Germ Layers

Q. What conclusion can be drawn from experiment I?

1. Sea urchins would be better adapted if they had smaller eggs.
2. Embryo cells are committed to different developmental fates on the basis of selection.
3. Different cells of an embryo can have equal potential for development.
4. A particular cell of an embryo always develops into the same structure.
5. Cell divison ensures that both cells will develop identically.

Q. Spicules are found in

1. Hydra
2. Sycon
3. Planaria
4. Obelia

Q.

The animals possessing the following types of germ layers (a and b) are _____________and _____________ respectively.

1. a - diploblastic, b - triploblastic

2. a - triploblastic, b - diploblastic

3. a - monoblastic, b - diploblastic

4. a - semi-triploblastic, b - triploblastic

Q.

Water diffusion into endodermis takes place through

1. Lignified cells

2. Casparian strips

3. Passage cells

4. Suberized cells

Q. Label the germ layers of a triploblastic organism.

1. Endoderm
2. Ectoderm
3. Mesoderm

Q.

is isthumus the connective tissue that connects the two lobes of thyroid glands

Q.

Mention the fern characters found in Cycas.

Q. Which among the following exhibit homospory?

1. Selaginella
2. Salvinia
3. Cycas
4. Lycopodium

Q.

The words diploblastic and triploblastic refer to _____ and _____ germinal layers respectively.

1. 1 & 2

2. 2 & 3

3. 3 & 2

4. 2 & 1