Free Biodiversity and Variety of Life MCQs with Answers

1971. In angiosperms, microsporogenesis and mega­sporogenesis:

• A. Involve meiosis
• B. Occur in ovule
• C. Occur in anther
• D. Form gametes without further divisions

Explanation: In angiosperms, microsporogenesis i.e., formation of microspores (or pollen grains) occurs by the meiotic divisions of diploid microspore mother cells (or pollen mother cells ). Microsporogenesis takes place in the anther. Megasporogenesis i.e. formation of megaspores occurs by the meiotic divisions of diploid megaspore mother cells. Megasporogenesis takes place in the ovule.

1972. Coconut water from a tender coconut is:

• A. Innermost layers of the seed coat
• B. Degenerated nucellus
• C. Immature embryo
• D. Free nuclear endosperm

Explanation: Coconut has multicellular endosperm (called coconut meal) in the outer part and free nuclear as well as vacuolate endosperm (called coconut milk or coconut water) in the centre. A. Inner part of coconut is fruit of the coconut which is composed of two layers , outer(exocarp) and inner (endocarp).B. This is incorrect as free nuclear endosperm is the coconut water.C. Immature embryo cannot be coconut water.

1973. Which one of the following statements is true?

• A. The flowers pollinated by flies and bats secrete foul odor to attract them
• B. Honey is made by bees by digesting pollen collected from flowers
• C. Pollen grains are not rich in nutrients
• D. Pollen grains of some plants cause severe allergies and bronchial afflictions in some people

Explanation: A. Flowers pollinated by insects are large, colorful, and secrete fruity odor.B. Honeybees transform saccharides (carbohydrates) into honey by regurgitating it a number of times, until it is partially digested. The bees do the regurgitation and digestion as a group. After the last regurgitation, the aqueous solution is still high in water, the process continues by evaporation of much of the water and enzymatic transformation.C. Pollen grains are rich in nutrients.D. This is true as pollen grains cause allergies.

1974. Transmission tissue is a characteristic feature of:

• A. Dry stigma
• B. Wet stigma
• C. Hollow style
• D. Solid style

Explanation: Style is traversed by the pollen tube to reach the ovule.It is of two types ­ hollow and solid. In hollow styles, the stylar canal is lined by glandular cells, which are usually multinucleate and polyploid whereas solid style has a core of transmitting tissue, composed of thin walled cells, through which, the pollen tube moves.

1975. An aggregate fruit develops from:

• A. Multicarpellary syncarpous gynoecium
• B. Multicarpellary apocarpous gynoecium
• C. Complete inflorescence
• D. Multicarpellary superior ovary

Explanation: An aggregate fruit or etaerio is a group of simple fruitlets that develop from free ovaries (apocarpus condition) of a single flower (single gynoecium).

1976. Pollen tablets are available in the market for:

• A. In-vitro fertilization
• B. Breeding programs
• C. Supplementing food
• D. Ex-situ conservation

Explanation: Pollen grains are believed to be rich in nutrients (protein 7-­26 % carbohydrates 24-­48%, fats 0.9­-14.5%). They are taken as tablets or syrups to improve health. They also enhance performance of athletes and race horses.

1977. The function of filiform apparatus is to:

• A. Recognize the suitable pollen at the stigma
• B. Stimulate division of generative cell
• C. Produce nectar
• D. Guide the entry of the pollen tube

Explanation: In the ovule, the pollen tube is attracted by secretions of synergids. Usually, the pollen tube enters the embryo sac by passing into one of the two synergids and is guided by the filiform apparatus of the synergids in their movement. The pollen tube then breaks open and releases its contents into the embryo sac. Antipodals and synergids later degenerate.

1978. Perisperm differs from endosperm in:

• A. Being a diploid tissue
• B. Its formation by fusion of secondary nucleus with several sperms
• C. Being a haploid tissue
• D. Having no reserve food

Explanation: Both perisperm and endosperm are nutritive layers. Perisperm is the residual persistent nucellus of seed prior to fertilization while endosperm develops when one of the sperm cells fuses with two haploid polar nuclei. Thus perisperm is diploid while endosperm is a triploid tissue.

1979. Albuminous seeds store their reserve food mainly in:

• A. Endosperm
• B. Cotyledons
• C. Hypocotyl
• D. Perisperm

Explanation: In some seeds, the endosperm persists in the seed as food storage tissue.Such seeds are called endospermic or albuminous, e.g.,castor, maize, wheat,barley,rubber,coconut.

1980. Animal vectors are required for pollination in:

• A. Vallisneria
• B. Mulberry
• C. Cucumber
• D. Maize

Explanation: In Vallisneria, water pollination occurs while mulberry and maize undergo wind pollination. In cucumber, animal pollination is observed.