Genetics Basics: 18 flashcards

The branch of biology that studies genes, heredity, and variation in living organisms.

The controlled reproduction of organisms (here, fish) to produce offspring with desired traits.

The passing of traits from parents to offspring through genes. Example: A colorful guppy parent producing colorful babies.

Differences in characteristics among individuals of the same species, arising from genetic and/or environmental causes. Example: Some tilapia in the same pond grow bigger than others.

An observable feature or characteristic of an organism. Examples: Body color, growth rate, fin shape, or disease resistance.

The observable physical or biochemical characteristics of an organism, resulting from the interaction of its genotype with the environment. Example: The actual color or weight of the fish (result of genes + food + environment).

The genetic constitution (allele combination) of an organism at one or more loci. Example: A fish may have genes for fast growth even if it looks average due to poor food.

The complete set of genetic material (DNA) present in an organism.

The basic unit of heredity; a segment of DNA that codes for a specific protein or trait and occupies a specific location (locus) on a chromosome. Example: A gene that decides whether a fish will be red or white.

A thread-like structure of DNA and associated proteins (histones) found in the nucleus, carrying genes in linear order.

Deoxyribonucleic acid; the molecule that carries genetic information, composed of two strands forming a double helix, built from nucleotides (A, T, G, C).

Ribonucleic acid; a nucleic acid involved in decoding and expressing genetic information (mRNA, tRNA, rRNA).

The building block of DNA/RNA, consisting of a sugar, phosphate group, and a nitrogenous base.

The specific physical location of a gene on a chromosome.

One of two or more alternative forms of a gene occupying the same locus.

A pair of chromosomes (one from each parent) that are similar in size, shape, and gene content.

Diploid (2n): a cell or organism having two complete sets of chromosomes (one from each parent) (normal body cells). Example: Most fish body cells are diploid. Haploid (n): a cell or organism having a single complete set of chromosomes, as in gametes. Example: Fish gametes (sperm/egg) are haploid.

The number, size, and shape of chromosomes characteristic of a species, usually displayed as an ordered image. Example: Scientists take photos of chromosomes to study a fish species.