About this Flash Card Set
14 Cards
by olivia_bennett
The essentials of genetics: DNA, genes, chromosomes, dominant vs. recessive traits, and how heredity works. Adapted from open introductory biology curricula.
Front
DNA
Back
Deoxyribonucleic acid — the molecule that stores an organism's genetic instructions as a sequence of four bases (A, T, C, G).
Tags
Front
Gene
Back
A segment of DNA that codes for a specific protein or trait; the basic unit of heredity.
Tags
Front
Chromosome
Back
A tightly coiled structure of DNA and protein. Humans have 23 pairs (46 total) in most cells.
Tags
Front
Nucleotide
Back
The building block of DNA: a sugar, a phosphate, and one of four bases (adenine, thymine, cytosine, guanine).
Tags
Front
Base pairing rule
Back
Adenine pairs with Thymine (A–T); Cytosine pairs with Guanine (C–G).
Tags
Front
Allele
Back
A different version of a gene. You inherit one allele from each parent.
Tags
Front
Dominant vs. recessive
Back
A dominant allele shows its trait even with one copy; a recessive allele shows only when both copies are recessive.
Tags
Front
Genotype vs. phenotype
Back
Genotype is the genetic makeup (e.g., Bb); phenotype is the observable trait (e.g., brown eyes).
Tags
Front
Homozygous vs. heterozygous
Back
Homozygous = two identical alleles (BB or bb); heterozygous = two different alleles (Bb).
Tags
Front
Punnett square
Back
A grid used to predict the probability of offspring genotypes and phenotypes from a cross.
Tags
Front
Mutation
Back
A change in the DNA sequence. Can be harmful, beneficial, or neutral, and is a source of genetic variation.
Tags
Front
Meiosis
Back
Cell division that produces gametes (sperm/egg) with half the chromosomes, creating genetic diversity.
Tags
Front
RNA
Back
Ribonucleic acid — carries DNA's instructions to build proteins. Uses uracil (U) instead of thymine.
Tags
Front
Trait
Back
A characteristic determined by genes (and sometimes environment), such as eye color or height.
Tags