs. Bronchioles - Smaller branches of the - Air passage: Directs air into bronchi, ending in alveolar sacs the alveoli for gas exchange. - Lack cartilage, but have - Regulation of airflow: smooth muscle for regulation of Smooth muscle helps constrict airflow or dilate bronchioles to control airflow. Alveoli - Small, thin-walled air sacs - Gas exchange: Site of clustered at the end of oxygen and carbon dioxide bronchioles exchange between the lungs - Surrounded by capillaries and bloodstream. - Oxygen diffusion: Oxygen passes from the alveoli into the blood; carbon dioxide diffuses out of the blood into the alveoli. Lungs - Pair of spongy, elastic organs - Gas exchange: Contain located in the thoracic cavity alveoli where oxygen is - Divided into lobes (3 lobes in absorbed and carbon dioxide is the right lung, 2 in the left) expelled - Respiration: Facilitates inhalation and exhalation, allowing for efficient gas exchange. Diaphragm - Large, dome-shaped muscle - Breathing regulation: located below the lungs Contracts and flattens to increase the volume of the thoracic cavity for inhalation. - Airflow dynamics: Relaxes and moves upward to decrease thoracic volume, aiding exhalation Intercostal Muscles - Muscles between the ribs - Breathing support: Contract to expand the chest during inhalation and assist with exhalation. Function Overview:  ​ Inhalation: ​ Inhalation is a negative pressure system (air pressure drops in the chest) ​ Brain signals the diaphragm to move downwards and the intercostal muscles to contract so the ribs coils move upwards and downwards ​ The lungs enlarge due to their attachment to the ribs and the decrease in the air pressure in the chest pulls the air inwards ​ Exhalation: ​ A positive air pressure ​ The brain tells the intercostal muscles and the diaphragm to relax (space in the lungs decrease and the air in the lungs pushed out) 3. Be able to discuss how the structure of organs/ organ parts enhances function. Nose/Nasal Cavity: 1. Nose and Nasal Cavity: ​ Structure: Has hairs, mucus, and blood vessels. ​ How it Helps: ○​ Hairs and mucus trap dust and germs. ○​ Moistens and warms the air to protect the lungs. 2. Pharynx (Throat): ​ Structure: A tube connecting the nose and mouth to the lungs. ​ How it Helps: ○​ Allows both air and food to pass through, with a flap (epiglottis) that prevents food from entering the windpipe. 3. Larynx (Voice Box): ​ Structure: Contains vocal cords and cartilage. ​ How it Helps: ○​ Makes sound when air passes through the vocal cords. ○​ The epiglottis prevents food from entering the airway. 4. Trachea (Windpipe): ​ Structure: A rigid tube made of cartilage, lined with mucus and tiny hairs (cilia). ​ How it Helps: ○​ Carries air to the lungs. ○​ Mucus and cilia trap dirt and move it out of the airways. 5. Bronchi and Bronchioles: ​ Structure: Branches that split off from the trachea and become smaller.  ​ How it Helps: ○​ Distribute air to both lungs. ○​ The smooth muscles control the airflow. 6. Alveoli: ​ Structure: Tiny air sacs surrounded by capillaries (small blood vessels). ​ How it Helps: ○​ Where oxygen enters the blood and carbon dioxide is removed. ○​ Their thin walls and large surface area make gas exchange efficient. 7. Diaphragm and Intercostal Muscles: ​ Structure: Muscles below the lungs (diaphragm) and between the ribs (intercostal muscles). ​ How it Helps: ○​ Help the lungs expand and contract when you breathe in and out. 4. Know the functions of the respiratory system. ​ To bring the oxygen to all the cells in the body ​ To remove CO2 from the cells ​ To maintain homeostasis (constant internal environment) Regulation of Blood pH: ​ The respiratory system helps maintain the acid-base balance in the blood by controlling the levels of carbon dioxide. An increase in carbon dioxide lowers blood pH (acidic), while a decrease raises it (alkaline). Protection: ​ Filtration: The respiratory tract filters out dust, pathogens, and foreign particles through mucus, cilia, and other defense mechanisms. ​ Coughing and Sneezing: These reflexes help expel irritants and pathogens from the airways. 5. Know disorders discussed in class. Asthma ​ When the small bronchioles become narrower. Asthma is a chronic respiratory condition that affects the airways, making it difficult to breathe. It causes the airways to become inflamed, narrowed, and produce excess mucus, leading to coughing, wheezing, shortness of breath, and chest tightness. Asthma can be triggered by various factors such as allergens, respiratory infections, exercise, cold air, smoke, or strong odors. ​ Large numbers of possible triggers including sports, allergies, weather (especially cold & damp air) aroma, hereditary  ​ Treatment- a bronchodilator (puffer) to relax the muscle for short term relief and a steroid based drug to reduce mucus Bronchitis ​ When the bronchioles will become inflamed and make excessive mucus. Symptoms include cough, sore throat, muscle ache and nasal congestion ​ Can be chronic infection when a virus settles in the lungs and keep reoccurring ​ Treatment includes puffers to relieve the symptoms and drugs to dry up the mucus. Your body still need to fight the viral infection Pleurisy ​ An active infection gets into the pleural membrane between the lungs and the ribs so the breathing becomes painful and restricted along with fever and cough Pneumonia Pneumonia is an infection that inflames the air sacs (alveoli) in one or both lungs. These air sacs may fill with fluid or pus, causing symptoms such as cough, fever, chills, and difficulty breathing. Pneumonia can be caused by bacteria, viruses, fungi, or other microorganisms. Antibiotics can treat the disease but the body has to fight off the bacterias Common Symptoms: ​ Cough (which may produce mucus) ​ Fever ​ Shortness of breath ​ Chest pain ​ Fatigue ​ Sweating or chills Emphysema ​ Breakdown at alveoli, less area for gas exchange in lungs ​ Symptoms : shortness of breath, wheezing, hyperventilation, fluid build up ​ Person would require portable oxygen supply Tuberculosis ​ Tuberculosis (TB) is a bacterial infection primarily affecting the lungs, caused by Mycobacterium tuberculosis. It can also affect other parts of the body, such as the kidneys, spine, and brain. TB spreads through the air when an infected person coughs or sneezes. Common Symptoms: ​ Persistent cough (sometimes with blood) ​ Chest pain ​ Night sweats ​ Fever ​ Fatigue ​ Weight loss  Causes: ​ Bacterial infection from Mycobacterium tuberculosis. Treatment: ​ Antibiotics: A combination of several antibiotics is used to treat TB, typically for a duration of 6 to 9 months. Cystic fibrosis ​ Is an inherited disease which is common to the european descendants ​ Results in mucus glands throughout the body being overactive which puts great strain on breathing and digestion ​ Symptoms: ​ Salt tasting shins ​ Continuous cough with phlegm ​ Numerous lung infection ​ Poor growth ​ Weight gain 6. Be able to discuss regulatory mechanisms – blood pH etc. Regulation of Blood pH: ​ The respiratory system helps maintain the acid-base balance in the blood by controlling the levels of carbon dioxide. An increase in carbon dioxide lowers blood pH (acidic), while a decrease raises it (alkaline). 