bio test 4

Question 1

What is the relationship between genotype and phenotype? What is an allele?

Answer 1

A phenotype is a visible characteristic as where the genotype is the genetic code- individuals genotype affects its phenotype
Allele: two versions of each gene

Question 2

If given two parents, be able to make a punnett square and interpret the phenotypic and genotypic ratios.

Answer 2

parent a: Yy
Parent b:Xx

Question 3

What are true breeding pairs? How would the offspring from a true breeding pair look like in the F1 generation? F2 generation?

Answer 3

True breeding pair: when mated, produces offspring with consistent traits over multiple generations (pure breed). Dominant trait should stay high through f1 and f2

Question 4

What information was gained from Mendel’s experiments?

Answer 4

dominant factors and recessive factors (only his idea)

Question 5

What are Mendel’s laws?

Answer 5

Law of segregation, law of independent assortment, and law of dominance vs recessiveness

Question 6

How does the behavior of chromosomes during meiosis dictate inheritance?

Answer 6

Crossing over, independent assortment, crossing over helps w determining inheritance

Question 7

What is an exception to the principle of independent assortment? How might the relative position of genes on a chromosome be characterized

Answer 7

Genetic linkage???

Question 8

Understand linkage, especially sex-linked genes

Question 9

If given a scenario about a sex linked gene, be able to determine genotype and make a punnett square

Question 10

What are other ways a genotype can be expressed besides dominant or recessive?

Answer 10

sex-linked inheritance, incomplete dominance, co-dominance, pleiotropy,

Question 11

How do human pedigrees allow analysis of human genetic conditions and inheritance mechanisms?

Answer 11

A pedigree is a diagram that shows occurring/appearance of a particular genetic trait across generations of family- thus analyzing these patterns can make one understand the genetic conditions and inheritance mechanisms

Question 12

What is eugenics? Why is it problematic?

Answer 12

It is the practice/advocacy of selective breeding of the human population- is problematic due to typically involving coercive measures

Question 13

What is sexual selection?

Answer 13

Certain traits are more likely to attract a mate and reproduce

Question 14

How do different types of selection (directional, stabilizing, diversifying and balancing) affect genetic variation? What types of conditions might lead to different modes of selection?

Answer 14

Directional: reduces variation as alleles that are associated with the favored extreme increase in frequency- can lead to environmental and migration changes
Stabilizing:** Eliminates** extreme phenotypes and maintains status quo- stability and birth weight
Diversifying:** Increases** genetic variation by favoring multiple extreme forms within the population- heterogeneous environments and resource competition
Balancing: maintains or increases genetic variation by ensuring no single allele becomes fixed in the population- heterozygote advantage and frequency-dependent selection

Question 15

Why is reproductive success so central to our understanding of natural selection? How is fitness defined?

Answer 15

It directly determines the continuation of the spread of genetic traits within a population.
Fitness: organisms ability to survive and reproduce in a particular environment

Question 16

How are anatomical, developmental and molecular homologies used to show evolutionary relationships between organisms? Give examples.

Answer 16

Anatomical evidence compares the anatomy, Development compares embryonic development, and molecular compares dna and protein sequences. which would help indicate common ancestry via limbs (ie vertebrate, forelimbs), shared/similar embryonic stages, and can point to common ancestry.

Question 17

What is convergent evolution? Give an example.

Answer 17

Convergent evolution: the process by which unrelated or distantly related organisms independently evolve similar traits or adaptations as a result of having to adapt to similar environments or ecological niches
example: wings of bats/birds
Sharks/dolphins

Question 18

What are several different types of evidence for evolutionary change? Give an example of each type of evidence.

Answer 18

Fossil record (fish -> amphibians), comparative anatomy (Vertebrate limbs ie human arms/bird wings/ whale flippers), comparative embryology (Embryos of vertebrates exhibit similar stages- ie pharyngeal pouches), molecular biology (genetic similarity between humans and chimpanzees), **biogeography (distribution of species- species could be isolated on an island), vestigial structure (human appendix, was important and doesn’t do anything for us now), and artificial selection** (breeding animals for specific traits- wolves = yorkies).

Question 19

What are the four criteria that need to be met for natural selection to occur?

