Inheritance Flashcards
DNA
A molecule that contains genetic information. DNA is stored in the nucleus of a plant or animal cell. It is passed on to offspring during reproduction.
Genetic Trait
A unit of genetic information.
A gene is a section of a
DNA molecule that provides instructions for building a specific protein.
Inheritance
The survival of organisms that are better adapted to their environment. Over generations, natural
selection causes a population to evolve in response to its environment
Variation
A difference in traits
between individuals of the same species. Variations in genetic traits arise because of mutations. Some traits
provide an advantage for survival or reproduction.
Gene
A feature that can be passed down by genes to the next generation.
Genetic traits, such as neck length and fur colour, can result in the evolution of a population.
Allele
Different versions of a gene.
Phenotype
An organism’s collection of observable traits. This is partly determined by its set of genes.
Simple Inheritance
When the appearance of a trait is controlled by a single gene.
Dominant Allele
A version of a gene that is expressed even when only one copy is present.
Genotype
A pair of alleles that influence the appearance of a particular trait.
Recessive Allele
A version of a gene that is only expressed when two copies are present.
Heterozygous
A genotype in which the alleles are different (e.g. Yy).
Homozygous
A genotype in which the alleles are the same (e.g. YY, yy).
Punnet Square
A Punnett square is a square diagram used to predict the genotypes of a particular cross or breeding experiment.
X Chromosome
One of the two sex chromosomes that are involved in sex determination. Females have two X chromosomes in their cells, while males have one X and one Y.
Y Chromosome
One of two sex chromosomes in mammals, including humans, and many other animals. Females have two X chromosomes in their cells, while males have one X and one Y.
A chromosome
A package of DNA with part or all of the genetic material of an organism.
Mendel
The principles of heredity.
Ovum (egg)
A mature reproductive cell of female animals. It is spherical, has a nucleus, is covered with an egg membrane, and is not mobile.
Fertilisation
Fertilization in biology refers to the process by which male and female gametes fuse to form a new cell referred to as a zygote.
Sperm
A male reproductive cell, produced by most animals. In higher vertebrates, especially mammals, sperm are produced in the testes.
