A - Only males ;
B - Only Females ;
C - Both Males & Females

Characters of biome 
(i) Location, geographical position (Latitude, Longitude)
(ii) Climate and physiochemical environment
(iii) Predominant plant and animal life
(iv) Boundaries between biomes are not always sharply defined. Transition or transient zones are seen as in case of grassland and forest biomes.

1. Amniocentesis is the pre-natal diagnostic technique in which a sample of amniotic fluid from the womb of a pregnant woman is taken during early stages of embryonic development and the cells are cultured and analysed synthetically.
2. Any chromosomal disorder or a metabolic error can be detected and if necessary MTP can be advised.
3. But this technique is misused for knowing the sex of the foetus followed by female foeticide.
4. Female foeticide refers to aborting the female in the mother's womb.
5. In order to prevent female foeticide and infanticide, Government of India has taken various steps like PCPNDT Act .(preconception and prenatal diagnostic technique act-1994) enacted to ban the identification of sex and to prevent the use of prenatal diagnostic techniques for selective abortion.

1. In this method of sex determination, the homogametic male possesses two 'X' chromosomes as in certain insects and certain vertebrates like fishes, reptiles and birds producing a single type of gamete.
2. The female sex consists of a single 'Y' chromosome. Thus the females are heterogametic and produce two types of eggs.
3. To avoid confusion with the XX-XO and XX-XY trues of sex determination, the alphabets 'Z' and 'W 'are used here instead of X and Y respectively.
4. Heterogametic females are of two types, ZO-ZZ type and ZW-ZZ type.

(i) "Wuchereria bancrofti".
(ii) Chronic inflammation of the lymph nodes. Obstruction of lymph in the vessels of the lower limb.
(iii) Transmitted through an agent/vector called Female Culex mosquito.

Endothecium is a single layer of radially elongated cells, The inner tangential wall of this cell develops bands of a cellulose, The cells are hygroscopic. The stomium of anther lobe lack these thickenings. Stomium along with the hygroscopic nature of endothecium helps in the dehiscence of anther

(a) 

Binary Fission in Amoeba	Multiple fission in Plasmodium
lt results in the production of two individuals from a single parent.	It results in the production of several individuals
lt occurs under favourable conditions	It occurs both under favourable and unfavourable conditions
Nucleus of the parent cell divides only once to form two daughter nuclei	Nucleus of the parent cell undergoes repeated divisions to form a number of daughter nuclei
Cytoplasm divides after nuclear division	Cytoplasm does not divide after each nuclear division but divides during favourable condition
No part of parent body is left unused (e,g: Amoeba)	A part of the body (covering and residuai cytoplasm) is left unused. (e,g: Paramecium)

(b) Budding in yeast and budding in hydra

(c) Regeneration is regrowth in the injured region

(i) A vaccine is a biological preparation that provides active acquired immunity to a particular disease and resembles a disease-causing microorganism and is often made from weakened or attenuated or killed forms of the microbes, their toxins, or one of its surface proteins.
(ii) Vaccines "teach" our body how to defend itself when viruses or bacteria, invade it.
(iii) Vaccine initiates the immunization process. The vaccines are classified as first, second and third generation vaccines.
First generation vaccine:
(i) First generation vaccine is further subdivided into live attenuated vaccine, killed vaccine and toxoids.
(ii) Live attenuated live vaccines use the weakened (attenuated), aged, less virulent form of the virus
(iii) Eg. Measles, Mumps and Rubella (MMR) vaccine and the Varicella (chickenpox) vaccine, killed (inactivated) vaccines are killed or inactivated by heat and other methods. Eg. Salk's polio vaccine.
(iv) Toxoid vaccines contain a toxin or chemical secreted by the bacteria or virus.
(v) They make us immune to the harmful effects of the infection, instead of to the infection itself.
(vi) Eg. DPT vaccine (Diphtheria, pertussis and Tetanus), (Triple antigen).
Second generation vaccine: contains the pure surface antigen of the Pathogen. :
Eg. Hepatitis-B vaccine 
Third generation vaccine: contains the purest and the highest potency vaccines which are synthetic in generation. The latest revolution in vaccine is DNA vaccine (or) recombinant vaccine

The fusion of male and female gamete is called fertilization. Fertilization in angiosperms is double fertilization type.
Pollen germinates on the stigma. Pollen tube produced grows through the style towards the micropyle of the ovule pollen tubes enter into one of the synergids of the embryo sac.
Discharge of male gametes occur syngamy - one gamete and an egg cell fuses to form diploid zygote Triple fusion - The other male gamete fuses with the two haploid female polar nuclei. A triploid primary endosperm nucleus results.

A. A and R are correct.

(a) A and R are true, R is the correct explanation of A

A. If both A and R are true and R is correct explanation for A

(a) Ovary ⟶ Fruit
(b) Secondary nucleus ⟶ Endosperm
(c) Outer integument of ovule ⟶ Outer seed coat (Testa)
(d) Funicle ⟶ Stalk of the seed

(a) Okra: Pusa Sawani and Pusa A-4 varieties of Okra are resistant to shoot and fruit borers.
(b) Rapeseed mustard: Pusa Gaurav variety of rapeseed mustard shown resistance against Aphids.

UV short waves, X-rays - Physical mutagens.
Nitromethyl, Urea - Chemical mutagens.

The International treaty called the Montreal Protocol (1987) was held in Canada on substances that deplete ozone layer and the main goal of it is gradually eliminating the production and consumption of ozone depleting substances and to limit their damage on the Earth's ozone layer.

Dobson Unit is the unit of measurement for total ozone. One DU is the number of molecules of ozone that would be required to create a layer of pure ozone 0.01 millimeter thick at a temperature of 0° C and a pressure of 1 atmosphere.

CO₂, CH₄, N₂O and CFC