Structural Organisation in Animals — BIOLOGY STD 11 Science — Question

How do fungi form partnership with most plants?

Solenocytes and metanephridia are excretory organs of:

1. Coelenterata and Mollusca.
2. Platyhelminthes and Annelida.
3. Aschelminthes and Annelida.
4. Annelida and Arthropoda.

A common characteristic of all vertebrates is:

1. Presence of skull.
2. Division of body into head, neck, trunk and tail.
3. Presence of two pairs of functional appendages.
4. Body is covered with an exoskeleton.

What happens when a normal cell turns into a malignant cell?

Radial symmetry occurs in:

1. Coelenterata and Platyhelminthes.
2. Arthropoda and Mollusca.
3. Coelenterata and Echinodermata.
4. Porifera and Coelenterata.

List the hormones secreted by the following :
G-I Tract

What does the visceral nervous system consist of?

While examining the mitotic stage in a tissue, one finds some cells with 16 chromosomes and some with 32 chromosomes. What possible reasons could you assign to this difference in chromosome number. Do you think cells with 16 chromosomes could have arisen from cells with 32 chromosomes or vice versa?

What effect does crossing over have on inheritance? Explain briefly.

What is the relation of thyroid gland enlargement to goiter?