Section A: High Order Thinking Skills (HOTS)
- Survival of Variations: A population of bacteria living in temperate water. If the
water temperature increases due to global warming, most of these bacteria might die, but a few
heat-resistant variants might survive. Explain the significance of variation here.
- DNA Accuracy: We say "Reproduction is the creation of a blueprint". If the copying
of DNA is not 100% accurate, is it a flaw or an advantage? Justify. (Advantage --> Evolution).
- Contraception Logic: Why does the use of Copper-T not protect against sexually
transmitted diseases? (Mechanism is uterine, not barrier).
- Placental Permeability: Why do we say that the embryo gets nutrition from the
mother's blood, but their blood never mixes? (Diffusion across placenta).
- Flower Modification: Why do wind-pollinated flowers produce huge amounts of pollen
compared to insect-pollinated ones? (Wastage compensation).
Section B: Experimental Competency (Case Studies)
Case I: Menstrual Cycle. The following graph shows the level of hormones (LH and FSH)
and the thickness of the endometrial lining during a 28-day cycle.
- On which day is the level of LH maximum? What does this cause? (Day 14, Ovulation).
- Why does the lining thickness decrease from Day 1 to Day 5? (Menstruation).
- If fertilization occurs on Day 16, how will the lining thickness change after Day 28? (It will
persist).
- Which hormone is responsible for the maintenance of the lining? (Progesterone).
Case II: Reproductive Parts. A student observes a slide of binary fission in Amoeba and
budding in Yeast.
- In Amoeba, what divides first: Nucleus or Cytoplasm? (Nucleus - Karyokinesis).
- In Yeast, does the bud separate immediately? (No, can form chains).
- Draw the sequence of stages for Amoeba.
Section C: Assertion & Reasoning
Directions: Read Assertion (A) and Reason (R) and select the correct option.
- Assertion (A): Amoeba reproduces by binary fission.
Reason (R):
All unicellular organisms reproduce by binary fission.
(A is True, R is False - e.g.
Plasmodium).
- Assertion (A): A flower is legally defined as a modified shoot.
Reason
(R): It carries out sexual reproduction in plants.
(Both true but R is not
explanation of 'modified shoot').
- Assertion (A): Testes are situated outside the abdominal cavity.
Reason
(R): Sperm formation requires a temperature lower than body temperature.
(Both true
and R explains A).
- Assertion (A): Warts is a sexually transmitted disease.
Reason
(R): It is caused by bacteria.
(A is True, R is False - Virus).
