Reproduction Practice Questions

Name the male gamete and the female gamete in humans.

Name the male gamete in a flowering plant.

Name the type of cell division that produces gametes.

Name the part of a cell where most of the cell's DNA is found.

DNA is made of two strands. Name the shape formed by the two strands of a DNA molecule.

What is a gene?

How many pairs of chromosomes are found in an ordinary human body cell?

Give the sex chromosomes found in the body cells of a human male.

Complete the Punnett square below to show the inheritance of sex in humans.

The father's gametes are shown across the top. The mother's gametes are shown down the side.

	X	Y
X
X

Use your Punnett square to give the probability that a baby will be a boy.

Name the type of cell division involved in asexual reproduction.

Explain why the new plants that grow from the bulbs are genetically identical to the parent plant.

Give one way in which plants grown from the seeds will be different from plants grown from the bulbs.

How many chromosomes are there in a rabbit sperm cell?

Explain why the fertilised egg cell of a rabbit contains 44 chromosomes.

The fertilised egg cell divides repeatedly to form an embryo. Name the type of cell division involved and describe what happens to the cells as the embryo develops.

Describe what happens when a cell divides by meiosis.

Explain why offspring produced by sexual reproduction show variation.

What is meant by the term genome?

Give two reasons why understanding the human genome is important for medicine.

Genes code for proteins. Describe how the order of bases in a gene determines the protein that is made.

Each nucleotide contains a sugar, a phosphate group and a base. Describe how nucleotides are joined together to form one strand of DNA.

Part of one strand of a DNA molecule has the base sequence:

T A C G G A T T C A G T

Write the base sequence of the complementary strand.

How many amino acids does this section of DNA code for?

Describe how a protein is made in a cell.

What is meant by the term phenotype?

Give the genotype of a mouse with brown fur.

A heterozygous black mouse is crossed with a brown mouse.

Complete the Punnett square below.

	b	b
B
b

Give the expected ratio of black-furred mice to brown-furred mice from this cross.

Two heterozygous black mice are bred together. They produce 24 offspring in total.

Calculate how many of these offspring would be expected to have brown fur.

The water flea Daphnia is a small animal that lives in ponds.

In spring and summer, when the water is warm and there is plenty of food, female Daphnia reproduce asexually. In autumn, when the pond begins to dry out and food becomes scarce, the Daphnia reproduce sexually.

Explain the advantage to Daphnia of reproducing by each method at these times of year.

Explain how Figure 1 shows that cystic fibrosis is caused by a recessive allele.

Give the genotype of person 1 and of person 2. Explain your answer.

Person 4 does not have cystic fibrosis. Give the two possible genotypes of person 4.

Calculate the total length of the DNA molecule in this bacterium.

Give your answer in millimetres.

Length = ............................... mm

The bacterial cell is $2\ \mu\mathrm{m}$ long. $1\ \mu\mathrm{m} = 1 \times 10^{-3}\ \mathrm{mm}$.

Calculate how many times longer the DNA molecule is than the cell.

Give your answer to 2 significant figures.

Explain how a change in one base in the gene may change the protein that is produced.

Explain why the enzyme produced from the mutated gene may no longer work.

Other mutations occur in non-coding parts of DNA. Explain how a mutation in a non-coding part of DNA could still affect an organism's phenotype.

Explain why Jacob's genotype must be $Dd$.

Jacob and his partner are expecting a child. His partner does not have polydactyly.

Determine the probability that the child will have polydactyly.

You should:

• draw a Punnett square diagram
• identify which offspring have polydactyly

Probability = ...............................

Ben and Aisha are both carriers of the allele for cystic fibrosis. Any child they have has a 1 in 4 chance of being born with cystic fibrosis.

A doctor tells them that they could use IVF treatment. In IVF, egg cells are fertilised outside the body. Each embryo can then be screened for the cystic fibrosis alleles, and only embryos without the disorder are placed in the mother's womb. The embryos that are not used are destroyed.

The treatment costs several thousand pounds. Treating one person with cystic fibrosis costs the NHS a large amount of money every year.

Evaluate the use of embryo screening in this situation.