Point source that brings pollutants through regular channels, and diffusion source that absorbs pollutants scattered on surface of soil.

1.Severe combined immunodeficiency(SCID), It is caused due to absence of T-cells and B-cells in new born children.
2.Acquired immuno-deficiency syndrome (AIDS).It is due to reduction in number of helper T-cells that activate other lymphocytes.

The adaptations are as follows:
1. Mammals of colder regions have shorter ears and limbs (called as Allen's rule).
2. Aquatic mammals of colder seas have a thick layer of fat, called blubber, below the skin, which acts as an insulator and reduces the loss of body heat. 

Pasturage/crop/flora value and quality of honey depends upon the flora or pasturage available for the nectar and pollen collection by honey bees. Availability of flora or pasturage should be in the visiting of apiary to facilitate nectar collection. Pollens serve as protein food for bees. Pasturage may be different as per geographical regions/locations i.e. mountains or plains and region to region. Therefore flora is responsible for quality and taste of honey. For example, Almond honey of Kashmir honey tastes good as nectar is collected from almond. Pasturage Flora of Honey Bee include Mango (Aam), Coconut (narial), Almond (badam), Tamarind (imli), ber, berseem, litchi, cotton, shisham, apple, mahua, coriander, cashew, coffee, rubber plant, guava, sunflower, etc.

Structure of Pollen grains
1. Pollen grains are normally spherical in outline.
2. Each pollen grain has a prominent two-layered wall.
3. The outer layer is called exine and the inner layer is called intine.
4. Exine is hard and made of sporopollenin; it shows a variety of architecture, characteristic of each species.
5. Intine is thin and it is made of cellulose and pectin.
6. At certain places exine is either absent or very thin and such places are called germ pores. In monocots there are germinal furrows.
7. A mature pollen grain has two cells-a vegetative cell and a generative cell.
8. The vegetative cell is larger, has abundant reserve food and a large irregular-shaped nucleus.
9. The generative cell is small, spindle-shaped and floats in the cytoplasm of the vegetative cell.

Brewing is a complex fermentation process, which involves the production of malt beverages such as beer, ale, porter and stout with the help of strains of saccharo-myces cerevisiae.

It leads to formation of fruit where ovules have been converted into seeds and ovary wall has formed fruit wall (pericarp). It is followed by dehiscence of fruits and seeds. Next step is dispersal of fruits and then germination of seeds occurs to form seedlings.

Foetal ejection reflex is neuroendocrine mechanism initiated by fully formed foetus and placenta which helps in parturition. It operates as below:
1.Foetus secretes hormone from its adrenal glands. These hormone stimulate the posterior pituitary of the mother to release oxytocin.
2.Oxytocin causes forceful contraction of smooth muscles of myometrium called labour pains, which further stimulates more secretion of oxytocin.
3.The stimulatory reflex between uterine contraction and oxytocin secretion continues which causes more forceful contraction of uterine muscles.
4.Uterine contractions pushes the young gradually out through the dilated cervix(caused by relaxin) and vagina.

1. UV-B has a wavelength of 280-315 nm.
2. It causes the most damage to plants and animals
3. Chlorofluorocarbons and nitrous oxide are responsible for ozone depletion; there is an increase in UV-B radiation reaching the earth.
UV-B radiation causes
1. Skin cancer (melanoma)
2. Cataract and snow-blindness
3. Weakening of immune system
4. Damage to DNA and mutation

(a) The recombinant/transformant can be selected out from the non-recombinants/non-transformants by plating the transformants on ampicillin containing medium.
1. The transformants will grow in it, while the non-transformants will not grow.
(b) It acts as a selectable marker.

1. The microbes are also heterotrophs.
2. Those microbes which meet their energy requirement by degrading the dead and decaying organic matter,are called decomposers.
3. Those microbes which depend on living organisms for their food as well as shelter, are called parasites.

Earth's atmosphere:
Water vapour, methane, carbon dioxide and ammonia were released from the molten mass covered the surface.
The UV rays from the sun broke up water into hydrogen and oxygen.
The lighter hydrogen escaped into the atmosphere.
Oxygen combined with ammonia and methane to form carbon dioxide and other gases.
Later ozone was formed from the oxygen.

