Q22 of 26 Page 1

The graph given below shows the distribution of biomes:


(a) What do the ‘X’ and ‘Y’ axes represent?


(b) Identify the ‘grassland’ and ‘coniferous forest’ biomes, from the above figure.


(c) Why is ‘F’ located at the given position in the graph?

(a) The X axis refers to mean annual temperature in degree Celsius. The Y axis refers to mean annual precipitation in centimetres.

(b) B refers to the grassland and E refers to the coniferous forest.


(c) F refers to Arctic and alpine tundra biome where the annual temperature is very low. That is why F is located at that given position in the graph.


More from this chapter

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20

Given below is the diagram of agarose gel kept under UV light:


(a) Mark the positive and negative terminals.


(b) What is the charge carried by DNA molecule and how does it help in its separation?


(c) How are the separated DNA fragments finally isolated?


OR


CryIAb is introduced in a plant to prevent infestation by corn borer.


(a) What is the resultant plant referred to as?


(b) Summarize the action of the gene introduced.

 21

(a) In pBR322, foreign DNA has to be introduced in tetR region. From the restriction enzymes given below, which one should be used and why:

PvuI, EcoRI, BamHI


(b) Give reasons, why the other two enzymes cannot be used.

 23

A son persuades his father to replace his old mobile phone with the latest model launched in the market. He also shares the latest features it has and explains how it can be of a help to him in the modern technological world. Father is reluctant in buying a new one and tries to explain about its environmental impact. How do you think, the biologist father has tried to convince his son? Justify the arguments of father and son both, by mentioning positive aspects of the behavior displayed by both of them in the situation concerned (three each).

 24

Given below is the diagram of a human ovum surrounded by a few sperms. Observe the diagram and answer the following questions:


(a) Compare the fate of sperms shown in the diagram.


(b) What is the role of zona pellucida in this process?


(c) Analyze the changes occurring in the ovum during the process.


(d) How is the entry of sperm into the ovum facilitated?


(e) Specify the region of female reproductive system where the event represented in the diagram takes place.


OR


The graph given below shows the variation in the levels of ovarian hormones during various phases of the menstrual cycle:



(a) Identify ‘A’ and ‘B’.


(b) Specify the source of the hormone marked in the diagram.


(c) Reason out why A peaks before B.


(d) Compare the role of A and B.


(e) Under which condition will the level of B continue to remain high on the 28thday?