Question

3.) .) Which of the following is NOT a part of Mendel’s Model (as described in class)?
A. If the alleles at a locus differ, the dominant allele determines the organism’s appearance.

B. For each trait, an individual inherits two copies of the gene, known as sister chromatids.

C. Two alleles separates during meiosis and end up in different gametes.

D. Alleles account for variation in traits.

10.) A true breeding black flowered plant is mated with a true breeding white flowered plant (P generation). Flower color in this plant is controlled by a single gene. Their F1 offspring are all gray-flowered.

Two of these gray-flowered plants are mated together, and produce an F2 generation of 100 offspring. 25 offspring are black, 50 offspring are gray, and 25 offspring are white flowered.

Which of the following is the BEST statement regarding this scenario?

A. The gene exhibits complete dominance, because the F1 offspring were all gray flowered, and the F2 generation contained both black and white flowers.

B. The gene is epistatic because alleles at multiple loci are interacting to produce the gray phenotype.

C. The gene exhibits codominance, because both black and white flowers were present in the F2 generation and the phenotypic ratio = 3:1 in the F2 generation.

D. The gene exhibits incomplete dominance, because the phenotypic ratio = 1:2:1 in the F2 generation.


42.) What is your conclusion regarding the hypothetical paternity of these two twins? Please state your conclusion in one sentence.

Note: there are several correct answers to this question!

41.) Fraternal (non-identical) twins develop when two eggs in a woman’s body are fertilized by different sperm gametes. In a court case over disputed paternity of two non-identical twins, the blood types of their mother, the twins, and two potential fathers are taken. You are assigned to this case to settle this dispute using the following blood type information.

The mother is blood type O
Twin A has blood type A and twin B has blood type B
Man #1 is blood type A
Man #2 is blood type B

Write the blood genotypes for both of the nonidentical twins below. Use the following format for your alleles:

IA = allele A

IB = allele B

i = allele O

Format your answer as:

Twin A: _____________. Twin B: _________________

Answer 1

3) B

For each trait ,an individual have two copy of genes ,they are located on non sister chromatids of homologous chromosomes ( Each chromosome is present in pairs one from maternal and one paternal chromosome).

10) D

The gene exhibition incomplete dominance ( when dominant allel does not completely mask the effect of recessive allel ,the organism results in blending of both allels and third phenotype will appears. Genotypic and phenotypic ratio is 1:2:1.