Answer 19

1. more offspring are produced than can survive
2. Phenotypic variation
3. Fitness differences associated with variation
4. Heritability

Question 20

What does genetic variation mean in the context of evolution?

Answer 20

Diversity in gene frequencies within a population

Question 21

How do Darwin and Lamarcks theories differ from one another?

Answer 21

Darmin proposed that variations are heritable and Lamark suggested it was based off of usage

Question 22

What did Darwin mean in describing evolution as “the theory of descent with modification through variation and natural selection”?

Answer 22

That would be the fundamental principles of evolutionary theory- descent is genetic info getting passed down from parents, variation is the differences of genetic makeup

Question 23

Why is it a misconception that Darwin was the only person to “discover” evolution?

Answer 23

He was the only one that came right out and said it, there was others before him which he based his research off of. One of which wrote 40 books that werent published to the public

Question 24

Discuss the three types of bonds that can occur between atoms. Include how each bond is formed (electrons shared/not shared, etc) and the relative strength of each bond. In your discussion, make sure you answer the question: How does electronegativity influence bonding within an atom and between molecules?

Answer 24

Ionic Bonds: Formed by electron transfer, strong but can be weakened in polar solvents.
Covalent Bonds: Formed by electron sharing, can be very strong depending on the number of shared pairs.
Metallic Bonds: Formed by delocalized electrons in a metal lattice, strong and give metals their characteristic properties.
Electronegativity: Influences the type of bond formed and the distribution of electrons, affecting both intramolecular and intermolecular interactions.

Question 25

Discuss the unique properties of carbon that make it the backbone of many biological molecules. Include a drawing of a carbon molecule showing the correct number of neutrons, protons, and electrons.

Answer 25

Tetravalency: Carbon forms four covalent bonds, enabling complex and stable molecular structures. Versatility in Bonding: Can form single, double, and triple bonds, allowing for diverse structures like chains, rings, and branches. Catenation: Ability to form long chains and stable bonds with itself. Stability: Carbon-carbon and carbon-hydrogen bonds are stable, maintaining molecule integrity under physiological conditions. Diversity of Organic Compounds: Forms the backbone for molecules with various functional groups (e.g., hydroxyl, carboxyl, amino, phosphate). Isomerism: Ability to exist in multiple forms (isomers) with the same molecular formula but different structures and properties.

Question 26

Examine the importance of water in living organisms. Discuss 3 specific properties of water that make it vital for various biological processes as well as its role in many chemical reactions. Explain how being a polar molecule determines the properties that you discuss.

Answer 26

Water's unique properties, driven by its polar nature, make it essential for life: Cohesion and Adhesion: Enable processes like capillary action in plants. High Specific Heat Capacity: Helps regulate temperature in organisms and environments. Solvent Properties: Facilitate the transport and chemical reactions of various substances.

Question 27

Describe the 3 major ways that molecules can be transported across the phospholipid bilayer in cells. Include the definitions of active and passive transport as well as any important transport proteins for each pathway of travel. Explain which types of molecules (large/small, charged/uncharged, etc…..) would use each method of travel.

Answer 27

simple diffusion, facilitated diffusion, and active transport. Simple diffusion involves small, nonpolar molecules like oxygen moving from high to low concentration without energy. Facilitated diffusion uses transport proteins to help larger or charged molecules, like glucose and ions, move across the membrane, also without energy. Active transport requires energy (ATP) to move molecules, like sodium and potassium ions, against their concentration gradient through specific transport proteins.

Question 28

What is cellular respiration and why is it biologically important? Describe in detail each of the four major metabolic pathways involved with aerobic (oxygen is present) respiration. Include any major molecules that we discussed in class. Your answer may be written out in paragraph form or explained using drawings.

Answer 28

Glycolysis: Breaks down glucose into pyruvate, generating a small amount of ATP and NADH. Pyruvate Oxidation: Converts pyruvate into acetyl-CoA, producing NADH and CO₂. Citric Acid Cycle: Oxidizes acetyl-CoA to CO₂, generating ATP, NADH, and FADH₂. Oxidative Phosphorylation: Uses NADH and FADH₂ to produce ATP and H₂O through the electron transport chain and chemiosmosis. Cellular respiration is vital because it provides the ATP needed for cellular activities, ensuring that cells have the energy required to sustain life.

