S. No	Anemochory	Zoochory
a	Dispersal of seeds or fruits by wind.	Dispersal of seeds or fruits by animals
b	Seeds are minute or may have wings.	Seeds or fruit surface may have hooks or sicky glandular hairs are seen.

(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.

5, - UACGUACGUACGU, ACGUACGUACGUACG UACG - 3'

syngamy	fertilization
It is the fusion of two haploid gametes to form a diploid zygote	It is the act (or) process of rendering fertile zygote as the result of Fertilization

 

Gymnosperms - Pollination is said to be direct as the pollen are deposited directly on the exposed ovules  Angiosperms - Pollination is said to be indirect as the pollen are deposited on the stigma of the pistil.

Common Name Botanical name Origin and area Uses PADDY/ RICE:Semi
aquatic crop grown in standing water. Second
position next to wheat Oryza sativa South East Asia - China, lndia,
Thailand- Delta of
TamilNadu 1. Staple food with calcium in many southern hill regions of lndia.
2. Made in to Porridge and gruel.
3. Ragi malt - nutrient drink and fermented beverages

Rain Water Harvesting - RWH (Solution to water crisis - A ecological problem)
Rainwater harvesting is the accumulation and storage of rainwater for reuse in-site rather than allowing it to run off.
Rainwater can be collected from rivers, rooftops and the water collected is directed to a deep pit.
The water percolates and gets stored in the pit.
RWH is a sustainable water management practice implemented not only in the urban area but also in agricultural fields, which is an important economic cost-effective method for the future.


Environmental benefits of Rain Water Harvesting:
(i) Promotes adequacy of underground water and water conservation.
(ii) Mitigates the effect of drought.
(iii) Reduces soil erosion as surface run-off is reduced.
(iv) Reduces flood hazards.
(v) Improves groundwater quality and water table / decreases salinity.
(vi) No land is wasted for storage purpose and no population displacement is involved.
(vii) Storing water underground is an eco- friendly measure and a part of sustainable water storage strategy for local communities.

Grassland ecosystem : There is a gradual decrease in the number of organisms in each trophic level from producers to primary consumers and then to secondary consumers, and finally to tertiary consumers. Therefore pyramids of number in grassland ecosystem are always upright.

i. Free floating hydrophytes: These plants float freely on the surface of water. They remain in contact with water and air, but not with soil. Examples: Eichhornia, Pistia and Wolffia (smallest flowering plant).
ii. Rooted floating hydrophytes: In these plants, the roots are fixed in mud, but their leaves and flowers are floating on the surface of water. These plants are in contact with soil, water and air. Examples: Nelumbo, Nymphaea, Potomogeton and Marsilea. Lotus seeds showing highest longevity in plant kingdom.
iii. Submerged floating hydrophytes: These plants are completely submerged in water and not in contact with soil and air. Examples: Ceratophyllum and Utricularia.
iv. Rooted-submerged hydrophytes: These plants are completely submerged in water and rooted in soil and not in contact with air. Examples: Hydrilla, Vallisneria and Isoetes.
v. Amphibious hydrophytes (Rooted emergent hydrophytes): These plants are adapted to both aquatic and terrestrial modes of life. They grow in shallow water. Examples: Ranunculus, Typha and Sagittaria.

(i) When trees are cut down and burnt or allowed to rot, their stored carbon is released into the air as carbon dioxide. This adds to the carbon dioxide content of the air. Carbon dioxide is a major greenhouse gas. The increase in concentration of carbon dioxide in the air increases the greenhouse effect and thereby causes global warming. It has been estimated that 25-30% of the greenhouse gases released into the atmosphere each year is because of deforestation.
(ii) Trees act as carbon sink since they utilize carbon dioxide for photosynthesis. When trees are cut down, the carbon footprint increases. This, in turn leads to global warming.

(i) Species have been evolving and becoming extinct since the origin of life. But species are now becoming extinct at a faster rate. This is destabilizing the ecological stability and the distribution of biological diversity on earth.
(ii) The current rate of biodiversity loss is 100-1000 times higher than the naturally occurring extinction rate. This loss of biodiversity will lead to a loss in diversity of species. It has a huge impact on plant, animal and human life. The negative effect includes dramatic influence on food web. Even a reduction in one species can affect the entire Food chain. This will affect the food sources of many species and will affect the stability of a community.
(iii) Many species may die due to lack of food. Thus species diversity will stabilize a community and also help the community to rebuild in case of any changes/ challenges faced by the community.

Similarities found in Neanderthal man and Homo sapiens.
(i) They knew to protect their bodies. Neanderthal man used animal hides to protect their bodies.
(ii) They knew the use of fire.
(iii) They buried their dead.

(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.

