Biology Chapter 5: Evolution and Classification
45 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What role do mutations in genes play in a population?

  • They lead to diversity in the population. (correct)
  • They eliminate the need for horizontal gene transfer.
  • They cause all traits to be equally favorable.
  • They decrease genetic diversity.

Which type of bond involves the transfer of electrons between atoms?

  • Hydrogen bond
  • Covalent bond
  • Ionic bond (correct)
  • Metallic bond

What is a characteristic of polar molecules?

  • They have equal sharing of electrons.
  • They are hydrophobic.
  • They do not interact with water.
  • They possess partial charges. (correct)

Which functional group is represented by the formula -CHO?

<p>Carbonyl (Aldehyde) group (D)</p> Signup and view all the answers

What is the primary function of the Golgi apparatus in a eukaryotic cell?

<p>Modification, sorting, and secretion of proteins (D)</p> Signup and view all the answers

Which component of a prokaryotic cell is responsible for allowing bacteria to attach to surfaces?

<p>Pili (A)</p> Signup and view all the answers

Which of the following correctly describes the pH scale?

<p>Acids release H+ ions when dissolved in water. (B)</p> Signup and view all the answers

Which organelle is primarily involved in ATP synthesis?

<p>Mitochondrion (A)</p> Signup and view all the answers

Which domain includes organisms with prokaryotic cells?

<p>Both B and C (D)</p> Signup and view all the answers

What is the role of the cytoskeleton in eukaryotic cells?

<p>Providing shape and aiding movement (D)</p> Signup and view all the answers

What does Mendel's Law of Segregation state about alleles during gamete formation?

<p>Alleles separate randomly during gamete formation. (A)</p> Signup and view all the answers

In a monohybrid cross of Tt x Tt, what is the expected phenotypic ratio?

<p>3:1 (D)</p> Signup and view all the answers

Which of the following best describes codominance?

<p>Both phenotypes are simultaneously expressed. (A)</p> Signup and view all the answers

What does the dihybrid cross of AABB x aabb produce in the F1 generation?

<p>AaBb only (C)</p> Signup and view all the answers

What is an example of polygenic inheritance?

<p>Skin color related to multiple genes. (A)</p> Signup and view all the answers

Which process describes the effect where multiple genes influence a single trait?

<p>Polygenic inheritance (A)</p> Signup and view all the answers

What is meant by linkage in genetics?

<p>Genes that are close together on a chromosome are less likely to separate. (C)</p> Signup and view all the answers

What occurs during X chromosome inactivation?

<p>One of the two X chromosomes is randomly condensed. (B)</p> Signup and view all the answers

What is the primary function of the plasma membrane?

<p>To act as a selectively permeable barrier (A)</p> Signup and view all the answers

Which of the following best describes passive transport?

<p>Occurs without the need for cellular energy (C)</p> Signup and view all the answers

In glycolysis, what is the net gain of ATP produced from one molecule of glucose?

<p>2 ATP (D)</p> Signup and view all the answers

Which reaction occurs during the transition state in an enzyme-catalyzed reaction?

<p>Substrates are converted to products (B)</p> Signup and view all the answers

What is the role of cyclic AMP (cAMP) in cellular signaling?

<p>It regulates protein activity inside the cell (A)</p> Signup and view all the answers

What is produced during anaerobic respiration in yeast cells?

<p>Ethanol (A)</p> Signup and view all the answers

What is the function of the porphyrin ring in chlorophyll?

<p>To absorb light energy (B)</p> Signup and view all the answers

What is the consequence of the domino effect during anaerobic respiration?

<p>Interruption of electron transport (C)</p> Signup and view all the answers

Which is NOT a characteristic of the G-protein-coupled receptors (GPCRs)?

<p>They directly catalyze a chemical reaction (D)</p> Signup and view all the answers

In the Calvin Cycle, what compound is fixed in the carbon fixation process?

<p>Ribulose bisphosphate (RuBP) (A)</p> Signup and view all the answers

How do enzymes specifically bind to their substrates?

<p>Through complementary shapes at the active site (C)</p> Signup and view all the answers

Which of the following statements about DNA structure is correct?

<p>Complete turn of the double helix consists of 10 base pairs (A)</p> Signup and view all the answers

What does the Meselson-Stahl experiment demonstrate about DNA replication?

