Structure of Microsporangium

Q. Microsporangia or ______i________ in anther contains microspores that develop into ______ii_______.

1. i-pollen grains, ii-pollen sacs
2. i-pollen sacs, ii-male gametophytes
3. i-embryo sac, ii-pollen grains
4. i-male gametophytes, ii-embryo sacs

Q. The chromosome number in a root cell of a plant X is 30. What would be the chromosome number in the cell of (i) endothecium, (ii) primary sporogenous cells of microsporangium, (iii) microspore?

1. i-30, ii-30, iii-30
2. i-30, ii-30, iii-15
3. i-30, ii-15, iii-15
4. i-15, ii-15, iii-15

Q. Assertion: Tapetal cells usually possess dense cytoplasm and never more than one nucleus.
Reason: Tapetal cells undergo mitosis which generally involves division of nucleus but cytokinesis does not happen.

1. Only assertion is correct
2. Both assertion and reason are correct and the reason is the correct explanation to the assertion
3. Only reason is correct
4. Both assertion and reason are correct but the reason is an incorrect explanation to the assertion

Q.

What is heterospory? Briefly comment on its significance. Give two examples.

Q. Match the column 1 with column 2 and choose the correct option.
$\begin{array}{cc}\text{Column 1}& \text{Column 2}\\ \text{p. Endothecium}& \text{1. Nourishes the developing pollen}\\ \text{q. Tapetum}& \text{2. Cannot be degraded by any enzyme}\\ \text{r. Pollen mother cell (PMC)}& \text{3. Protection of microsporangium}\\ \text{s. Sporopollenin}& \text{4. Forms microspores}\end{array}$

1. p-2, q-4, r-1, s-3
2. p-3, q- 1, r-4, s-2
3. p-4, q-3, r- 2, s-1
4. p-3, q- 2, r-1, s-4

Q. Spicules are formed by

1. Calcoblasts
2. Scleroblasts
3. Spongioblasts
4. Silicoblasts

Q. Why is the female gametophyte of selaginella considered as precursor of seed habit

Q. Larval form found in sponge is

1. Glochidium
2. Parenchymula
3. Planula
4. Cysticercus

Q. Select the option depicting the correct order of development in an anther.

1. Sporogenous tissue $\to$ pollen mother cell $\to$ microspore $\to$ pollen grain
2. Pollen grain$\to$ sporogenous tissue $\to$ microspore $\to$ pollen mother cell
3. Sporogenous tissue $\to$ male gametes $\to$ pollen mother cell $\to$ pollen grain
4. Sporogenous tissue $\to$ microspore $\to$ male gametes $\to$ pollen grain

Q. Spicule producing cells of sponges are

1. Spongioblasts
2. Calcoblasts
3. Silicoblasts
4. Both B and C

Q.

The correct sequence of cell layers in an anther is

1. Epidermis - Middle layers - Endothecium - Tapetum - Sporogenous tissues.

2. Epidermis - Tapetum - Middle layers - Endothecium - Sporogenous tissues.

3. Epidermis - Endothecium - Middle layers - Tapetum - Sporogenous tissue.

4. Epidermis - Middle layers - Tapetum - Sporogenous tissue

Q. Larva of Leucosolenia is

1. Auricularia
2. Parenchymula
3. Veliger
4. Trochophore

Q. The secondary wood of Pinus is characterised by

1. Presence of resin cells
2. Presence of resin ducts
3. Absence of resin ducts
4. Presence of vessels

Q. Scleroblasts of sponges occur in

1. Mesodermis
2. Mesophyl layer
3. Epidermis
4. Endodermis

Q. Parenchymula is the larva of

1. Hydra
2. Ascaris
3. Leucosolenia
4. Pheretima