Hello, master strategists!
You've mastered every type of question. Now, let's drill down on the final, most conceptually challenging format: the Assertion-Reason (A-R) Questions. These 30 questions test your ability to understand the causal link between two facts. By mastering these, you prove your true mastery of the chapter!
Part 1: The Assertion-Reason Gauntlet (Q1 - Q30)
Directions: For the following questions, two statements are given—one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the codes (a), (b), (c), and (d) as given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Q1.
Assertion (A): The process of reproduction is essential for the survival of an individual.
Reason (R): Reproduction ensures the continuity of the species generation after generation.
Answer: (d). A is false (Reproduction is not essential for individual survival). R is true.
Q2.
Assertion (A): DNA copying is the most basic event in reproduction.
Reason (R): DNA contains the information for inheriting body design features.
Answer: (a). Both are true, and R correctly explains why DNA copying is essential.
Q3.
Assertion (A): Variation is crucial for the survival of a species.
Reason (R): Environmental conditions can change dramatically, threatening the survival of a stable population.
Answer: (a). Both are true, and R explains why variation is needed (it allows some individuals to survive the changes).
Q4.
Assertion (A): The offspring produced by asexual reproduction are often called clones.
Reason (R): Asexual reproduction involves only a single parent and does not mix genetic material.
Answer: (a). Both are true, and R correctly explains why the offspring are genetically identical (clones).
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Q5.
Assertion (A): Binary fission in Leishmania occurs in a definite orientation.
Reason (R): Leishmania has a whip-like structure at one end of its cell.
Answer: (a). Both are true, and R explains the presence of the structure that dictates the fixed plane of division.
Q6.
Assertion (A): Simple multicellular organisms can reproduce by fragmentation.
Reason (R): The body of these organisms is not composed of specialized tissues and organs.
Answer: (a). Both are true, and R explains the simplicity of the body design that allows every fragment to grow into a complete organism.
Q7.
Assertion (A): Regeneration is the same as reproduction.
Reason (R): Both processes result in the formation of new individuals.
Answer: (d). A is false (Regeneration is fundamentally a repair mechanism). R is true (it can result in new individuals, but this doesn't make it the same process).
Q8.
Assertion (A): Spores of Rhizopus are covered by thick walls.
Reason (R): The thick walls protect the spores under unfavourable conditions like high temperature or dryness.
Answer: (a). Both are true, and R correctly explains the protective function of the thick walls.
Q9.
Assertion (A): Vegetative propagation is useful for growing plants like banana, orange, and rose.
Reason (R): These plants are capable of producing large quantities of viable seeds.
Answer: (c). A is true. R is false (These plants have generally lost the capacity to produce viable seeds).
Q10.
Assertion (A): Grafting is a method of artificial vegetative propagation.
Reason (R): The scion and stock fuse, and the resulting plant has the combined characteristics of both.
Answer: (b). Both are true, but R does not explain why it is classified as artificial vegetative propagation (it explains the result).
Q11.
Assertion (A): Bisexual flowers require an external pollinating agent like wind or insects.
Reason (R): Bisexual flowers contain both the stamen and pistil.
Answer: (b). Both are true. Bisexual flowers can self-pollinate, so they don't require an agent (A is not strongly supported by R). R simply states the definition.
Q12.
Assertion (A): Post-fertilization, the ovule develops into the seed.
Reason (R): Post-fertilization, the ovary develops into the fruit.
Answer: (b). Both are true, but R does not explain A (they are two separate, correct events).
Q13.
Assertion (A): Pollination must occur before fertilization in flowering plants.
Reason (R): Pollination transfers the male gamete directly to the egg cell.
Answer: (c). A is true. R is false (Pollination transfers the pollen grain; fertilization transfers the male gamete via the pollen tube).
Q14.
Assertion (A): The testes are located outside the abdominal cavity in the scrotum.
Reason (R): The lower temperature in the scrotum is necessary for sperm production.
Answer: (a). Both are true, and R correctly explains the physiological reason for A.
Q15.
Assertion (A): The placenta is essential for the development of the human embryo.
Reason (R): The placenta provides a surface area for glucose and oxygen to pass from the mother to the embryo.
Answer: (a). Both are true, and R correctly explains the primary function that makes the placenta essential.
Q16.
Assertion (A): The lining of the uterus becomes thick and spongy after fertilization.
