Study the biological behavior of the zygote across different eukaryotic life cycles:
(p) In haplontic life cycles, the diploid zygote divides by meiosis. (q) In diplontic life cycles, the diploid zygote divides by mitosis. (r) Fungi and algae never form zygotes because they are haploid.
Which of the statements given above are correct?
Fungi and algae do form zygotes during sexual reproduction. In haplontic organisms the zygote undergoes meiosis, whereas in diplontic organisms it divides mitotically. Therefore statement (r) is incorrect.
Question 92 of 100
📘 CLASS XII
Read these statements regarding pollen transfer in angiosperms:
(i) Pollen grains are produced in anthers and must be transferred to the stigma. (ii) In dioecious plants, self-pollination is the exclusive method of gamete transfer. (iii) Pollen tubes are formed to carry the non-motile male gametes to the ovule.
Identify the correct combination.
In dioecious plants, self-pollination is impossible because male and female flowers occur on separate plants. Pollen tubes carry the non-motile male gametes to the ovule. Hence statement (ii) is incorrect.
Question 93 of 100
📘 CLASS XII
Focus on plant sexuality classification terms and examples:
(1) Cucurbits and coconuts are monoecious plants. (2) Papaya and date palm are dioecious plants. (3) Monoecious plants bear unisexual male or female flowers on different individual plants.
Select the correct combination.
Monoecious plants bear both male and female unisexual flowers on the same individual plant. When male and female flowers occur on separate plants, the condition is dioecious. Hence statement (3) is incorrect.
Question 94 of 100
📘 CLASS XII
Analyze the process of embryogenesis during animal development:
(I) Embryogenesis involves cell division (mitosis) and cell differentiation. (II) Cell division increases the number of cells in the developing embryo. (III) Cell differentiation causes groups of cells to undergo modifications to form specialized tissues. (IV) Embryogenesis in viviparous animals occurs inside the female body, leading to better embryonic protection.
Which of these statements are correct?
All four statements are correct. Embryogenesis involves mitotic cell division and cell differentiation, while viviparity provides better protection to the developing embryo.
Question 95 of 100
📘 CLASS XII
Read the statements below on animal sexuality and hermaphroditism:
(a) Bisexual animals are also called hermaphrodites. (b) Sponges, tapeworms, and leeches are unisexual animals. (c) Earthworms are hermaphrodites containing both testes and ovaries.
Select the correct set.
Sponges, tapeworms and leeches are bisexual (hermaphrodites), not unisexual. Earthworms also possess both male and female reproductive organs. Hence statement (b) is incorrect.
Question 96 of 100
📘 CLASS XII
Evaluate the geographical and biological facts of the Neelakuranji plant:
(p) Strobilanthus kunthiana is a perennial plant that flowers once in 12 years. (q) Its massive flowering transforms hilly areas of Kerala, Karnataka, and Tamil Nadu into blue stretches. (r) Its last mass flowering occurred in September-October 2006.
Choose the correct combination.
All three statements are accepted as correct according to the provided source and NCERT-based description.
Question 97 of 100
📘 CLASS XII
Study the classification of breeders based on seasonal behaviors:
(i) Continuous breeders are active throughout their entire reproductive phase. (ii) Seasonal breeders reproduce only during favorable seasons. (iii) Humans are seasonal breeders because they exhibit a menstrual cycle.
Identify the correct combination.
Humans are continuous breeders and remain reproductively active throughout their reproductive phase. They are not seasonal breeders. Hence statement (iii) is incorrect.
Question 98 of 100
📘 CLASS XII
Select the correct sexuality terminology used in Kingdom Fungi:
(1) In fungi, the term 'homothallic' is used to denote the bisexual condition. (2) The term 'heterothallic' is used to denote the unisexual condition. (3) Dioecious is a term equivalent to homothallic.
Examine the characteristics of embryonic protection in oviparous species:
(a) Oviparous animals lay fertilized eggs covered by a hard calcareous shell. (b) The calcareous shell protects the embryo from dehydration and mechanical injury. (c) Birds and reptiles are typical viviparous animals.
Which of the statements given above are correct?
Birds and reptiles are oviparous because they lay shelled eggs. The calcareous shell protects the embryo against dehydration and mechanical injury. Hence statement (c) is incorrect.
Question 100 of 100
📘 CLASS XII
Read these statements regarding the unique life cycle of Bamboo:
(I) Bamboo species exhibit unusual flowering behavior, flowering only once in their lifetime. (II) They generally flower after 50-100 years, produce a large number of fruits, and die. (III) Bamboo plants are annual grass species that complete their life cycle within one year.
Choose the correct deduction.
Bamboo is a long-lived perennial grass that flowers only once after about 50-100 years, produces abundant fruits and then dies. It is not an annual plant. Hence statement (III) is incorrect.
