Genetics Review

23 How many pairs of chromosomes do humans have?

Gregor Mendel Who is considered the father of genetics?

Gene A _______ is a section of DNA that codes for a protein and determines a trait.

Phenotype The _________ is the physical characteristic of an organism.

Trait A ________ is a specific characteristic that varies from one individual to another.

Principle of Dominance “Some alleles are dominant and some are recessive” describes which of Mendel’s 3 Laws?

Incomplete Dominance ________ creates a blended phenotype; one allele is not completely dominant over the other.

Heterozygous Has two different alleles for a particular trait; hybrid

Allele A(n) ________ is a form of a gene.

Multiple Alleles Three or more versions exist for a particular trait.

Recessive A ________ trait is one that will only appear in the phenotype if the organism inherits two of them

Principle of Segregation During gamete formation, alleles are separated from each other so that each gamete carries only a single copy of each gene. This describes which of Mendel’s 3 Laws?

Independent Assortment Principle that genes do not influence each other’s inheritance because they are separated independently during meiosis

Gamete A ________ is a sex cell; sperm or egg.

Probability ________ is the likelihood an event will occur.

Hybrid A(n) ________ is an offspring of a cross between parents with different traits; heterozygous

Dominant Trait that will show up in an organism’s phenotype if present at all in the organism’s genotype

Genotype An organism’s ________ is its genetic makeup for a particular trait.

Homozygous Has two identical alleles for a particular trait; true-breeding or purebred

Punnett Square A _________ is a diagram that shows the possible results of a genetic cross

Law of Independent Assortment Genes for different traits can segregate independently during the formation of gametes. This describes which of Mendel’s 3 Laws?

Segregation ________ is the separation of alleles during meiosis or gamete formation.

Pea Plants On what organisms did Gregor Mendel do his hereditary experiments?