Question 29

Compare and contrast cellular respiration and photosynthesis in terms of their chemical reactions and overall significance for life. (I am looking for “big picture” concepts rather than every minor detail about the two processes.) Explain how these processes are interconnected.

Answer 29

Photosynthesis: Converts light energy into chemical energy (glucose), releases oxygen, and reduces atmospheric CO₂. Cellular Respiration: Breaks down glucose to release ATP, produces CO₂ and water, and consumes oxygen. Interconnected Processes: The products of photosynthesis serve as the reactants for cellular respiration and vice versa, sustaining the balance of energy and matter in ecosystems. These processes together maintain life by ensuring a constant supply of energy and the cycling of essential molecules.

Question 30

Draw out a cell (2n=4) going through all of the stages of Mitosis and Meiosis. Be sure to include which phase crossing over occurs. (A complete answer will include accurate drawings of each phase (Prophase, Prometaphase, Metaphase, Anaphase, Telophase) in mitosis and meiosis 1 & 2.)

Question 31

What is the central dogma of biology? A complete answer will include the major steps involved and their locations in the cell, discussion of the genetic code (what is it and how is it read), and how mutations can cause a change in protein structure. A good answer will also include the concept of gene expression.

Answer 31

The central dogma of biology outlines the flow of genetic information: DNA is transcribed into mRNA in the nucleus, and then translated into proteins by ribosomes in the cytoplasm. The genetic code, read in codons, specifies amino acids for protein assembly. Gene expression ensures accurate protein production. Mutations in DNA can alter the genetic code, impacting protein structure and function, as seen in disorders like sickle cell anemia

Question 33

Why are small populations particularly sensitive to genetic drift? What are causes of genetic drift in natural populations?

Answer 33

Sensitivity in Small Populations: Genetic drift has a larger impact on small populations due to the significant influence of random changes in allele frequencies. Causes: Bottleneck Effect: Sudden reduction in population size. Founder Effect: Establishment of a new population by a small group. Random Sampling: Unpredictable fluctuations in allele frequencies during reproduction

Question 34

Why does gene flow result in allele frequencies becoming similar between populations?

Answer 34

MIGRATION allows for populations to meet, combining their genes/alleles, resulting in populations becoming similar

Question 35

How does inbreeding affect populations?

Answer 35

It decreases alleles/genes, slowly killing them off

Question 36

What could be a potential outcome of a mutation in a population?

Answer 36

Could change fur color (amino acid chain),

Question 37

What is a gene pool?

Answer 37

All of the alleles for every gene in a given population

Question 38

What is a polymorphic gene?

Answer 38

two or more alleles

Question 39

How are allele frequency and genotype frequency calculated?

Answer 39

Allele frequency = (# of copies of a specific allele in a population) / (Total # of all alleles for that gene in the population) Genotype frequency = (# of individuals with a particular genotype in a population) / (Total # of individuals in the population)

Question 40

What are the two fundamental claims of the Hardy-Weinberg principle?

Answer 40

1. Allele frequencies remain constant 2. Genotype frequencies can be predicted

Question 41

What are the assumptions made by the Hardy-Weinberg model?

Answer 41

No new mutations occur, no natural selection occurs, the population is large, no migration occurs between different populations, random mating

Question 42

How does the Hardy-Weinberg principle serve as a null hypothesis for whether non-random mating, natural selection or other evolutionary processes are at work in a population?

Answer 42

serves as a null hypothesis by providing a model of genetic stability in the absence of evolutionary forces. Deviations from this model indicate that non-random mating, natural selection, genetic drift, gene flow, or mutations are influencing the population's genetic structure. This framework is essential for understanding and detecting evolutionary processes in natural populations.

Question 43

What statistical test is appropriate to compare observed versus expected frequencies?

Answer 43

Hardy Weinburg equilibrium?

Question 44

Why is defining a species a complicated task?

Answer 44

Species Variability: Significant genetic and morphological variation within and between populations. Multiple Concepts: Different species concepts (biological, morphological, phylogenetic) offer varying criteria, each with limitations. Hybridization: Gene flow and hybridization blur species boundaries. Ecological Factors: Temporal and ecological differences complicate species definitions. Fossil Record: Incomplete and sometimes ambiguous data from fossils.

