Question 2 :
During adolescence, several changes occur in the human body.&#160;Find out the&#160;change which is&#160;associated with sexual maturation in boys.<br/>

Question 3 :
Plants are able to produce fruits with the help of insects as they are

Question 12 :
If an organism is a diploid (or 2n) with 16 chromosomes, then how many chromosomes its sperm cells or egg cells will contain?

Question 13 :
If a starfish is cut into pieces, each piece grow into a complete animal. The process is called as<br/>

Question 15 :
The process of propagation of new individual from the existing one is called as

Question 19 :
At the time of puberty, there is a rapid change in voice in males than females. This is because

Question 20 :
Withdrawal of which of the following hormones&#160;is the immediate cause of menstruation?

Question 21 :
The plant, whose seeds are known to have longest viability&#160;period is<br/>

Question 22 :
The stage when the reproductive organs reach sexual maturity is called as

Question 23 :
The human body undergoes several changes during adolescence. These changes mark the onset of<br/>

Question 27 :
Assertion: The estrogen level falls after menopause. Reason: The estrogen is synthesised and secreted mainly by uterine lining.

Question 28 :
Assertion: Reproduction cannot be considered as defining property of living organisms. Reason: There are many living organisms which do not reproduce, e.g., mules, worker bees, infertile human couples, etc.

Question 31 :
<table class="wysiwyg-table"><tbody><tr><td>Progesterone, ovulation, 28 days,&#160;puberty, menarche,&#160;45-50 years, menopause,&#160;fallopian tube,&#160;13$^{th}$ or 14$^{th}$&#160;days<br/></td></tr></tbody></table>Fill in the blanks using the given words.<br/>Menstrual cycle is a series of cyclic changes that occur in the reproductive system of human females with a periodicity of about ..........(1) ........... <br/>The cycle begins with ..........(2)........... <br/>The first menstruation is called as ..........(3) ........... <br/>It stops between age of .........(4) ............<br/>Stoppage of menstruation permanently is called as ........(5) .............<br/>At about the middle of the menstrual cycle on .........( ) ..........., the growing follicle bursts and mature ovum is released from the ovary under the influence of higher levels of estrogen and LH. <br/>The phenomenon is called as .........(7).............. <br/>The empty follicle grows into corpus luteum that secretes hormone ........... (8) .......... <br/>The released ovum is drawn into ..................(9) ...................... with the help of inward lashing movements of its internal cilia.<br/>It rests for 1-2 days in the ampulla. <br/>The period is called as fertility period.<br/>Pregnancy can occur only during this phase.<br/>

Question 32 :
In a twenty year old unmarried female who has never conceived and whose age of attainment of puberty was at twelve years. Approximately how many ovum would have been formed till date-

Question 37 :
Hot water of Manikaran is used for generating electricity. It is known as&#160;<br/>

Question 38 :
A bird that one may see in the forest, but not in a garden is

Question 40 :
Check dams are build along seasonal flooded gullies for water harvesting.

Question 44 :
An important protective function of forest is reduction of atmospheric pollution.

Question 49 :
The use of disposable paper cups is more beneficial over disposable plastic cups, because&#160;

Question 51 :
Geothermal energy is produced in India from hot springs by a 5 KW geothermal power plant at

Question 52 :
Assertion : 'Chipko Andolan' was done by women of Reni village.<br/><br/>Reason : 'Chipko Andolan' was done to protect wildlife.<br/>

Question 53 :
The branch of science that deals with the development of<br>forest and utilization of forest product is<br><br>

Question 54 :
Which one of the following aquatic weed has been exploited for&#160;biogas production?<br/>

Question 58 :
Planting of mulberry trees in plains would be connected to _________.