Biology Notes - Cell Theory, DNA, Organ Systems PDF

Lesson 1: The cell is the basic unit of life. It makes up tissues, organs, systems and organisms. The Cell Theory: 1.​ Cells are the basic unit of life. 2.​ All living things are made up of cells. 3.​ All cells come from preexisting cells. Each cell have organelles and those organelles hav...

Lesson 1: The cell is the basic unit of life. It makes up tissues, organs, systems and organisms. The Cell Theory: 1.​ Cells are the basic unit of life. 2.​ All living things are made up of cells. 3.​ All cells come from preexisting cells. Each cell have organelles and those organelles have different functions such as: -​ Nutrient intake -​ Movement -​ Growth -​ Response to changing conditions -​ Gas exchange -​ Waste Removal -​ Reproduction Cell Membrane: -​ Protects the cell, controls which substances enter and leave the cell -​ thin outer line visible in cell drawings. -​ Lipid bilayer Cytoplasm: -​ Jelly-like substance that surrounds the organelles and has dissolved nutrients. -​ In the diagrams, it’s the empty space in the cell. Nucleus: -​ It is the control center of the cell. -​ Contains DNA and the instructions Vacuoles: Stores water and other materials Vesicles: Stores wastes, nutrients, and other materials for packaging and shipment through, and out of the cell. Mitochondria: -​ Energy source for the cell. -​ Location for Cellular Respiration called ATP. -​ Usually known as the powerhouse of the cell. Lysosomes: -​ Vesicles filled with enzymes and used to digest parts, or complete cells in apoptosis. Golgi Apparatus: -​ Receives and distributes “stuff” throughout the cell.. -​ Processes proteins and packages them for use outside of the cell. -​ Vesicles move into and leave once processing is complete. Endoplasmic Reticulum: -​ Rough ER has ribosomes attached to it to make it look bumpy and rough. -​ It creates proteins that are being sent to the Golgi apparatus -​ They surround the nucleus. -​ Smooth ER transfers fats. Cytoskeleton: -​ Helps cells keep their shape. -​ Sits under membrane and around organelles to help them hold in place. Made of protein fibres. Things only found in plant cells: Cell Wall: -​ A structural layer connects to the cell membrane providing support for the plant cell. Made of cellulose. Chloroplasts: -​ where photosynthesis occurs in plant cells. Filled with chlorophyll. Lesson 2: The cell cycle is a repeating cycle of events in the life of the cell. Apoptosis is regulated death which is a natural part of the cell cycle. Reproduction: An amoeba, a single celled eukaryote, is divided into two cells. Each new cell will be an individual organism. Growth and Development: Allows multicellular eukaryotic organisms to grow and mature. Tissue renewal: These dividing bone marrow cells will give rise to new blood cells.​ Apoptosis: Cells age mostly because they lose a bit of their DNA each time they divide. After around 50 or 60 divisions, they lose too much DNA to keep dividing. The main goal of cell division is to produce genetically identical cells. DNA (Deoxyribonucleic acid): -​ Genetic information that governs cell structure and function -​ Found in the nucleus (if not undergoing mitosis) -​ Can be found as chromatin or condensed into chromosomes DNA is a single, long double stranded molecule that wraps around proteins to make chromatin. Chromosomes are made up of chromatin that is even more condensed even further during mitosis. The unduplicated chromosome does not occur in mitosis since DNA is duplicated before chromatin condenses to form chromosomes. ` Duplicated chromosomes are what start to form at the start of mitosis. *(2 SISTER CHROMATIDS) Chromosomes are photographed when they are highly condensed, then the photo of the individual chromosomes are arranged in order of decreasing size. Humans have 23 homologous pairs of chromosomes, one pair are the sex chromosomes (XX or XY). Each chromosome in the pair comes from each parent. Diploid: A cell possessing two copies of each chromosome. Homologous chromosomes have the same type of genes but each come from a different parent. Duplicated homologous chromosomes are made up of sister chromatids joined at the centromere. The cell cycle: 1.​ Interphase: normal cell activity as the cell grows and prepares for cell division. 2.​ Mitosis: process to equally divide the DNA 3.