Explore topic-wise InterviewSolutions in Current Affairs.

The answer is (b) Pavlov

The answer is (c) 12 Pairs

Both B-cells and T-cells are formed in bone marrow. B-cells matures in bone marrow while T-cells matures in thymus. B-cells provides humoral immunity and T-cells provides cell mediated immunity (CMI).

The vector of malaria is anopheles mosquito while that of chikungunya Aedes mosquito.

B-lymphocytes, T-lymphocytes are the two special types of lymphocytes.

B- Cells produce pathogen specific antibodies and provide humoral immune response.

T- Cells help the B-cells to produce antibodies to fight with the pathogens and are responsible for cell mediated immunity.

Colostrum,rich in nutrients, rich in antibodies rich in IgA/ provide passive immunity / provides immunity to new' born / helps to develop resistance in new born / readily available for new born/hygienic/develops a bond between mother and child.

Detailed:

Breast - feeding is recommended during the initial period of an infant' growth as:

(a) It provides passive immunity to the baby through colostrum.

(b) It provides a balanced baby from allergens.

(c) Also, it protects baby from allergens.

B-cells and T-cells are formed in bone marrow. B-cells produce antibodies but T-cells do not produce antibodies but help B-cells produce them.

The mother‘s milk consists of antibodies (IgA) such antibodies are not available to bottle fed.

Rheumatoid arthritis, multiple sclerosis. Insulin dependent diabetes.

Cancer detection 

a. Blood and bone marrow tests are done for increased cell counts in case of leukemia. 

b. Histopathological study or biopsy: In biopsy, a piece of the suspected tissue cut into thin sections is stained and examined under microscope by a pathologist. 

c. Radiography: X-rays are used to detect cancer of the internal organs. 

d. Computed tomography: It uses X-rays to generate a three-dimensional image of the internal of an object. 

e. Resonance imaging: Non-ionising radiation and strong magnetic field are used in MRI to accurately detect pathological and physiological changes in the living tissue. 

f. Monoclonal antibodies: Antibodies against cancer-specific antigens are also used for detection of certain cancers

Widal test confirms typhoid.

Infectious diseases spread from an infected person to a healthy person through many ways.While, non-infectious diseases remain confined to the affected person.

T-lymphocytes and B-lymphocytes work for specific immunity. Features of specific immunity are as follows: 

i. Specificity: Specific antibody response to specific antigen. 

ii. Memory: During the first interaction of antigen with B-cells and T-cells, few cells are stored as memory cell which encounter vigorously in second infection. 

iii. Distinction between self and non-self: The immune system can recognise foreign particles and kill them without killing its own or self cells. 

iv. Diversity: The immune system provides various or diverse antibodies to kill or destroy diverse antigens.

B-lymphocytes and T-lymphocytes.

The type of gene, Recessive in the presence of a contrasting allele is not expressed.

The study of heredity and variation in Genetics.

Heredity: The process of transmission of parental characters to the progeny through the generations.

Variation: Occurrence of differences in progeny of same parents and individuals of same species.

(i) Axial round 

(ii) Axial round, axial wrinkled, terminal round, terminal wrinkled. 

(iii) 9:3:3:1 

(iv) Law of independent assortment: When there are two pairs of contrasting characters, the distribution of factors of each pair in the gametes is independent of the distribution of other pair of characters.

Monohybrid cross: It is a cross where two forms of a single trait are crossed or hybridized. Mendel performed this experiment on pea plant. He crossed the true breeding forms of tall and dwarf plants and obtained the hybrid progeny. This is called as first generation (F₁) offspring plant to self-pollinate and produced the second generation (F₂).

50% heterozygous tall pea plants would be obtained in F₂ generation when tall heterozygous pea plants are selfed. 

Alleles are the alternative forms of the same gene. 

For example, tallness and dwarfness are the two alternative forms of a gene for height and are called alleles. Similarly, attached earlobes and free earlobes are alleles for the type of earlobes.

Mendel selected pea plants for his experiment because of the following reasons :

1. A pea plant has many contrasting characters.

2. Self-fertilization takes place in pea plants and so it is possible to get a pure line of traits.

3. Flowers are bisexual and hermaphrodite. Therefore, cross-pollination is achieved easily.

A cross was made between tall and dwarf plants. In F₁ generation all plants were tall, when the F₁ plants were selfed, the tall and dwarf plants appeared in 3: 1 ratio in F₂generation. This phenomenon is known as Segregation.

(C) 4

The four phenotypes: Tall round, Tall wrinkled, Dwarf round, Dwarf wrinkled.

The pattern of arrangement of genes along a chromosome in Linearly.

Crossing-over is the interchange of the parts of the chromatid of a pair of chromosomes. High temperature, X-rays and radiation treatment are the factors affecting crossing-over.

A specific part of chromosome that determine hereditary characteristics is Gene.

Mutation: Any change brought about into the genetic composition through external or internal factors.

Mutation alerts the hereditary material of an organisms cell and result into change in certain characters of traits. For example:

(a) Sickle-cell anemia, is a blood disease caused by gene mutation. The mutation causes change in the DNA which controls productivity of RBCs.

(b) Radioactive radiations also alter th e gene structure and their effects can be seen generation after generation.

The diploid number for cell of man is 46.

Because these are produced by the effects of environment.

The gene that causes haemophilia is recessive and lies in the X-chromosomes.

Because in honey bee the fertilized diploid egg develops into a female but on unfertilized haploid egg develops into male.

(a) When the BOD of sewage or waste is reduced significantly, the effluent is then passed into a settling tank where the bacterial 'flocs' are allowed to sediment. This sediment is called activated sludge. 

(b) A small part of the activated sludge is pumped back into aeration tanks to serve as the inoculum. The remaining major part of the sludge is pumped into large tanks called anaerobic sludge digesters. Other kinds oi bacteria, which grow anaerobically, digest the bacteria and the fungi in the sludge. During this digestion, bacteria produce a mixture of gases such as methane, hydrogen sulphide and carbon dioxide. These gases form biogas and can be used as a source of energy as it is inflammable.

Winds that blow due to the difference in temperature and air pressure of a particular location are called local winds.

The major local winds found in the world are Chinook, Blizzard, Bora, Fohn, Harmattan, Karaburan, Loo, Gibli, Pamparo, Jonda, Brick Fielder, Khamsin, Sirocco, Willy – Willy, etc.

It is a violent dry and cold wind, which blows on the eastern shore of the Adriatic Sea. Especially, the parts of Northern Italy are influenced by these winds.

The warm and dry winds blowing in the eastern part of the Sahara Desert in Africa, from the north – east and east towards the west, are called Harmattan.

(a) Image will form between pole and focus. 

(b) At focus.

Correct option is A) Concave mirror
 

Correct option is  C) 2.27 cm

The least distance of the distinct vision for a normal human eye is about 25 cm. 

The greatest degree of refraction of light occur in the eye At cornea

(C) Look towards the raindrops with the light source behind him 

Solution : Away from the normal

A) frequency

A) only the lens

Violet light is refracted the most because violet colour has the minimum speed in glass prism.