7. Be able to explain gas exchange at the alveoli and tissue level. Alveoli Air enters the alveoli through the respiratory system which is rich in O2 and that’s why the partial pressure for oxygen (PPO2) is high in Alveoli and the PPC02 is lower on the other hand. The partial pressure of carbon dioxide is higher in capillaries so the diffusion takes place and oxygen gets diffused into capillaries and the carbon dioxide is diffused in Alveoli and out of the lungs Capillaries In a cell mitochondria produces energy for the cell and that is why PPCO2 is higher in cells and PPO2 is lower. The capillaries are rich in oxygen that’s why the PPO2 is higher in capillaries and PPCO2 is lower. So the gas diffusion will take place because the gas wants to move from higher concentration to lower concentration areas. So the cells get the oxygen and the capillaries carry the CO2. Circulatory System 1. Be able to distinguish between types of circulation. 1.​ Pulmonary circulation: To the lungs  ​ Deoxygenated blood from the right side of the heart to the lungs and back to the left side of the heart 2.​ Coronary Circulation: Blood to the heart muscle itself ​ Arteries branch off the blood to the aorta before it leaves the heart and bring blood to the heart muscle through 4 main coronary arteries. The blood leaves the aorta to the coronary arteries rich in oxygen and returns the oxygen poor blood to the right atrium. 3.​ Systemic circulation: To the body ​ The supply of blood to all the systems of the body ​ Blood leaves the left side of the heat (O2) rich and returns to the right side of the heart(O2 poor) 2. Know the functions of this system. Functions: ​ Deliver O2 and nutrients to the cell ​ To remove CO2 and wastes from the cells ​ To carry hormones around the body ​ To provide for body defense by transporting white blood cells ​ To carry heat (for warm blooded organisms) Types: simple diffusion ​ Single and small multicellular organisms have no need for blood ​ Diffusion is used to provide nutrients to the cells and remove wastes. High to low. Limits- ​ As a cell grows larger, its internal volume increases faster than its surface area, the nutrients supply cannot match the demands. ​ Multicellular organisms evolved- specialized organs were needed to deliver nutrients to the cell (heart) Open Transport- ​ Blood doesn't remain in blood vessels, (veins, arteries) ​ Bathes the cells ​ Ex. insects- circulatory and respiratory systems are separated Closed Transport: ​ Blood remains in the blood vessels (tubes) & nutrients diffuse in/out of the blood ​ Blood vessels run without 2 cells distance of any cell in the body. ​ Sino atrial node (SA Node) - A cluster of nerves in the upper right atria of the heart - sets the rhythm at which the heart beats and therefore it is known as pacemaker of the heart ​ Atrial Venticular Node (AV Node) - is a cluster of nerve cells in the center of the heart between the atria and ventricles. It is an amplifier of the S.A node signal  ​ Purkinje Fibers - are nerves that spread out from the AV node to the ventricles so that the signals reaches the bottom first - that way the ventricles contract from the bottom up to push the blood up and out of the arteries Heart Rate Control 1.​ Nervous control (brain) ​ Vagus Nerve ( increased signals - slow down the heart rate) ​ Cardio- acceleration ( increased signals increase heart rate) 2.​ Chemical control ​ Stimulants- heart rate increases, Ex- caffeine and nicotine ​ Depressants- lower the heart rate, Ex- alcohol ​ Hormones - adrenaline increases our heart rate on the other hand when we have no adrenaline our heart rate decreases ​ Stimulants- like caffeine and nicotine increase our heart rate ​ Depressants - like alcohol decreases our heart rate 3. Be able to explain how the structure of arteries, veins and capillaries are suited to their function. Know visually and their key features. Arteries ​ Function: Carry oxygenated blood away from the heart (except the pulmonary artery which carries deoxygenated blood). ​ Structure: ○​ Thick, muscular walls: Arteries need to withstand and maintain high pressure as blood is pumped from the heart. The muscular walls help regulate the blood flow by constricting or dilating. Veins Function: Carry deoxygenated blood back to the heart (except the pulmonary vein which carries oxygenated blood). Structure: ​ Thinner walls: Veins have thinner walls compared to arteries because the blood pressure is much lower. The walls do not need to withstand as much force. ​ Valves: Veins have one-way valves that prevent the backflow of blood, ensuring that blood flows in the correct direction, especially in the extremities where blood has to travel against gravity. Capillaries ​ Function: Facilitate the exchange of oxygen, nutrients, and waste products between the blood and tissues. ​ Structure:  ○​ One-cell-thick walls: The very thin walls allow for the efficient exchange of gases and nutrients between the blood and surrounding tissues. ○​ Large surface area: Capillaries form a vast network that increases the surface area for exchange. heart to arteries to arterioles to capillaries to venules to veins to vena cava 4. Be able to describe the structure and function of blood components. Titles RBC WBC WBC Platelets (Erythrocyte) (leukocytes) (lymphocyte) Description Disk shaped, Clear cells Clear cells Smallest blood (component) red, no nucleus cell, cell fragment, no nucleus Production Red bone Bone marrow Lymph gland- Produced in marrow spleen bone marrow Number Female (4.5 6000/ml 2000/ml 250000/ml million/ml) Male (5.5 million/ml) Life spans 120 days Hours- days unknown 7-8 days Function Carry O2 and Travel around Includes T cells Clots blood CO2 engulfing direct immune bacteria system Special Contains iron in Travel around B cells produce Clots blood properties hemoglobin engulfing antibodies Hemoglobin bacteria carries O2 280 million hemoglobins / RBC Blood Plasma: Description- A yellow thin fluid, contains dissolved gasses, proteins, vitamin wastes, sugar. Serum albumin- maintains volume and pressure ​ Transports carbon dioxide Serum globulin - antibodies 5. Be able to discuss the role of the different blood cells (Red and white) RBC Function: Red blood cells are mainly responsible for carrying oxygen from the lungs to all the body's tissues and returning carbon dioxide (a