Explore topic-wise InterviewSolutions in Current Affairs.

1. Behavioural responses to cope with variations in their environment are shown by few animals.

2. Desert lizards manage to keep their body temperature fairly constant by behavioural adaptations. They bask in the sun and absorb heat, when their body temperature drops below the comfort zone, but move into shade, when the ambient temperature starts increasing. Even snakes also show basking during winter months. 

3. Since they are ectothermic, this kind of behaviour saves them from extreme temperatures. 

4. Many smaller animals show burrowing behaviour to adapt to the temperature extremes. 

5. Some species burrow into the sand to hide and escape from the heat. 

6. Migrations shown by the birds and mammals are also behavioural responses for adapting to severe winter temperatures.

Correct answer is (d) stenohaline

Correct answer is (d) Vegetation on that soil

Few fish species such as salmons, crustacean prawns and crabs are able to survive in fresh water as well as sea water. Among plants, few phytoplankton, some algal species and mangorves show similar phenomena.

In deep ocean trenches, the sunlight does not penetrate. Hence photosynthesis is not possible here. Most of the organisms that live here depend upon subsistence on falling organic matter. This organic matter falls off down from the upper photic zones, where phytoplankton can perform photosynthesis. This organic matter acts as source of energy for the life in deep oceanic trenches.

include 

using namespace std;

int main()

{

int i,j= 4;

cout<<"The prime numbers less than 100 is given below\n2,3,";

while(i<=100)

{

for(i=2;i<=j/2;i++)

if(j%i==0)

  break;

if(i==j/2+10)

cout<<j<<"'";

j++;

}

}

Sodium = \(^{23}_{11}Na\) 

Neutrons = 23 - 11 = 12

There are 8 electrons in the M shell of argon.

When the number of the valence electrons in an element x is 4 or more than 4, then (8-x) matches with the valency of that element. (8-x) electrons are used to complete the octet.

Distribution of electrons in carbon is 2, 4. 

Distribution of electrons in sodium is 2, 8, 1.

• Valency is the number of electrons present in the outer most orbit of an atom. 
• The distribution of electrons in fluorine (atomic number 9) is 2, 7. 
• Hence the valency of fluorine could be 7. 
• But it is easier to fluorine to gain one electron for becoming octet. 
• Hence its valency is determined by subtracting seven electrons from 8 and which gives you a valency ‘1’ for fluorine.

There is one electron in the L shell of lithium.

The symbol of the innermost shell is K and ordinal number of the innermost shell is 1.

Electrons in the K or first shell have minimum energy.

Atomic masses are measured in a unit called dalton.

Maximum number of electrons present in M-shell is 2 × 32 = 2 × 9 = 18.

• The number of electrons present in outer most orbit of an atom is called its valency. 
• Valency of hydrogen is 1.

Water molecular formula = H₂O

 At. wt. of water = (2 × 1) + 16 = 18 

1 mole, water = 18 gr. 

36g. of water = \(\frac{36}{18}\) = 2 moles

Correct Answer is: (a, b, c)

Tension in B = T_B + mg/3.

Tension in A = T_A = T_B + mg = 4mg/3.

∴ T_A = 4T_B.

Stress T/πr² = S. Wire breaks when S = breaking stress. 

For r_A = r_B, S_A = 4S_B. ∴ A breaks before B.

For r_A = 2r_B, S_B = T_B/πr_B².

S_A = T_A/πr_A² = 4T_B/π(2r_B)² = TB/πr_B² = S_B.

As the stresses are equal, either may break.

Correct Answer is: (a) ω²R² / g

The Correct option is  B. Zero 

As the temperature of substance increases, its elasticity decreases.

(b) surviving of a fish in a lake

This device is used to measure the rate of flow (or say flow speed) of the incompressible fluid flowing through a pipe. It works on the principle of Bernoulli’s theorem.

Elasticity : The property of matter by virtue of which a body tends to regain its original shape and size after the removal of deforming force is called elasticity. 