​ Cytokinesis: cell physically divided. A cell spends about 90% of its time here G1 - Cells undergo majority of growth and produces new proteins and organelles S - DNA replicates (Synthesizes) ​ G2 – Cell continue to grows - Assemble machinery for division such as centrioles. G phases are important to ensure the cell is large enough that when it is split each daughter cell has enough organelles and mass. Each new cell receives one copy of every chromosome that was present in the original cell. Produces 2 new cells that are both genetically identical to the original cell. Before Mitosis: Interphase A nuclear envelope is intact around the nucleus. The nucleus contains one or more nucleoli (singular, nucleolus). In animal cells, each centrosome has two centrioles. Chromatin duplicated during S phase, no chromosomes yet (they have not yet condensed). Prophase: The chromatin condensed into chromosomes as fibers become more tightly coiled. The nucleoli disappear. The mitotic spindle begins to form. The centrosomes move away from each other. Nuclear envelope begins to disappear. Metaphase: Metaphase is the longest stage of mitosis, lasting about 20 minutes. The centrosomes are now at opposite ends of the cell. The chromosomes line up on the metaphase plate, an imaginary plane that is equidistant between the spindle’s two poles. Anaphase: Anaphase is the shortest stage of mitosis, lasting only a few minutes. Anaphase begins when the two sister chromatids of each pair suddenly part. The two liberated chromosomes begin moving toward opposite ends of the cell, as their spindle microtubules shorten. By the end of anaphase, the two ends of the cell have equivalent—and complete—collections of chromosomes. Telophase: Two daughter nuclei begin to form in the cell. Nuclear envelopes begin to reform.The chromosomes become less condensed. Mitosis, the division of one nucleus into two genetically identical nuclei, is now complete. After Mitosis:Cytokinesis Cleavage of cell into two halves Animal cells Cleavage furrow pinches cell until two separate cells form Plant cells​ cell plate forms from vesicles until daughter cells separates Lesson 3: A cancer cell can continue to divide without limit, compared to a normal healthy cell which has an upper limit of 50 to 60 divisions. These excessive divisions form a tumour. Cancer arises from the accumulation of genetic changes or mutations. People can be susceptible to cancer based on their genetic makeup, but cancer is not directly passed from parent to child. Many genes that are involved in cancer are involved in regulating the cell cycle. Cancer cells generally have multiple mutations before control over cell division is lost. Most cancers have a minimum of 6­9 genes involved. Benign: (non cancerous) harmless tumour, Has a regular and smooth shape, Grows locally and does not invade nearby tissue, Does not spread throughout the body Malignant: (cancer) harmful tumour, Grows fast and has an irregular shape, Spreads rapidly and invades nearby tissues, Has the potential to spread through the body Metastatic: (advanced stage cancer) harmful systemic tumours, Spread into the bloodstream and travelled to other areas Common Causes of Cancer Smoking and Tobacco use, Exposure to toxins Poor Diet and Low Physical Activity. Exposure to Sun and Other Types of Radiation. Viruses and Other Infections. Oncology is the study of cancer. An oncologist is a doctor who treats cancer and provides medical care for a person diagnosed with cancer. Common treatments include: Surgery ­which physically removes local cancer cells. Not practical for large areas. Radiation which uses high­energy rays to kill cancer cells. A large machine directs focused radiation at the body. Useful for small to medium areas (not whole body). Chemotherapy which uses anticancer drugs to kill cancer cells. This is a systemic approach which addresses cancer throughout the body. Immunotherapies (see slide). Used less in Canada than other treatments. Patients may use combinations of these. Lesson 4: DNA is the instruction manual for the cell Cell Specialization: the process in which cells develop in special ways to perform a particular function. Specialized cells have a specific role in the body. To help fulfil that role, they have specific shape or structure. They have specific amounts of