Direction : In the following questions, a statement of Assertion
is followed by a statement of Reason. Mark the correct choice
as :
(a) If both assertion and reason are true and reason is the
correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the
correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If both assertion and reason are false.
sTrucTurAL OrGAnIsATIOn In AnImALs- Assertion : Compound epithelium is multi-layered and has
a limited role in secretion and absorption.
Reason : The main function of compound epithelium is
to provide protection against chemical and mechanical
stress. - Assertion : Gap junctions perform cementing function to
keep the neighbouring cells together.
Reason : Tight junctions facilitate the cells to communicate
with each other by connecting the cytoplasm of adjoining
cells, for rapid transfer of ions, small and big molecules etc. - Assertion : Tendons which attach skeletal muscles to
bones and ligaments which attach one bone to another are
examples of dense regular connective tissue.
Reason : In dense regular connective tissue, the collagen
fibres are present in rows between many parallel bundles
of fibres. - Assertion : In humans, at the time of birth, red bone
marrow is present throughout the skeleton.
Reason : By 20-25 years, all the red bone marrow is
replaced by yellow bone marrow with red bone marrow
present nowhere in the body. - Assertion : The intercellular material of cartilage is solid,
pliable and resists compression.
Reason : Most of the cartilage present in vertebrate embryo
is replaced by bones in adults.
6. Assertion : Lymph transports nutrients, oxygen, hormones
etc. from the blood to the body cells and brings CO 2 and
other wastes from the body cells to blood.
Reason : Lymph has a low glucose concentration and it does
not play any role in maintaining the volume of blood.
7. Assertion : Crop is a small part of alimentary canal of
cockroach which mainly functions to grind the food.
Reason : Gizzard is a part of alimentary canal of cockroach
which is directly connected to mouth at one end and rectum
at other end.
8. Assertion : Malpighian tubules in cockroach reabsorb a
large amount of water and bicarbonates of sodium and
potassium and then transfer them to the haemolymph.
Reason : Malpighian tubules are long, fine and unbranched
blind tubules which are attached at the junction of mid-gut
and hind-gut.
9. Assertion : Each ovary of a cockroach consists of eight
ovarioles which function to produce ova.
Reason : All the eight ovarioles of each ovary unite to form
oviduct, which transfer the ova to the common oviduct.
10. Assertion : A fasciculum consists of a bundle of nerve
fibres and is surrounded by a connective tissue called endo-
neurium.
Reason : A dense layer of connective tissue that surrounds
the entire nerve is called as perineurium.
11. Assertion : The conduction of nerve impulse is faster in
medullated nerve fibres than in non-medullated nerve fibres.
Reason : When an impulse travels along a non-medullated
nerve fibre, it does not proceed uniformly along the length of axis
cylinder rather it jumps from one nodes of Ranvier to the next.
12. Assertion : The epithelium present in mucous membrane
of intestine is highly absorptive.
Reason : This epithelium possesses microvilli which
increase the absorptive surface area of the epithelium.
13. Assertion : Areolar tissue acts as a supporting framework
for epithelium.
PRACTICE QUESTIONS ON
Assertion & Reason
sTrucTurAL OrGAnIsATIOn In AnImALs
EVOLuTIOn