Question 1: Define meiosis and describe its primary purpose in sexually reproducing organisms.

Answer: Meiosis is a type of cell division that reduces the chromosome number by half, producing four haploid gametes, which increases genetic diversity in sexually reproducing organisms.

Question 2: Explain the main difference between meiosis and mitosis.

Answer: Meiosis involves two divisions resulting in four genetically diverse haploid cells, whereas mitosis involves a single division producing two identical diploid cells.

Question 3: List the key stages of meiosis and briefly describe what occurs in each.

Answer: Meiosis consists of two stages: Meiosis I (homologous chromosomes pair, exchange genetic material via crossing over, and segregate into two cells) and Meiosis II (similar to mitosis, separating sister chromatids, resulting in four haploid cells).

Question 1: If a diploid organism has 16 chromosomes in its somatic cells, how many chromosomes will each gamete contain after meiosis?

Answer: 8

Question 2: Calculate the total number of chromosomes in a zygote formed from two gametes each containing 12 chromosomes.

Answer: 24

Question 1: Describe a safe and ethical way to observe meiosis in plant cells in a laboratory setting.

Answer: Use a prepared slide of a plant's anther tissue, wear appropriate protective equipment, handle chemicals carefully, and follow all safety protocols to observe cell division under a microscope without disrupting the specimen.

Question 2: Identify at least two variables that should be controlled in an experiment observing meiosis in a cell sample.

Answer: Temperature and pH levels should be controlled to ensure normal cell division.

Question 1: A sample of germ cells shows 32 chromosomes during metaphase I. How many chromosomes are present in each of the resulting gametes after meiosis?

Answer: 16

Question 2: In a scenario where crossing over occurs between homologous chromosomes during meiosis, explain how this affects genetic variation among the resulting gametes.

Answer: Crossing over involves exchange of genetic material between homologous chromosomes, resulting in new combinations of alleles, which increases genetic diversity among the gametes.

Question 3: A researcher observes that in a particular species, the chromosome number in somatic cells is 24. After meiosis, the gametes contain 12 chromosomes. What does this indicate about the species' chromosome number and the process of meiosis?

Answer: The species has a diploid number of 24 chromosomes, and meiosis reduces this to 12 in gametes, ensuring haploid cells for sexual reproduction.

Question 1: Discuss the significance of genetic variation resulting from meiosis for evolution and adaptation in populations. (6 marks)

Answer: Genetic variation produced by meiosis, through crossing over and independent assortment, creates diverse genetic combinations in gametes. This diversity allows populations to adapt to changing environments, promotes evolution by natural selection, and enhances survival rates of species over generations.

Question 1: Explain how understanding meiosis is important in the context of human fertility treatments.

Answer: Understanding meiosis helps in diagnosing causes of infertility, developing assisted reproductive technologies like IVF, and understanding genetic disorders caused by errors in meiosis such as nondisjunction.

Question 2: Describe how knowledge of meiosis can be utilised in agriculture to produce genetically diverse crop varieties.

Answer: By understanding meiosis, breeders can select for desirable traits, induce genetic variation through controlled crossing over, and develop crop varieties with improved yield, disease resistance, and adaptability.