Secondary treatment removes the dissolved organic matter by the use of biological agents and hence, known as biological treatment. This is achieved by microbes which can consume and degrade the organic matter converting it to carbon dioxide, water, and energy for their own growth and reproduction. There are certain chemicals can be used which can help in concentration and sedimentation. This helps to reduce the amount of BOD of the sewage water.

(i) The two methodologies involved in human genome project are: 
i. Expressed Sequence Tags: Identifying all the genes that are expressed as RNA 
ii. Sequence Annotation: Sequencing the whole set of genome coding or non coding sequences and later assigning different region with functions.
(ii) YAC stands for Yeast Artificial Chromosome. These were used as vectors in which fragments of whole DNA of human were inserted and cloned.

EcoRlfirst inspects the length of a DNA sequence, then it binds with specific recognition sequence of DNA, EcoRl cut each of the two strands of double
helix at specific points in their sugar-phosphate backbones//diagram with same value points to be accepted.

(i)The mitochondrion present in a cell are collectively referred to as chondriosome
(ii)Mitochondria are associated with cellular respiration (ie.oxidation of cellular nutrients) and energey generation of cell.Thus,it is also referred to as power house the cell.
(iii)Out of the total enzyme present in a cell,mitochondria alone contribute to 70%.The enzymes of Krebs, cycle are present in matrix of mitochondrial membrance) while that of Electron Transport System(ETS) and oxidative phosphorylation are situate in cristae

(a) Protocooperation
(b) Mutualism
(c) Mutualism
(d) Parasitism

Saheli is an oral pill.
1. It inhibits ovulation and implantation.
2. It alters the quality of cervical mucus and retards the entry of sperms into cervix.

hnRNA is required to undergo splicing because of the presence of introns (the non-coding sequences) in it. These need to be removed and the exons (the coding sequences) have to be joined in a specific sequence for translation to take place.

Prevention and control measures of use alcohol/drugs
1.Avoid under peer pressure.
2.Educating and counselling to face problems and stresses and to accept failures and disappointments as partof life..
3.Seeking help from parents and peer s, could help to vent their feelings of anxiety and guilt.
4.Looking for danger signals would kelp in initiating proper remedial steps or treatment.
5.Seeking professional and medical help for deaddiction and rehabilitation would help individuals to come out of the problem co0mpletely. 

The flowers of Salvia, Nasturtium and Sunflower are pollinated by insects. The insect pollinated flowers are usually large, conspicuous, bilabiate in Salvia,  brightly coloured and showy. They produce specific odours to attract specific insects.

This is because plasmid is a circular DNA molecule. When cut with enzyme, it becomes linear, but does not get fragmented.
Whereas, a linear DNA molecule gets cut into two fragments. Hence, a single DNA band is observed for plasmid while, two DNA bands are observed for linear DNA in agarose gel.

(i) The DNA containing insulin gene is isolated from human cell. Two DNA sequences corresponding to A and B chains of human insulin are prepared and introduced into the plasmid vector of E. coli to produce insulin chains A and B. Separate chains are extracted and combined by creating disulphide bonds to form genetically engineered human insulin which is also called as humilin.
(ii) The insulin produced through recombinant DNA technology is better than one used earlier by diabetic patients because it does not produce sensitive allergic reactions and other immunological complications, whereas the earlier insulin extracted from the pancreas of slaughtered cattle and pig cause allergy or other types of reactions, because they are foreign proteins.
(iii) Sohan exhibited the sense of responsibility and care towards his parents. He is aware of various biotechnical applications. He makes use of this knowledge to convince his mother

(a) (i) Normal cells whow a property celled contact inhibition by virtue of which contact with other cells inhibits their uncontrolled growth.Cancer cells appear to have lost this property and as result continue to divide to give masses of cells called tumours.
(ii) Metastasis: Cancerous cells sloughed off from tumours reach distant sites through blood or other body fluids and start a tumour there.This property is called metastasis.It is the most fearsome property of malignant tumours.
(b) (i) Viral oncogenes 
(ii) Cellular oncogenes (C-onc) or proto-oncogenes when activated under certain conditions, whether could head to oncogenic transfermation of the cells.
(c) Technique like radiography (use of X-rays),CT (Compiled Tomography) and MRI (magnetic Resonance Imaging are useful to detect cancer of internal organs.
(d) \(\alpha \)-interferons are biological response modifiers are given to cancer patients.These substances activate immune system and help in destroy the tumour.

(I) When resources are limiting, the population growth curve is sigmoid and it is represented by the equation:
\(dN/dt=rN\left( \frac { K-N }{ K } \right) \), where
N = population density at time t
r = intrinsic rate of natural increase
K = carrying capacity
When resources are not limiting, the growth curve is J shaped and is represented by the equation: dN/dt = rN 
\(N_{ t }={ N }_{ 0 }^{ e^{ rt } },where\)
\(N_{ t }\) =population density after time t
\(N_{ 0 }\)= population density at time zero
r = intrinsic rate of natural increase
e = the base .of  natural logarithm (2.71828)

(a) Colony 4 got transformed as it failed to grow on agar containing ampicillin and tetracycline. Since, it is transformed, its gene for tetracycline and ampicillin resistance became inactive, thus it lost its ability to grow in both of them (ampicillin and tetracycline).
(b) Selectable markers are sites where ampicillin and tetracycline resistance genes are inserted. They are very important in genetic engineering as they help in the selection of the transformants from those of the non- transformants.
(c) EcoRI, Hind III
Or
(c) \(\beta\)- galactosidase acts as a reporter enzyme. It is produced by lac z, a reporter gene. In insertional inactivation, when there is inactivation of lac z gene due to insert , no B- galactosidase is formed and thus no blue colour in formed. Thus, giving a white coloured colonies of transformants.

(a) A - Chasmogamous flower
B - Cleistogamous flower
(b) A - Autogamy, geitonogamy and xenogamy
B - Autogamy only.

(b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.


 

(b) If both A and R are true, but R is not the correct explanation of A

(b) : Milk secretion is maintained as long as breast feeding, and hence hormone production continues. A woman does not conceive during the lactation period because lactation stimulates prolactin secretion and there is evidence that prolactin inhibits GnRH secretion, and antagonises the action of gonadotrophins on the ovaries. Ovulation is inhibited, and the ovaries are inactive, so estrogen and progesterone output falls to low levels. Thus during lactation a woman does not conceive. Only 5-10% chances are there during lactation period. This can also be interpreted as mechanism devised by nature so that mother can look after the new born child by providing it with milk.