different organelles. For example, mature RBCs are missing the nucleus (no DNA), mitochondria, and endoplasmic reticulum. This allows it to carry more hemoglobin which helps transport oxygen from lungs to tissues in the body. Stem Cells: An unspecialized cell, can become specialized (can become any cell type in the body) when exposed to proper conditions. May be used to treat diseases or injury because they are able to become any cell in the human body. Most Human cells, When cells are specialized, it means they have specific functions. Their shape and structure determines their function. Tissues: Group of cells that work together to perform a specific function. Found in multicellular (>1 cell) organisms. Epithelial tissue: Protects & covers surfaces inside and outside the body. Forms glands that make hormones (chemical signals), enzymes (proteins), mucus & sweat. Examples: Skin, lining of esophagus & intestines Connective tissue: Supports & Protects parts of the body, Fills space, Stores fat, Forms blood. Examples: Blood, bone & tissues under the skin Muscle Tissue: Allows Movement THREE TYPES: Skeletal: Moves your bones (voluntary) Cardiac: Pumps your heart (involuntary) Smooth: Surrounds organs (involuntary); found in places like your digestive system and respiratory system where you don’t have to think to act Nervous tissue: Responds to stimuli, Transmits & stores information. Examples: Neurons (brain & nerve cells) Tissue Type Function Protective barrier Epithelial tissue Lines body cavities & outer surface of the body  Joins other tissues together Connective tissue Examples: tendons, ligaments, bones, cartilage, blood Skeletal, smooth & cardiac muscle tissue Muscle tissue For movement Nerve cells Nervous tissue Transmits information Tissue Type Function All plant tissues formed from this tissue Meristematic tissue Found on leaves Epidermal tissue Stomata allows exchange of gases & materials in & out of plant In stem it provides the support In roots it stores food & water Ground tissue In leaves there is specialized ground tissue called mesophyll, where photosynthesis occurs Transports water and nutrients in the plants Vascular tissue Lesson 5: Organ systems A group of organs work together to perform a specific function. The integumentary system: Organ: Skin Accessory Structures (not organs): horns, antlers, hooves, quills, claws, hair, nails Glands: sweat glands, sebaceous glands, scent glands. Function: to act as a barrier form the outside world, regulate body temperature Skin is the largest organ in the body. Protects inner cells from damage and acts as defense from disease. Epidermis: outlayer, made of epithelial tissue, prevents bacteria and viruses from entering, makes vitamin D from UV light, vitamin D is essential for bone development. Dermis: middle layer, supports the epidermis, sensations, sweat producing, moisturizing, and hair producing. Hypodermis: bottom layer, made of connective tissue, nervous tissue and muscle tissue Circulatory system: Organs: arteries, veins, capillaries and heart Function: to transport nutrients, gases and wastes The heart: Muscular pump; supplies body with blood, about the size of your fist, beats an average of 3.5 billion times/life, four-chamber organ, left and right atria(Artium), and left and right ventricles. The atria: receiving chambers The ventricles: pumping chambers The valves: prevent backflow The septum: separates chambers 1.​ Deoxygenated blood comes from the body and fills the right atrium 2.​ Blood moves from the right atrium to the right ventricle 3.​ Blood travels to the lungs 4.​ Oxygenated blood leaves the lungs and enters the left atrium 5.​ Blood moves from the left atrium to the left ventricle 6.​ Blood travels to the body via the aorta Arteries: thick walled vessels that carry blood away from the heart Veins: thin walled vessels that carry blood into heart Capillaries: connects veins to arteries. This is where gas exchange occurs via diffusion ​ Diffusion: flowing from high concentration to low concentration Lesson 5.2: THe digestive system: The digestive system is the first system that forms during embryonic development. Key Organs: mouth, esophagus, stomach, small and large intestine, rectum, anus. Function: to process nutrients and water for use in the rest of the body The digestive system is just a long tract through which food travels, technically considered external! The digestive system is controlled by the autonomic nervous system. This means we do not have any voluntary control on the processes of digestion or what and when the digestive organs carry out their functions. We are mostly unaware of the processes as they occur. Different systems in different organisms can look different depending on the different types of functions they need to perform. Stages of Digestion: 1.