Solved CSIR Life sciece cell biology questions Part 5

91. The three most common cell junctions in animals are:
(a) adhesive junctions, tight junctions, gap junctions
(b) adhesive junctions, tight junctions, plasmodesmata
(c) tight junctions, plasmodesmata, adhesive junctions
(d) gap junctions, tight junctions, plasmodesmata

92. The reason urine does not seep out of the bladder is due to the role of:
(a) adherens junctions (b) hemidesmosomes
(c) gap junctions (d) tight junctions

93. Desmosomes and hemidesmosomes are anchored in the cytoplasm by:
(a) desmocollins (c) actin fibers
(b) collagen (d) tonofilaments

94. Gap junctions consist of channels formed by:
(a) hydrophilic, connexons (b) hydrophobic, cadherins
(c) hydrophobic, connexons (d) hydrophilic, cadherins

95. A plant cell wall includes all of the following EXCEPT:
(a) hemicellulose (b) extensins
(c) cellulose (d) collagen

96. Which of the following would be most likely to lead to cancer?
(a) hyperactivity of both a proto-oncogene and a tumor-suppressor
(b) amplification of a proto-oncogene and the failure of a tumor-suppressor gene
(c) hyperactivity of bith a proto-oncogene and a tumor suppressor gene
(d) failure of a proto-oncogene to produce a protein and amplification of tumor
suppressor gene

97. The characteristic strength of woody tissues is due to:
(a) the secondary cell wall (b) hemicellulose
(c) the middle lamina (d) the primary cell wall

98. The rule is derived from the ER and is continuous with the ER of two adjacent plant
(a) middle lamina (b) annulus
(c) plasmodesma (d) desmotubule

99. One can estimate the length of M phase by knowing:
(a) the S phase (c) the age of the cell
(b) the mitotic index (d) the generation time

100. What is true of proto-oncogenes?
(a) cells produce proto-oncogenes as a by-product of mitosis
(b) proto-oncogenes are necessary for normal control of cell division
(c) proto-oncogenes are genetic junk that has not yet been eliminated by natural
(d) proto-oncogenes are unavoidable environmental carcinogens.

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