<p>DNA replication is semiconservative (D)</p> Signup and view all the answers

What is served by the structure of the promoter in DNA?

<p>Facilitates RNA polymerase binding (D)</p> Signup and view all the answers

What is the role of the 5' cap in mRNA?

<p>Protects mRNA from degradation (C)</p> Signup and view all the answers

Which phase of the cell cycle involves the replication of DNA?

<p>S phase (B)</p> Signup and view all the answers

What primarily provides a signal for the transition from metaphase to anaphase?

<p>Alignment of chromosomes (A)</p> Signup and view all the answers

Which type of RNA directly carries amino acids during translation?

<p>tRNA (A)</p> Signup and view all the answers

What happens during the process of transcription termination?

<p>RNA polymerase dissociates from the DNA (D)</p> Signup and view all the answers

What is the significance of crossing over during meiosis?

<p>It increases genetic variation among gametes (B)</p> Signup and view all the answers

What is the function of the ribosomal-binding site in mRNA?

<p>To provide a binding site for ribosomes (B)</p> Signup and view all the answers

Which cellular structure is responsible for the removal of introns from pre-mRNA?

<p>Spliceosome (D)</p> Signup and view all the answers

What is the primary error-checking mechanism in the cell cycle?

<p>P53 protein (A)</p> Signup and view all the answers

In which phase of mitosis do sister chromatids align at the metaphase plate?

<p>Metaphase (A)</p> Signup and view all the answers

What cellular event occurs during telophase in mitosis?

<p>Nuclear envelope reforms (D)</p> Signup and view all the answers

During which phase of the cell cycle do cyclin D and E synthesis occur?

<p>G1 phase (B)</p> Signup and view all the answers

What is the role of amino acid transferase in protein synthesis?

<p>Attaches amino acids to tRNA (D)</p> Signup and view all the answers

Flashcards

Vertical Descent with Mutations

The primary mechanism of evolution where genetic information is passed down from generation to generation, with occasional changes (mutations) introduced into the DNA sequence.

Horizontal Gene Transfer

The transfer of genetic material between organisms that are not related by descent, often through mechanisms like plasmids or viruses.

Phylogenetic Tree

A diagram that represents the evolutionary relationships between different groups of organisms, based on shared ancestry and genetic similarities.

Covalent Bond

A type of chemical bond where two atoms share electrons to form a stable electron pair.

Signup and view all the flashcards

Ionic Bond

A type of chemical bond where one atom transfers an electron to another atom, creating oppositely charged ions that attract.

Signup and view all the flashcards

Hydrophilic

A substance that dissolves or mixes readily with water, typically due to its polar nature.

Signup and view all the flashcards

Hydrophobic

A substance that does not dissolve or mix readily with water, typically due to its nonpolar nature.

Signup and view all the flashcards

pH

A measure of the acidity or alkalinity of a solution, based on the concentration of hydrogen ions (H+).

Signup and view all the flashcards

Pili (in prokaryotes)

Short, hair-like appendages that allow bacteria to attach to surfaces and to each other, facilitating adhesion and exchange of genetic material.

Signup and view all the flashcards

Nucleoid (in prokaryotes)

The region within a prokaryotic cell where the DNA is located, often in a circular form, but not enclosed by a membrane.

Signup and view all the flashcards

Allele

Different versions of a gene that determine a specific trait. For example, the gene for flower color could have alleles for purple or white flowers.

Signup and view all the flashcards

Law of Segregation

During gamete formation, the two alleles for a trait separate, so each gamete receives only one allele.

Signup and view all the flashcards

Law of Independent Assortment

The segregation of alleles for one trait is independent of the segregation of alleles for other traits.

Signup and view all the flashcards

Incomplete Dominance

The heterozygote phenotype is a blend of the two homozygous phenotypes.

Signup and view all the flashcards

Codominance

Both alleles are expressed equally in the heterozygote.

Signup and view all the flashcards

Pleiotropy

One gene influences multiple phenotypes or traits.

Signup and view all the flashcards

Epistasis

The expression of one gene affects the expression of another gene, often masking the effects of other genes.

Signup and view all the flashcards

Polygenic Inheritance

Multiple genes contribute to a single trait, resulting in a continuous range of phenotypes.

Signup and view all the flashcards

Promoter

A DNA sequence that signals the beginning of a gene, where RNA polymerase binds to start transcription.

