JAMB Biology questions

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

All topics Cell structure and organisation · 30 Cellular activities · 32 Co-ordination and control · 31 Ecology · 38 Evolution · 27 Excretion · 30 Growth · 27 Heredity and variation · 36 Nutrition · 34 Reproduction · 33 Respiration · 30 Support and movement · 28 Transport · 30 Variety of organisms · 32

Question 241· Heredity and variation· JAMB
In the cross shown, T (tall) is dominant over t (dwarf). What percentage of the offspring are dwarf?
Explanation and discussion
Question 242· Heredity and variation· JAMB
If a heterozygous tall plant (Tt) is crossed with a dwarf plant (tt), the ratio of tall to dwarf offspring is:
Explanation and discussion
Question 243· Heredity and variation· JAMB
A scar on the skin is an example of
Explanation and discussion
Question 244· Heredity and variation· JAMB
Down's syndrome is caused by
Explanation and discussion
Question 245· Heredity and variation· JAMB
In a dihybrid cross between two double heterozygotes (AaBb × AaBb), the expected phenotypic ratio is
Explanation and discussion
Question 246· Heredity and variation· JAMB
A mother is a carrier of haemophilia and the father is normal. What is the probability that a son of theirs has haemophilia?
Explanation and discussion
Question 247· Heredity and variation· JAMB
A test cross is used to find out whether an organism showing a dominant trait is
Explanation and discussion
Question 248· Heredity and variation· JAMB
Genes are located on
Explanation and discussion
Question 249· Heredity and variation· JAMB
Which of the following is an example of continuous variation?
Explanation and discussion
Question 250· Heredity and variation· JAMB
In peas, round seed (R) is dominant to wrinkled seed (r). What fraction of the offspring of Rr × rr will be wrinkled?
Explanation and discussion
Question 251· Heredity and variation· JAMB
An organism with two identical alleles for a trait is
Explanation and discussion
Question 252· Nutrition· JAMB
A deficiency of vitamin D in children causes
Explanation and discussion
Question 253· Nutrition· JAMB
Roughage in the diet helps to
Explanation and discussion
Question 254· Nutrition· JAMB
Hydrochloric acid in the stomach helps digestion by
Explanation and discussion
Question 255· Nutrition· JAMB
A food sample gives a blue-black colour with iodine solution and no colour change with Benedict's solution. The food contains
Explanation and discussion
Question 256· Nutrition· JAMB
A plant kept in a box without carbon(IV) oxide for two days will lack
Explanation and discussion
Question 257· Nutrition· JAMB
The end products of the digestion of proteins are:
Explanation and discussion
Question 258· Nutrition· JAMB
Benedict's solution is used to test for
Explanation and discussion
Question 259· Nutrition· JAMB
Herbivores such as cattle lack canine teeth and have a gap called the
Explanation and discussion
Question 260· Nutrition· JAMB
Before an experiment on photosynthesis, a potted plant is kept in darkness for 48 hours in order to
Explanation and discussion

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JAMB Biology questions

In the cross shown, T (tall) is dominant over t (dwarf). What percentage of the offspring are dwarf?

If a heterozygous tall plant (Tt) is crossed with a dwarf plant (tt), the ratio of tall to dwarf offspring is:

A scar on the skin is an example of

Down's syndrome is caused by

In a dihybrid cross between two double heterozygotes (AaBb × AaBb), the expected phenotypic ratio is

A mother is a carrier of haemophilia and the father is normal. What is the probability that a son of theirs has haemophilia?

A test cross is used to find out whether an organism showing a dominant trait is

Genes are located on

Which of the following is an example of continuous variation?

In peas, round seed (R) is dominant to wrinkled seed (r). What fraction of the offspring of Rr × rr will be wrinkled?

An organism with two identical alleles for a trait is

A deficiency of vitamin D in children causes

Roughage in the diet helps to

Hydrochloric acid in the stomach helps digestion by

A food sample gives a blue-black colour with iodine solution and no colour change with Benedict's solution. The food contains

A plant kept in a box without carbon(IV) oxide for two days will lack

The end products of the digestion of proteins are:

Benedict's solution is used to test for

Herbivores such as cattle lack canine teeth and have a gap called the

Before an experiment on photosynthesis, a potted plant is kept in darkness for 48 hours in order to