10.2 Mendelian Genetics basic punnetts (Glencoe Biology),

Genetics

Scientific study of heredity

Heredity

Passing on of characteristics from parents to offspring.

Gene

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

Punnett square

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

monohybrid cross

crosses that examine the inheritance of only one specific trait

Allele

Alternate variants of a gene. Each parent contributes an allele (letter) to an offspring.

Dominant

A trait that overpowers or covers up a recessive trait.

recessive

An allele that is masked when a dominant allele is present.

genotype

Genetic makeup of an organism. Say the letters ie. Pp => say "Big p little p"

Phenotype

PHysical outcome of a genetic cross. The trait that showed up due to the letters in a Punnett

trait

Characteristic that is inherited

Homozygous

When there are two identical alleles for a trait. Same letters AA

Heterozygous

When there are two different alleles for a trait. Different letters. ie. Aa or Bb.

phenotypic ratio

the ratio of phenotypes that could appear in offspring. i.e. 3 out of 4 will be tall, one will be short

genotypic ratio

the ratio of the genotypes (think letters) that appear in offspring. i.e.. 1 will be TT, 2 will be Tt, and 1 will be tt. 1:2:1 ratio

Offspring

A baby. In Punnetts it is what is found inside the boxes.

dihybrid crosses

A cross between two individuals, concentrating on two definable traits

Hybrid

Offspring formed by parents having different forms of a trait.

Pollination

The transfer of pollen from male reproductive structures to female reproductive structures in plants

Fertilization

Fusion of male and female gametes.

Gregor Mendel

"The Father of Genetics"

self-pollination

Self fertilize. The pollen and eggs involved in fertilization came from the different flowers of the same plant.

cross-pollination

Fertilization between two different plants. The pollen and eggs involved in fertilization came from two different plants

probability

A number that describes how likely it is that an event will occur

Gregor Mendel's "law of independent assortment"

Law stating that pairs of genes separate independently of one another in meiosis

Gregor Mendel's "law of segregation"

the two copies of each hereditary factor segregate so that offspring acquire one factor from each parent.

P Generation

parental generation, the first two individuals that mate in a genetic cross

F1 Generation

the first generation of offspring obtained from an experimental cross of two organisms

F2 Generation

the offspring of self-pollinated F1 generation plants

gamete

A haploid cell such as an egg or sperm. Found on the outside of punnett squares