QUESTION 68 (5 marks)
Compare spermatogenesis and oogenesis in humans.
a) State one similarity in the ploidy of their functional gametes. [1 marks]
b) Describe two differences in the products formed from one primary meiotic cell. [2 marks]
c) Explain how unequal cytoplasmic division in oogenesis relates to the function of an egg. [2 marks]
Practice marking scheme
Answer
a) Both produce haploid gametes. b) Spermatogenesis produces four functional sperm; oogenesis produces one large functional egg plus polar bodies. c) The egg retains cytoplasm and resources supporting early development.
Working
Both processes reduce chromosome sets through meiosis. Spermatogenesis divides cytoplasm relatively evenly among four haploid cells that develop into sperm. Oogenesis distributes cytoplasm unequally, retaining most in one functional egg and forming small polar bodies. The egg’s cytoplasm contains organelles, molecules and resources used before the developing embryo can obtain external supplies.
Marking criteria
- Identifies haploid functional gametes in both processes. [1 mark]
- States four functional sperm from one primary spermatocyte. [1 mark]
- States one functional egg plus polar bodies from one primary oocyte. [1 mark]
- Explains retention of most cytoplasm in the egg. [1 mark]
- Links retained cytoplasm/resources to early development. [1 mark]
Practice question aligned to the current QCAA syllabus; review the worked solution and marking criteria.
View the QCAA syllabusCompare your working with the guide above.