Hardy-Weinberg and Mutation: Population Genetics Key Concepts

What does Hardy-Weinberg Equilibrium (HWE) indicate about a population?

HWE provides a framework to understand the genetic variation and allele frequencies in a population under certain conditions.

What are the five requirements for Hardy-Weinberg Equilibrium?

1. Large population size, 2. No mutations, 3. No gene flow, 4. Random mating, 5. No natural selection.

What is the Hardy-Weinberg equation?

p² + 2pq + q² = 1, where p and q represent the frequencies of two alleles.

Why is variation important for evolution?

Variation is necessary for natural selection, mutation, genetic drift, and gene flow to occur.

What is DNA and its role in genetics?

DNA (deoxyribonucleic acid) is the genetic material that carries the instructions for the development and functioning of all living organisms.

What are the four types of nucleic acids in DNA?

Adenine (A), Thymine (T), Guanine (G), Cytosine (C).

What are chromosomes?

Chromosomes are long strings of DNA bound together with proteins that carry genetic information.

What are genes?

Genes are segments of chromosomes that code for proteins and determine specific traits.

What are alleles?

Alleles are different variants of a gene that can produce variations in traits.

What is a codon?

A codon is a sequence of three DNA bases that codes for a specific amino acid.

How many possible codons are there?

There are 64 possible codons, derived from 4 bases arranged in sets of three.

What is a point mutation?

A point mutation is a change in a single DNA base pair.

What is a synonymous substitution?

A synonymous substitution is a point mutation that does not alter the amino acid being coded.

What is a nonsynonymous substitution?

A nonsynonymous substitution is a point mutation that alters the amino acid being coded.

What is sickle cell disease caused by?

Sickle cell disease is caused by a single point mutation in the gene coding for hemoglobin.

What are structural mutations?

Structural mutations affect more than one DNA base and can lead to significant genetic changes.

What are the types of structural mutations?

Deletions, insertions, duplications, inversions, fissions, and fusions.

What is gene mixing by segregation?

Gene mixing by segregation occurs during meiosis when one of the two copies of a locus is selected for gamete formation.

What is gene mixing by recombination?

Recombination combines gene copies from both parents, randomizing allele combinations in offspring.

What is linkage disequilibrium?

Linkage disequilibrium occurs when alleles at two loci are found together more often than expected by chance.

How does recombination affect linkage disequilibrium?

Recombination erodes linkage disequilibrium, restoring variation but not creating new variation.

What are the fitness effects of mutations?

Mutations can be deleterious (harmful), neutral (no effect), or beneficial (increase fitness).

What is pleiotropy in genetics?

Pleiotropy occurs when a single mutation affects multiple traits.

What is the relationship between mutation rates and genome size?

Mutation rates can vary widely across the genome and species, often correlating with genome size.

What role do mutations play in evolution?

Mutations are the ultimate source of genetic variation, necessary for evolution to occur.