1. In pea plants, inflated pods (R) are dominant to constricted pods ( r ). Which of the following crosses represents a testcross?
A. RR x RR B. RR x Rr C. RR x rr D. Rr x Rr
2. In humans, long eyelashes are dominant (L). Short eyelashes are recessive. What is the probable phenotypic ratio if two heterozygous individuals for short and long eyelashes are married?
A. 100% long eyelashes C. 75% long, 25% short
B. 75% short, 25% long D. 100% short
3. Varieties of plants or animals that when crossed with each other always produce offspring that are identical to themselves are:
A. true-breeding B. heterozygous
C. homozygous D. F1 hybrids E. A and C
4. How many different kinds of gametes can be produced by an individual with the genotype AABbCCddEeFf?
A. 2 B. 4 C. 8 D. 16 E. 64 F. None of these choices
5. If two or more forms of the same gene exist, the different forms are called:
A. incomplete dominance. B. penetrance and expressivity.
C. pleiotrophic. D. alleles. E. dihybrid.
6. If a corn plant has a genotype of Ttyy, what are the possible genetic combinations that could be present in a single grain of pollen from this plant?
A Ty, ty B TY, ty
C TY, Ty, ty D Ty, ty, tY, TY
7. In carrier pigeons there is a rare inherited condition that causes the death of the chicks before hatching. In order for this disease to be passed from generation to generation there must be parent birds that
A are heterozygous for the disease. B have the disease themselves.
C produce new mutations for this disease. D are closely interbred.
8. You cross two mouse strains...