Unisexuality of flowers prevents
A) autogamy and geitonogamy B) geitonogamy, but not xenogamy C) both geitonogamy and xenogamy D) autogamy, but not geitonogamy Answer:D)... View Article
Latest Posts
Which one of the following pairs of plant structures has a haploid number of chromosomes?
A) Egg nucleus and secondary nucleus B) Nucellus and antipodal cells C) Egg cell and antipodal cells D) Megaspore mother... View Article
Wind pollinated flowers are
A) small, producing a large number of dry pollen grains B) small, brightly coloured, producing a large number of pollen... View Article
Apomictic embryos in Citrus arise from
A) maternal sporophytic tissue in ovule B) synergids C) diploid egg D) antipodal cells Answer:A) maternal sporophytic tissue in ovule... View Article
Wind pollination is common in
A) lilies B) legumes C) orchids D) grasses Answer:D) grasses Explanation: Wind pollination is also called anemophily. It is common... View Article
The ‘eyes’ of the potato tuber are
A) flower buds B) root buds C) axillary buds D) shoot buds Answer: C) axillary buds Explanation: Potato is a stem... View Article
Which one of the following pollinations is autogamous?
A) Xenogamy B) Geitonogamy C) Cleistogamy D) Chasmogamy Answer:C) Cleistogamy Explanation: Autogamy refers to the transfer of pollen within the... View Article
Nucellar polyembryony is reported in species of
A) Gossypium B) Citrus C) Brassica D) Triticum Answer:B) Citrus Explanation: Polyembryony is a condition, where there are more than... View Article
Plants with ovaries having only one or a few ovules, are generally pollinated by
A) butterflies B) bees C) wind D) birds Answer:C) wind Explanation: Wind-pollinated flowers often show a single ovule in the... View Article
Which one of the following statements is wrong regarding pollen grains?
A) Vegetative cell is larger than generative cell B) When pollen is shed at the two-celled stage, double fertilization does... View Article
Which one of the following is the correctly matched mode of reproduction?
A) Ginger–Sucker B) Onion–Bulb C) Yeast–Zoospores D) Chlamydomonas–Conidia Answer:B) Onion–Bulb Explanation: Onions propagate by the bulb. Chlamydomonas is an alga... View Article
An organic substance that can withstand environmental extremes and cannot be degraded by any enzyme is
A) sporopollenin B) cuticle C) cellulose D) lignin Answer:A) sporopollenin Explanation: Sporopollenin is the most resistant organic compound present in... View Article
Both, autogamy and geitonogamy are prevented in
A) cucumber B) papaya C) maize D) castor Answer:B) papaya Explanation: Autogamy refers to the transfer of pollen from anther... View Article
Which of the following statements is correct regarding sporopollenin?
A) Sporopollenin is made up of inorganic materials B) Sporopollenin can be degraded by enzymes C) Sporopollenin can withstand high... View Article
Which one of the following statements is correct regarding pollination?
A) Xenogamy occurs only by wind pollination B) Cleistogamous flowers are always autogamous C) Geitonogamy involves the pollen and stigma... View Article
Megaspores are produced from the megaspore mother cells after
A) formation of thick wall B) mitotic division C) meiotic division D) differentiation Answer:C) meiotic division Explanation: The diploid megaspore... View Article
What Represents Lock And Key In The Lock And Key Hypothesis?
It was suggested by Emil Fisher in 1894. Enzymes perform their action by combining with a specific part of the... View Article
How Did Darwin Explain The Survival Of The Fittest And Natural Selection Theory?
Darwin explained the survival of the fittest and natural selection by giving an example of a Giraffe. According to Darwin,... View Article
What Is Industrial Melanism?
Industrial melanism in the peppered moth, Boston betularia provides the most dramatic evidence of Natural selection. In the early part... View Article
How Does The Fluid Mosaic Model Propose The Arrangement Of Proteins?
Arrangement of proteins – The extrinsic proteins are found both on the outer and on the inner side of the... View Article
