Biology Chapter 6 Quiz

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Questions and Answers

What is the primary role of the citric acid cycle?

To break down glucose into pyruvate

To transfer electrons to the electron transport chain

To produce ATP and carbon dioxide through oxidation reactions (correct)

To convert pyruvate into acetyl CoA

What happens to pyruvate under anaerobic conditions in animals?

It enters the electron transport chain

It is reduced to lactate (correct)

It transforms into acetyl CoA

It is converted to citric acid

Which of the following compounds is produced during glycolysis?

NADH (correct)

Lactate

Acetyl CoA

Citric acid

Where does the process of glycolysis occur?

In the cytoplasm Signup and view all the answers

Which process generates the most ATP per glucose molecule under aerobic conditions?

Electron transport chain Signup and view all the answers

What is the primary function of proto-oncogenes?

Promote the cell cycle Signup and view all the answers

What can occur if tumor suppressor genes are mutated?

Stimulation of cell cycle progression Signup and view all the answers

How does cancer typically develop in cells?

Due to genetic mutations disrupting normal cell function Signup and view all the answers

What is the role of growth factors in the cell cycle?

To initiate cell cycle events Signup and view all the answers

What is a critical factor in preventing cancer development during the cell cycle?

Proper distribution of chromosomes Signup and view all the answers

What is the primary function of a tissue in multicellular organisms?

To group similar cells performing a specific function Signup and view all the answers

Which kingdom includes organisms that are photosynthetic and multicellular?

Plant Kingdom Signup and view all the answers

What type of organism is classified in the Protista Kingdom, according to their characteristics?

Unicellular and autotrophic Signup and view all the answers

What is the correct format for writing a scientific name?

Both words italicized, genus capitalized Signup and view all the answers

What defines an experimental variable in a scientific experiment?

The factor that is tested in the experiment Signup and view all the answers

Why are model organisms important in scientific research?

They can be used to replace human subjects safely Signup and view all the answers

What does the concept of statistical significance help researchers determine?

The likelihood that the study results occurred by chance Signup and view all the answers

What is the main purpose of scientific peer review?

To ensure the accuracy and reliability of research Signup and view all the answers

What is a characteristic feature of prokaryotic cells?

Lack of a membrane-bound nucleus Signup and view all the answers

Which structure is present in some bacteria but not in all prokaryotic cells?

Capsule Signup and view all the answers

Which statement correctly describes the cell wall of Archaea?

Usually present, no peptidoglycan Signup and view all the answers

What is the primary function of ribosomes in prokaryotic cells?

Protein synthesis Signup and view all the answers

Which of the following describes the genetic material in prokaryotic cells?

Found in the nucleoid region Signup and view all the answers

How do spirilla bacteria differ from spirochetes?

Spirilla are long rods twisted into rigid spirals, spirochetes are flexible spirals Signup and view all the answers

Which characteristic distinguishes eukaryotic cells from prokaryotic ones?

Membrane-bound organelles Signup and view all the answers

What component of the prokaryotic cell membrane contributes to its fluidity?

Phospholipid bilayer Signup and view all the answers

Which statement accurately describes the function of ribosomes in a cell?

Ribosomes synthesize proteins using mRNA as a template. Signup and view all the answers

What is the primary role of the Golgi apparatus in a cell?

To collect, sort, package, modify, and distribute materials. Signup and view all the answers

Which type of cytoskeletal component is primarily responsible for maintaining cell shape and aiding in organelle movement?

Microtubules Signup and view all the answers

What characteristic is unique to mitochondria compared to other organelles?

Mitochondria contain their own DNA. Signup and view all the answers

Which function is performed by lysosomes in a cell?

Breaking down unwanted foreign substances and cellular debris. Signup and view all the answers

Which feature differentiates chloroplasts from mitochondria?

Chloroplasts are primarily involved in photosynthesis. Signup and view all the answers

How do actin filaments contribute to cellular function?