waste product) from the tissues back to the lungs for exhalation. ​ They contain hemoglobin, a protein that binds to oxygen. ​ No nucleus allows more room for hemoglobin, which helps carry more oxygen. In the Circulatory System: RBCs travel through arteries, veins, and capillaries, delivering oxygen to tissues and collecting carbon dioxide as they pass through the body. When they reach the lungs, they release the carbon dioxide and pick up more oxygen. White Blood Cells (WBCs) ​ Function: White blood cells are part of the immune system, helping to defend the body against infections, bacteria, viruses, and other harmful invaders. ​ Types of White Blood Cells: ○​ Phagocytes (e.g., neutrophils): These cells "eat" or engulf and destroy harmful pathogens, dead cells, and debris. ○​ Lymphocytes (e.g., T cells and B cells): They are involved in more specific immune responses, such as producing antibodies to fight infections and "remembering" past infections for faster responses in the future. ○​ Monocytes: These cells become macrophages and help clear infections by swallowing pathogens or dead cells. ​ Structure: ○​ White blood cells have a nucleus (unlike red blood cells) that is important for recognizing and responding to infections. ○​ They can change shape and move through tissues to reach infection sites. ​ In the Circulatory System: WBCs travel in the bloodstream to detect and fight infections. They are crucial for protecting the body from diseases, and when an infection is detected, they move from the blood vessels into tissues to fight off the invaders. Summary: ​ Red Blood Cells (RBCs): Carry oxygen to tissues and remove carbon dioxide. They support energy and tissue function. ​ White Blood Cells (WBCs): Protect the body by fighting infections and foreign invaders, ensuring the body's defense system works effectively. 6. Know the role of platelets in clotting. ​ Injured cells make platelets sticky, to see form a plug ​ Platelets release an enzyme called thromboplastin ​ Thromboplastin breaks down into prothromboplastin (plasma protein) to thrombin ​ Thrombin then digests fibrinogen in plasma to fibrin threads ​ Fibrin acts like a net and traps the RBC forming a clot 7. Be able to discuss how O2 and CO2 are picked up and released by hemoglobin. 8. Know the structure of the heart and be able to label 10. Initiation and regulation of heart beat. ventricular Contraction ​ blood is moving into the right atrium and right ventricle ​ blood moves from 2 vena cava into the right atrium and into the left atrium through the pulmonary veins ​ the forces open the tricuspid valve on the right and the bicuspid valve on the left allowing the blood to move in the atriums Atrial contracting ​ brain (medulla and oblongata) sends electrical impulse to SA Node ​ this causes the atria to contract on both the sides ​ forces blood into ventricles which are enlarging rapidly ​ What happens? The atria contract (squeeze), pushing even more blood into the ventricles. This gives the ventricles that final bit of blood they need before they start to  contract. ​ Why it’s important: This step ensures the ventricles are completely filled with blood, maximizing the amount of blood that can be pumped out. ventricular contraction ​ AV node begins to spread electrical impulse from the SA node ​ tricuspid and bicuspid valve shuts down creating a lub sound ​ blood cannot leave the ventricle because there is not enough pressure yet to open semilunar valve ​ What happens? Now, the ventricles contract, increasing the pressure inside them. The AV valves (which were open) now close to prevent blood from flowing backward into the atria. ​ Why it’s important: The high pressure in the ventricles gets the heart ready to pump blood into the arteries Ventricular Ejection ​ signals passes through purkinje fibres ​ ventricles contract and create force that open the two semilunar valves (Aortic and Pulmonary) ​ Approximately 50 to 60% of the blood leaves the ventricles ​ What happens? The pressure in the ventricles becomes so high that it forces open the semilunar valves (leading to the aorta and pulmonary artery), and blood is ejected (pumped out) from the ventricles. The left ventricle pumps blood to the body, while the right ventricle pumps blood to the lungs. ​ Why it’s important: This step is when blood is actually sent to where it needs to go—either oxygen-rich blood to the body or oxygen-poor blood to the lungs. Ventricular relaxation ​ ventricles stops contracting ​ pressure drops down in the ventricles ​ semilunar valves shut creating the dub sound ​ happens in left and right ventricles simultaneously and it only takes a second for all of this to happen. ​ What happens? After the blood is ejected, the ventricles start to relax, and the pressure inside them decreases. The semilunar valves close to prevent blood from flowing back into the heart. The cycle is ready to start again with more blood flowing into the heart. ​ Why it’s important: This relaxation phase allows the ventricles to get ready for the next filling, and it helps maintain the normal rhythm of the heartbeat. ​ 12. Be able to discuss factors affecting bp., normal values and what it is, how it's measured. The force that blood exerts against artery walls; measured in mm of mercury (mm Hg), a standard unit of liquid pressure. systolic pressure, the highest recorded pressure in an artery when the ventricles contract. Diastolic pressure, the second number, is the lowest recorded pressure in an artery during the relaxation phase of the heartbeat. Salt, high cholesterol, caffeine, nicotine and stress, age, genetics, medication and obesity are some of the factors which increase our blood pressure. 13. Know disorders discussed in class and ways of diagnosing them. Analysis Description Diagnose How is it performed Pulse Surging of blood Vascular Index or middle pathologies, Heart finger, inside the rate wrist. Press lightly to feel blood pumping count for 15 sec and multiply by 4 Find jugular artery, press lightly and count for 15 seconds and multiply by 4 Stethoscope An instrument used Blood pressure, Used to listen to the to listen to the collapsed lungs, sounds made by the internal organs ( asthma and heart, lungs, heart, lungs, congestive heart intestines, as well as intestinal tract) blood failure the blood flow in flow and heart arteries and veins sounds of fetuses in pregnant women Echocardiogram Test using and Can help to A lubricant will be waves to see the diagnose and applied to your chest shape/size of the monitor certain heart or the ultrasound heart. Allows doctors conditions such as: cable. Then we have to analyze the Congenital heart to lie down on the pumping, chambers disease left side and the and valves of the Heart failure probe will be moved heart Cardiac tumor