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Exexel IG Bio 3b Inheritance (cell division and variation) – Summary Questions

Inheritance (cell division and variation) – Summary Questions

1. How many pairs of chromosomes are there in a body cell of a human baby? (1)

2. Place the following in order of size, starting with the smallest, by writingnumbers 1 – 4 in the boxes underneath the words. (1)

chromosome nucleus gene cell

3. For a baby to grow, its cells must develop in a number of ways. Explain how each of the following is part of the growth process of a baby.

(a) Cell enlargement (1)

(b) The process of cell division by mitosis. (2)

(c) Cell specialization (differentiation). (3)

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4. The diagrams A, B, C, D, E and F show an animal cell at different stages of mitosis and cell division.

(a) Use the letter by each diagram to arrange these stages in the correct order. Write your answers in the table. The first and last stages have been done for you. Write one letter only in each box. (3)

Order Stage in mitosis Label letter1 Prophase C2 Early metaphase3 Late Metaphase 456 Cytokensis D

(b) What is the diploid chromosome number of this cell? (1)

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5. The diagram shows the stages in mitosis in a cell with four chromosomes.

Complete cells M and N by accurately drawing in the chromosomes present. (2)

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6. The diagrams show stages in the process of an animal cell dividing during mitosis. The stages are in the wrong order.

(a) Complete the table to show the correct order for cell division by mitosis. (5)

Order 1 2 3 4 5 6LetterName of the stage

(b) Describe evidence from the diagrams which shows that the cell is dividing by mitosis and not meiosis. (2)

(c) State one function of mitosis. (1)

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7. Diagrams A to G represent different stages during cell division in a cell with four chromosomes.

(a) Complete this sequence to show the stages of cell division in the correct order. (1)

C D

(b) Name the type of cell division represented in the diagrams. (1)

(c) Give reasons for your answer. (2)

(d) Name and describe the process shown in stage G. (3)

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8. The diagram shows three types of cells in a life history of a simple animal.

(a) How do the chromosomes of the body cells compare with the chromosomes in the fertilised egg from which they came? (2)

(b) Describe what happens to chromosomes in the nucleus of a body cell when it forms reproductive cells. (4)

9. The diagram shows two stages (A and B) in meiosis in an organism containing one pair of chromosomes. One gene pair is shown.

(a) Describe what happens during stage A that results in stage B. (1)

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(b) Which two of the following cells, P, Q, R, S, T, are gametes? (1)

10. Complete the table to show the differences between mitosis and meiosis.

Mitosis MeiosisNumber of cells producedParent cell (diploid/ haploid)Daughter cell (diploid/ haploid)Lining up of chromosomesHow many cell divisionsGenetically identical or different

11. Explain the terms diploid and haploid. (2)

12. The diagram shows some stages in human reproduction.

(a) Complete the table. (2)

cell number of chromosomes

ovum 23spermzygote 46cell A

(b) Draw a letter H in the nucleus of one cell that is haploid. (1)

(c) The embryo will develop into a boy. How many cells in the diagram have an X chromosome? (1)

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13. Use words from the box to complete the following sentences. (9)

Baby diploid fertilisation haploid ovulation zygoteGametes identical information inherit reproduce similargenes pollen grains seeds sperm(s)

Body cells contain 46 chromosomes. Gametes contain half this number and aretherefore said to be ................................................ . Male and female gametes fuse to form a ............................................. during ............................................. .

Genes pass on ..................................................... from parents to children. The genes are passed on by the parents’ reproductive cells. These cells are called .................................................................... . Children are ....................................... to their parents because they ................................... their parents’ genes.

A young animal looks like its parents. This is because of information passed on in the egg and ................................................................. from which it formed. These reproductive cells carry information in ............................................................... .

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14. The drawing shows a potato plant producing new tubers (potatoes). Buds on the stem of the parent plant produce stolons. The new tubers are formed at the ends of the stolons (stems that grow downwards).

(a) Explain why the new tubers are genetically identical to each other. (2)

(b) Some of the tubers are used to produce potato plants. These new potato plants will not all grow to the same height. Give one reason why. (1)

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15. Identical twins lived apart for several years. They now look different, as shown in the diagram.

(a) Use words from the box to explain how the twins may have become different.(4)

alleles diet geneticidentical similar variation

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16. The drawing shows a female lion and her two cubs. The table gives information about the lion cubs. Use this information to answer these questions.

Features Cub 1 Cub 2sex male femalemass at birth (kg) 2.8 2.4mass at 12 months (kg)

21.4 21.4

eye colour light brown dark brownteeth none broken two broken

(a) State one feature that is not affected by the environment. (1)

(b) State one feature that is affected by the environment. (1)

(c) Which cub, 1 or 2, has grown faster from birth? Explain your answer. (2)

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