​ Ingestion 2.​ Digestion 3.​ Absorption 4.​ elimination Ingestion: Digestion typically occurs in two phases: 1.Mechanical breakdown of the food into smaller pieces occurs in the mouth and stomach Chew, tear, grind, mash, mix 2. Chemical breakdown Enzymatic reactions to improve digestion of food Occurs in mouth, stomach and small intestine Mouth takes in food, Mechanical breakdown of food, Teeth are used to chew the food, Chemical digestion Salivary glands release enzymes that start breaking down food into smaller pieces, Tongue moves food and sends it down tube in a bolus Peristalsis : Contractions of the muscles moves food from the mouth to the stomach via the esophagus, Made of smooth muscle tissue Stomach is basically a really strong mixing muscle. Mechanical digestion, Churning and moving the food around, Chemical digestion, Gastric juices, Hydrochloric acid, Pepsin When the food leaves the stomach it is called chyme (liquid consistency) Absorption (Small Intestine - Absorbs Nutrients) Nutrients from food in the digestive system are absorbed into the bloodstream. 90% occurs in the smal intestine, 10% occurs in the large intestine and stomach. Therefore, the small intestine and the large intestine are surrounded by small blood vessels (aka capillaries). Small Intestine: Contains villi and microvilli that have greater surface area in order to increase absorption. 23 feet (7m) long with a surface area of ~250ft2 Chemical digestion Breaks down fats, proteins and carbs Absorbs nutrients and minerals from food Large Intestine: Not longer than small intestine, but wider. Attached to the appendix (probably a reserve for good gut bacteria) Absorption of water as it passes the rest of the waste through the large intestine. Egestion: Absorption of water as it passes the rest of the waste through the large intestine Undigested food is then stored in the rectum and eliminated through the anus Accessory Organs of Digestion: Liver: produces bile to break down fats in small intestine Gallbladder- concentrates bile (for breaking down fat) and releases it into the small intestine Pancreas - releases pancreatic juices/enzymes into small intestine to help break down carbs/proteins Respiratory System: Organs: nose, mouth, trachea, bronchi, bronchioles, alveoli, lungs, diaphragm Function: gas exchange (oxygen in, carbon dioxide out) Works with the circulatory system. Path of Airflow: Nasal/Oral cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli Nasal cavity Warms up the air and makes it humid Allows us to smell things because it connects to olfactory nerve Has mucus and hair to trap pathogens Allows warmed and clean air to pass to trachea  Oral cavity Allows air to pass to trachea Helps us taste things (sweet, sour, salty, bitter and umami) Pharynx Air goes to the back of the throat before going to trachea Larynx Voicebox; when you speak, air is pushed up from trachea causing vocal cords to vibrate which creates sound. Trachea Windpipe; open at all times except when we swallow If food/water goes to the trachea by accident = coughing Bronchi Two main branches of the trachea; allow air to pass into each lung Bronchioles Even smaller airways; about 30,000 terminal bronchioles. At the end of the bronchioles there are small sacs called alveoli Alveoli Location of gas exchange (O2 is exchanged for CO2) Wrapped up in capillaries How Breathing Works Inhalation: Diaphragm contracts + rib cage rises Increases size and volume of chest cavity = decreases internal pressure Air flows into the lungs because pressure inside the lungs is lower than the pressure outside the body. Exhalation Diaphragm relaxes + rib cage lowers Decreases size and volume of chest cavity = increases internal pressure Air flows into the lungs because pressure inside the lungs is higher than the pressure outside the body. Gas Exchange - Alveoli to Capillaries The