114. Cyclosis is a type of movement shown by
a) Bacterial cell
b) Cynobacterial cell
c) Eukaryotic cell d) b and c
115. The thickness of plasma membrane is about
a) 70 to 100 Aº
b) 100 to 7 A
c) 40 to 50 A
d) 50 to 40 Aº
116. The latest model proposed to explain the structure
of plasma membrane is
a) Unit membrane b) Trilaminar .c) fluid mosaic .d) bilaminar
117. who proposed fluid mosaic model for plasma membrane
a) singer and nicholson
b) cramer and naegli
c) denielli and davson
d) robertson
118). each phospholipid molecules in lipid layer consist of .
a)head
b) head and tail
c) denielli and two tails
d) two heads and one tail
119) head and tail of phopolipids. molecules are
a) hydrophilic
b) hydrophobic
c) hydrophobic and hydrophilic respectively
d) hydrophilic and hydrophobic respectively
120) thickness of lipid layer is about
a)20A^0
b) 30A^0
c)45A^0
d)60A^0
Answers
Answer:
cyclosis sīklō´sĭs [key], streaming of cytoplasm within a living cell without deformation of the external cell membrane. In some plant cells there is a rapid rotatory cytoplasmic movement, which is limited to the peripheral parts of the cell next to the cell wall; chloroplasts and granules move in this stream. This movement may be increased by light, and is dependent on temperature and p H. Auxins, or growth hormones, may also increase the rate of movement. Specialized cell components, microtubules, may direct the flow or may serve as a framework upon which the streaming occurs. Examples of cells in which cyclosis can be seen are the leaf cells of small aquatic plants, such as Elodea, and root hair cells of many plants. In some protozoans , e.g., the ciliates, slower cyclotic movements transport digestive vacuoles through the cell body.
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