By interacting with motor molecules for muscle contraction. Signup and view all the answers

What is the primary function of smooth endoplasmic reticulum?

Synthesis of phospholipids and other functions depending on cell type. Signup and view all the answers

Which statement accurately describes the composition of cilia and flagella?

They both contain a 9+2 pattern of microtubules. Signup and view all the answers

According to the endosymbiotic theory, mitochondria and chloroplasts are thought to have originated from what type of organisms?

Cyanobacteria and heterotrophic bacteria Signup and view all the answers

Which process is specifically responsible for the uptake of liquids and small particles?

Pinocytosis Signup and view all the answers

Which protein in the extracellular matrix (ECM) provides resilience?

Elastin Signup and view all the answers

Which type of junction connects cytoskeletal filaments of adjacent cells?

Adhesion Junctions Signup and view all the answers

In photosynthesis, what do plants primarily store solar energy as?

Chemical energy Signup and view all the answers

According to the first law of thermodynamics, which statement is true?

Energy is conserved in all transformations. Signup and view all the answers

What type of energy transformation occurs in an exergonic reaction?

Energy is released Signup and view all the answers

What is the primary structure of ATP that stores energy?

Phosphate bonds Signup and view all the answers

What component of plant cell walls allows for flexibility and stretching?

Pectin Signup and view all the answers

What is the main role of fibronectin in the extracellular matrix?

Link cells to the cytoskeleton Signup and view all the answers

What is the primary role of cholesterol in the cell membrane?

Stiffen and strengthen the membrane Signup and view all the answers

Which statement accurately describes entropy in biological systems?

All cellular processes increase total entropy. Signup and view all the answers

Which type of protein is responsible for facilitating the movement of solutes through the cell membrane?

Channel proteins Signup and view all the answers

In receptor-mediated endocytosis, what is the role of the receptor proteins?

Provide specificity for certain molecules Signup and view all the answers

Which statement is true regarding hypotonic solutions?

Cells gain water and may burst Signup and view all the answers

What type of energy is primarily generated from the breakdown of glucose?

Chemical energy Signup and view all the answers

What characterizes facilitated diffusion?

Involves carrier proteins that do not require energy Signup and view all the answers

What is the term for the diffusion of water across a selectively permeable membrane?

Osmosis Signup and view all the answers

What is the primary function of the cytoskeleton in animal cells?

Assist in cell shape and transport Signup and view all the answers

Which type of transport requires energy due to moving substances against their concentration gradient?

Active transport Signup and view all the answers

What do glycoproteins primarily assist with?

Cellular identification and recognition Signup and view all the answers

In what process do vesicles form to take substances into a cell?

Endocytosis Signup and view all the answers

What happens to a cell placed in a hypertonic solution?

The cell loses water and shrivels Signup and view all the answers

Which of the following is NOT a type of endocytosis?

Exocytosis Signup and view all the answers

What occurs during enzymatic protein function?

Speeding up metabolic reactions Signup and view all the answers

What characterizes a cell’s movement down a concentration gradient?

Is considered passive transport Signup and view all the answers

What is the significance of aquaporins in the cell membrane?

They facilitate water transfer Signup and view all the answers

What is the primary role of peer review in scientific studies?

To challenge statements and hypotheses Signup and view all the answers

What defines a compound in chemistry?

A substance formed from two or more different types of elements Signup and view all the answers

Which element is NOT considered part of CHNOPS?

Silicon Signup and view all the answers

What is the process called when water is added to break down polymers?

Hydrolysis Signup and view all the answers

In terms of electron configurations, how many electrons can the first shell hold?

2 electrons Signup and view all the answers

What type of bond is formed when atoms share electrons equally?

Nonpolar covalent bond Signup and view all the answers

Which of the following describes a Prokaryotic cell?

Cells that lack a membrane-bound nucleus Signup and view all the answers

Which of the following statements about molecules and compounds is true?