(i) The inheritance of a trait that is determined by a gene located on one of the sex chromosomes is called sex linked inheritance.
(ii) Genes present on the differential region of X or Y chromosomes are called sex linked genes. The genes present in the differential region of "X" chromosome are called X linked genes. The X-linked genes have no corresponding alleles in the Y chromosome.
(iii) The genes present in the differential region of Y chromosome are called Y- linked or holandric genes. The Y linked genes have no corresponding allele in X chromosome.
(iv) The Y linked genes inherit along with Y chromosome and they phenotypically express only in the male sex.
(v) Sex linked inherited traits are more common in males than females because, males are hemizygous and therefore express the trait when they inherit one mutant allele.
(vi) The X - linked and Y - linked genes in the differential region (non-homologus region) do not undergo pairing or crossing over during meiosis. The inheritance of X or Y linked genes is called sex-linked inheritance.
X linked Inheritance - Eg. Colour blindness
Y linked Inheritance - Eg. hypertrichosis 

Zea mays is a monoecious plant with
(i) Male inflorescence - the tassel with staminateflowers
(ii) Female inflorescence - ear or cob with pistillate flowers. 
(iii) Unisexuality in maize is through selective abortion of stamens - in ear florets and Pistils - in tassel florets. 
(iv) A substitution of two single gene pairs 'ba' for barren plant and 'ts' - for tassel seed makes the differences between monoecious and dioecious (rare) maize plants. 
(v) The allele for barren plant (ba) when homozygous makes the stalk staminate by eliminating silk and ears. 
(vi) The allele for tassel seed (ts) transforms tassel into a pistillate flower. 
(vii) The development of both inflorescence is the result of selective abortion of pistils or stamens. 

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.

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.

Euheterosis: True heterosis
(i) Mutational Euheterosis: Simplest type Often lethal, recessive mutant genes from cross pollinated genes.
(ii) Balanced Euheterosis: Well balanced gene combinations, more adaptive to environmental conditions and agricultural.
Pseudo heterosis: Also called luxuriance, has superiority over parents in vegetative growth but not in yield and adaptation, usually sterile or poorly fertile.

(i) The proportion of the age groups in a population is its age distribution attribute.
(ii) This determines the reproductive status of the population at the given time and is an indicator of the future population size.
(iii) Usually a rapidly growing population will have larger proportion of young individuals.
(iv) A stable population will have an even distribution of various age classes.
(v) A declining population tends to have a larger proportion of older individuals

(i) Dolly was the first mammal (sheep) Clone developed by Ian Wilmot and Campbell in 1997.
(ii) Dolly the transgenic clone was developed by the nuclear transfer technique and the phenomenon of totipotency.
(iii) Totipotency, refers to the potential of a cell to develop different cells, tissues, organs and finally an organism.
(iv) Dolly was the first animal to be cloned from a differentiated somatic cell taken from an adult animal without the process of fertilization.

Cryopreservation (- 195.C)
1. Cryopreservation, also known as Cryo conservation.
2. A process by which protoplasts, cells, tissues, organelles, organs, extracellular matrix, enzymes or any other biological materials are subjected to preservation by cooling to very low temperature of -196^oC using liquid nitrogen.
3. At this extreme low temperature any enzymatic or chemical activity of the biological material will be totally stopped and this leads to preservation of material in dormant status.
4. Later these materials can be activated by bringing to room temperature slowly for any experimental work.
5. Protective agents like dimethyl sulphoxide, glycerol or sucrose are added before cryopreservation Process.
6. These protective agents are called cryoprotectants, since they protect the cells, or tissues from the stress of freezing temperature.

1. Directly gametes cannot be transferred into the uterus, because the uterine environment is not suited for the survival of the gametes.
2. If the gametes directly transferred into the uterus, gametes will undergo degeneration (or) could be phagocytosed and viable zygotes will not be formed.
3. In this method, the own collected from a donor female is transferred to the fallopian tube of another woman.
4. The ovum has to be fertilized by the sperm of the woman's husband; the fallopian tube is the site for fertilization in a human female.
5. The gamete (ovum) if introduced into the uterus cannot move to the fallopian tube, the site of fertilization.

The advantages of Bt cotton are:
1. Yield of cotton is increased due to effective control of bollworms.
2. Reduction in insecticide use in the cultivation of Bt cotton
3. Potential reduction in the cost of cultivation.
Disadvantages
Bt cotton has some limitations:
1. Cost of Bt cotton seed is high.
2. Effectiveness up to 120 days after that efficiency is reduced.
3. Ineffective against sucking pests like jassids, aphids and whitefly.
4. Affects pollinating insects and thus yield.

Relaxin  
(i) It is a hormone secreted by the placenta and also by the corpus luteum during pregnancy.
(ii) It promotes parturition by relaxing the pelvic joints and by dilation of cervical ligaments with continued powerful contractions.
Oxytocin:
(i) It causes the "Let-Down" reflex.
(ii) The actual ejection of milk from the alveoli of the mammary glands.
(iii) During lactation, oxytocin also stimulates the recently emptied uterus to contract, helping it to return to pre-pregnancy size..

(i) Mild tremors to convulsions.
(ii) Severe agitation and fits.
(iii) Depressed mood.
(iv) Anxiety.
(v) Nervousness.
(vi) Restlessness.
(vii) Irritability.
(viii) Insomnia.
(ix) Dryness of throat.