Body Fluids and Circulation — BIOLOGY STD 11 Science — Question

Bring out the major differences between thallophytes (algae) and bryophytes.

Describe how Englemann arrived at the first action spectrum of photosynthesis.

How does a gap junction facilitate intercellular communication?

How does a muscle return to its original form during relaxation? Also draw a diagram showing relaxation of muscle. What causes muscle fatigue?

Name the pathological condition when uncontrolled cell division occurs.

Why does our mouth become watery sometimes when we eat or think about the food we like?

Which of the following pairs are correctly matched?

S.no.	Animals		Morphological features
(i)	Crocodile	-	4-chambered heart
(ii)	Sea urchin	-	Parapodia
(iii)	Obelia	-	Metagenesis
(iv)	Lemur	-	Thecodont

1. (i), (iii) and (iv).
2. (ii), (iii) and (iv).
3. Only (i) and (iv).
4. Only (i) and (ii).

A farmer adds/ supplies Na, Ca, Mg and Fe regularly to his field and yet he observes that the plants show deficiency of Ca, Mg and Fe. Give a valid reason and suggest a way to help the farmer improve the growth of plants.

Enumerate the process of guttation. How is it affected by root pressure?

How does Cycas resemble bryophytes and pteridophytes?