rapid growth of the stem to form a cavity called protoxylem
cavity or lacuna.- (a) The balloon like structures ‘X’ represent tyloses in dicot
stem.
(b) Tyloses are found in the heartwood or duramen of older
stems.
(c) They are formed when tracheids and vessels of the
heartwood get plugged by the ingrowth of the adjacent
xylem parenchyma into the lumen of xylem vessels
through the pits.
CHAPTER-7 : STRUCTURAL ORGANISATION IN ANIMALS
- (a) 2. (c) 3. (d) 4. (d) 5. (d)
- (d) 7. (d) 8. (d) 9. (c) 10. (d)
- A-(iii), B-(iv), C-(ii), D-(i)
- A-(i, iv), B-(v, viii), C-(ii, vii), D-(iii, vi)
- (i) muscle fibre (ii) mesodermal
(iii) myocytes (iv) sarcocytes
(v) myoblasts (vi) sarcoplasm
(vii) sarcolemma (viii) fasciculi
(ix) perimysium (x) endomysium
(xi) epimysium - (c) 15. (a) 16. (a) 17. (b) 18. (d)
- (a) A is monocyte. It is phagocytic in nature and engulf
germs and cellular debris.
B is eosinophil that is non-phagocytic but its number
increases during allergy and plays important role in immune
response.
C is neutrophil which phagocytose germs and dead cells.
D are platelets that help in blood clotting by releasing
certain clotting factors.
(b) Monocytes - 2-10%
Eosinophils - 1-6%
Neutrophils - 40-70%
Platelets - 2,50,000 per mm^3 of blood- (a) The given figure shows the structure that constitutes
the respiratory system of cockroach. Here, L is spiracle, M is
tracheal epithelium, N is atrial muscles, O is tracheae and
P are tracheoles.
(b) These structures play an important role during breathing
or respiration of the insect.
(c) Labelled part ‘P’ is tracheoles that terminate blindly in
the tissues and contain a tissue fluid at the distal end
which plays a significant role during the diffusion of the
gases. When the air enters the spiracles, tracheae and
tracheoles, oxygen from the air is dissolved into the tissue
fluid present in the tracheoles from which it is diffused
into the body cells.
Unscramble the words given in column I and match them with their explanations in column II.Column I Column II- IEPCLOEN (a) The study of reptiles and amphibians.
- ARPMALYNO (b) A covering of dead spongy tissue over aerial roots.
- RAARCNGIENE (c) A false septum that develops between the two parietal placentae in the
members of Brassicaceae. - REPELOGOYHT (d) A gelatin like substance that can be obtained by boiling cartilage in water.
- LAEVNME (e) Fixed macrophages in bone.
- PEULMR (f) Phycocolloid used as a clearing agent in liquors.
- NOHDCNIR (g) Specialised complex carbohydrate as reserve food in Euglenoids.
- SAEOSLTOSTC (h) Epoch known for the divergent evolution of modern mammals.
- ONALNLI (i) The individuals that have exact copies of genetic characteristics of their parent.
- ESARTM ( j) A wax that forms a protective water insoluble coating on animal fur.
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