S.No	Primary Immune Response	Secondary Immune Response
1.	It occurs as a result of primary contact with an antigen.	It occurs as a result of second and subsequent contacts with the same antigen
2.	Antibody level reaches peak in 7 to 10 days	Antibody level reaches peak in 3 to 5 days.
3.	Prolonged period is required to establish immunity	It establishes immunity in a short time.
4.	There is rapid decline in antibody level	Antibody level remains high for longer period.
5.	It appears mainly in the lymph nodes and spleen.	It appears mainly in the bone marrow followed by the spleen and lymph nodes

Mechanism of decomposition
Decomposition is a step wise process of degradation mediated by enzymatic reactions.
Detritus acts as a raw material for decomposition.
It occurs in the following steps.
(a) Fragmentation - The breaking down of detritus into smaller particles by detritivores like bacteria, fungi and earth worm is known as fragmentation. These detritivores secrete certain substances to enhance the fragmentation process and increase the surface area of detritus particles.
(b) Catabolism - The decomposers produce some extracellular enzymes in their surroundings to break down complex organic and inorganic compounds in to simpler ones. This is called catabolism.
(c) Leaching or Eluviation - The movement of decomposed, water soluble organic and inorganic compounds from the surface to the lower layer of soil or the carrying away of the same by water is called leaching or eluviation.
(d) Humification - It is a process by which simplified detritus is changed into dark coloured amorphous substance called humus. It is highly resistant to microbial action, therefore decomposition is very slow. It is the reservoir of nutrients.
(e) Mineralisation - Some microbes are involved in the release of inorganic nutrients from the humus of the soil, such process is called mineralisation.

(i) Extremely cold climate
(ii) Low biotic diversity
(iii) Simple vegetation structure
(iv) Limitation of drainage
(v) Short season of growth and reproduction
(vi) Energy and nutrients in the form of dead organic material
(vii) Large population oscillations

In binary fission, the parent organism divides into two halves and each half forms a daughter individual. The nucleus divides first amitotically or mitotically (karyokinesis), followed by the division of the cytoplasm (cytokinesis). The resultant offsprings are genetically identical to the parent. Depending on the plane of fission, binary fission is of the following types
(i) Simple irregular binary fission
(ii) Transverse binary fission
(iii) Longitudinal binary fission
(iv) Oblique binary fission
(i) Simple irregular binary fission is seen in Amoeba like irregular shaped organisms, where the plane of division is hard to observe. The contractile vacuoles cease to function and disappear. The nucleoli disintegrate and the nucleus divides mitotically. The cell then constricts in the middle, so the cytoplasm divides and forms two daughter cells.

(ii) In Transverse binary fission, the plane of the division runs along the transverse axis of the individual. E.g. Paramecium and Planaria. In Paramecium the macronucleus divides by amitosis and the micronucleus divides by mitosis.

(iii) In Longitudinal binary fission the nucleus and the cytoplasm divides in the longitudinal axis of the organism. In flagellates, the flagellum is retained usually by one daughter cell. The basal granule is divided into two and the new basal granule forms a flagellum in the other daughter individual. E.g. Vorticella and Euglena.
(iv) In Oblique binary fission the plane of division is oblique. It is seen in dinoflagellates. E.g. Ceratium.

(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.

Continuous variation Discontinuous variation Inheritance of phenotype is determined by the combined effects of many genes. The characteristics are controlled by one or two major genes which may have two or more allelic forms. Most of the characteristics exhibit a complete gradation, from one extreme to the other. Individuals produced by this variation show differences without any intermediate form between them. The variation may be due to the combining effects of environmental & genetic factors. They are unaffected by environmental conditions. This is also known as quantitative inheritance. This is also known as qualitative inheritance, E.g. Human height & skin colour E.g. Style length in Primula, plant height of garden pea.

(i) A mature ovule (megasporangium) consist of a stalk and a body
(ii) Funicle - The stalk of the ovule by which it attaches the ovule to the placenta.
(iii) Integuments - one or two protective covering around the nucellus
(iv) Micropyle - Pore present at the tip of the ovule where the integument is absent
(v) Chalaza - The basal region of the body of the ovule where the nucellus, the integument and funicle meet or merge
(vi) Embryosac- The female gametophyte oval sac like structure in the nucellus, toward the micropylar end.