around our chest. Cardiomyopathy The probe is connected by a cable to a nearby machine that will display and record the images produced Stress test Test to measure the Heart diseases are By the checking the activity of your heart easier to find it tells heart rate while  and ability to us how well our doing intense respond to external heart works when it workouts, running on test is pumping hard a treadmill or on a stationary bicycle Electrocardiogram Diagnostic test that heart attacks and p to 12 sticky (ECG) checks the heart irregular heartbeats, patches called functioning by called arrhythmias electrodes are measuring the attached to the chest electrical activity of and sometimes to the heart ( as with the arms or legs. each heartbeat, an Wires connect the electrical impulse patches to a travels through the computer. The heart) computer prints or displays results. Results are shown in waves. Evolution 1. Know key terms like fossils, paleontology, archaeopteryx, Homologous features, Analogous features, Vestigial features, Fossil- fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers. Paleontology - scientific study of life of the geologic past that involves the analysis of plant and animal fossils, including those of microscopic size, preserved in rocks. the branch of science concerned with fossil animals and plants. Archaeopteryx- the oldest known fossil bird, of the late Jurassic period. It had feathers, wings, and hollow bones like a bird, but teeth, a bony tail, and legs like a small coelurosaur dinosaur. Homologous structures - structures in different organisms that have similar anatomy and a recent shared ancestry but different functions Analogous structures - refers to the parts that have similar functions but different anatomical structures and no recent shared ancestry. (wing bat, birds, butterfly) Vestigial structures - anatomical parts that appear to have no functions. Ex- thumbs on dog paws, hip bone in whales, bats having eyes 2. Know early ideas about evolution. ​ Evidence for evolution - Molecular similarities ○​ DNA sequence - humans and chimpanzees share roughly about 98 to 99% of DNA sequence ○​ Pseudogenes - non functional sequence of DNA that have lost their ability to code for proteins due to mutation, similarities seen between species  ○​ Similar amino acid sequence between species ○​ These similarities are evidence of evolutionary relationships and that species evolved from a common ancestor gradually over a long period of time ​ Evidence for evolution - Anatomical similarities ○​ Homologous structures - structures in different organisms that have similar anatomy and a recent shared ancestry but different functions ○​ Analogous structures - refers to the parts that have similar functions but different anatomical structures and no recent shared ancestry. (wing bat, birds, butterfly) ○​ Vestigial structures - anatomical parts that appear to have no functions. Ex- thumbs on dog paws, hip bone in whales, bats having eyes ​ Evidence for evolution - Development similarities ○​ In the embryonic stage many organisms have anatomical features that are similar to other organisms but these disappear before birth ​ Evidence for evolution - Fossil records ​ These provide a timeline of evidence of evolution, showing how species have changed over time and adapted to their environments, including through transitional forms. They also have allowed scientists to study extinct species, support common ancestry through comparative anatomy, and highlight evolutionary adaptations, such as marine fossils found in dry regions. ​ Evidence for evolution - Biogeography ○​ Similar species are found around the world as the scientists believed all the continents were joined together (pangea), millions of years ago but they continents got split over time and the animals which were from same species lived in different parts got spread around the world 3. Know Darwin’s Theory of Natural Selection. ​ Darwin’s observations: ​ Species vary globally ○​ Distantly related species living in similar habitats around the world act similarly. Ex- rhea, ostrich ○​ Some areas have very unique organisms not present anywhere else. Ex- kangaroos in Australia ​ Species vary locally ○​ Related animals that lived in different habitats within a local environment had different features. Ex- galapagos islands ( very different climate - related animals had different features) ○​ Galapagos tortoise - tortoise varied locally. These islands have very different climates. Tortoise adapted differently to the climate they lived in. ​ Darwin’s theory  ○​ All species of organisms living on the earth today are descended from an ancestral species ○​ Species evolve overtime ○​ The mechanism that causes the species to change is called natural selection ​ Natural selection - is not random. Organisms with traits better suited for the environment are more likely to survive and reproduce and pass on their traits to their offsprings. The fittest individuals have the reproductive advantage so the frequency of their allele in the gene pool is higher. Selective pressure in the environment change the relevant frequencies of phenotypes in a population: ​ Stabilizing selection - this happens when the average traits are best suited for survival and the extreme traits are less helpful. Ex - human birth weight, average sized babies have least problems ​ Directional selection - this happens when an extreme trait is best for survival causing the population to change in that direction over time ex antibiotic resistance ​ Disruptive selection - this happens when extreme traits on both the ends are better for the survival than the average traits, leading to two very different groups in population 4. Know Modern Synthesis, Random Change in DNA, Genetic Drift, Gene Flow. ​ Genetic Drift: ​ Random change in the allele sequence due to chance. It has a much greater effect on small populations ​ Bottleneck effect: occurs when a population decreases generally due to a natural disaster. This decrease in population reduces variation in alleles, decreasing genetic diversity ​ Founders effect: a reduction in genetic diversity that occurs when a small group of individuals establishes a new population. ​ Gene flow: ​ The moment of alleles from one population to another ​ Happens when individuals from different populations mate and produce offsprings, sharing their genetic material ​ Can lead to increase in genetic diversity and sometimes introduce new traits to the population ​ Ex birds from one group migrate to another island and breed with a different group 5. Be able to explain patterns of selection. ○​ Natural selection - is not random. Organisms with traits better suited for the environment are more likely to survive and reproduce and pass on their traits to their