alveoli are surrounded by tiny capillaries. Here, blood cells exchange carbon dioxide for oxygen through the process of diffusion. Lesson 6: Integumentary System - skin + associated structures Circulatory system - heart, blood, veins, arteries and capillaries Respiratory system - nose, mouth, lungs, trachea, bronchi, bronchioles, diaphragm Skeletal system - bones Muscular system - muscles Nervous system - brain, nerves Body systems working together: -​ Our body systems work together to perform daily tasks, and function in a way to maintain homeostasis. -​ Homeostasis: is a steady state, an acceptable range of physical and chemical conditions in order for cells, tissues and organs to operate efficiently. -​ Our organ systems are independent The complexity of our organ systems make it difficult for doctors to diagnose and treat problems in our organ systems. Blood pressure: -​ Measure of the pressure of blood against the wall of the arteries. -​ A normal blood pressure level is less than 120/80 mmHg. -​ High blood pressure causes damage to arteries and can lead to heart attacks. Blood Test: -​ Tests for levels of nutrients, blood cells count, and sugar in the blood. -​ Hormone levels can also be tested. Plasma: Water, proteins, nutrients, hormones, etc. Buffy Coat: White blood Cells, Platelets Hematocrit: Red Blood cells ​ Checking the Excretory System: ​ Urine Testing: -​ If white blood cells are present, infection in the excretory system -​ Not much urine being produced could indicate kidneys are not functioning properly. -​ Too much urine could indicate that the pancreas is not working properly. -​ Drugs can also be detected in the urine. Lesson 7:​ The roots: -​ Anchor the plant in the soil -​ Collect water from the soil to transport to stem -​ Store food that had been created from other parts of the plant -​ Meristematic tissue at the end of the roots allow them to grow (also present in the shoots) The Stem: 2 major functions: 1.​ Transport water and nutrients throughout the plant 2.​ Support leaf and flowers. Vascular tissue transports substances. Epidermal tissue coats and protects the stem. The leaf: -​ Tissues work together to accomplish photosynthesis. -​ Vascular system carries water from the root up to the leaf sugar produced is carried from the leaf to the rest of the plant. -​ Photosynthesis takes place in the mesophyll. The Flower: -​ Reproductive structure of the plant -​ Main function of the flower is to produce seeds -​ “Male” organs - stamen (filament and anther) which produces pollen -​ “Female” organs - pistil (ovary, style, stigma) Plant Organ systems: Both systems are responsible for movement for water. Water → root hairs → xylem → stem → leaves (transpiration) Transpiration: evaporation of water through the stomata leaves. The “pulling” of water molecules through transpiration is stronger than gravity. Lesson 10: Medical Imaging Technology: -​ Produces images of organs and tissues within the body for use in diagnosis and treatment. -​ Types of imaging technologies include: x-ray, ultrasound, computed tomography (CT) scan, Magnetic Resonance imaging (MRI), positron emission tomography (PET) and biophotonics X-Ray: -​ Most common form of medical imaging -​ Uses high energy radiation to easily penetrate the skin and tissue, but cannot penetrate metals and bones -​ A radiograph is produced when X-Rays pass through the body to produce an image -​ X-rays are absorbed by bone, and bone appears whiter -​ Images are viewed by Radiologists as a photographic film/computer -​ Using X-rays to image the body is quick, painless and non-invasive -​ BUT, X-ray is high energy radiation, it can cause changes and mutations to DNA. -​ To prevent this, a protective lead apron is used to cover the body so X-rays cannot penetrate Fluoroscopy: -​ Uses a continuous beam of X-rays to produce images that show the movement of bones or organs (eg. stomach, intestine and colon)  -​ Patient may be required to ingest a contrast liquid such as barium or iodine to make tissues visible -​ Can also be used to study blood vessels of the heart and brain, creating an image called an angiogram -​ In a coronary angiogram, a special dye is injected in the groin which enables the blood flow to the heart to be visualized -​ A cerebral angiogram shows any blockages in the blood vessels in the brain