CBSE Questions for Class 12 Medical Biology Sexual Reproduction In Flowering Plants Quiz 1 - MCQExams.com

Tissue culture technology is grounded on the fact that the entire plant can be regenerated from explants. This capacity to produce a whole plant from any cell/explant is named totipotency. Individually these plants will be genetically identical to the original plant. Several important food plants like tomato, apple, banana, etc., can be generated on the commercial scale by this method.

Thus, the correct option is C.

• Dryopteris and Selaginella are Bryophytes. Bryophytes require water for fertilization because their gametes are released in water, thus, fusion occurs inside the water and a diploid zygote is formed which then develops into a sporophyte.
  
• Vallisneria is a submerged hydrophyte. In Vallisneria, the male flowers detach on maturity and float on the surface of the water while the female flowers grow under water and they come up to the surface with the help of their thin long stalk. As the stalk grows further, the flowers which were vertical become horizontal and thus, a cup-like depression is formed around the female flower. The male flowers which are floating on the surface of the water, fall into the cup and due to jerk, the anthers dehisce and pollens are transferred to the stigma and thus, pollination occurs on the surface of the water. 
• Pisum or the pea plant is a bisexual plant having male and female flowers on the same plant. Thus, self-pollination occurs in pea plant.
• Maize which is also known as Corn plant is pollinated by wind. The anthers are born in long tassels that move with the wind and shake off their pollen. The stigma is feathery and hairy so as to catch the wind-borne pollen. Thus, in Maize, pollens are transferred from the anthers of one plant to the stigma of another plant by means of wind i.e. cross-pollination occurs by the wind. 
• Hence, water is not required for the fertilization of Pisum and Maize. So, the correct answer is D.

• Polyembryony is the phenomenon of occurrence of two or more embryos in one ovule. When the embryos arise in the same embryo sac it is known as true polyembryony. 
• When extra embryos develop in one embryo sac other than the zygotic embryo sac, it is known as false polyembryony. 
• When the embryos are formed from cells of nucellus which penetrate into the embryo sac, it is known as adventitious polyembryony such as in mango.
• Sometimes when one of the embryo develops from synergid, which is haploid tissue and other from nucellus which is diploid, then it is known as haploid-diploid polyembryony such as in flax. 
• Thus, the correct answer is option A. 

• During sexual reproduction in all eukaryotes (plants and animals) the male and female gametes fuse leading to the formation of zygote.
• Generally, gamete formation is not a part of asexual reproduction.
• But in haploid parthenogenesis, a rare form of parthenogenesis that occurs in a few species of bees, nematodes, and plants, offspring develop from haploid eggs to produce haploid adults.
  
• We still consider this a type of asexual reproduction as gametes are formed but there is no fusion of gametes to form zygote, .

• Apocarpous gynoecium means the presence of more than one carpel and the carpels are separate or unfused. It is a primitive condition.  
• Examples of apocarpous gynoecium include strawberries and buttercup.
• So, the correct answer is option B.