A) butterflies B) bees C) wind D) birds Answer:C) wind Explanation: Wind-pollinated flowers often show a single ovule in the ovary and many... View Article
A) Vegetative cell is larger than generative cell B) When pollen is shed at the two-Âcelled stage, double fertilization does not take place C)... View Article
A) sporopollenin B) cuticle C) cellulose D) lignin Answer:A) sporopollenin Explanation: Sporopollenin is the most resistant organic compound... View Article
A) cucumber B) papaya C) maize D) castor Answer:B) papaya Explanation: Autogamy refers to the transfer of pollen from anther to the stigma of... View Article
A) Sporopollenin is made up of inorganic materials B) Sporopollenin can be degraded by enzymes C) Sporopollenin can withstand high temperatures... View Article
A) Xenogamy occurs only by wind pollination B) Cleistogamous flowers are always autogamous C) Geitonogamy involves the pollen and stigma of... View Article
A) formation of thick wall B) mitotic division C) meiotic division D) differentiation Answer:C) meiotic division Explanation: The diploid... View Article
It was suggested by Emil Fisher in 1894. Enzymes perform their action by combining with a specific part of the substrate molecule. It is... View Article
Darwin explained the survival of the fittest and natural selection by giving an example of a Giraffe. According to Darwin, giraffes exhibited... View Article
Industrial melanism in the peppered moth, Boston betularia provides the most dramatic evidence of Natural selection. In the early part of the... View Article
Arrangement of proteins - The extrinsic proteins are found both on the outer and on the inner side of the phospholipid bilayer. The intrinsic... View Article
Cell transporter - The central transporter is a protein ring with two irises of 8 arms each. These work like a diaphragm in a camera so that... View Article
Chromosomes are composed of nucleoproteins. Most of the nucleic acid is in the form of DNA. Small amounts of RNA are also found. The proteins are... View Article
It was first seen by E.G. Balbiani in salivary gland cells of Chironomus larvae. Hence, they are called salivary gland chromosomes. Koller names... View Article
Lampbrush chromosomes appear during the diplotene stage of meiosis in a developing oocyte, measuring about 700 m - 5900 m in length. These occur... View Article
M phase lasts for a short period when compared to the interphase. The cell undergoes division during the M phase. There is a definite ratio... View Article
Prophase I lasts for a long duration including leptotene, zygotene, pachytene, diplotene and diakinesis. During leptotene, the chromosomes appear... View Article
Cancer producing agents are called carcinogens. They could be - Physical carcinogens Chemical carcinogens Biological carcinogens Physical... View Article
Class Schizomycetes is classified into 10 orders, out of which six are as follows - Pseudomonadales - rod-shaped or spiral bacteria with or... View Article
