Inheritance

Flashcards about genetic information.

DNA

A molecule that contains genetic information. It is stored in the nucleus of a plant or animal cell and passed on to offspring during reproduction.

Gene

A unit of genetic information.

Genetic trait

A feature that can be passed down by genes to the next generation.

Inheritance

The survival of organisms that are better adapted to their environment.

Allele

A variation of a gene / A version of a gene.

Homozygous

A genotype in which the alleles are the same, such as YY or yy.

Heterozygous

A genotype in which the alleles are different, such as Yy. When an individual has 2 different alleles.

Genotype

The set of genes carried by an organism that influence the appearance of its traits.

Phenotype

The set of observable traits in an organism.

Simple inheritance

When the appearance of an inherited trait is controlled by a single gene.

Dominant

A version of a gene that is expressed even when only one copy is present. The dominant allele is always symbolized by a capital letter.

Recessive

A version of a gene that is only expressed when two copies are present. The recessive allele is symbolized by the lower-case form of the same letter.

Punnett Square

A diagram used to determine the probability of offspring inheriting pairs of genes from their parents.

Fertilisation

The process by which male and female gametes are fused together, initiating the development of a new organism.

Ovum (egg)

The egg cell, also known as the ovum, is the female reproductive cell.

Sperm

The male reproductive cell that unites with the ovum to produce a new offspring.

Mendel

The principles of heredity, forming the system of particulate inheritance by units, or genes.

Variation

Any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences or by the effect of environmental factors.

Chromosomes

Structures containing DNA, organized in 23 pairs (46 total) in human cells, with one of each pair from each parent.

X Chromosome

A sex chromosome; females have two X chromosomes (XX), while males have one (XY).

Y Chromosome

A sex chromosome present in males (XY), which determines maleness.