Reproduction
- Which of the following flowers only once in its life-time ? Answer: 1. Bamboo species Some plants are monocarpic and flower only once in life; bamboo flowers once after about 50 to 100 years and then... 1
- Which of the following has proved helpful in preserving pollen as fossils ? Answer: 4. Sporopollenin Sporopollenin, the material of the pollen exine, is extremely resistant to heat, acids, alkalis and enzymes. So the... 1
- Functional megaspore in an angiosperm develops into : Answer: 2. Embryo sac The functional megaspore divides mitotically to form the female gametophyte, the embryo sac. Endosperm and embryo form... 1
- A dioecious flowering plant prevents both : Answer: 1. Autogamy and geitonogamy A dioecious plant bears male and female flowers on separate plants. Autogamy (pollen to stigma of the sa... 1
- Attractants and rewards are required for : Answer: 1. Entomophily Insect pollinated flowers (entomophily) need attractants such as colour and scent and rewards such as nectar and poll... 1
- Flowers which have single ovule in the ovary and are packed into inflorescence are usually pollinated by : Answer: 2. Wind Key idea: A single ovule per ovary with flowers packed into an inflorescence is a classic wind-pollination syndrome (e.g. gr... 1
- Double fertilization is exhibited by : Answer: 3. Angiosperms Key idea: In double fertilisation, one male gamete fuses with the egg (syngamy) and the other with the two polar nucl... 1
- Which one of the following statements is not correct? Answer: 2. In potato, banana and ginger, the plantlets arise from the internodes present in the modified stem. In potato, banana and ginger... 1
- Which one of the following generates new genetic combinations leading to variation? Answer: 2. Sexual reproduction Sexual reproduction involves meiosis (crossing over, independent assortment) and fusion of gametes from two p... 1
- In majority of angiosperms Answer: 2. reduction division occurs in the megaspore mother cells In most angiosperms the megaspore mother cell (2n) divides by meiosis (re... 1
- The ovule of an angiosperm is technically equivalent to Answer: 4. megasporangium The ovule is the structure in which the megaspore mother cell and then the embryo sac form. It is therefore equiva... 1
- Pollination in water hyacinth and water lily is brought about by the agency of Answer: 1. insects or wind Water hyacinth and water lily are aquatic plants, but their flowers rise above the water and are pollinated by in... 1
- Seed formation without fertilization in flowering plants involves the process of : Answer: 4. Apomixis Formation of seeds without fertilisation is called apomixis, in which the embryo develops from diploid cells of the ovul... 1
- Which of the following statements is not correct ? Answer: 1. Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into th... 1
- Which one of the following statements is not true ? Answer: 1. Tapetum helps in the dehiscence of anther The tapetum nourishes the developing pollen grains; it does not help in anther dehiscen... 1
- The coconut water from tender coconut represents : Answer: 4. Free nuclear endosperm Key idea: Coconut water is a liquid free nuclear endosperm. In coconut, the triploid primary endosperm nuc... 1