Signup and view all the flashcards

Transcription Region

The portion of DNA that is transcribed into RNA.

Signup and view all the flashcards

Terminator

A DNA sequence that signals the end of transcription.

Signup and view all the flashcards

Sigma Factor

A protein that helps RNA polymerase recognize and bind to the promoter sequence.

Signup and view all the flashcards

Elongation

The process of building an RNA transcript using the DNA template.

Signup and view all the flashcards

5' Cap

A modified guanine nucleotide added to the 5′ end of eukaryotic mRNA.

Signup and view all the flashcards

3' Poly-A Tail

A string of adenine nucleotides added to the 3′ end of eukaryotic mRNA.

Signup and view all the flashcards

Intron

Non-coding regions within eukaryotic genes that are removed during RNA processing.

Signup and view all the flashcards

Spliceosome

A complex of proteins and RNA molecules that removes introns from pre-mRNA.

Signup and view all the flashcards

Start Codon

The first codon in an mRNA sequence that signals the beginning of translation, typically AUG.

Signup and view all the flashcards

Stop Codon

A codon in mRNA that signals the end of translation, UAA, UAG, or UGA.

Signup and view all the flashcards

Codon

A three-nucleotide sequence in mRNA that specifies a particular amino acid during translation.

Signup and view all the flashcards

Ribosomal-binding Site

A sequence in mRNA that binds to the ribosome, initiating translation.

Signup and view all the flashcards

tRNA

Transfer RNA, a molecule that carries a specific amino acid to the ribosome during translation.

Signup and view all the flashcards

Anticodon

A three-nucleotide sequence in tRNA that base pairs with a complementary codon in mRNA.

Signup and view all the flashcards

Endosymbiotic Theory

The theory that explains the origin of mitochondria and chloroplasts in eukaryotic cells. It posits that these organelles were once free-living prokaryotes that were engulfed by a larger cell and formed a symbiotic relationship.

Signup and view all the flashcards

Plasma Membrane

A selectively permeable phospholipid bilayer that surrounds the entire cell, acting as a barrier between the cell's internal environment and its external surroundings. It controls the passage of molecules, ions, sugars, and water in and out of the cell.

Signup and view all the flashcards

Passive Transport

The movement of substances across a cell membrane without requiring energy. Molecules move from a high concentration area to a low concentration area. Examples include diffusion, osmosis, and facilitated diffusion.

Signup and view all the flashcards

Active Transport

The movement of substances across a cell membrane that requires cellular energy (ATP). Molecules move from a low concentration area to a high concentration area.

Signup and view all the flashcards

Enzyme

A biological catalyst that speeds up chemical reactions by reducing the activation energy needed for the reaction to occur. Enzymes have specific active sites where substrates bind.

Signup and view all the flashcards

Transition State

The unstable, high-energy intermediate state that molecules must reach during a chemical reaction before forming products.

Signup and view all the flashcards

Active Site

The specific region on an enzyme where substrates bind and the chemical reaction takes place.

Signup and view all the flashcards

Aerobic Respiration

The process of generating ATP using oxygen as the final electron acceptor. It occurs in four stages: glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation.

Signup and view all the flashcards

Glycolysis

The first stage of aerobic respiration where glucose is broken down into pyruvate, producing ATP and NADH. This occurs in the cytoplasm.

Signup and view all the flashcards

Pyruvate Oxidation

The second stage of aerobic respiration where pyruvate is converted into acetyl-CoA, producing CO2 and NADH.

Signup and view all the flashcards

Citric Acid Cycle

The third stage of aerobic respiration where acetyl-CoA is oxidized, producing ATP, NADH, and FADH2.

Signup and view all the flashcards

Oxidative Phosphorylation

The fourth and final stage of aerobic respiration where electrons are transported along the inner mitochondrial membrane, generating ATP through the proton gradient.

Signup and view all the flashcards

Anaerobic Respiration

The process of generating ATP without using oxygen as the final electron acceptor. Instead, other molecules like nitrate (NO3-) are used.

Signup and view all the flashcards

Fermentation

The process of generating ATP through glycolysis only, without using oxygen. Pyruvate is converted into lactic acid (in human muscle cells) or ethanol (in yeast or bacteria cells).

Signup and view all the flashcards

Light-Dependent Reactions

The first stage of photosynthesis where light energy is absorbed by chlorophyll and used to split water molecules, releasing oxygen and producing ATP and NADPH.

