D. If both A and R are false.

Intrauterine Devices (IUDs) are inserted by medical experts in the uterus through the vagina. These devices are available as copper releasing IUDs, hormone-releasing IUDs and nonmedicated IUDs. IUDs increase phagocytosis of sperm within the uterus. IUDs are the ideal contraceptives for females who want to delay pregnancy. It is one of the popular methods of contraception in India and has a success rate of 95 to 99%.
Copper releasing IUDs differ from each other by the amount of copper. Copper IUDs such as Cu T-380 A, Nova T, Cu 7, Cu T 380 Ag, Multiload 375, etc. release free copper and copper salts into the uterus and suppress sperm motility. They can remain in the uterus for five to ten years.
Hormone-releasing IUDs such as Progestasert and LNG - 20 are often called as intrauterine systems (IUS). They increase the viscosity of the cervical mucus and thereby prevent sperms from entering the cervix.
Non-medicated IUDs are made of plastic or stainless steel. Lippes loop is a double S-shaped plastic device.

(i) In eukaryotes, chromatin is formed by a series of repeating units called nucleosomes.
(ii) Korenberg proposed a model for the nucleosome, in which 2 molecules of the four histone proteins H₂A, H₂B, H3 AND H4 are organized to form a unit of eight molecules called histone octamere.
(iii) The negatively charged DNA is wrapped around the positively charged histone octamer to form a structure called nucleosome. A typical nucleosome contains 200 bp of DNA helix.
(iv) The histone octameres are in close contact and DNA is coiled on the outside of nucleosome.
(v) Neighbouring nucleosomes are connected by linker DNA (Hl) that is exposed to enzymes. The DNA makes two complete turns around the histone octameres and the two turns are sealed off by an HI molecule
(vi) Chromatin lacking HI has beads on a string appearance in which DNA enters and leaves the nucleosomes at random places.
(vii) HI of one nucleosome can interact with HI of the neighbouring nucleosomes resulting in the further folding of the fibre.

(a) The figure 'F' represent ovulation.
Stage of oogenesis - Ovulatory or luteal stage of oogenesis
(b) (i) The ovarian hormone is progesterone which is released during ovulation.
(ii) The pituitary hormones are the follicle-stimulating hormone (FSH) and Luteinizing hormone (LSH) which are released during and ovulation from anterior pituitary gland.
(c) The endometrium of the uterus gets thickened and blood supply to the endometrium increase.
(d) Figure 'C' represents the secondary follicle and figure h represents the degenerating corpus luteum.

Secondary follicle	Corpus luteurn
lt is surrounded by layers of granulosa cells	Absence of granulosa cells
Theca layer is present	Theca layer is absent.

High blood pressure
Stress related ailments
Sleep disruption
Hearing impairment

RZWT Root Zone Wastewater Treatment
DEWATS Decentralized Wastewater Treatment System

Biopiracy can be defined as the manipulation of intellectual property rights laws by corporations to gain exclusive control over national genetic resources, without giving adequate recognition or remuneration to the original possessors of those resources.

(a) Stigma
(b) Locule
(c) Ovule
(d) Ovary

(a) Budding - Hydra
(b) Fragmentation - Spirogyra
(c) Regeneration - Planaria
(d) Gemma cup formation - Marchantia

Phytoplanktons form the pioneer community and a variety of trees makes the climax community of a Hydrosere.

(i) Biogas is a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen.
(ii) The slurry is drained through another outlet and is used as fertilizer.
(iii) Biogas is used for cooking and lighting.

1. Avoid sex with unknown partner/multiple partner
2. Use condoms.
3. In case of doubt, consult a doctor for diagnosis and get complete treatment.

(i) Selected mating
(ii) Flow of genes (either by immigration or emmigration)
(iii) Occurrence of mutation
(iv) Definite population size

During sporulation, Bacillus thuringiensis produces crystal proteins called Delta-endotoxin which is encoded by cry genes. Delta-endotoxins have specific activities against the insects of the orders Lepidoptera, Diptera, Coleoptera, and Hymenoptera. When the insects ingest the toxin crystals their alkaline digestive tract denatures the insoluble crystals making them soluble. The cry toxin then gets inserted into the gut cell membranes and paralyzes the digestive tract. The insect then stops eating and starves to death.

(a) Cell-mediated immunity
When pathogens are destroyed by cells without producing antibodies, then it is known as cell mediated immune response or cell mediated immunity. This is brought about by T cells, macrophages, and natural killer cells.
(b) Antibody mediated immunity or humoral immunity
When pathogens are destroyed by the production of antibodies, then it is known as antibody mediated or humoral immunity. This is brought about by B cells with the aid of antigen presenting cells and T helper cells. Antibody production is the characteristic feature of vertebrates only.

In secondary treatment of sewage, once the BOD of sewage water is reduced significantly, the effluent is passed into a settling tank where the bacterial "floes" are allowed to sediment. This sediment is calleda as activated slidge. A small part of activated sludge is pumped back into the aeration tank to serve as the inoculum.

A change in the speed of locomotion (or frequency of turning) in a motile organism or cell which is made in response to a change in light intensity is called photokinesis. It involves undirected random movement in response to light.

The yeast Saccharomyces cerevisiae is more suitable for production of recombinant interferons than E.coli, since E.coli does not possess the machinery for glycosylation of proteins