offsprings. The fittest individuals have the reproductive advantage so the frequency of their allele in the gene pool is higher. Selective pressure in the environment change the relevant frequencies of phenotypes in a population:  ○​ Stabilizing selection - this happens when the average traits are best suited for survival and the extreme traits are less helpful. Ex - human birth weight, average sized babies have least problems ○​ Directional selection - this happens when an extreme trait is best for survival causing the population to change in that direction over time ex antibiotic resistance ○​ Disruptive selection - this happens when extreme traits on both the ends are better for the survival than the average traits, leading to two very different groups in population ○​ Sexual selection- not random mates are often chosen based on their phenotypes. Other individuals in the species screen, or select their traits. ○​ Artificial selection - Not random humans have been modifying species for thousands of years. Can be fast - only a few generation traits that are selected from can occur at a high frequency. Can have unintended consequences, usually in the form of genetic diseases. Ex all dogs come from the wolves. 6. Formation of a species. ​ Prezygotic barriers - a barrier that either impedes mating between species or prevent fertilization of eggs ○​ Behavioral isolation - difference in mating calls or mating rituals. Ex courtship rituals of elk, birds song ○​ Temporal isolation - mating occurs at different times of the year or day. Ex: orchids - times of the day, ○​ Habitat isolation - differences in using resources and living spaces within the same habitat. Ex: cichlids- feeding on different sources within the same habitat ○​ Mechanical Isolation- where species can attempt mating but fail because they are automatically incompatible. Ex- dogs - size incompatible, Damselflies - different shaped reproductive organs ○​ Gemate isolation - when the sperm and eggs of different species are incompatible preventing fertilization. Ex coal protein , flowers - pollen vs stigma, sea urchin - red vs purple ​ Postzygotic barriers - a barrier that prevents hybrid zygotes developing viable, fertile individuals ○​ Hybrid sterility - when the offspring of the cross between 2 individuals is infertile. Ex mule (horse and donkey) ○​ Hybrid inviability - when a hybrid cannot develop into a healthy adult or the zygote dies shortly after fertilization. Ex- sheep and goat has a shorter life span ○​ Hybrid breakdown - when the first generation (F1) is viable and fertile but when the hybrid species mate with each other, or another parental species, the next generation F2 is weak or infertile. Ex- cotton and rice ​ Allopatric speciation (aka geographic isolation)  ○​ Physical barriers like a mountain, ocean or canyon that separates populations may eventually lead to an inability to interbreed because the gene pool has been too different. Both groups are reproductively related ​ Sympatric speciation ○​ Same geographic location but reproductively isolated ○​ Happens due to prezygotic and postzygotic barriers ​ Peripatric speciation ○​ A small population becomes isolated on the edge of the main population leading to rapid genetic drift ​ Parapatric speciation ○​ Adjacent population evolves into distinct species while maintaining a shared border where interbreeding is limited 7. Know Human Evolution ​ Human evolution ​ Australopithecus ○​ Binocular vision (eyes to the front) ○​ Opposite thumbs (muscle grasping easier) ○​ Were knuckle walkers (were more upright than previous species) ​ After Australopithecus (different generation) ○​ Was so different that it becomes its own genus known as homo ○​ Walked completely upright ○​ Reduced body fur ○​ Enlargement of the brain case in the skull ○​ Reduction in the size of the jaw and its supporting muscles ​ Homo - Habilis ​ Enlarged brain case ​ First primate descent to use stone tools ​ Fossils found primarily in Africa ​ Homo - Erectus ​ Walked completely upright ​ Used tools ​ Fire for the first time ​ Emigrated to Europe and Asia ​ Homo - Neanderthalis ​ About 600,000 years ago were an offshoot of homo - erectus ​ Thick bone structures ​ Greater muscle mass ​ Practiced complex speech and funeral rituals ​ Homo - Sapiens ​ Brain case enlargement  ​ Complete smaller teeth ​ Forward looking eyes ​ These are modern humans (diverged for roughly 130000 years ago) 8. Adaptive Radiation, Convergent, Divergent Evolution. ​ Divergent evolution ○​ Closely related species that have evolved different phenotypes ○​ Happens due to different environments or pressures ○​ Homologous features are generally seen in distinct species ○​ Ex grand canyon squirrels ​ Convergent evolution ○​ Unrelated or independent species that have independently evolved similar phenotypes ○​ Happens due to similar but unrelated environments or pressure ○​ Analogous features are usually seen in distinctly related or unrelated species (similar phenotypes ) ○​ Ex sharks (fish) and dolphins (mammal) live in similar habitats and have analogous features ​ Parallel evolution ○​ Related species that have independently evolved similar phenotypes ○​ Happens due to similar environments or pressures ○​ Ex flightless birds ​ Co - Evolution ○​ Mutualism: A relationship where both species benefit from each other's pressure. Ex flowers and pollinators ○​ Predators or prey - A relationship where one species (predators) hunts and feeds on another prey. Rough skinned newts and California's red-sided garter snakes ○​ Competition - A relationship where two or more species are competing for the same resources, driving adaptation to reduce overlap or increase efficiency. Ex- lions and hyenas, squirrels and birds ○​ Parasite or Host - A relationship where one species (parasite) benefits at expense of another (host), leading to defensive and offensive adaptations. Ex- cuckoo birds and host birds, ticks and mammals ​ Adaptive radiation - when a single species evolve into multiple distant species; ex- darwin finches (divergent evolution) ​ Gradual equilibrium- evolution as a slow and continuous process of change; transition of horse species from small multi toed animals to large single toed for 50 million years ​ Punctuated equilibrium - evolution occurs in rapid burst of change followed by long periods of stability  ​ Triloboats, which show sudden changes in morphology after millions of years after radiation The Digestive System 1. Outline the way your body physically and chemically digests carbohydrates, protein and fat. Include organs, enzymes and hormones. Be able to label a diagram. Carbohydrate Digestion 1.​ Mouth: Salivary amylase starts breaking down starches into sugars. 2.​ Stomach: No carbohydrate digestion. 3.