Reason (R): This lining is prepared every month to receive and nurture the developing embryo.
Answer: (d). A is false (the lining becomes thick and spongy before fertilization, in anticipation). R is true.
Q17.
Assertion (A): If the egg is not fertilized, menstruation occurs.
Reason (R): The menstrual flow consists of the unfertilized egg and the thick, soft lining of the uterus.
Answer: (a). Both are true, and R describes the composition of the discharge that occurs because of the event mentioned in A.
Q18.
Assertion (A): The male gamete (sperm) is much larger than the female gamete (egg).
Reason (R): The sperm needs a lot of stored food to travel a long distance to reach the egg.
Answer: (d). A is false (the egg is much larger). R is false (it is the egg that has stored food; sperm are small and mobile).
Q19.
Assertion (A): The oviduct (fallopian tube) is the site of fertilization in human females.
Reason (R): The uterus is too thick and does not allow the fusion of gametes.
Answer: (c). A is true. R is false (the uterus's role is implantation, not fertilization, but the Reason's statement about the thickness preventing fusion is not the correct biological reason).
Q20.
Assertion (A): Contraceptive pills are often called hormonal methods.
Reason (R): They use hormones to stop the ovary from releasing the egg (ovulation).
Answer: (a). Both are true, and R correctly explains how the pill functions as a hormonal method.
Q21.
Assertion (A): Barrier methods of contraception are preferred over chemical methods.
Reason (R): Barrier methods protect the user from acquiring sexually transmitted diseases (STDs).
Answer: (a). Both are true, and R gives a major advantage of barrier methods (like condoms) that makes them preferred.
Q22.
Assertion (A): Tubectomy is a surgical method of contraception performed on females.
Reason (R): In tubectomy, the vas deferens is cut and tied to prevent the transport of sperm.
Answer: (c). A is true. R is false (R describes vasectomy, which is performed on males).
Q23.
Assertion (A): HIV is a viral sexually transmitted disease.
Reason (R): HIV can be spread through the exchange of infected body fluids during sexual contact.
Answer: (a). Both are true, and R explains one major route of transmission for the disease mentioned in A.
Q24.
Assertion (A): Fragmentation is a mode of asexual reproduction in Spirogyra.
Reason (R): Spirogyra is a simple filamentous alga that breaks into small fragments upon maturation.
Answer: (a). Both are true, and R correctly describes the structure and process that enables fragmentation.
Q25.
Assertion (A): A wind-pollinated flower is typically small, dull, and lacks scent.
Reason (R): Wind pollination is efficient and does not require the flower to attract insects or animals.
Answer: (a). Both are true, and R correctly explains why the flower lacks the features mentioned in A.
Q26.
Assertion (A): In multiple fission (Plasmodium), the nucleus divides only once.
Reason (R): Multiple fission is a rapid process that occurs under favourable environmental conditions.
Answer: (d). A is false (the nucleus divides repeatedly). R is false (it occurs under unfavourable conditions, inside a cyst).
Q27.
Assertion (A): The menstrual cycle occurs only if the egg is not fertilized.
Reason (R): The cycle is the body's method of preparing the uterus for pregnancy every month.
Answer: (b). Both are true, but R is not the direct explanation of A. (R is the explanation of the whole cycle; A is the explanation of the shedding phase).
Q28.
Assertion (A): In grafting, the resulting plant is a hybrid of the two parent plants.
Reason (R): Grafting is a form of asexual reproduction.
Answer: (d). A is false (since it is asexual, it is not a hybrid; the scion part retains its traits). R is true.
Q29.
Assertion (A): The cotyledons of a seed store food for the developing embryo.
Reason (R): Once the seed germinates, the root (radicle) and shoot (plumule) start producing food immediately.
Answer: (c). A is true. R is false (The embryo relies on stored food until the leaves develop and the plant can begin photosynthesis).
Q30.
Assertion (A): The male gametes in humans are produced in the testes.
Reason (R): Testosterone is the hormone released by the seminal vesicles.
Answer: (c). A is true. R is false (Testosterone is released by the testes; seminal vesicles produce part of the semen fluid).
Excellent work! That was the deepest test of your conceptual knowledge. You have now completed all the major question types for the chapter!
Your final post in this chapter series will be the Detailed Revision and Final Study Checklist. Stay tuned! 🚀
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