All compounds are molecules Signup and view all the answers

What is the basic energy storage form of glucose in plants?

Starch Signup and view all the answers

What occurs if a cell doubles in size regarding its surface area and volume?

Surface area increases fourfold, volume increases eightfold Signup and view all the answers

Which functional group is crucial for the consistent reactions of organic molecules?

Functional groups Signup and view all the answers

What does electronegativity refer to in a covalent bond?

The attraction of an atom for electrons Signup and view all the answers

What describes valence shells in terms of their electron capacity?

They hold 8 electrons, except the first shell Signup and view all the answers

What is the importance of high heat capacity in water?

It helps maintain stable internal temperatures for organisms Signup and view all the answers

What happens to the lac repressor when lactose is absent?

It binds to the operator, preventing transcription. Signup and view all the answers

What is the function of the promoter in the lac operon?

To serve as the binding site for RNA polymerase. Signup and view all the answers

Which statement accurately describes the lac operon?

It is an inducible operon activated by lactose. Signup and view all the answers

What role does RNA polymerase play in the lac operon?

It initiates the transcription of lactose metabolism genes. Signup and view all the answers

What happens when lactose binds to the lac repressor?

The repressor can no longer bind to the operator. Signup and view all the answers

In what scenario is the lac operon not transcribed?

When lactose is absent. Signup and view all the answers

What distinguishes prokaryotic operons from eukaryotic genes?

Prokaryotic operons serve multiple genes with one promoter. Signup and view all the answers

Which mechanism is primarily responsible for regulating gene expression in eukaryotes?

A variety of regulatory mechanisms employed for control. Signup and view all the answers

What is the end product of glycolysis?

2 pyruvate Signup and view all the answers

Which type of organisms are known for undergoing photosynthesis?

Autotrophs Signup and view all the answers

In which part of the plant does photosynthesis primarily occur?

Leaves Signup and view all the answers

What is the main role of chlorophyll in photosynthesis?

To absorb sunlight Signup and view all the answers

Which of the following is produced during the light reactions of photosynthesis?

Oxygen Signup and view all the answers

What is the primary function of the Calvin Cycle?

To fix carbon dioxide into carbohydrates Signup and view all the answers

How many times does the Calvin Cycle need to occur to produce one glucose molecule?

Which pigments primarily absorb light for photosynthesis?

Chlorophyll a and b Signup and view all the answers

What occurs during the photolysis of water in photosynthesis?

Electrons are released and oxygen is produced Signup and view all the answers

What is the primary role of caspases in apoptosis?

To carry out cell destruction Signup and view all the answers

Which phase of the cell cycle is associated with DNA synthesis?

S Phase Signup and view all the answers

What is the purpose of DNA methylation in eukaryotic gene expression?

To keep genes turned off Signup and view all the answers

What is the role of cyclin in the regulation of the cell cycle?

To regulate timing of cell division Signup and view all the answers

Which factor is crucial for the binding of RNA polymerase to a promoter?

Transcription factors Signup and view all the answers

What modification occurs to primary mRNA before it becomes mature mRNA?

Addition of a poly-A tail and guanine cap Signup and view all the answers

What happens during the G2 phase of interphase?

Cell prepares for mitosis Signup and view all the answers

What effect does the length of the poly-A tail have on mRNA?

It affects the availability of mRNA for translation Signup and view all the answers

What is the outcome of mitosis?

Two identical daughter cells are formed Signup and view all the answers

What type of mutation occurs in the germline that can affect future generations?

Germ-line mutation Signup and view all the answers

Which of the following is classified as an induced mutation?

Environmental factors like radiation Signup and view all the answers

What is one potential outcome of a base substitution mutation?

Formation of a STOP codon Signup and view all the answers

What kind of mutation results from inserting or deleting nucleotides in the DNA sequence?

Frameshift mutation Signup and view all the answers

How do transposons affect gene expression?

By moving within and between chromosomes Signup and view all the answers

What type of chemical modification can affect a protein's activity after its synthesis?

