Question
In one species of plant, the allele for red-coloured fruit is dominant and is represented by the letter R.
The allele for white-coloured fruit is recessive and is represented by the letter r.
Two plants that are heterozygous for fruit colour are crossed.
What are the possible genotypes of the offspring plants from this cross?
(A) RR, Rr and rr
(B) all Rr
(C) all rr
(D) Rr and rr only
▶️Answer/Explanation
Ans : A
Question
In a species of plant, the allele for red flower colour, R, is dominant to the allele for yellow flower colour, r.
What would be the flower colour of the offspring of a cross between a parent with the genotype Rr and a parent with the genotype rr?
(A) 100% red
(B) 75% red and 25% yellow
(C) 50% red and 50% yellow
(D) 25% red and 75% yellow
▶️Answer/Explanation
Ans: C
Question
Which human phenotype is caused by genes only?
A ABO blood group
B body mass
C foot size
D height
▶️Answer/Explanation
Ans A
Question
The seed shape of peas can be smooth or wrinkled. The allele for smooth is dominant and the allele for wrinkled is recessive. Two heterozygous plants are crossed. What is the expected percentage of offspring with a smooth shape?
A 0%
B 50%
C 75%
D 100%
▶️Answer/Explanation
Ans C