IGCSE Biology Paper-1: Specimen Questions with Answers 117 - 118 of 208

Question 117

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Question

MCQ▾

The diagram shows a plant cell.

Palisade Cell

Palisade Cell

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Which feature indicates that it is a palisade cell?

Choices

Choice (4)
a.a thick cell wall
b.a large vacuole
c.a large nucleus
d.many chloroplasts

Answer

b.

Explanation

  • Palisade tissues: Their cells are rectangular, tightly fitted together & Inter cellular spaces are absent. They are present towards adaxial/ventral/upper side of leaf. Number of chloroplasts are more in palisade tissue as compare to spongy parenchyma. So upper surface of a leaf appears greener as compared to lower surface.
Palisade Tissues

Palisade Tissues

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Question 118

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MCQ▾

What is produced by anaerobic respiration in a muscle?

Choices

Choice (4)
a.lactic acid-no, carbon dioxide-yes
b.lactic acid-no, carbon dioxide-no
c.lactic acid-yes, carbon dioxide-yes
d.lactic acid-yes, carbon dioxide-no

Answer

d.

Explanation

  • Certain body tissues of even aerobes also show anaerobic metabolism e. g. , during the vigorous contraction of skeletal muscle fiber. In this, the glucose is metabolized into the lactic acid in anaerobic conditions. The rapid formation and accumulation of lactic acid are responsible for muscle-fatigue. The mammalian RBCs shows anaerobic respiration as these lack the mitochondria. In lens of eye and cornea of eye respiration is anaerobic because these structures are a non-vascular. Anaerobic respiration appeared first in primitive organisms because there was absence of O2 in primitive atmosphere.
Primitive Atmosphere

Primitive Atmosphere

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