Plasticity : The property of matter by virtue of which it does not regain its original shape and size after the removal of deforming force is called plasticity.

If a body does not regain its original shape and size after removal of the deforming force, it is said to be a plastic body and the property is called plasticity.

Example : Glass.

The force which changes the size or shape of a body is called a deforming force.

As the ivory ball is more elastic than the wet-clay ball, it will tend to retain its shape instantaneously after the collision. Hence, there will be a large energy and momentum transfer compared to the wet clay ball. Thus, the ivory ball will rise higher after the collision.

Correct option is: (B) normal force

(d) Both (b) and (c)

Ex situ conservation (Off-site conservation)

▪ This approach involves placing threatened animals and plants in special care units for their protection. 

▪ India has 35 botanical gardens and 275 zoological parks where animals which have become extinct in wild are maintained.

▪ By using cryopreservation (preservation at –196°C) technique, sperms, eggs, animal cells, tissues and embryos can be stored for long period in genes banks, seed banks, etc. 

▪ Plants are propagated in vitro using tissue culture methods (micropropagation). 

▪ It is the desirable approach when urgent measures to save extinction are required.

a. 

i. a is S = CA² b is log S = log C + Z log A 

ii. Slope is Z (regression coefficient). Its normal value ranges from 0.6 to 1.2.

iii. In frugivorous birds and mammals, value of Z=1.15

b. Reasons for greater diversity of animals are: 

i. Animal are mobile and can avoid predator or unfavourable event. 

ii. Well developed nervous system to receive stimuli against external factors and respond to them.

It is the particular location or position where a gene is located on a chromosome.

Biologists are not sure about the number of prokaryotic species because:

i. The conventional taxonomic methods are not sufficient for identifying these microbial species. 

ii. Many of the species cannot be cultured under laboratory conditions. 

iii. Biochemical and molecular biology techniques would put their diversity into millions.

One map unit is equivalent to 1% recombination.

(i) (a) The natural habitats of wild animals and birds should be preserved by establishing national parks and sanctuaries. 

(b) To conduct a periodic surveys of national parks and bio-reserves. 

(ii) (a) Hunting of tigers should be banned. 

(b) A campaign like paper dipping should be arranged for the awareness of the people. 

(c) The survival of captive-bred animals in the wild life is more.

Haemophilia is a sex-linked recessive disease and the defective gene is present on X chromosome only and not on Y chromosome. Father never passes X chromosome to the son as father only contributes Y chromosome to the son.

Correct option (b)  Form one linkage group

Explanation:

Linkage groups: A linkage group is a group of linked gene (on the same chromosome) and corresponds to the genome of organism, like human has 23 linkage groups, pea and Ngurospora has 7 linkage groups, Drosophila has 4 linkage groups.

There are three levels of biodiversity: 

i. Genetic diversity 

ii. Species diversity 

iii. Ecological diversity

a. Lichens. 

b. Mosses and ferns are few as they need humid conditions in forests that are fast disappearing. 

c. Fungi are able to sustain themselves as a large population because of their wider adaptability to the changing environmental conditions. 

d. Most advanced group is of angiosperms and most primitive group is of fungi.

More biodiversity is found in the tropics. This is because tropical regions remain undisturbed from frequent glaciations as in polar regions. Also, the tropics are less seasonal/more constant.

0.2 is obtained in studies regardless of the taxonomic group or the region 1.2 is obtained if species area relationship is analysed among very large areas like the entire continents.

Ramsar sites are conserved wetlands which are of international importance.

As one moves from the equator to the polar regions, the length of the day decreases and the length of the night increases. The length of day and night are same at the equator.

Therefore, it is true that there is more solar energy available in the tropics.

All the chromosomes that do not determine the sex of an individual are called autosomes.

The genetic constitution of an organism is called genotype.

In nature, a given habitat has enough or limited resources to support a maximum possible number and nature’s carrying capacity indicates that no further growth in population is possible.

There will be 9 pairs of autosomes in the karyotype of this animal.

Henking (1891).