InheritanceOxford AQA IGCSE Biology: Topic test

20 questions, 54 marks

Oxford AQA IGCSE Biology

Inheritance topic test

Total 54 marks

Name

Class

Date

1
A biology student examines the process of cell division taking place in the growing root tip of an onion, comparing how body cells divide for growth with how cells in reproductive organs divide to form gametes.
(a)
Which type of cell division produces two genetically identical body cells for growth and repair?
[1 mark]
AMitosis
BMeiosis
CFertilisation
DDifferentiation
(b)
How many gametes, and with how many sets of chromosomes each, are produced when a single cell in a reproductive organ divides by meiosis?
[1 mark]
ATwo gametes, each with two sets of chromosomes
BFour gametes, each with a single set of chromosomes
CTwo gametes, each with a single set of chromosomes
DFour gametes, each with two sets of chromosomes
(c)
State two differences between the cells produced by mitosis and the gametes produced by meiosis.
[2 marks]
Total for question 1: 4 marks
2
A biotechnology company is genetically engineering bacteria to produce a human blood-clotting protein for patients with haemophilia, by inserting the human gene for the protein into bacterial cells.
(a)
What is first used to remove the required gene from the human chromosome before it can be inserted into a bacterium?
[1 mark]
AA vector
BA plasmid
CAn enzyme
DA gamete
(b)
What is commonly used as the vector to carry the human gene into the bacterial cell?
[1 mark]
AA chromosome
BAn enzyme
CA protein
DA bacterial plasmid
(c)
Explain how the genetically engineered bacteria are able to produce the human blood-clotting protein.
[2 marks]
Total for question 2: 4 marks
3
A newborn baby is found to have an extra finger on each hand, a condition called polydactyly that is known to run in the baby's family and is caused by a dominant allele.
(a)
The baby's father is heterozygous for the polydactyly allele and the mother does not have the condition. Using P for the dominant polydactyly allele and p for the recessive normal allele, determine the probability that a child of this couple will have polydactyly. Show your genetic cross.
[3 marks]
(b)
Explain, in terms of genes, chromosomes and alleles, how the information that causes polydactyly is passed from parent to offspring, and why polydactyly can appear even though only one copy of the altered allele is inherited.
[4 marks]
Total for question 3: 7 marks
4
A microbiologist studies a colony of bacteria that reproduces asexually by simple cell division, and compares this with a population of a small mammal that reproduces sexually, to explain to students why the two populations differ in genetic variation.
(a)
Compare sexual and asexual reproduction in terms of the number of parents involved, whether gametes are involved, and the amount of genetic variation produced in the offspring.
[6 marks]
(b)
Explain, at a molecular level, how the genetic information in an organism's DNA leads to the characteristics that make individuals genetically varied.
[6 marks]
Total for question 4: 12 marks
5
A biology class studies prepared samples of human sperm cells and egg cells, comparing their size, structure and the numbers produced, as part of a topic on human reproduction.
(a)
Which feature helps a sperm cell to reach an egg cell during fertilisation?
[1 mark]
AA tail for swimming
BA large store of cytoplasm
CA tough outer shell
DA large nucleus with two sets of chromosomes
(b)
Which statement about human egg cells and sperm cells is correct?
[1 mark]
ABoth cells are produced continuously in very large numbers throughout life
BThe sperm cell is larger than the egg cell
CThe egg cell contains a food store to support early development if fertilised, but the sperm cell does not
DNeither cell contains a nucleus
(c)
State two ways in which the sperm cell is adapted for its function of reaching and fertilising an egg cell.
[2 marks]
Total for question 5: 4 marks
6
A gardener grows two flowering plant species side by side in their garden: one species relies on insects to transfer pollen between flowers, and the other relies on the wind.
(a)
Which feature would you expect an insect-pollinated flower to have, rather than a wind-pollinated flower?
[1 mark]
ASmall, dull-coloured petals
BBrightly coloured petals and scent to attract insects
CLarge amounts of light, smooth pollen released into the air
DA feathery stigma hanging outside the flower
(b)
What is pollination?
[1 mark]
AThe fusion of a male and female gamete nucleus
BThe growth of a seed into a new plant
CThe division of a cell to form gametes
DThe transfer of pollen from the anther to the stigma
(c)
State two differences between the flowers of an insect-pollinated plant and a wind-pollinated plant.
[2 marks]
Total for question 6: 4 marks
7
A revision guide asks students to explain why two children of the same parents, both produced by sexual reproduction, are genetically different from each other and from their parents, even though sexual reproduction always involves the fusion of one sperm and one egg.
(a)
Explain how the process of meiosis results in gametes that are genetically different from one another, and from the parent cell that divided to form them.
[3 marks]
(b)
Explain, in terms of genes and chromosomes, why fertilisation then increases the genetic variation seen between the two children even further.
[4 marks]
Total for question 7: 7 marks
8
A school garden club plants sunflower seeds collected after cross-pollination between two different sunflower plants in their garden, and after a few weeks, the seedlings that grow show a range of different heights and flower colours, differing from both parent plants.
(a)
Describe the process of sexual reproduction in a flowering plant such as the sunflower, from pollination through to the formation of seeds.
[6 marks]
(b)
Explain why the sunflower seedlings show a range of different heights and flower colours, all different from both of the parent plants that were cross-pollinated.
[6 marks]
Total for question 8: 12 marks

End of questions