1. Emasculation is the process of removal of stamens from a bisexual flower before they shed pollen in order to prevent self-pollination and permit cross-pollination of stigma with desired pollen. During breeding, the breeder wants to make sure that the desired pollen grains are used for pollination and the stigma is protected from contamination (from unwanted pollen).
2. A plant breeder employs this technique to select and incorporate specific traits in the progeny.

Bacteria are present almost everywhere.To see them under a microscope, we can take samples of bread or curd.These samples are preferred because both of them can be easily mounted, stained and observed under a microscope.

Mendel selected pea plant because it is normally self pollinated but can be easily cross pollinated and has 7 traits with distincitly constrasting forms.

Name of the Restriction enzyme : Bam H1
The substrate DNA on which it acts :

The product it produces :
 

Yes.
Many animals other than human have self-consciousness. For example, dolphins are highly intelligent. They have a sense of self and they also recognise others among themselves. They can communicate with each other by whistles, tail slapping, and other body movements. Besides dolphins some other animals such as parrots, chimpanzees, orangutans, gorilla, etc. are also found to have self-consciousness.

Use of contraceptives is justified due to the following reasons
(i) In the absence of contraceptives, the population growth rate will rise at an explosive rate and there will be scarcity of even the basic necessities.
Earth's resources are limited. We have already started facing the problems of overcrowding, food price inflation, power and water shortage, etc. Further increase in population will only aggrevate situation.
(ii) Contraceptives provide an option for planning the family by spacing the pregnancies and avoiding unwanted pregnancies.
(iii) Contraceptives also guard against STDs to some extent.

For properties of genetic material

Double Fertilisation
1.The process was demonstrated for the first time by Nawasch in in 1898 in Lilium and Fritillaria. The most important and unique characteristic feature of angiosperms is the participation of both male gametes in the act of fertilisation. The pollen tube releases the two male gametes into the cytoplasm of one of the synergids, then the penetrated synergid starts degenerating. One male gamete fuses with the egg cell to form a diploid (2n) zygote. This process is called syngamy or generative fertilisation.
2.The diploid zygote finally develops into the embryo. The second male gamete fuses with the two polar nuclei or secondary nucleus in the central cell to form the triploid Primary Endosperm Nucleus (PEN). This process is called triple fusion as three haploid nuclei are involved in the fusion.
3.After triple fusion, the central cell becomes the Primary Endosperm Cell (PEC) which gives rise to the endosperm, while the zygote develops into the embryo. As both the fusions, syngamy and triple fusion, occur in an embryo sac, the phenomenon is termed as double fertilisation.

(i) True - natural abortion (miscarriage) also happens. This may be due to poor health of mother or poor development of foetus.Sometimes, the uterus of mother is not well developed to continue pregnancy. 
(ii) False - Infertility is defined as the inability of the couple to produce baby even after unprotected coitus. It might occur due to abnormalities/defects in either male or female or both.
(iii) True - complete lactation has been reported to be effective, but only upto a maximum period of six months following parturition.
(iv) True - awareness of sex-related issues will lead to reduction of unhealthy reproductive practices.

(a) PCR - Polymerase chain reaction technique amplify the DNA from one copy to more than one in three steps namely denaturation of target DNA (thermal cycle to separate the DNA strands), annealing of primers to the ssDNA and polymerization (extension of primer into complete DNA strand complementary to the template strand).
(b) Restriction enzymes recognize specific sequences, mostly 4-6 bp, in the DNA and cut it into fragments by breaking the phosphodiester linkage between two successive nucleotides of DNA. DNA is polymer of deoxyribonucleotides and serves as genetic material
(c) Chitinases are class of enzymes that can digest chitin; the major component of fungal cell wall.

The human male reproductive system consists of a scrotum, testes, testicular lobules, seminiferous tubules, urethra and penis.  The scrotum is a pouch of deeply pigmented skin divided into two separate sacs. Each sac contains one testis. Testes are the primary sex organs of the man. Each testicular lobules consists of 2-3 seminiferous tubules, blood vessels, nerves, and connective tissue. The male urethra is a common pathway for both semen and urine. The penis is the male copulatory organ and for conducting urine from the body.

Tapetum is the innermost layer of the microsporangium. It produces the exine layer of the pollen grains, which is composed of the sporopollenin, the most resistant organic material. During microsporogenesis, the cells of tapetum produce various enzymes, hormones, amino acids and other nutritious materials required for the development of pollen grains.

(a) Intra Uterine Devices-CuT, Cu7, Multiload 375.
(b) Suppress sperm motility, supress fertilizing capacity of sperms, increase phagocytosis of sperms within uterus.

(i) According to Chargaff's rule, ratio of purines to pyrimidines is equal, i.e A+G=C+T
Since, the number of adenine (A) is equal to the number of thymine (T) and A=140 (given)
Therefore, T = 240
Also, the number of guanine (G) is equal to cytosine (C). Thus, G+C=1000-(A+T)
G + C = 1000 - 480 = 520
Hence, G = 260, C = 260
The number of pyrimidine bases, i.e. C + T = 240 + 260 = 500
(ii)

\((a)All\quad tall;\quad (b):\frac { 3 }{ 4 } tall;\frac { 1 }{ 4 } dwarf\quad (c)All\quad tall\quad (d)\frac { 1 }{ 2 } tall;\frac { 1 }{ 2 } dwarf\) 

(a) Theory of chemical evolution or abiogenesis was proposed by Oparin and Haldane.
It states that the first form of life could have come from pre-existing non-living organic molecules (like RNA, proteins, etc.) and that formation of life was preceded by chemical evolution, i.e. formation of diverse organic molecules from inorganic constituents.
(b) Miller's experiment:
He created conditions similar to the primitive earth in the laboratory.
Electric discharge was produced (by using electrons) in a closed flask, containing methane, hydrogen, ammonia and water vapour.
The temperature was kept at \(800\)\(^{ \circ }{ C }\). 
After a week, he observed formation of amino acids.
Such molecules must have reacted among themselves to form giant, self-replicating molecules, the first form of life.

(i) XX-XY type of sex-determination is an example male heterogamety. This is because it is the mechanism in which male produces two different types of gametes, some gametes with X-chromosome and some with Y-chromosome.
(ii) This type of sex-determination method is seen certain insects like Drosophila melanogaster and mammals including human.

(a) Cannabinoids and cocaine/coca alkaloids.
(b) (i) Cannabinoids are obtained from Cannabis sativa.
(ii) Cocaine is obtained from Erythroxylum coca.
(c) Atropa bel/adona and Datura show hallucinogenic properties.

(d) If A is false, but R is true