 

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

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

A - Neisseria Gonorrhoea
B - AIDS
C - Jaundice

Comutagens:
The compounds which are not having own mutagenic properties but can enhance the effects of known mutagens are called comutagens.
Example: Ascorbic acid increase the damage caused by hydrogen peroxide.

Secondary metabolites are chemical compounds that are not required by the plant for normal growth and development but are produced in the plant as 'byproducts' of cell metabolism. For Example: Biosynthesis and isolation of indole alkaloids from Catharanthus roseus plant cell culture.

Queen of Spices	King of Spices
Cardamom (Elettaria cardamomum)	Black pepper (Piper nigrum)
Family : Zingiberaceae	Family : Piperaceae

Detritus food chain
(i) This type of food chain begins with dead organic matter which is an important source of energy.
(ii) A large amount of organic matter is derived from the dead plants, animals and their excreta.
(iii) This type of food chain is present in all ecosystems
(iv) The transfer of energy from the dead organic matter is transferred through a series of organisms called detritus consumers. (detrivores)-Small carnivores -large (top) carnivores with repeated eating and being eaten respectively.

Co-evolution: The interaction between organisms, when continues for generations, involves reciprocal changes in genetic and morphological characters of both organisms. This type of evolution is called co-evolution. It is a kind of co-adaptation and mutual change among interactive species.

1. Cuscuta is a total stem parasite of the host plant Acacia, Duranta and many other plants Cuscuta even gets flower inducing hormone from its host Plant.
2. Balanophora, orobanche and Refflesia are the total root parasites found on higher plants.

Properties of Vectors:
1. Vectors are able to replicate autonomously to produce multiple copies of them along with their DNA insert in the host cell.
2. It should be small in size and of low molecular weight, less than 10 Kb (kilo base pair) in size so that entry/transfer into host cell is easy.
3. Vector must contain an origin of replication so that it can independently replicate within the host.
4. It should contain a suitable marker such as antibiotic resistance, to permit its detection in transformed host cell.
5. Vector should have unique target sites for integration with DNA insert and should have the ability to integrate with DNA insert it carries into the genome of the host cell. Most of the commonly used cloning vectors have more than one restriction site. These are Multiple Cloning Site (MCS) or polylinker. Presence of MCS facilitates the use of restriction enzyme of choice.

1. Testes are the primary male sex organs.
2. They are a pair of ovoid bodies lying in the scrotum.
3. The scrotum is a sac of skin that hangs outside the abdominal cavity.
4. Since viable sperms cannot be produced at normal body temperature, the scrotum is placed outside the abdominal cavity to provide a temperature 2-3°C lower than the normal internal body temperature.
5. Thus, the scrotum acts as a thermoregulator for spermatogenesis.

1. In unicellular organism there is no special structure for reproduction.
2. In binary fission the entire parent body constitute the reproductive unit and disappears when its division into two daughter unicellular cell is completed.
3. These two daughter cells function as two new individuals.
4. There is no remains of parent body cell and parent cannot be said to have died.
5. In fact after binary fission parent continues living as two daughter individual.
Hence, the unicellular organisms which undergo binary fission are called immortal (no natural death).

1. In Greek Parthenos means Virgin, Genesis means Produce.
2. Development of a haploid (n) egg into a complete individual without fertilization is known as parthenogenesis.
3. It was first discovered by Charles Bonnet in 1745.
4. Parthenogenesis occurs naturally in some invertebrates (e,g:) Nematodes, Water fleas, Scorpians, Parasitic (wasps).

UGA, UAA and UAG are the non-sense codons, which terminates translation.

Erythromycin, Chloromycetin, Neomycin, Kanamycin

Royal Bengal Tiger, Lion Tailed Macaque, Nilgiri Langur and Gray Wolf.

(a) Ethyl methanesulphonate (EMS)
(b) Mustard gas
(c) Maganous salt
(d) Formaldehyde

1. Culture media are sterilized by Autoclaving.
2. Explants are surface sterilized by chemicals.

Azotobacter and Clostridium

Organic farming is an alternative agricultural system in which plants/crops are cultivated in natural ways by using biological inputs to maintain soil fertility and ecological balance thereby minimizing pollution and wastage.

Methane, carbondioxide, ammonia and water vapour.

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.