#Question id: 26457
#Unit 3. Fundamental Processes
#Question id: 5660
#Unit 5. Developmental Biology
Following statement regarding to acrosome reaction in sea urchin.
A. Activation of the acrosome reaction serves as a barrier to intraspecies fertilizations.
B. The acrosome reaction is initiated by sulfate-containing polysaccharides in the egg jelly that bind to specific receptors located directly above the acrosomal vesicle on the sperm cell membrane.
C. These polysaccharides are often highly species specific, but egg jelly factors from one species of sea urchin generally activate the acrosome reaction in closely related species.
D. The elevated Ca2+ level in a relatively basic cytoplasm triggers the fusion of the acrosomal membrane with the adjacent sperm cell membrane, releasing enzymes that can lyse a path through the egg jelly to the vitelline envelope.
Which of the following statements are correct?
#Question id: 5452
#Unit 8. Inheritance Biology
What are polygenes?
#Question id: 12718
#Unit 6. System Physiology – Plant
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COLUMN I
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COLUMN II |
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A) Physical sensing
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i) usually results from the
detection of by-products that accumulate in cells due to the uncoupling of
enzymatic or electron transfer reactions, such as the accumulation of ROS
during stress caused by too much light.
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B) Biophysical sensing
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ii) often involves the presence of
specialized proteins that have evolved to sense a particular stress; for
example, calcium channels that can sense changes in temperature and alter
Ca2+ homeostasis.
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C) Metabolic sensing
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iii) refers to modifications of
DNA or RNA structure that do not alter genetic sequences, such as the changes
in chromatin that occur during temperature stress.
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D) Biochemical sensing
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iv) refers to the mechanical
effects of stress on the plant or cell structure, for example, the
contraction of the plasma membrane from the cell wall during drought stress.
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E) Epigenetic sensing
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v) might involve changes in
protein structure or enzymatic activity, such as the inhibition of different
enzymes during heat stress.
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#Question id: 378
#Unit 1. Molecules and their Interaction Relevant to Biology
Which of the following statements about buffers is true?