scject~~
1. Christine and Connie are identical twins at the age of 20, but they were brought up in different countries. Christine is taller and heavier than Connie. These differences between the two sisters may be due to the fact that :
(1) they received different genes from their parents.
(2) they had different physical training.
(3) they had different diets.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
2. In a family, both parents are brown-eyed but their single child is blue-eyed.
Which of the following implications can be made?
A. The blue-eyed child is homozygous.
B. The chance of a second child being blue-eyed is 1/2.
C. The father is homozygous for eye colour.
D. The blue eye allele comes from a mutation of the brown eye allele in the parents.
3. In garden pea, the allele for yellow stem (Y) is dominant to the allele for green stem (y). A cross between a yellow plant and a green plant gave rise to 94 yellow plants and 102 green plants in the F1 generation.
What is the genotype of the parent plants?
A. YY and yy
B. Yy and yy
C. YY and Yy
D. Yy and YY
