Section 9-1 Review: Mendel's Legacy & Section 9-2 Review: Genetic Crosses

a genetic cross performed many times produces 798 long-stemmed plant in a similar cross is

266/1,064

A monohybrid cross of two individuals that are heterozygous for a trait exhibiting complete dominance would probably result in a phenotypic ratio of

3 dominant: 1 recessive

What does the term allele mean as it is used in genetic crosses

An allele is each of two alternate forms of a gene

F2 generation

F2 generation is the plants generated when F1 self pollinates

A cross between true-breeding green-podded pea plants and true-breeding yellow-podded pea plants produces only green-podded plants. When the F1 generation is allowed to self pollinate, the F2 generation consists of

about three-quarter green-podded plants and one-quarter yellow-podded plants

Mendel obtained plants that were true-breeding for particular traits by

allowing plants to self-pollinate for several generations

Dominant

dominant genes are the common genes

Recessive

genes which are not as common

To determine the genotype of an individual that shows the dominant phenotype, you would cross that individual with one that is

homozygous recessive

When alleles for different characteristics are on separate chromosomes, they are distributed to gametes independently. This observation is summarized by the law of

independent assortment

incomplete dominance

neither allele is more dominate than the other

codominance

occurs when both alleles for a gene are expressed in a heterozygous offspring

The appearance of an organism is its

phenotype

self-pollination

pollination of a flower by pollen from the same flower or from a flower on the same plant

cross-pollination

pollination of a flower with pollen from another flower

F1 generation

the first filial generation of offspring from p generation

when Mendel crossed a strain of tall pea plants with a strain of short pea plants, he observed that all of the plants in the F1 generation were tall. This suggests that

the tall trait was controlled by a dominant factor

Explain how the events of meiosis account for the law of segregation and the law of independent assortment

two alleles of each gene are segregated when the two chromosomes in each pair of homologues are separated into different gametes

Complete dominance

when one allele is completely dominate over another