Cut is an intra-uterine device (IUD) and functions as follows:
1. It suppresses sperm motility and the fertilising capacity of sperms.
2. It increases phagocytosis of sperms within the uterus.

(i) The population density is the number of individuals of a population found per unit area at a given times. Whatever ecological process we wish to investigate in a population (competition/pesticide applicable) we always evaluate in terms of any change in population size (numbers/biomas)
(ii) Number of organism
Biomas of organism
Example: Less than 10 Siberian cranes at Bharatpur wetlands
In an area there may be a single banyan tree or 200 Parthenium plants

(i) To understand the problem faced by the family and the nation due to increasing population and the benefits of having a small family.
(ii) Role of Government in controlling population explosion are:
(a) Creating public awareness through mass media.
(b) Education at all Levels.
(c) Family planning.
(d) Increasing marriageable age (18 for girls and 21 for boys)
(iii) In India, these programmes called 'family planning' were initiated in 1951.
(iv) Rohit and his friends showed understanding about the problem of population explosion, teamwork, and motivational capacity.

(i) It is known as ecological succession.
(ii) This is the terminal stage of the process of ecological succession. The final community becomes more or less stabilized for a long period of time and can maintain itself in a perfect equilibrium with climatic and edaphic conditions.

(i) DNA test refers to profiling of DNA of an individual
(ii) It is done by comparing the base pair sequences of DNA of the child with those of the parents

Ozone layer as protective layer:
The ozone layer in the stratosphere is very useful to human beings because it absorbs the major part of harmful ultraviolet radiation coming from the sun. Therefore, it is called protective layer. However, it has been observed that the ozone layer is getting depleted. One of the reasons for depletion of ozone layer is action of aerosols spray propellants. These are the chemicals such as fluorocarbons and chloro-fluorocarbons. These compounds react with ozone gas in the atmosphere thereby depleting it. Scientists all over the world are worried at the destruction of ozone layer. If the ozone layer in the atmosphere is significantly decreased, these harmful radiations would reach the earth and would cause many damages such as skin cancer, genetic disorders in man and other living forms. Efforts are being made to find substitutes of these chemicals which do not react with ozone.

The results can be easily analysed. If you follow the monohybrid cross where the F1 is test crossed, a ratio of 1:1 will be obtained. On the same basis.iyou can work out that in a dihybrid case, the test cross ratio will be 1:1:1:1. Test cross can also be used for another purpose. The homo and heterozygous genotypes for dominant trait cannot be differentiated because they show the same phenotype. If put them through a test cross, it is observed that all homozygous dominant combinations will breed true but heter Z gous gen~types will follow the segregation.

1. Aeration to prevent alcohol formation.
2. Optimum pH = 5.
3. Ammonium phosphate that stimulates then growth of yeast.

Cancer-Diagnosis:
Cancer can be diagnosed/detected by:
(i) Biopsy and histopathological studies of the tissue.
(ii) Blood and bone marrow tests for increased cell counts as in leukaemia.
(iii) Use of techniques like radiography,Magnetic Resonance Imagine (MRI) and computed tomography (CT) for cancer of internal organs.
(iv) Use of antibodies against cancer specific antigens.
(v) Applying principles of molecular biology to detect genes in individuals with inherited susceptibility to certain types of cancer.

Successful bee keeping
It requires the following considerations:
(i) Knowledge of the nature and habits of bees.
(ii) Selection of suitable location of keeping beehives.
(iii) Catching and hiving of swarms.
(iv) Management of beehives at different seasons.
(v) Handling and collection of honey and beewax.

(a) Frogs and Bony fish.
 More gametes are produced by these organisms in order to enhance the chances of syngamy.
(b) A bird (parrot, crow, etc.), monkey and human beings.
1. The female gametes are retained inside the body of the female animals; they are produced in less numbers-one or a few.
2. The male gametes are motile; they are produced in sufficiently large numbers.

