Anatomy of Flowering Plants — BIOLOGY STD 11 Science — Question

What is the difference between florigen and other plant growth hormones?

Give reasons for the following.

1. Plants are the lungs of nature.
2. Chlorophyll-b and other accessory pigments are necessary for photosynthesis.
3. In the high light intensities, the chlorophyll-a gets damaged.

What is called the powerhouse of the cell? Draw its picture and write any three of its functions.

Explain various steps involved in cellular respiration.

What is special about tissue present in the heart?

(i) Renin hormone is secreted by which cells? Write one function of it.
(ii) Make a labelled diagram of the longitudinal section of the kidney.

During the guest lecture organised by the school biology club, the professor explained students how soil acts as medium in providing growth to the plant. And how plants obtain most of their inorganic nutrients from the soil. Ravi was curious to know the mechanism behind. He reached tution in the evening and asked his biology tutor about what basic functions does soil play and how these inorganic nutrients 21 formed in the soil. Tutor explained that inorganic nutrients are formed from the weathering of rocks etc.

1. Why are inorganic nutrients called mineral nutrients?
2. Give any two functions of soil.
3. How the ions of these elements are absorbed by the plants.
4. What values are reflected from Ravi's tutor's character.

S. No.	column I	S. No.	column II
A.	Compound epithelium	1.	Alimentary canal
B.	Compound eye	2.	Cockroach
C.	Septal nephridia	3.	Skin
D.	Open circulatory system	4.	Mosaic vision
E.	Typhlosole	5.	Earthworm
F.	Osteocytes	6.	Phallomere
G.	Genitalia	7.	Bone

Draw labelled diagrams of. Gametophyte and sporophyte of Funaria.

Many discoveries in science have been accidental. This is true for plant hormones also. Can you justify this statement by giving an example? Also what term is used for such accidental findings?