WAEC Biology questions: Heredity and variation

24 questions with answers and explanations. Tap an option to check yourself.

All topics Cell structure and organisation · 26 Cellular activities · 24 Co-ordination and control · 27 Ecology · 33 Evolution · 18 Excretion · 22 Growth · 18 Heredity and variation · 24 Nutrition · 30 Reproduction · 29 Respiration · 25 Support and movement · 22 Transport · 27 Variety of organisms · 28

Question 1· Heredity and variation· WAEC
In a monohybrid cross, the ratio of tall to short plants in the F₂ generation is
Explanation and discussion
Question 2· Heredity and variation· WAEC
The genotype of a person who is a carrier of sickle cell is
Explanation and discussion
Question 3· Heredity and variation· WAEC
A person with blood group O can donate blood to people of
Explanation and discussion
Question 4· Heredity and variation· WAEC
Which of these shows continuous variation?
Explanation and discussion
Question 5· Heredity and variation· WAEC
An allele that shows its effect only when two copies are present is
Explanation and discussion
Question 6· Heredity and variation· WAEC
In humans, the sex of a child is determined by the
Explanation and discussion
Question 7· Heredity and variation· WAEC
A couple already has four daughters. What is the probability that their fifth child will be a boy?
Explanation and discussion
Question 8· Heredity and variation· WAEC
Height in humans is an example of
Explanation and discussion
Question 9· Heredity and variation· WAEC
The units of inheritance found on chromosomes are
Explanation and discussion
Question 10· Heredity and variation· WAEC
The passing on of characteristics from parents to offspring is called
Explanation and discussion
Question 11· Heredity and variation· WAEC
A man of blood group AB marries a woman of blood group O. What blood groups can their children have?
Explanation and discussion
Question 12· Heredity and variation· WAEC
The physical appearance of an organism is its
Explanation and discussion
Question 13· Heredity and variation· WAEC
If a man of blood group AB marries a woman of group O, their children can have blood group
Explanation and discussion
Question 14· Heredity and variation· WAEC
A child has sickle-cell anaemia (SS) when he receives
Explanation and discussion
Question 15· Heredity and variation· WAEC
The sex chromosomes of a human male are
Explanation and discussion
Question 16· Heredity and variation· WAEC
Which of these is an example of discontinuous variation?
Explanation and discussion
Question 17· Heredity and variation· WAEC
A characteristic that shows in the offspring whenever its gene is present is
Explanation and discussion
Question 18· Heredity and variation· WAEC
Crossing two heterozygous tall plants (Tt × Tt) gives a phenotypic ratio of
Explanation and discussion
Question 19· Heredity and variation· WAEC
The ABO blood groups are an example of
Explanation and discussion
Question 20· Heredity and variation· WAEC
A cross between two heterozygous tall pea plants (Tt × Tt) produces offspring in the ratio
Explanation and discussion

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WAEC Biology questions: Heredity and variation

In a monohybrid cross, the ratio of tall to short plants in the F₂ generation is

The genotype of a person who is a carrier of sickle cell is

A person with blood group O can donate blood to people of

Which of these shows continuous variation?

An allele that shows its effect only when two copies are present is

In humans, the sex of a child is determined by the

A couple already has four daughters. What is the probability that their fifth child will be a boy?

Height in humans is an example of

The units of inheritance found on chromosomes are

The passing on of characteristics from parents to offspring is called

A man of blood group AB marries a woman of blood group O. What blood groups can their children have?

The physical appearance of an organism is its

If a man of blood group AB marries a woman of group O, their children can have blood group

A child has sickle-cell anaemia (SS) when he receives

The sex chromosomes of a human male are

Which of these is an example of discontinuous variation?

A characteristic that shows in the offspring whenever its gene is present is

Crossing two heterozygous tall plants (Tt × Tt) gives a phenotypic ratio of

The ABO blood groups are an example of

A cross between two heterozygous tall pea plants (Tt × Tt) produces offspring in the ratio