Broadly utilitarian arguments: Biodiversity plays an important role in maintaining sustaining supply of good & ecological services.
The different ecosystem services provided are: purify air, cycling of nutrients, habitat for wildlife, pollinating crops, aesthetic pleasure.
Ethical reasons: 
It is our philosophical/spiritual & moral duty to ensure well being of all living brings for utilization of future generations.

Two chains of DNA sequence corresponding to A and B chains of human insulin prepared, introduced them into plasmids of E. coli to produce separate A and B chains, A and B chains extracted combined by creating disulphide bonds.

Functions:
Acrosome : filled with enzymes that help enter the ovum.
Mitochondia (middle piece) : energy source for movement of tail to reach ovum.
Tail : For motility

Co-extinction is most severe in mutualism and parasitism.

(i) The septal nuclei or septum present in the amygdala is associated with sexual emotions.
(ii) Yes, it is necessary to guide and instruct the nature of HIV/AID, methods of its transmission, strategies to reduce the risk of human immunodeficiency virus infection and society related issues to the students in school.
(iii) Amygdala and hippocampus together from a region which was formerly called rhinencephalon but is also called emotional brain due to its association with emotional functioning.

Three uses of PCR are:
(i) It is used to during rDNA for production of newer and desired DNA
(ii) It is used for DNA sequencing.
(iii) It is used in DNA figerprinting.

1.(i); 2. (d), (h), 3. (g); 4. (a); 5. (c); 6.(f) ; 7.(b), (e)

Griffith's experiment to demonstrate
DNA as genetic material.
Transformation experiments were initially conducted by F. Griffith in 1928.
1. He injected a mixture of two strains of Pneumococcus (Diplococcus pneumoniae) into mice. One ofthese two strains S III as virulent and the other strain RII was non-virulent, i.e., causes no infection.
2. The S III type bacteria when injected into mice cause pneumonia and ultimately to death. The R II type bacteria when injected, no pneumonia occurred.
3.The S III bacteria, prior to injection are killed by heating. It is then injected into the mice. It did not cause the disease.
4. Heat killed S III and R II (non-virulent) bacteria, when injected into mice, caused pneumonia. Finally death occurred.

5. This proved that DNA of S III type bacteria has transformed the DNA of R II type bacteria into virulent type S III. This phenomenon of transferring characters of one strain to another by using a DNA extract of former is called transformation.
Conclusion. Griffith concluded that virulence was transferred fromS-Typedead cells to R-Type living cells in the form of capsule (some component of cell) rather than the whole cells.
Contribution of Avery, MacCleod and McCarty
6. Avery, MacCleod and McCarty gave the proof that transforming agent is DNA. They carried out the experiments with Diplococcus and showed transformation of type R-U to type S-III. They gave proof that active component was DNA and not the RNA or Proteins or Polysaccharides.

(a) Disadvantages of inbreeding among cattle.
1. It reduces fertility.
2. It also reduces productivity (Less milk per lactation).
It is termed inbreeding depression.
(b) It can be overcome by breeding selected animals with unrelated superior animals.

(i) 'a' represents exponential growth curve. 'K' represents carrying capacity, i.e. the maximum number of individuals of a population that the given environment can sustain.
(ii) Curve 'b' is considered more realistic.
(iii) Curve 'a'. In the absence of predators and unlimited resources, the populations grow exponentially.

(i) Acetic acid - Acetobacter aceti
(ii) Butyric acid - Clostridium butylicum
(iii) Lacteric acid - Lactobacillus delbruekii

1. After entering the body of a person,the virus enters the macrophages.
2. The viral genome (RNA) undergoes replication and reverse transcription  to become viral DNA with the help of reverse transcriptase.
3. The viral DNA gets incorporated into the DNA of the cells and directs these cells to produce virus particles.
4. The macrophages function as HIV factory and produce a number of HIV particles.
5. These HIV particles move out of macrophages and infect the helper T-lymphocytes and replicant to produce progeny viruses.
6. The progeny viruses released in the blood attack new helper T- cells.
7. This process is repeated and there is a progressive decrease in the number of helper T-cells. 

(i) Silurian                 - Zosterophyllum, Psilophyton
(ii) Devonian             - Progymnosperm
(iii) Carboniferous     - Seed fern
(iv) Permian              - Arborescent   Lycopods