Genetics and Epigenetics Flashcards
What are genes?
Units of heredity that maintain their identity across generations.
What are chromosomes?
Paired strands of genes.
What is DNA?
Double-stranded molecule; blueprint for RNA.
What is RNA?
Single-stranded molecule that helps synthesize proteins.
What is a dominant gene?
Has an effect in both homozygous and heterozygous conditions.
What is a recessive gene?
Only expressed when both gene copies are recessive (homozygous).
What is homozygous?
Two identical genes on a pair of chromosomes.
What is heterozygous?
A pair of different genes on a chromosome pair.
What is a mutation?
A heritable change in DNA.
What are microduplications/deletions?
Small sections of DNA are repeated or missing.
What is epigenetics?
Changes in gene expression due to environmental influences.
What are histones?
Proteins that DNA wraps around, affecting gene accessibility.
What are sex-linked genes?
Genes on X or Y chromosomes.
What are autosomal genes?
Genes on non-sex chromosomes.
What are sex-limited genes?
Genes active mainly in one sex, though present in both.
What is heritability?
Proportion of variation due to genetic differences (0 to 1).
How is heritability studied?
Through twin studies, adoption studies.
What are monozygotic twins?
Identical twins from a single egg.
What are dizygotic twins?
Fraternal twins from two separate eggs.
How do genes influence behaviour?
Directly via brain chemistry, indirectly via body changes.
What is PKU?
Inability to metabolize phenylalanine; can cause brain damage if untreated.
What is evolution?
A genetic change over generations.
What is natural selection?
The survival and reproduction of organisms best suited to their environment.
What is artificial selection?
Human-directed breeding for specific traits.