​ Small Intestine: ○​ Pancreatic amylase breaks down starch further. ○​ Brush border enzymes (maltase, sucrase, lactase) convert disaccharides to monosaccharides (like glucose). 4.​ Absorption: Glucose is absorbed into the bloodstream. Protein Digestion 1.​ Mouth: No protein digestion. 2.​ Stomach: Pepsin breaks proteins into smaller peptides. 3.​ Small Intestine: ○​ Trypsin and chymotrypsin (from the pancreas) break down peptides further. ○​ Peptidases (from the intestinal lining) break peptides into amino acids. 4.​ Absorption: Amino acids are absorbed into the bloodstream. Fat Digestion 1.​ Mouth: Lingual lipase starts breaking down fats. 2.​ Stomach: Gastric lipase further breaks down fats. 3.​ Small Intestine: ○​ Bile (from the liver) emulsifies fat. ○​ Pancreatic lipase breaks fat into fatty acids and monoglycerides. 4.​ Absorption: Fatty acids and monoglycerides are absorbed into the cells of the small intestine and later enter the lymphatic system. Key Hormones Involved: ​ Gastrin: Stimulates stomach acid and enzyme release. ​ Secretin: Stimulates the pancreas to release bicarbonate. ​ Cholecystokinin (CCK): Stimulates bile release and enzyme release from the pancreas. 2. Make a chart of organ structure and function. Organ Function  Esophagus , Swallowing ​ In mouth food in shaped into a ball (bolus) which tongue moves to back of your throat ​ Entering the Pharynx- the uvula moves up to stop food from entering the trachea ​ The esophagus is a tube surrounded by 2 layers of muscles (circular and lengthwise) ​ The wave of muscle motion that pushed the food down is called peristalsis ​ The waves work continuously to push food throughout the digestive system. Stomach Functions : Structure: ​ To continue mechanical digestion of ​ It is a j shaped organ located to the the food by muscular motion until the center left side of the abdomen just food is not thoroughly broken and below the ribcage mixed with gastric juices ​ Entrance of food to the stomach is Gastric Juice in Stomach controlled by the cardiac sphincter ​ Pepsin: an enzyme which breaks which allows food to enter the down protein into groups of amino stomach but not leave (usually) acids ​ Exit is controlled by the pyloric ​ Hydrochloric Acid: provides the sphincter which also prevents food necessary pH level needed for pepsin from leaving before it is ready to work (pH-2) ​ Renin: A chemical which helps to clot milk into lumps which could be digested easily ​ Mucus: A thick protective layer on the stomach wall, which protects the stomach from acids. Small Intestine: ​ Where majority of the digestion and ​ Small Intestine Functions absorption takes place in our body ​ The majority of S.I. is for absorbing (stomach only absorbs alcohol & nutrients from the food aspirin) ​ The walls of S.I. are folded to form ​ Total length is between 5-7m finger like projections called villi ​ Food requires 7-10 hours to pass ​ The Villi slows down food & increase through the surface area of the intestine to ​ It is composed of 3 main parts in the achieve the maximum nutrient following order :duodenum, ileum and absorption jejunum. ​ Inside the villi are the blood vessels to ​ Duodenum: pick up carbs and amino acids while ​ It is about 20 to 30 cm long the tubes called lacteal ducts absorb ​ It is the most important part of S.I. the fatty acids & glycerol ​ This is where most of the digestive enzymes flow in order to reach the food ​ Several glands along the walls of S.I. produce enzymes to assist with digestion ​ Pancreas: ​ Creates insulin and glycogen two hormones needed to regulate blood sugar ​ Insulin: removes glucose from blood ​ Glucagon: releases glucose from glycogen; get stored in liver and muscles ​ Pancreas: lost of enzymes pancreatic amylase ​ Sodium bicarbonate to neutralize acidic chyme leaving stomach Liver: Produces blue (mixes in fat) Gallbladder: Stores bile and secretes it in the small intestine large intestine: ​ No nutrient digestion occurs ​ Larger in diameter and shorter in length ​ Reabsorbs water from the wastes  ​ Contains bacteria called E-Coli which digests some water while producing VitaminK for us (as well as CO2) ​ 10 - 24 hours CCK ( cholecystokinin) ​ It is secreted by duodenum ​ It triggers the release of amino acids and as in duodenum ​ It stops gastric secretion and gastric motility ​ It mainly STIMULATES the production of enzymes and gallbladder contraction ​ It also stimulates the production of bicarbonate, bile secretion and intestinal juice secretion Gastric: ​ It is secreted by stomach ​ It triggers the release of protein( peptide in stomach) ​ It mainly Stimulates gastric secretion but it also stimulates gastric motility ​ It also stimulates the main production of bicarbonate, bile secretion and intestinal juice secretion Secretin: ​ It is secreted by duodenum ​ It triggers the release of bicarb in duodenum (chyme in stomach) ​ It stops gastric secretion and gastric motility ​ It mainly STIMULATES the production of bicarbonate and the secretion of bile ​ It also stimulates the production of enzymes, gallbladder contraction and intestinal juice secretion Define Enzyme: ​ A protein molecule to speed up chemical reactions in the body and it is not consumed in a reaction ​ Enzymes are catalysts, that are never used up in a reaction, it just speeds up the reaction ​ Enzymes are found everywhere in the body ​ Many are in the digestive system ​ Ex: trypsin, Lactose Functions: ​ Enzymes reduce the amount of energy needed to start a reaction (making it easier for reactions to occur. Activation energy) ​ Enzymes have a spot in their tertiary structure that allows a substrate (molecule they are reacting with) to join (Active site) ​ When joined together they are the enzyme subtract complex  ​ Chemical reactions takes place, enzymes and products separate ​ Every enzyme has a specific structure it joins with ​ Ex Lactase reacts upon lactose, sucrase, reacts upon sucrose ​ Enzymes usually combine substrate name with ending -ASE ​ Maltase digests Maltose Factors Affecting Enzyme: ​ As enzymes are proteins, they can also be denatured by temperature changes and pH change ​ Each enzyme will have an optimal temperature and pH change ​ Outside of that range it’s activity will increase 3. Be able to discuss how the structure of organs/organ parts enhances function. 1. Mouth: ​ Structure: The mouth has teeth, a tongue, and salivary glands. ​ Function Enhancement: ○​ Teeth: Teeth are structured for different types of mechanical breakdown (cutting, tearing, grinding), increasing the surface area of food for digestion. ○​ Tongue: Helps mix food with saliva, forming a bolus that is easier to swallow. ○​ Salivary Glands: Produce saliva containing enzymes like amylase, which starts breaking down carbohydrates. The moisture helps soften food for easier swallowing. 