Genetics and Alleles Quiz

Alleles are different variations of a specific gene.
Genotype refers to the specific combination of alleles within an individual.
Phenotype encompasses the observable traits produced from the interaction of genotype and environmental influences.
Genetic diversity indicates the variation of alleles present within a population or species.
Gene pool is the complete set of alleles available in a population.
Allele frequency measures the proportion of a specific allele within that population.

Low genetic diversity in a population decreases the likelihood of having advantageous alleles necessary for survival under changing conditions.
Evolution is defined as the shift in allele frequencies in a population over time.

Mutation involves any change in the DNA sequence, potentially leading to new alleles and individual variations.
Despite causing changes, mutations may not always result in altered alleles due to redundancy in the genetic code.

Somatic mutations occur in body cells and are not inherited, affecting only the individual.
Germline mutations happen in gametes and can be passed to offspring, impacting population evolution.
Mutations may arise from natural processes or induced by external factors (mutagens), such as radiation and certain chemicals.
Spontaneous mutations result from errors during DNA replication, creating new alleles rapidly.
Induced mutations are slower and occur due to environmental factors like radiation (UV, X-rays) and chemicals (Benzene, pesticides).

Gene mutations can lead to beneficial changes, harmful effects, or have neutral impacts on the organism.

Point mutations involve localized changes to a single base in a nucleotide sequence.
Substitution mutations are a type of point mutation where one nitrogenous base is replaced; they can be classified into three types:
- Silent mutation: No change in the amino acid produced, maintaining protein structure and function due to the degeneracy of the genetic code.
- Missense mutation: Alters the amino acid coded, potentially affecting protein function; the degree of impact depends on the specific amino acid change.
- Nonsense mutation: Replaces a base with a STOP codon, halting protein production prematurely; the effect's severity is influenced by the mutation's position in the gene.

Frameshift mutation: Caused by the insertion or deletion of a base, disrupting the codon reading frame, which alters all downstream codons and amino acids.
These mutations typically result in more significant consequences for protein structure and function compared to substitution mutations.