Bird flu refers to the illness caused by any of the strains of influenza virus. It has been around for thousands of years that several varieties of the existing virus mutate sufficiently to affect humans.
Fear is intended to be the warning system to protect us against imminent danger and thus, it is justified. However, it can be prevented by practicing good hygiene and by taking some precautions in eating habits of poultry food.

Clouds, dust particles and water vapours can produce green house effect. This is the reason why cloudy, dusty and humid nights are warmer than the clear, dust-free and dry nights.

(i) Parallel evolution.
(ii) Convergent evolution.
(ii) Divergent evolution.

(a) (i) LH increases and FSH decreases.
(ii) LH peaks and FSH peaks.
(iii) LH level decreases and FSH level maintained.
(b) Source of FSH and LH are anterior pituitary.

Yes. Ostrich and rhea, two flightless birds placed in separate orders, are parasitised by an identical species of tapeworm and two identical species of feather mites. These parasites do not occur in any other bird. This similarity of parasites shows that the ostrich and rhea birds have evolved from a common ancestor.

In ecological succession, the climax community remains stable as long as the environment remains unchanged.

(a) The cross was made by Carl Correns in Mirabilis Japala 9Four O'clock,vern. Gulbansi).
(b) The cross shows incomplete dominance.

A polynucleotide chain comprises of a long chain of nucleotides joined by 3'-5' phosphodiester linkages.Such a polymer has at one a free phosphate moiety at 5'-end of ribose sugar.This end of polymer is referred to as 5'-end.Similarly, at the other end of the polymer, the pentose sugar has a free 3'-OH group.This end of polymer is referred to as 3'-end.

(a)Correct
(b)The genetic code is non-ambiguous
(c)The genetic code is degenerate
(d)Transfer RNA(tRNA) carry amino acids to mRNA codons and used again and again in translation
(e)Correct
(f)Correct

The main reasons for low milk production in India are insufficient number of improved breeds and the improper feeding of the cattle. Improved breeds should be increased in number by proper management which include fascilities, processes, materials and labour. Cattle should be fed with proper and balanced feed consisting of appropriate quantities of proteins, carbohydrates, fats, vitamins and water.

  'A' = Saccharomyces cerevisiae ; 'B' = Acetic acid

(i) It will produce two sticky ends.
(ii) Human DNA pieces will also form sticky ends.
(iii) Some molecules will form with pieces of human DNA inserted into the plasmid vector at the Eco RI site.

a = 5'- G-G-A-T-C-C-3',    
b = Escherichia coli RY 13,    
c = Hin d II
3'-C-C-T-A-G-G-5'

(a) This technique is called test tube baby.
(b) Zygote or early embryo (upto 8 blastomere stage) is transferred into the fallopian tube of mother (ZIFT, zygote intra fallopian transfer) or embryo with more than 8 blastomeres in transferred into the uterus of the mother (Intra uterine transfer or IUT).

(a)  (i) creating awareness among the people about various reproduction related aspects, and
 (ii) providing facilities and support for building up a reproductively healthy society
(b) Some Prominent Assisted Reproduction Technologies are:
(i) 'Test tube baby' programme.
(ii) Gamete intra fallopian transfer (GIFT).
(iii) Intra cytoplasmic sperm injection (ICSI).
(iv) Artificial insemination technique (AIT).

(a) Amniocentesis and Chorionic Villus Sampling(CVS).
(b) Ultrasound imaging

(i) A - Fish B - Algae
(ii) (a) Presence of large amount of nutrients in water
(b) Algal bloom

(a) Continuous synthesis of DNA
(b) Discontinuous synthesis of DNA

Green algae are not likely to be found in the deepest strata of sea because the environment is perpectually dark and sun as source of energy not available.

Menarche represents the beginning of menstrual cycle which is an indication of attainment of sexual maturity.It usually occurs at the age of 12-15 years.Menopause, on the other hand, refers to the cessation of menstruation, which in turn means stoppage of gamete production i.e., it marks the end of reproductive fertile life of the female.It occurs between 45 to 55 years.Menopause, on the other hand, refers to the cessation of menstruation, which in turn means stoppage of gamete production i.e., it marks the end of reproductive fertile life of the female.It occurs between 45 to 55 years of age. 

1.Amniocentesis is a foetal determination test based upon the chromosomal pattern in the amniotic fluid surrounding the developing embryo.It should be legally banned throughout the country as such a ban shall check increasing female foeticide cases and maintain a normal sex ratio in the country.
2. Use This technique can be used to identify some abnormalities in the number of chromosomes and to detect certain biochemicals and enzymatic abnormality.

1. Organic farming is a holistic approach that seeks to develop an understanding of the webs of interaction among the myriads of organisms that form the flora and fauna of the field.
2. The organic farmer works to create a system where the insects (called pests) are not eradicated, but kept at manageable levels by a complex system of checks and balance within a living and vibrant ecosystem.
3. According to the organic farmer, the eradication of the creatures, called pests, is not only possible but also undesirable, because many beneficial predatory and parasitic insects cannot survive without them.
4. Such a use of biocontrol measures reduces the use of chemical pesticides and thereby the pollution.

(i) Fossils of dinosaurs provide palaeontological evidences for evolution.
They represent extinct organisms.
A study of fossils indicates the geological time period in which these organisms existed and that life forms varied over time.
(ii) Forelimbs of cheetah, bat, whale and humans provide evidences of evolution from comparative anatomy and morphology.
The similarity in the anatomy of these organs indicates that the same structure has developed along different directions as adaptations to different needs; homology indicates common ancestry.
(iii) Thorns of Bougainvillea and tendril of Cucurbita also provide evidences from comparative anatomy and morphology.
They represent homology (both are stem modifications) and homology represents common ancestry and divergent evolution.

1.Anthropogenic actions, i.e. human activities have been found to enhance evolution.
e,g. 1.Use of DDT has resulted in evolution of DDT-resistant mosquitoes.
2.Evolution of antibiotic or drug-resistant microbes.
3. When DDT was used fo the first time, many mosquitoes died, but a few survived.
4. These few mosquitoes showed resistance to DDT and reproduced in the presence of DDT.
5. Most of the offspring were also resistant to DDT.
6. Hence, the mosquito populations of today consist mainly of DDT-resistant mosquitoes and hence, DDT is not effective.
7. In the absence of DDT, these DDT-resistant mosquitoes had no advantage over those mosquitoes, which were sensitive to DDT.
8. This is an example of evolution due to anthropogenic activities.

(i) Replication of DNA occurs in small replication forks, because DNA is such a long molecule that the separation of the two strands along its entire length requires a very high amount of energy.
(ii) DNA polymerase can catalyse the polymerisation of nucleotides only in \({ 5 }^{ ' }\rightarrow { 3 }^{ ' }\) direction.So on the template strand with \({ 3 }^{ ' }\rightarrow { 5 }^{ ' }\) polarity, DNA replication is continuous.On the template strand with \({ 5 }^{ ' }\rightarrow { 3 }^{ ' }\) polarity, DNA synthesis occurs in short stretches as the opening of replication fork continues; later these short stretches are joined by the action of DNA ligases
(iii) Replication of DNA does not initiate randomly, and DNA polymerases on their own cannot initiate replication.So, there is a specific sequence on DNA, called origin of replication; DNA polymerase binds to it and continues the process.