which can lead to a stroke Ultrasound: -​ Imaging uses high frequency sound waves to produce images of body tissues and organs -​ Transducer produces sound waves is placed on skin, they enter the body and are reflected back by structures, like an echo, forming an image on the screen -​ Used for studying soft tissues and organs -​ Not used on bones because the sound waves cannot penetrate the bone Computed Tomography (CT): -​ Sometimes also called computer assisted tomography (CAT), uses x-rays equipment to form 3D images from a series of images taken from different angles -​ CT scans can produce detailed cross-section images of bones, soft tissues and blood vessels at the same time Magnetic Resonance Imaging (MRI): -​ Uses a powerful magnetic field which interacts with hydrogen atoms in the body -​ This interaction + different radio frequencies produces images to show the structure and function of the brain, heart, liver, soft tissues and the inside of bones -​ MRI can diagnose forms of cancer, brain diseases, and cardiovascular conditions Nuclear Medicine: -​ Uses radioactive isotopes such as barium or iodine to produce images of how tissues or organs function -​ Radio isotope is mixed with a chemical that is absorbed by certain tissues -​ Isotope emits radiation that the camera + computer detect as radiation to form an image -​ Can be used to detect diseases such as thyroid cancer, prostate cancer and certain types of breast cancer Positron Emission Tomography (PET): -​ A type of nuclear medicine -​ Patient is given a radioisotope that emits positively charged electrons called positrons  -​ Used to detect cancers in tissues, brain disorders such as Alzheimer's disease and epilepsy -​ Often combined with CT or MRI scans, to produce both anatomic and metabolic information -​ (ie. What a structure is and what it is doing biochemically) Biophotonics: -​ An endoscope is a thin, flexible tube that has a bright light and a camera which enables doctors to view tissues deep within the body -​ A gastrointestinal endoscopy or colonoscopy provides images and samples of the digestive tract Lesson 10: Two most common types of microscopes: Optical and Electron We use compound light microscopes at school. Optical and focuses light through two different lenses (ocular and objective) to form a magnified image. Electron Microscope: -​ Uses a beam of electrons instead of light -​ Pro: capable of producing much greater magnifications (1500000X) -​ Con: Requires very thin cell sections so only dead cells can be examined A Arm B Objective lenses C Eyepiece/ ocular lens D Coarse & Fine adjustment knobs E Ocular tube F Rotating/ revolving nosepiece G Stage & stage clips H Diaphragm and condenser lens Resolution: ability to distinguish between two objects that are very close together. Contrast: Difference in light intensity between the image and the background. Stains can be used to create a greater contrast, such as: Iodine, Methylene Blue, Crystal Blue Calculating the Magnification: TOTAL MAGNIFICATION = OBJECTIVE LENS X OCULAR LENS For a compound microscope: Objective lens is either 4X OR 10X OR 40X (revolving nosepiece to change) Eyepiece/ Ocular lens - 10X (sometimes 15X - check the microscope) Calculating Field of View : Low Power Field Diameter (LPFD) When you are looking at something under a microscope, you want to be able to measure the specimen. You can do this by calculating field diameter. On low power, measure the diameter of the field of view. You must convert this to micrometers (μm) by multiplying by 1000. 2. The size of the specimen/ object can now be estimated by comparing its size to the field diameter. To figure measurements at higher magnifications, you must use the following equation: Remember magnification is the product of the ocular and objective lens! If you are calculating high power field diameter, simply substitute “high” instead of “medium” in the equation above Use the following procedures for correct biological drawings Draw only what you observe Only use a pencil for drawings and labels Put drawings on the left of the space Put labels on the right Label lines are created with a ruler Underline the title and put it in the top left hand corner of the drawing Put the magnification in the bottom right hand corner To shade something, use stippling, or dots WATCH AMOEBA SISTERS