Genotypic Diversity Overview

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Questions and Answers

What is a primary factor that leads to the decrease in genetic diversity within a population?

Reproductive isolation among species

Random mating among individuals

Habitat loss and hunting (correct)

Increased migration among individuals

Which of the following best describes variation among populations?

Different individuals can have multiple alleles for the same gene.

Isolated populations can exhibit different types and numbers of alleles. (correct)

Populations may share identical alleles due to migration.

Variation among species is less significant than variation among populations.

How does genetic divergence contribute to the formation of new species?

It facilitates the exchange of alleles between different populations.

It prevents interbreeding between two populations with different phenotypes. (correct)

It ensures that populations remain genetically identical.

It maintains the genetic similarities among populations over time.

What is the most common definition of a species?

A group of organisms that can breed and produce viable offspring. (D) Signup and view all the answers

Which of the following statements is true regarding genetic variation among species?

Species generally exhibit greater genetic variation than populations within a single species. (A) Signup and view all the answers

What role does adaptive processes play in species diversity?

They contribute to divergence through different adaptations in varied environments. (A) Signup and view all the answers

What is the consequence of a reduction in genetic transfer due to limited migration between populations?

Increased genetic divergence between populations. (A) Signup and view all the answers

Which factor is least likely to contribute to species diversity?

Interbreeding among individuals of different species (C) Signup and view all the answers

What is meant by the term 'fitness' in the context of evolution?

A measure of an organism's viability and reproductive success (D) Signup and view all the answers

How can a phenotype be advantageous in a specific environment?

It helps in better camouflage from predators (C) Signup and view all the answers

Why has the allele for sickle-cell disease persisted in certain populations?

It provides resistance against malaria for carriers of one copy (C) Signup and view all the answers

What is a potential consequence of having alleles that are harmful to individuals in a population?

The alleles will likely die out with affected individuals (B) Signup and view all the answers

What impact does natural selection have on the average phenotype of a species?

It can change the average phenotype over generations (C) Signup and view all the answers

What role did Charles Darwin play in the development of evolutionary theory?

He synthesized existing concepts of natural selection into a unifying theory (D) Signup and view all the answers

In the example provided, what does a longer-legged frog primarily benefit from?

Its ability to hop faster for better food access (A) Signup and view all the answers

What is one of the consequences of repeated changes in genotype over time?

It may generate a variety of phenotypes within a species (B) Signup and view all the answers

Study Notes

Genotypic Diversity

Four types identified:
- Variation within individual organisms (e.g., pea plant’s white and purple alleles).
- Variation among individuals within a population; population size reduction leads to decreased genetic diversity.
- Variation among populations; isolated populations can exhibit distinct allele types or numbers.
- Variation among species; generally greater genetic variation occurs between species compared to within species.

Genetic Divergence

New species form through genetic divergence between isolated populations.
Distinct alleles can lead to the evolution of divergent genotypes and phenotypes.
When two populations diverge sufficiently, they may become unable to interbreed, potentially becoming separate species.

Species Definition and Diversity

A species is typically defined by distinct morphology, physiology, or biochemistry, and the ability to produce viable offspring.
Species diversity arises from adaptive (environment-driven) and nonadaptive processes.
Adaptive processes may include different environmental adaptations in populations and reduced migration preventing genetic interchange.

Evolution and Fitness

Repeated genetic changes over time can result in varying phenotypes within a species.
Some phenotypes enhance survival (e.g., longer legs in frogs for better mobility), increasing reproductive success or fitness.
Fitness is evaluated based on survival capability and reproductive outcomes.

Impact of Alleles on Fitness

Harmful alleles usually diminish in populations, while beneficial alleles can persist and enhance survival prospects.
Sickle-cell disease allele exemplifies this principle; while detrimental in double doses, it provides malaria resistance with a single copy, promoting its continued presence in populations where malaria is prevalent.

Darwin and Natural Selection

Charles Darwin’s synthesis of evolution through natural selection became a unifying theory of evolution.
His journey as the ship’s naturalist on the HMS Beagle allowed him to observe diverse species, shaping his insights into evolutionary processes.

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Description

Explore the four types of genotypic diversity, focusing on variations within individual organisms and among individuals within a population. Understand how environmental changes can affect genetic diversity and the implications of decreased population size. This quiz will help deepen your knowledge of genetic variations in biology.