Phosphorylation Signup and view all the answers

Which stage of mitosis is characterized by the alignment of chromosomes at the metaphase plate?

Metaphase Signup and view all the answers

What is the primary outcome of meiosis II?

Formation of four haploid daughter cells Signup and view all the answers

Which process utilizes ATP to drive an endergonic reaction?

ATP hydrolysis Signup and view all the answers

What role do enzymes play in chemical reactions?

They act as catalysts to speed up reactions. Signup and view all the answers

Which process ensures genetic variation during meiosis?

Independent assortment Signup and view all the answers

What is the purpose of the induced fit model in enzyme function?

To explain how enzymes can change shape when binding substrates. Signup and view all the answers

In human reproduction, what are the gametes formed in males called?

Sperm cells Signup and view all the answers

What can happen if the temperature exceeds an enzyme's optimal range?

The enzyme may lose its structure and function. Signup and view all the answers

What best describes the function of proto-oncogenes?

To initiate cell division Signup and view all the answers

What effect do cofactors have on enzymes?

They assist the enzyme in catalyzing reactions. Signup and view all the answers

What is the expected chromosome number in a human zygote after fertilization?

46 Signup and view all the answers

What happens to NADH during the NAD cycle?

It gives up electrons to recycle NAD. Signup and view all the answers

During which phase of mitosis do sister chromatids become individual chromosomes?

Anaphase Signup and view all the answers

Which phase of cellular respiration occurs in the cytoplasm?

Glycolysis Signup and view all the answers

What happens during prophase I of meiosis?

Homologous chromosomes undergo synapsis Signup and view all the answers

What is the primary function of enzymes in metabolic pathways?

To link reactions in a specific sequence. Signup and view all the answers

Which type of cells are produced by oogenesis?

Both B and C Signup and view all the answers

What is the composition of eukaryotic chromosomes?

Chromatin (DNA and protein) Signup and view all the answers

How does enzyme inhibition typically occur?

Through binding at the active site or altering its shape. Signup and view all the answers

In which phase of the cell cycle does DNA replication occur?

S phase Signup and view all the answers

Which of the following describes oxidation?

The loss of electrons or hydrogen atoms. Signup and view all the answers

What is the main purpose of cellular respiration?

To release energy from glucose for ATP synthesis. Signup and view all the answers

What occurs during telophase of mitosis?

Nuclear membrane reforms around chromosomes Signup and view all the answers

Which term refers to an individual's genetic makeup?

Genotype Signup and view all the answers

What is true about enzyme activity?

Each enzyme has a specific optimal pH and temperature range. Signup and view all the answers

What process describes the random distribution of maternal and paternal chromosomes during meiosis?

Independent assortment Signup and view all the answers

Which statement about ATP is correct?

ATP breakdown can drive endergonic reactions. Signup and view all the answers

What process turns glucose into two molecules of pyruvate?

Glycolysis Signup and view all the answers

What is the primary function of meiosis in gamete formation?

To ensure only one allele per trait is present in gametes Signup and view all the answers

What unique characteristic is true about gametes in terms of allele representation?

Gametes contain one allele from each parent Signup and view all the answers

Which disorder is classified as an autosomal recessive disorder?

Sickle-cell disease Signup and view all the answers

In the context of genetic inheritance, what is true about co-dominance?

Both alleles are fully and equally expressed Signup and view all the answers

How does polygenic inheritance primarily affect phenotypes?

By producing a continuous range of phenotypic expressions Signup and view all the answers

What condition arises when a person inherits alleles for blood type A and B?

Type AB blood Signup and view all the answers

Which statement accurately describes incomplete dominance?

Heterozygotes exhibit a blend of traits from both parents Signup and view all the answers

Which characteristic is true of a pedigree chart?

It illustrates the inheritance pattern of a trait over generations Signup and view all the answers

Which of the following is NOT a symptom of Cystic Fibrosis?

