Biology chapter 4 -

Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This suggests

that the parents were both heterozygous.

what is independent assortment?

the distribution of one pair of alleles into gametes does not influence the distribution of another.

If B represents the allele for black eyes (dominant) and b represents the allele for orange eyes (recessive), what would be the genotypic ratio of a cross between a heterozygous black-eyed MendAlien and an orange-eyed MendAlien?

0 homozygous black (BB): 1 heterozygote (black) (Bb): 1 homozygous orange (bb) he heterozygous black-eyed MendAlien has the genotype Bb. The orange-eyed MendAlien has the genotype bb. The result of this cross is two Bb offspring and two bb offspring. This 2:2 ratio reduces to 1:1.

If B represents the allele for black eyes (dominant) and b represents the allele for orange eyes (recessive), what would be the phenotypic ratio of a cross between a heterozygous black-eyed MendAlien and an orange-eyed MendAlien?

1 black : 1 orange. The heterozygous black-eyed MendAlien has the genotype Bb. The orange-eyed MendAlien has the genotype bb. The result of this cross is two Bb offspring and two bb offspring. This means that two of the offspring have black eyes and two of the offspring have orange eyes. This 2:2 ratio then reduces to 1:1.

How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?

8

What is the difference between a monohybrid cross and a dihybrid cross?

A dihybrid cross involves organisms that are heterozygous for two characters and a monohybrid only one.

epistasis

A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited.

Mendel's second law of independent assortment has its basis in which of the following events of meiosis I?

Alignment of tetrads at the equator

what is Mendels law of segregation

During gamete formation by a diploid organism, the pair of alleles for a particular trait seperate or segragate, during the formation of gametes.

A BbGg x bbgg cross yields a phenotypic ratio of approximately 5 black eyes, green skin : 5 orange eyes, white skin : 1 black eyes, white skin : 1 orange eyes, green skin. Which of the following best explains these results?

Mendel's law of independent assortment is being violated. If the genes for eye color and skin color assorted independently, then the outcome of this cross would have been a 1:1:1:1 ratio.

pleiotropy

The ability of a single gene to have multiple effects.