Signup and view all the flashcards

Calvin Cycle

The second stage of photosynthesis where carbon dioxide is fixed into organic molecules using ATP and NADPH from the light-dependent reactions. This process produces glucose.

Signup and view all the flashcards

Study Notes

Mechanisms of Evolution

  • Vertical descent with mutations: Mutations in genes create diversity within a population. Genes for advantageous traits become more common in subsequent generations.
  • Horizontal gene transfer: Genetic material is exchanged between different organisms (e.g., plants to animals).

Phylogenetic Trees and Classification

  • Phylogenetic trees illustrate evolutionary relationships among groups.
  • Taxonomy uses evolutionary relationships to categorize organisms.
  • Principle categories: Domain (bacteria, archaea, eukarya), Kingdoms (plants, protists, fungi, animals), Phylum, Class, Order, Family, Genus (capitalized), Species (underlined).

Chemical Bonding and Water Properties

  • Covalent Bonds: Atoms share electrons to form stable electron pairs.
  • Ionic Bonds: Atoms transfer electrons.
  • Polarity: Unequal electron sharing creates partial charges (mainly in nitrogen and oxygen).
  • Hydrophilic: Substances attracted to water (polar).
  • Hydrophobic: Substances repelled by water (nonpolar).
  • Water as a Solvent: Water dissolves solutes with similar properties ("like dissolves like"). Hydrophilic compounds (polar) dissolve in water; hydrophobic compounds (nonpolar) do not.
  • pH: Measures acidity or basicity. Water dissociates into H+ and OH-. pH 7 is neutral. Higher numbers indicate basicity; lower numbers indicate acidity. Acids release H+ in water; bases accept H+.

Functional Groups

  • Amino (-NH2)
  • Carbonyl (Ketone -CO, Aldehyde -CHO)
  • Carboxyl (-COOH)
  • Hydroxyl (-OH)
  • Methyl (-CH3)
  • Phosphate (-PO4 2-)

Prokaryotic and Eukaryotic Cell Structures

  • Prokaryotic:*

  • Pili: Attachment to surfaces/each other.

  • Cytoplasm: Metabolic site.

  • Ribosomes: Synthesize polypeptides.

  • Nucleoid: DNA location.

  • Plasma membrane: Encloses cytoplasm.

  • Cell wall: Support and protection.

  • Glycocalyx: Gelatinous outer covering.

  • Flagella: Movement.

  • Eukaryotic:*

  • Centrosome: Microtubule growth and centriole location.

  • Rough ER: Protein sorting/secretion.

  • Smooth ER: Detoxification/lipid synthesis.

  • Mitochondria: ATP synthesis.

  • Cytoskeleton: Protein filaments for shape and movement.

  • Peroxisome: Breakdown of harmful molecules.

  • Golgi apparatus: Modification, sorting, and secretion of lipids/proteins.

  • Cytosol: Site of many metabolic pathways.

  • Plasma membrane: Controls substance movement, cell signaling.

  • Ribosomes: Polypeptide synthesis.

  • Lysosomes: Macromolecules degradation.

  • Nuclear envelope: Double membrane surrounding the nucleus.

  • Nucleus: Passageway for molecules

  • Nuclear pore: Passageway for molecules into/out of nucleus.

  • Endosymbiotic theory: Mitochondria and chloroplasts originated from engulfed prokaryotes.

Plasma Membrane and Transport

  • Plasma membrane: Selectively permeable phospholipid bilayer. Controls movement of molecules.
  • Passive transport: Movement down a concentration gradient (no energy required).
  • Active transport: Movement against a concentration gradient (requires energy).

Enzyme Mechanisms

  • Enzymes reduce activation energy for reactions.
  • Substrates bind to active sites (specific).
  • Enzymes catalyze reactions by pushing substrates toward products.
  • Steps of enzyme-catalyzed reactions: substrate binding, conformational change, product formation, product release.

Aerobic Respiration

  • Glycolysis: Glucose (6C) → 2 pyruvates (3C), producing 2 ATP and 2 NADH in the cytoplasm.
  • Pyruvate oxidation: Pyruvate → Acetyl CoA (2C), producing CO2 and NADH.
  • Citric acid cycle: Acetyl CoA → 2 ATP, 6 NADH, 2 FADH2.
  • Oxidative phosphorylation (ETC): Electron transport chain and ATP synthesis; ATP production from electron transport.

