mod 6 Flashcards
(30 cards)
Explain what a mutagen is and how it causes mutations
A mutagen is an agent that alters DNA, causing mutations which can affect protein function or regulation, potentially leading to disease.
Outline the different types of mutagens
Mutagens include physical (e.g. radiation), chemical (e.g. cigarette tar), and biological (e.g. viruses) agents that change DNA structure or function.
Discuss the effects of mutations on phenotype
Mutations can have no effect (silent), alter traits (missense), or result in non-functional proteins (nonsense), impacting an organism’s traits.
Explain the difference between somatic and germ-line mutations
Somatic mutations occur in body cells and are not inherited, while germ-line mutations occur in gametes and can be passed to offspring.
Describe how point mutations affect protein synthesis
Point mutations change a single nucleotide, potentially altering amino acids in a protein, which can change its structure and function.
Explain how chromosomal mutations can lead to genetic disorders
Chromosomal mutations like deletions, duplications, or translocations can disrupt gene function, leading to disorders like Down syndrome.
Discuss the role of frameshift mutations in gene expression
Frameshift mutations shift the reading frame, altering every codon after the mutation and usually producing non-functional proteins.
Outline how meiosis introduces genetic variation
Genetic variation arises through crossing over, independent assortment, and random segregation of chromosomes during meiosis.
Explain how nondisjunction leads to aneuploidy
Nondisjunction occurs when chromosomes fail to separate properly, resulting in gametes with abnormal chromosome numbers, e.g. trisomy 21.
Describe how fertilisation contributes to genetic diversity
It combines genetic material from two parents, producing unique zygotes and contributing to population diversity.
Discuss the impact of gene flow on a population
Gene flow introduces new alleles to a population through migration, increasing genetic variation and potentially altering allele frequencies.
Explain genetic drift and how it affects populations
Genetic drift is a random change in allele frequency, especially in small populations, potentially leading to reduced genetic diversity.
Compare the bottleneck effect and founder effect
Both are types of genetic drift; bottleneck effect results from population reduction, founder effect from a small group starting a new population.
Outline how mutation, gene flow, and genetic drift impact gene pools
Mutations introduce new alleles, gene flow mixes alleles between populations, and drift randomly changes allele frequencies.
Discuss how natural selection acts on polygenic traits
Natural selection shapes polygenic traits by favouring certain phenotypic ranges, resulting in directional, stabilising, or disruptive selection.
Explain the concept of polygenic inheritance
Polygenic traits are influenced by multiple genes, producing a continuous range of phenotypes, such as height or skin colour.
Outline the causes and effects of mutations in coding DNA
Mutations in coding DNA can change amino acid sequences, potentially altering protein structure and leading to disease.
Explain how mutations in non-coding DNA affect gene expression
These mutations can disrupt promoters or enhancers, affecting when and how much a gene is expressed, leading to disorders.
Describe the process and importance of biotechnology in genetics
Biotechnology uses living organisms to modify genes for applications in medicine, agriculture, and conservation.
Discuss the historical uses of biotechnology
Ancient biotechnology includes selective breeding and fermentation; classical biotechnology includes antibiotics and pasteurisation.
Explain how CRISPR technology is used in gene editing
CRISPR allows precise modification of DNA sequences, enabling correction of genetic defects and development of disease-resistant crops.
Outline the process and purpose of selective breeding
It involves choosing parents with desirable traits to produce improved offspring, used widely in agriculture and animal husbandry.
Explain the advantages and disadvantages of artificial insemination
AI allows for genetic control and reduced transport costs, but can reduce genetic diversity and may not guarantee trait expression.
Describe the role of IVF in genetics and reproduction
IVF enables fertilisation outside the body, helping with fertility issues and allowing genetic screening before implantation.
