(a) Linnaeus classified organisms into 2 groups :
plants and animals.
(c) In Hydra, some invaginations are present in the
epithelia-muscular cells of tentacles.
Nematoblasts are found in groups in these
invaginations. These groups are called as battery
or cnidom. 10 – 12 nematoblasts are present in one
battery.
(c) Palaeognathae comprises a number of well-
known flightless birds: the Ostrich, Rhea, Emu,
Cassowaries, Kiwis and Tinamous.
(a) Slime moulds aggregate into plasmodium in
favourable condition but in unfavourable condition,
plasmodium get differentiated into fruiting bodies
which bears spores.
(d) Anabaena is a prokaryotic organism. It is also
called as Blue-green algae or Cyanobacteria which
are included in the Kingdom Monera. As they are
prokaryotic they lack true nucleus.
(a) Prokaryotic cell lacks a true nucleus and
membrane bound organelles, there is an
undifferentiated, unorganised fibrillar nucleus
without any nuclear membrane in a prokaryotic
cell. The genetic material of prokaryotic cell is
dispersed in cytoplasm and is known as nucleoid.
(c)
(b) Torpedo is a marine fish having cartilaginous
body and they can produce electric currents when
threatened by an enemy.
(b) Herdmania has myogenic valveless heart. It
has a double circulation. The blood of Herdmania
is green due to the presence of vanadium in blood.
(b) Nephridia in earthworm, Malpighian tubule in
cockroach and urinary tubules in rat have similar
functions. They are homologous organs, they have
similar function (excretion of nitrogenous wastes).
But differ in their origin.
(d)
(d) All the six matches properly.
(b)
(c)
16. (c) Somatic hybridisation in higher plant is a
valuable tool for conventional plant breeding to
improve cultivated crops. It is fusion between
somatic protoplasts under invitro conditions and
subsequent development of their product to a
hybrid plant is known as somatic hybridisation. The
sources of Protoplasts are Leaves, Cell suspension
culture, Callus culture and pre- conditioned plant
materials.
17. (a) In Convergent evolution, structures are not
similar but perform similar functions resulting in
analogous organs. In divergent evolution, origin
of structures is same but it performs different
functions which results in homologous organs.
18. (c) Retinal is a derivative of Vitamin A which is an
aldehyde, whereas, ascorbic acid is Vitamin C.
19. (c) 20. (a)
21. (d)
22. (c) Chitin is a polysaccharide that has nitrogen and
is a derivative of glucose.
23. (a) Gonadocorticoids or sexocorticoids are the
hormones secreted by both zona reticularis and
zona fasciculata of adrenal cortex.
24. (a)
25. (d) Bordeaux mixture is used to control fungal
diseases and no vector is reported for bacterial
blight disease, the use of disease-free seeds and
disease resistant varieties can control disease.
26. (a) At high altitude, the atmospheric O 2 level is
less and hence, more RBCs are needed to absorb
the required amount of O 2 to survive. That is why,
the people living at sea level have around 5 million
RBC/mm3 of their blood whereas, those living at
an altitude of 5400 meter have around 8 million
RBC/mm3 of their blood.
27. (b) A nephron is a long tubule differentiated into
four regions having different anatomical features
and physiological role: Bowman’s capsule,
proximal convoluted tubule (PCT), loop of Henle,
and distal convoluted tubule (DCT). The latter
opens into one of the collecting ducts.
28. (a) Gonorrhea infected mothers may transmit the
infection to their new born babies which may harm
their eyes.
29. (a) Hepatitis C virus may respond to interferon
therapy.