2. Esophagus: ​ Structure: A muscular tube with smooth muscle layers. ​ Function Enhancement: ○​ Peristalsis: The muscular layers enable peristalsis, a wave-like motion that pushes food down into the stomach, ensuring the food moves efficiently. 3. Stomach: ​ Structure: The stomach has three layers of smooth muscle and a lining that secretes gastric juices. ​ Function Enhancement: ○​ Muscle Layers: The three layers (longitudinal, circular, and oblique) allow for strong contractions, which churn and mix food with digestive enzymes and acids. ○​ Gastric Lining: The stomach lining secretes hydrochloric acid and pepsinogen. The acidic environment activates pepsin, which helps break down proteins into smaller peptides. 4. Small Intestine: ​ Structure: The small intestine is long and has many folds, villi, and microvilli. ​ Function Enhancement:  ○​ Length: The length of the small intestine (about 20 feet) increases the surface area for nutrient absorption. ○​ Villi and Microvilli: These finger-like projections further increase surface area, allowing for more efficient absorption of nutrients (amino acids, sugars, fatty acids) into the bloodstream. ○​ Circular Folds: These folds slow down the passage of food, allowing more time for digestion and absorption. 5. Large Intestine: ​ Structure: Shorter and wider than the small intestine, with fewer villi. ​ Function Enhancement: ○​ Absorption of Water: The large intestine absorbs water and electrolytes, concentrating waste into solid form. ○​ Bacteria: The colon houses bacteria that help digest fiber and produce certain vitamins (like vitamin K). 6. Liver: ​ Structure: The liver is a large organ with a network of cells and blood vessels. ​ Function Enhancement: ○​ Bile Production: The liver produces bile, which is stored in the gallbladder and released into the small intestine. Bile emulsifies fats, breaking them into smaller droplets, making it easier for enzymes to digest them. ○​ Metabolism: The liver also processes nutrients absorbed from the small intestine, converting them into forms that can be used by the body or stored for future use. 7. Pancreas: ​ Structure: The pancreas has exocrine cells that secrete digestive enzymes and endocrine cells that release hormones. ​ Function Enhancement: ○​ Digestive Enzymes: The pancreas secretes enzymes like amylase (for carbohydrates), lipase (for fats), and proteases (for proteins), which aid in digestion in the small intestine. ○​ Bicarbonate Production: The pancreas also produces bicarbonate to neutralize stomach acid, creating an optimal pH for enzymes to function. 8. Gallbladder: ​ Structure: A small, pear-shaped organ located under the liver. ​ Function Enhancement: ○​ Bile Storage: The gallbladder stores bile produced by the liver and releases it when needed to emulsify fats in the small intestine. 4. What are the four types of teeth? How is their structure tied to their function? Enamel- very hard outer lining Dentin- bone like inner core of teeth Crown- the part above the gum Root - the part above the gum Structure & Functions: Incisor - bite Canine - tear Premolar - tear and crush Molar- grind 5. Be able to identify disorders discussed in class. 1.​ Halitosis ​ Symptoms- bad breath ​ Causes - ​ Poor dental health ​ Maybe a sign of cavity or stomach trouble ​ Treatment - ​ Better dental habits or have your teeth checked for a cavity or have your stomach checked 2.​ Ulcers ​ Symptoms- ​ Abdominal pain, burning after a spicy meal or when stomach is empty ​ Causes - ​ Stress about 15%, 85% are due to a bacterial infection( H-polyric) that causes the mucus lining to become thin and the stomach acids attack the muscle lining and then the pepsins attacks protein in the muscle lining ​ 3 types: ​ Regular- ulcer affects the first few layers of cells in the stomach lining ​ Bleeding- ulcer has penetrated to blood vessels so blood builds up in the stomach or maybe thrown up ​ Perforated- A hole has been eaten completely through the stomach and the juices can escape into the abdominal cavity ​ Treatment - ​ For mild cases- taking antacids (Mcalox) ​ In more severe cases, medications(like Zantac) will be used to control the amount of acid made by the stomach ​ Antibiotics are used to eliminate H-pylori when its presence is confirmed ​ Perforated ulcers require emergency surgery 3.​ Heartburn (aka Acid Reflux Disorder)  ​ Symptoms- ​ Stomach acid moves up the esophagus causing it to feel irritated (burning sensation) ​ Causes - ​ Pregnancy, cardiac sphincter not working, overweight ​ Treatment - ​ The main treatment is to find and treat the cause but the symptoms are generally treated by antacids 4.​ Hiatal Hernia ​ Symptoms- ​ Bulky and uncomfortable feelings usually during a meal, heartburn as well. ​ Severe cases may feel like a heart attack (trouble breathing, pain in chest and left arm) ​ Causes - ​ Part of the stomach is pulled up into the chest cavity either through the cardiac sphincter into the esophagus (sliding the hernia) or besides the esophagus through a weakness in the diaphragm. It can put pressure on the heart ​ Treatment - ​ Involves watching what and when you eat, dropping some weight and use of medications to control the attacks. ​ Surgery can be used to repair the more severe cases 5.​ Crohn's disease ​ Symptoms- ​ Combinations of severe pain, bloating or swelling the abdomen, nausea, lack of appetite. ​ Causes - ​ Is believed to be hereditary - results in the severe inflammation of the portion of large intestine (rarely small intestine) which block the food and limit the ability of the intestines to absorb the nutrients ​ Treatment - ​ Involves support care- inflammatory drugs, painkillers and possible feeding by I.V until the problem subsides ​ Surgery can be used to remove inflamed portions 6.​ Appendicitis- Appendix ​ Symptoms- ​ nausea and vomiting ​ Severe pain in lower right abdomen ​ Causes -  ​ Opening to the appendix has become blocked and the appendix has become infected and swollen. If left untreated, it will burst ​ Treatment - ​ Antibiotics for mild cases ​ Surgery for severe cases 7.​ Diabetes - Blood ​ Symptoms- ​ Extreme thirst, weight loss, tiredness, vision trouble, slow healing or sore ​ Type 1 ​ Is usually hereditary, pancreas suddenly fails to produce insulin ​ Type 2 ​ Pancreas wears out slowly and produces smaller and smaller quantities of insulin. Treatment involves weight control, possibly insulin pills or insulin shots or insulin pumps. ​ Gestational Diabetes ​ Occurs in about 4-8% of pregnant women. Occurs because of the weight change in pregnancy stresses their pancreas and they become temporarily diabetic. The majority of these women go back to normal after the baby has been born 8.