Question 45

What are the most common criteria for defining species? What are advantages and disadvantages of different criteria?

Answer 45

Biological Species Concept: Focuses on reproductive isolation but is limited to sexually reproducing organisms. Morphological Species Concept: Based on physical traits, useful for fossils but can be subjective and mislead by convergent evolution. Phylogenetic Species Concept: Uses genetic characteristics and evolutionary relationships, requires extensive genetic data, and can be subjective in defining groups. Ecological Species Concept: Defines species by their ecological roles, highlighting adaptations but can be subjective and overlook genetic differences.

Question 46

What is the biological species concept? What are the disadvantages of this concept? What are other species concepts that could be used?

Answer 46

The biological species concept defines species through reproductive isolation but has limitations, especially for asexual organisms, fossils, and hybridization. Alternative species concepts include morphological, phylogenetic, ecological, evolutionary, recognition, and genotypic cluster concepts, each with its own advantages and challenges.

Question 47

What are the mechanisms and patterns of speciation?

Answer 47

Mechanisms of Speciation: Allopatric: Geographic separation leads to reproductive isolation. Sympatric: Genetic or behavioral changes within the same area cause isolation. Parapatric: Adjacent populations with limited gene flow and different selection pressures. Peripatric: Small populations isolated at the edge of a larger population undergo rapid changes. Patterns of Speciation: Gradualism: Slow, continuous evolution. Punctuated Equilibrium: Long periods of stability interrupted by rapid changes. These mechanisms and patterns illustrate the diversity and complexity of the evolutionary processes that generate biodiversity.

Question 48

How does geographic separation lead to allopatric speciation?

Answer 48

geographic separation prevents gene flow and allows populations to evolve independently, leading to allopatric speciation

Question 49

How can species arise even when organisms are living in sympatry?

Answer 49

Sympatric speciation occurs through mechanisms such as polyploidy, habitat differentiation, sexual selection, and behavioral isolation. These processes can lead to reproductive isolation and genetic divergence even in populations that live in the same geographic area.

Question 50

What is a niche?

Answer 50

The role an organism plays in a community. physical and environmental conditions and interactions with other species

Question 51

How do changes in whole genome ploidy lead to speciation? How does this relate to what you know about meiosis?

Answer 51

Changes in whole genome ploidy through polyploidy can lead to speciation by creating reproductive isolation. This process is closely related to errors in meiosis, such as nondisjunction, which result in gametes with extra chromosomes. Polyploid individuals are often genetically distinct and reproductively isolated from their parent species, facilitating the emergence of new species.

Question 52

What is demography?

Answer 52

Birth rates, death rates, age distribution, and sizes of population

Question 53

What type of information does a life table give about a population?

Answer 53

all the data on a particular age class and all of their information (males are usually not included, harder to trace heritage)

Question 54

What can the net reproductive rate tell us about a population?

Answer 54

Tells us overall growth rate per generation

Question 55

How would you calculate what a population may look like in the future? If given a problem, be able to apply the correct equation to calculate the answer.

Question 56

What is a survivorship curve? What are the three types of curves that a population might have?

Answer 56

Survivorship curve: surviving individuals at each age Three types: Type 1 (most individuals die late in life), Type 2 (uniform rate of decline), and Type 3 (huge decline in young)

Question 57

What factors limit growth rates and population sizes?

Answer 57

Death and emigration (habitat quality, degree of habitat fragementation, dispersal patterns)

Question 58

Compare and contrast exponential growth and logistic growth. Give examples of each type of growth.

Answer 58

Exp: resources not limiting, prodigious growth Log: resources are limiting, limits the amounts of growth

Question 59

What is the carrying capacity? What limiting resources contribute to a carrying capacity? Is the carrying capacity always going to be the same?

Answer 59

Carrying Capacity: The maximum sustainable population size an environment can support. Limiting Resources: Include food, water, shelter, nutrients, light, and mates. Dynamic Nature: Carrying capacity can fluctuate due to environmental changes, seasonal variations, human activities, inter-species interactions, and technological advances.

Question 60

Be able to interpret what a R0 and an r value means about a population.

Answer 60

R0 is the net reproduction rate