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Class 12 Human Reproduction worksheet
CBSE Biology. Gametogenesis counts, menstrual cycle and hormones, fertilisation to birth, sex determination. Every sheet has 20 questions in three sections and an answer key, and the numbers change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
The testes lie outside the body in the scrotum because sperm formation needs a temperature:
- equal to body temperature
- below 0 °C
- above body temperature
- about 2–2.5 °C below body temperature
Answer
(d) about 2–2.5 °C below body temperature
- 2.
The number of chromosomes in a spermatid of a human is:
- 23
- 46
- 92
- 69
Answer
(a) 23
haploid, after meiosis I
- 3.
490 primary oocytes complete oogenesis (after fertilisation). The number of ova formed is:
- 1,960
- 980
- 490
- 1,470
Answer
(c) 490
each primary oocyte gives one ovum and polar bodies
Section B · short answer
- 4.
What is the role of the acrosome?
Answer
It is a cap on the sperm head containing enzymes that help the sperm penetrate the layers around the ovum.
- 5.
A healthy ejaculate has about 246 million sperms. For normal fertility at least 60% should have a normal shape and at least 40% should swim vigorously. Find the minimum numbers of each.
Answer
147.6 million normal; 98.4 million vigorously motile
60% and 40% of 246 million
Section C · long answer
- 6.
Describe spermatogenesis and its hormonal control.
Answer
In the seminiferous tubules, spermatogonia (2n) divide by mitosis; some grow into primary spermatocytes (2n), which complete meiosis I to form secondary spermatocytes (n) and then meiosis II to form spermatids (n), which change into sperms (spermiogenesis). GnRH from the hypothalamus causes LH and FSH release: LH makes Leydig cells secrete androgens, which drive spermatogenesis; FSH acts on Sertoli cells, which help spermiogenesis.
Fresh sheets for your child
In the app, every Human Reproduction sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
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