Progressive deterioration of psychomotor functions Signup and view all the answers

Which of the following statements is true regarding Tay-Sachs disease?

It is particularly prevalent among Jewish people in the U.S. Signup and view all the answers

What is the function of helicase during DNA replication?

To separate the double-stranded DNA Signup and view all the answers

What signifies the end of the transcription process?

RNA polymerase detaches from the DNA Signup and view all the answers

What is the role of DNA ligase in DNA replication?

To connect Okazaki fragments and seal breaks Signup and view all the answers

Which molecule serves as a template for the synthesis of mRNA during transcription?

DNA Signup and view all the answers

What is the first step that occurs during the initiation of transcription?

RNA polymerase binds to the promoter Signup and view all the answers

Which component is NOT involved in the translation process?

DNA Signup and view all the answers

How does the antiparallel nature of DNA affect replication?

It necessitates the use of Okazaki fragments on the lagging strand Signup and view all the answers

What type of molecule is formed after processing of pre-mRNA?

Mature mRNA Signup and view all the answers

What is the significance of the genetic code being degenerate?

Most amino acids are coded by more than one codon Signup and view all the answers

Which of the following describes the lagging strand during DNA replication?

Synthesized in fragments and requires ligase to connect Signup and view all the answers

What triggers the termination phase of translation?

A stop codon on the mRNA is reached Signup and view all the answers

What role does the poly-A tail play in mRNA processing?

Enhances mRNA stability and export from the nucleus Signup and view all the answers

Which of the following is an accurate statement about gene expression control in eukaryotic cells?

Gene expression is responsible for cell specialization Signup and view all the answers

In prokaryotes like E. coli, what allows for rapid adjustment of gene expression based on environmental conditions?

The operon system for gene regulation Signup and view all the answers

What characterizes the ability of cancer cells to avoid apoptosis?

They continue to divide despite genetic damage. Signup and view all the answers

Which of the following best describes the function of the P53 gene?

A major tumor suppressor gene that controls cell cycle inhibitors. Signup and view all the answers

What type of mutation is primarily involved in the formation of a STOP codon?

Point mutations. Signup and view all the answers

How do cancer cells typically affect surrounding normal tissues?

They deprive surrounding tissues of blood and nutrients. Signup and view all the answers

What is the result of a frameshift mutation?

It alters the entire downstream amino acid sequence. Signup and view all the answers

Which statement is true regarding germ-line mutations?

They can lead to mutations that are incorporated into the germ cells. Signup and view all the answers

What is recombinant DNA technology primarily used for?

Producing proteins such as insulin and developing GMOs. Signup and view all the answers

What is a common mechanism by which cancer cells move to other body parts?

They use the blood or lymphatic vessels to spread. Signup and view all the answers

What is the significance of angiogenesis in cancer?

It supplies blood and nutrients to the tumor, promoting its growth. Signup and view all the answers

What characterizes polygenic traits?

They follow a bell-shaped curve in phenotype distribution. Signup and view all the answers

Which of the following statements is true regarding environmental influences on traits?

Temperature can influence the color of primrose flowers. Signup and view all the answers

What was a major finding from the work of Frederick Griffith?

R strain bacteria can become virulent through transformation. Signup and view all the answers

In Oswald Avery's experiment, what role did DNase play?

It prevented the transformation by digesting DNA. Signup and view all the answers

What conclusion did Hershey and Chase reach regarding DNA and proteins?

DNA is the genetic material, while proteins are not. Signup and view all the answers

Which components make up a nucleotide in DNA?

Phosphate, deoxyribose sugar, and a nitrogen base. Signup and view all the answers

What holds the two strands of DNA together?

Hydrogen bonds between complementary bases. Signup and view all the answers

What does the antiparallel orientation of DNA strands refer to?

One strand runs from 5' to 3' while the other runs from 3' to 5'. Signup and view all the answers

In DNA replication, what does it mean to copy one double helix into two identical double helices?