Anaerobic Respiration and Fermentation

  • Anaerobic respiration: Alternatives to oxygen as final electron acceptors (e.g., nitrate).
  • Fermentation: Only glycolysis occurs; pyruvate is reduced to lactic acid (humans) or ethanol (yeast/bacteria).

Photosynthesis: Light-Dependent and Calvin Cycle

  • Light-dependent reactions: Light absorption by pigments (chlorophyll a absorbs red, violet, and blue light; reflects green). Electrons are ejected.
  • Calvin Cycle: Carbon fixation (CO2 + RuBP → 3PGA), reduction (ATP + NADPH used to convert 3PGA to sugars), regeneration of RuBP.

Cellular Receptors

  • Enzyme-linked receptors: Often kinases; often involve phosphorylation cascades (e.g., receptor tyrosine kinases).
  • G protein-coupled receptors (GPCRs): 7 transmembrane domains; G protein activation; second messenger signaling (e.g., cAMP).
  • Ligand-gated ion channels: Channels open/close in response to ligands.

DNA Structure and Replication

  • DNA structure: Double helix; nucleotides (A, T, G, C).
  • Chargaff's rule: %A = %T, %G = %C.
  • Watson and Crick's model: Used Franklin's X-ray data.
  • DNA replication: Semiconservative (each original strand serves as a template for a new strand).
  • PCR (Polymerase Chain Reaction): Amplifies DNA segments; steps: denaturation, annealing, extension.
  • Sanger sequencing: Determines DNA sequence.

Transcription

  • Gene structure: Promoter, transcribed region, terminator, regulatory sequences.
  • Transcription process: RNA polymerase binds promoter, elongation (complementary RNA strand built), termination.
  • RNA modifications: 5' cap and 3' poly-A tail for stability and translation signals. Removal of introns via spliceosomes.

Translation

  • mRNA structure: Ribosomal binding site (prokaryotes only), start codon (AUG), coding sequence, stop codon. Codons code for amino acids (degenerate code).
  • tRNA structure: Cloverleaf model; anticodon; amino acid attachment site.
  • Ribosome structure and composition: Composed of RNA and proteins; have A, P, and E sites. Bacterial (70S) and eukaryotic (80S) ribosomes.

Lac Operon Regulation

  • Lac operon: Bacterial gene regulation of lactose metabolism. Regulated by a repressor protein.

Eukaryotic Cell Cycle

  • Cell cycle phases: G1, S, G2, M (mitosis).
  • G0 phase: Non-dividing cells.
  • Cyclins and CDKs: Regulate the cell cycle.
  • Checkpoints: Control points in the cell cycle (G1, G2, M). p53 regulates these checks.
  • Proto-oncogenes and tumor suppressor genes: Control cell division.
  • Mitosis and cytokinesis: Process of cell division.
  • Meiosis: Cell division for gamete formation.

Mendelian Genetics

  • Mendel's laws of segregation and independent assortment.
  • Monohybrid and dihybrid crosses.
  • Extensions of Mendel's laws: incomplete dominance, codominance, environmental influence, pleiotropy, epistasis, polygenic inheritance.
  • Linkage and extranuclear inheritance (mitochondria, chloroplasts).
  • Epigenetic inheritance (X chromosome inactivation).

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

This quiz covers mechanisms of evolution, including vertical descent with mutations and horizontal gene transfer. Additionally, it explores phylogenetic trees, taxonomy, and the basic principles of chemical bonding and properties of water. Test your knowledge on how these concepts are interrelated in biology.

More Like This

Evolutionary Mechanisms
6 questions

Evolutionary Mechanisms

FlatterHill avatar
FlatterHill
Evolutionary Mechanisms Quiz
10 questions

Evolutionary Mechanisms Quiz

EfficientMoldavite7290 avatar
EfficientMoldavite7290
Evolutionary Mechanisms Quiz
5 questions

Evolutionary Mechanisms Quiz

PurposefulHummingbird avatar
PurposefulHummingbird
Evolutionary Mechanisms Quiz
12 questions

Evolutionary Mechanisms Quiz

ComfortableSnail9131 avatar
ComfortableSnail9131
Use Quizgecko on...
Browser
Open
Browser
Browser