MeiosisIB MYP Biology: Subtopic test

1. 1
   A biology teacher in Mumbai tells her class that human body cells each contain 46 chromosomes, but the sex cells (gametes) that parents pass on are made by a special type of cell division.

   (a)

   Which type of cell division produces gametes?

   [1 mark]

   • AMitosis
   • BBinary fission
   • CMeiosis
   • DFertilisation

   (b)

   How many chromosomes are in a normal human sperm cell?

   [1 mark]

   • A23
   • B46
   • C92
   • D2

   (c)

   Distinguish between the terms haploid and diploid.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A student in Toronto is making a revision table that compares cell division in the skin with cell division in the testes of a man. Skin cells divide to heal cuts, while cells in the testes divide to make sperm.

   (a)

   How many cells are produced at the end of one complete meiosis of a single cell?

   [1 mark]

   • A2
   • B4
   • C8
   • D1

   (b)

   Which statement about the cells made by mitosis is correct?

   [1 mark]

   • AThey are genetically different and haploid
   • BThey are genetically different and diploid
   • CThey are genetically identical and haploid
   • DThey are genetically identical and diploid

   (c)

   Describe two differences, other than the number of cells made, between mitosis and meiosis.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A cell in the testes of a man contains 46 chromosomes. This cell divides by meiosis to make sperm cells, and one of the sperm later fertilises an egg cell from his partner.

   (a)

   State the number of chromosomes in each sperm cell made from this cell, and explain why gametes must have this number.

   [3 marks]

   (b)

   Explain how meiosis and fertilisation lead to variation in the offspring.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A research station in Costa Rica studies a fruit crop. Most farmers grow it from cuttings, so all the plants are genetically identical to one parent plant, but the station can also grow it from seeds, which are made by sexual reproduction. In one field, 40 cutting-grown plants and 40 seed-grown plants were planted side by side, with the same soil, watering and spacing. When a fungal disease spread through the field, 38 of the 40 cutting-grown plants died, compared with 14 of the 40 seed-grown plants. Farmers are now deciding whether to switch from cuttings to seeds.

   (a)

   Process the data and evaluate the hypothesis that seed-grown plants are more resistant to the disease, using your knowledge of cell division.

   [6 marks]

   (b)

   Discuss whether the farmers should switch from growing the crop from cuttings to growing it from seeds.

   [6 marks]

   Total for question 4: 12 marks

End of questions