Vocab Science

variation

Any difference between individuals of the same species.

dominant allele

An allele whose trait always shows up in the organism when the allele is present.

recessive allele

An allele that is masked when a dominant allele is present

Codominance

A condition in which both alleles for a gene are fully expressed

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

Phenotype

An organism's physical appearance, or visible traits.

Genotype

An organism's genetic makeup, or allele combinations.

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

acquired trait

A trait that is not in your genes but is picked up from environmental factors.

inherited trait

A characteristic that is passed from parent to offspring.

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Traits

Characteristics that are inherited

Enzymes

Proteins that speed up chemical reactions

Nucleus

A part of the cell containing DNA.

Pedigree

A diagram that shows the occurrence of a genetic trait in several generations of a family.

Alleles

Different forms of a gene

Gene

A segment of DNA on a chromosome that codes for a specific trait

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape.

Punnett Square

A chart that shows all the possible combinations of alleles that can result from a genetic cross

blood types

A, B, AB, O

double helix

Shape of DNA

Stamen

Male part of the flower

Pistil

Female part of the flower

Homozygous

An organism that has two identical alleles for a trait

Heterozygous

An organism that has two different alleles for a trait

offspring

Product of reproduction, a new organism produced by one or more parents

sex-linked traits

Traits controlled by genes located on sex chromosomes.

genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection.

dihybrid cross

Cross or mating between organisms involving two pairs of contrasting traits

Albinism

Absence of pigment in the skin, hair, and eyes

selective breeding

The process of selecting a few organisms with desired traits to serve as parents of the next generation

Autosomal

all the other genes in the body that are not sex-linked.

Carrier

A person who has one recessive allele for a trait, but does not have the trait.

Heredity

Passing of traits from parents to offspring

Probability

likelihood that a particular event will occur