It duplicates both strands simultaneously. Signup and view all the answers

Which base pairs are connected by two hydrogen bonds?

Adenine and Thymine. Signup and view all the answers

Which of the following is the primary role of the capsule in the S strain of Streptococcus pneumoniae?

It protects the bacteria from the host's immune system. Signup and view all the answers

What type of bond connects the sugar-phosphate backbone in DNA?

Covalent bonds. Signup and view all the answers

Which of the following pairs of nitrogenous bases are considered purines?

Adenine and Guanine. Signup and view all the answers

Which statement is true about the genetic role of proteins and DNA based on early 20th-century research?

Both proteins and DNA were believed to be equally probable as genetic material. Signup and view all the answers

Study Notes

Cell Biology

Cells are the basic units of life. Tissues are groups of similar cells with a specific function. Organs are formed from tissues, and organ systems are formed from organs.
The plant kingdom comprises multicellular, photosynthetic organisms. Fungi include molds and mushrooms. The animal kingdom comprises multicellular organisms that ingest and process food.
Classification follows a hierarchy: Domain → Supergroup → Kingdom → Phylum → Class → Order → Genus → Species.
Systematics helps biologists understand the diversity of life. Examples include Amoeba (Protista, unicellular, eukaryotic, no fixed shape), Mushroom (Fungi, heterotrophic, non-mobile), Fern (Plantae, multicellular, photosynthetic), and Lion (Animalia, multicellular, carnivorous).

Classification and Scientific Names

Taxonomists use binomial nomenclature (Genus + species epithet) to name species. Examples include Homo sapiens, Pisum sativum, and Felis domesticus.
Scientific names are capitalized for Genus and italicized .

Hypothesis and Experimental Design

A hypothesis proposes a relationship between a variable (e.g., fertilizer) and a response variable (e.g., potato prices).
Control groups are maintained without the experimental variable.
Experimental groups receive the variable being tested (ex: fertilizer example).
Responding variable is influenced and altered.

Model Organisms

Model organisms are alternative to human testing. They are important in research to understand how treatments affect humans, without harming humans.

Statistical Significance

Statistical significance helps determine whether results of an experiment are reliable.

Scientific Publication

Peer review is important to challenge and ensure the reliability of scientific studies.

Chi-Square Tests

Chi-square tests are used to determine the significance of experimental results.

Basic Chemistry

Key elements include oxygen, carbon, hydrogen, nitrogen, phosphorus, and sulfur.
Atoms consist of protons (positive), neutrons (neutral), and electrons (negative), with electrons orbiting the nucleus.
The periodic table organizes elements based on atomic number and properties.
Groups are vertical columns and periods are horizontal rows.
Electron shells/orbitals determine electron arrangement.
Electron shells fill in a distinct order with distinct atomic configurations & characteristics of elements.

Molecules and Compounds

Molecules are formed by two or more atoms. Compounds involve two or more different elements combined. Not all molecules are compounds, but every compound is a molecule.
An example of chemical formula is CHNOPS (Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulphur).

Bonding

Ionic bonding occurs when electrons are transferred, forming ions with opposite charges.
Covalent bonding involves sharing electrons to achieve stable electron configurations.
Nonpolar covalent bonds share electrons equally, while polar covalent bonds share unequally. Electronegativity measures the attraction for electrons in a covalent bond.

Water

Water has a high heat capacity, meaning its temperature changes slowly, which is important for regulating temperature in organisms.
A calorie is the amount of heat energy required to raise the temperature of one gram of water by one degree Celsius.

Organic Molecules

Organic molecules always contain carbon and hydrogen.
Functional groups are specific combinations of atoms that consistently react in a predictable manner.
Macromolecules are large molecules formed by combining monomers (smaller units) to form polymers.
Reactions involving monomers in polymers are typically dehydration reactions. Polymers can be broken down by hydrolysis reaction.
Common organic molecules are carbohydrates, lipids, proteins, and nucleic acids, each serving specific functions within living organisms.
Monosaccharides (simple sugars like glucose), disaccharides (two monosaccharides like sucrose), and polysaccharides (long chains of monosaccharides like starch and glycogen) are examples of carbohydrates, providing energy and structural support.
Starch is plant energy storage; glycogen is animal energy storage.

