3 questions. Try each one, then open the answer to check yourself and read the explanation.
In artificial selection, individuals without desirable traits may be prevented from mating by
Answer: B (sterilization)
Sterilising unwanted individuals stops them from breeding, so only animals with the desired traits pass on their genes.
In a family of eight (8) all the children are girls. Which of the following reasons correctly explains this?
Answer: D (The X component of the man's sex chromosome was always involved)
The mother always gives an X; a child is a girl when the father's sperm carries an X, so his X was involved every time.
Which of the following statements is correct about the structure of a chormosome? A chromosome consists of
Answer: A (two chromatids joined at the centromere)
A replicated chromosome is two sister chromatids held together at the centromere.