​ Hepatitis - liver ​ Symptoms- ​ Tiredness and swelling in the upper right abdomen, yellowing ​ Causes - ​ 5 different letters listed below: ​ A - spread orally ​ B,C,D,E - transmitted by blood fluid (blood, saliva) ​ Treatment - ​ Cure exists for type A, a vaccine exists for type B 9.​ Gallstones - gallbladder ​ Symptoms- ​ Sharp and severe pain in the upper right abdomen ​ Causes - ​ Bile crystals have formed in the gallbladder and have become stuck in the duct leading from the GB to intestines ​ Treatment - ​ Lasers can be used to try to shatter the stone or the GB surgically 10.​Diarrhea ​ Symptoms- ​ Belly cramps or pain. ​ Blood in the stool. ​ Causes -  ​ Too much muscle motion in the large intestine (prevents water from being reabsorbed, so wates stay liquid ​ Treatment - ​ Drugs like imodium or cornstarch water, limits sugar 24h 11.​Constipation ​ Symptoms- ​ Too much water is absorbed due to muscle motion ​ Causes - ​ Not enough motion in Large intestine ( too much water gets absorbed, wastes become excessive hard) ​ Treatment - ​ Eats a lot of roughage like celery and carrots, prunes, ex lax, metamucil Biodiversity 1.​ Taxonomy and level of organization, Kingdom, Phylum… ​ Taxonomy: Linnaeus Classifications -​ The science of naming, identifying, and classifying species. -​ Relies on Observable traits (Morphology) Domain (eukarya, bacteria, archaea) Kingdom (plants, archaebacteria, eubacteria, protists) Phylum (ex. Chordoma) Class (ex. mammals) Order (ex. Primates) Family (hominidae) Genus (ex. Homo) Species (ex. Sapiens) 2.​ Eukaryotic vs. Prokaryotic Cells (info. and be prepared to label) 3.​ Viruses, Lytic Cycle, Bacteriophage parts Viruses: ​ Viruses do not meet the requirements for living things ​ They do contain nucleic acid (DNA, RNA) adapt to changing conditions (mutote)  ​ They cannot: reproduce on their own (need a host cell). Made up of protein coat and nucleic acids. NOT A CELL. Structures and Functions ​ Made of a short piece of DNA or RNA that’s surrounded by a protein coat. ​ Some viruses protein coat can merge with the host cell ​ Has a perfect structure to enter a host cell and reproduce ​ Bacteriophage (a virus that infects bacteria) Lysogeny ​ Some viruses have a dominant phase where they are inactive ​ Flow the injection of the nucleic acid into the host cell’s DNA ​ HIV is a virus that does this. That’s why some individuals will appear healthy/but actually have infection Nutritional Made: -​ Heterotroph: absorbs organic molecules from environment or eats others -​ Photoautotroph: uses sunlight to move CO2 into carbon compounds like sugar -​ Photoheterotroph: absorbs organic molecules from environment or uses light energy -​ Chemoheterotroph: uses energy released through chemical reactions involving ammonia, hydrogen, sulphide and others. 4.​ Prokaryotes- bacterial shapes, cell wall types, and gram-positive or negative, binary fission, conjugation and transduction Prokaryotes: ​ Includes ArChaea & Bacteria -​ Bacteria are alive. They grow, reproduce ​ 2 domains of life just for bacteria -​ Some are good and some are bad -​ Good- (ex. the ones in our gut) -​ Ex. Yogurt Cell Shape: 1.​ Spherical= cocci 2.​ Rod Shaped= Bacilli 3.​ Spiral Shaped= Spirochetes Colony Shaped= Bacteria are joined together 1.​ Strep= Chain of Bacteria 2.​ Staph= cluster, clump Gram-Positive; ​ Turns purple ​ Cell wall with lots of Peptidoglycan Gram-Negative;  ​ Turns pink ​ A thin peptidoglycan layer surrounded by an outer membrane 5.​ Protists- Diagrams of paramecium, euglena, amoeba- methods of movement, methods of eating (classification) Classification: 1.​ Animal-like protists called protozoans are heterotrophs that capture and ingest their food. * Amoebas use their pseudopods to capture and ingest prey. 2.​ Plant-like protists are autotrophs that make using their own food, often from sunlight, & CO2 using chloroplasts. *Algae 3.​ Fungus-like protists are heterotrophs that feed on decaying organic matter, as fungi do: Ex Slime molds, cellular slime molds, and water molds. 6.​ Fungi ​ Fungi are heterotrophic eukaryotes that release powerful enzymes to digest organic matter outside of their bodies ​ They then absorb nutrients ​ They obtain oxygen from the environment as well Diversity of Fungi: ​ Fungi include mushrooms, molds, yeast, truffles, and rusts  ​ More than 100,000 species that differ in size, shape, and color ​ Are important decomposers and sometimes parasites Structure and Function: ​ Yeasts are unicellular ​ Most bodies of fungi are made up of Hyphae (tiny threads of cytoplasm surrounded by a cell membrane and cell wall, differs from contains chitin, not cellulose) ​ Hyphae have cross-walls that divide the long filaments into separate end-to-end cells ​ This helps cytoplasm distribution and movement of nutrients ​ As they grow, the hyphae branches and forms a mycelium ​ In large mushrooms, the part of the mycelium above ground that we see is the: “fruiting body” ​ This mycelium extends below ground to increase nutrient absorption as they can’t move. Mycorrhizae ​ Vast networks of mycelia extend throughout many types of soil ecosystems ​ Often from mutualistic relationships with plant roots ​ Fungi gets sugar, scratch, lipid from roots and helps the plant collect phosphate. Sexual Reproduction 1.​ Fungi exhibit two different sexes called “+” and “-” 2.​ Opposite-sex hyphae will grow towards each other and fuse forming a diploid zygospore that have two sets of chromosomes 3.​ This helps increase genetic diversity in fungi as it has two sets of chromosomes. Major Groups of Fungi ​ Zygomycota- common molds ​ Basidiomycota- club fungi (button mushrooms) ​ Ascomycota- sac fungi (morels) ​ Chytridiomycota- chytrids, fungi with flagella 1.​ Protists- types of movement, ways of getting energy Types of movements: ​ Protists have a variety of methods of moving ​ Movement can be toward food or away from danger 1.​ Pseudopodia are used by amoebas; pseudopod= “False foot” 2.​ Flagella are long, hair-like projections 3.​ Ciliates use cilia, cilia are much smaller than flagella, and appear in groups or completely covering an organism. Cilia move together like tiny oars on the plasma membrane. 4.​ Passive movement by wind, water currents, or passing  How protists reproduce: 1.​ Miosis 2.​ Many protists reproduce by alternation of generations, alternating between haploid and diploid stages. Ex. slime molds, Trypanosoma brucei Protists= The Origin of Eukaryotes ​ The most common belief is a two-step process. 1.​ Infolding: where internal membranes formed from inwards fold of the plasma membrane of ancient prokaryotes. -​ Infolding formed structures like the endoplasmic reticulum, Golgi apparatus, and nuclear envelope. 2.​ Endosymbiosis occurred, where smaller prokaryotes were captured inside larger host cells. ​ Symbiosis occurred at first, evolving into the formation of orga