Cells

Prokaryotic cells lack a nucleus and membrane-bound organelles; Eukaryotic cells contain a nucleus and membrane-bound organelles.
The cell theory postulates that all organisms are composed of cells, cells are the basic units of structure and function, and new cells arise from pre-existing cells.
Small cell size is beneficial for nutrient absorption and waste removal, although volume increases faster than surface area so cells of larger dimensions (volume) will require more adaptations in surface area.

Prokaryotic Cells

Prokaryotic cells are small and come in various shapes: rod-shaped (bacilli), spherical (cocci), spiral (spirilla/spirochetes).
Cell walls with peptidoglycan, capsules (external layer for protection), flagella for movement, fimbriae for attachment, nucleoid (region with DNA), and ribosomes are all prokaryotic cell structures.

Eukaryotic Cells: General Structure and Organelles

Eukaryotes include animals, plants, fungi, and protists. Eukaryotic cells contain a nucleus and membrane-bound organelles.
Cell walls are found in some eukaryotic cells, e.g., plant cell walls containing cellulose, fungi's containing chitin.
The nucleus contains chromatin (DNA + protein). Ribosomes synthesize proteins using mRNA as a template.
Endoplasmic reticulum (ER), Golgi apparatus, lysosomes, vacuoles, chloroplasts, mitochondria, and the cytoskeleton are key eukaryotic organelles each with distinct functions.
The endomembrane system consists of the ER, Golgi, lysosomes, and vacuoles that work in a regulated fashion to produce, process, modify, and distribute substances within the cell.

Eukaryotic Cells: Organelles (Detailed)

Rough ER is associated with protein synthesis; Smooth ER synthesizes lipids.
Golgi apparatus modifies, sorts, and packages proteins.
Lysosomes contain digestive enzymes.
Vacuoles store water, salts, or waste products.
Chloroplasts are the sites of photosynthesis.
Mitochondria are the sites of cellular respiration, and have their own DNA.
The cytoskeleton consists of actin filaments, intermediate filaments, and microtubules, maintaining cell shape, facilitating movement, supporting the cell, and facilitating movement within the cell. Centrioles are found in animal cells.
Cilia and flagella are involved in cell movement.

Membrane Structure and Function

Plasma membranes are composed of a phospholipid bilayer with embedded proteins.
Proteins span the membrane. The hydrophobic tails of lipids face inwards while the hydrophillic heads face outwards. Proteins that are embedded within the membrane are considered integral proteins. Peripheral proteins are usually associated with one side of the membrane while integral proteins usually span the entire membrane due to the hydrophobic amino acid side chains within the protein.
Glycolipids and glycoproteins act as cell markers.
Channel proteins facilitate passage of substances through the membrane.
Carrier proteins facilitate passage of substances across the membrane via binding and conformational changes by combining with the substance.
Receptor proteins initiate cellular responses when specific molecules bind to them.
Enzymatic proteins catalyze reactions.

Membrane Transport

Diffusion moves substances down their concentration gradients. Osmosis is the diffusion of water across a selectively permeable membrane.
Isotonic solutions have equal solute concentrations inside and outside the cell. Hypotonic solutions have lower solute concentrations outside the cell. Hypertonic solutions have higher solute concentrations outside the cell.
Active transport moves substances against their concentration gradients using energy (ATP).
Passive transport, like diffusion and facilitated diffusion, does not require energy.
Bulk transport moves large substances using vesicles (endocytosis and exocytosis).

Cell Surfaces

Extracellular matrix (ECM) provides support and communication.
Junctions (tight, gap, adhesion junctions) connect cells.
Plant cells have cell walls made of cellulose, with plasmodesmata connecting adjacent cells.

Energy

Energy is the ability to do work. The first and second laws of thermodynamics govern energy transformations in ecosystems.
Cells use energy for growth, metabolism, response, and reproduction.

Cellular Respiration

Cellular respiration releases energy from molecules (such as glucose) and uses it to generate ATP.
The process involves glycolysis, the preparatory reaction, the citric acid cycle (Krebs cycle), and the electron transport chain, generating 32-38 ATP molecules from one glucose molecule.

Photosynthesis

Photosynthesis converts solar energy into chemical energy (carbohydrates). Plants, algae, and cyanobacteria are examples of photosynthetic organisms (autotrophs).
Photosynthesis occurs in chloroplasts with two primary stages: light-dependent reactions and the Calvin cycle.
Chlorophyll absorbs light energy.

Cell Cycle, Mitosis, and Apoptosis

A cell cycle includes stages of G1 (growth), S (DNA replication), and G2 (preparation). Then M (mitosis which includes the segregation of chromosomes into daughter cell) and then cytokinesis (separation of the cytoplasm). Mitosis and Cytokinesis result in two daughter cells from the one original cell. Mitotic division is a critical aspect for human reproduction and general growth and development. Apoptosis (Programmed Cell Death) is essential for removing unwanted or damaged cells (ex: tail of a tadpole).
Specific checkpoints control the cycle.
Growth factors trigger the cell cycle.

Cancer

Cancer development involves mutations in proto-oncogenes and tumor suppressor genes, leading to uncontrolled cell division.
Carcinogens may be environmental factors such as radiation, chemicals, or viruses that contribute to the development of cancer.
Cancer cells lose the normal controls associated with cell division to proliferate with other cells throughout the system.

DNA Structure and Replication

DNA is a double helix composed of nucleotides.
DNA replication is semiconservative, producing two identical DNA molecules from one original molecule. Leading and lagging strands are used.

Gene Expression and Control

Gene expression involves transcription (DNA → mRNA) and translation (mRNA → protein).
Control mechanisms regulate gene expression in prokaryotes (e.g., operons) and eukaryotes (e.g., transcription factors, DNA methylation). Specific sequences of DNA regulate and modify expression within a gene.

Mutations

Mutations are changes in DNA sequences.
Point mutations involve changes in a single nucleotide. Frameshift mutations involve insertions or deletions of nucleotides.
Mutations can lead to altered traits and play a role in cancer development.

Biotechnology

Biotechnology uses biological systems for applications like gene cloning, GMO production, and gene therapy. Genetic engineering alters genomes to enhance traits, improve productions, or for therapy applications.
Recombinant DNA technology involves combining DNA segments from different sources to create rDNA molecules for cloning / gene therapy / genetic engineering. Cloning produces identical copies.

Inheritance

Inheritance patterns include single-trait inheritance, multiple allele inheritance, codominance, polygenic inheritance, and environmental influences. Mendelian genetics explains patterns of inheritance in offspring. Genetic traits are governed by alleles present in the parents.

Meiosis

Meiosis is cell division that produces haploid gametes (sex cells). Meiosis involves two rounds of cell division to ensure genetic variation through crossing over and independent assortment.

Human Life Cycle

Humans involve meiosis for reproducing. Haploid gametes fuse to form diploid zygotes, which develop by mitosis into a multicellular fetus and eventually an individual.

Human Genetic Disorders

Genetic disorders can be caused by autosomal recessive (e.g., cystic fibrosis) or autosomal dominant (e.g., Huntington's disease) alleles, as well as incomplete dominance and multiple allele inheritance / polygenic inheritance.

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Description

Test your knowledge on the citric acid cycle, glycolysis, and cancer biology in this chapter quiz. Explore the important roles of genes and growth factors in cell processes, and understand key biological concepts and terms related to multicellular organisms and scientific classification.