There is a gradual decrease in energy transfer at successive tropic levels from producers to higher levels, hence the pyramid of energy is always upright.

It is a technique of encasing seeds in a mixture of clay & soil humus & scattering them on to suitable ground, not planting of trees manually.

Methane, carbondioxide, ammonia and water vapour.

Polyethylene Glycol (PEG) and Dextran Sulphate.

Gametogenesis is the process of formation of gametes i.e., Sperms from primary spermatocytes and ova from primary oocyte in testes and ovaries respectively. Meiosis plays the most significant role in the process of gametogenesis.

Spermiogenesis Spermatogenesis lt is a process of formation of sperms from immature germ cells It is a process of transformation of a non-motile spermatid into a motile
spermatozoan Number of cells increased as each spermatogonium produces four spermatids No change in number of cells as only one spermatid develops into a spermatozoa

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 on X chromosome. The Y linked genes inherit along with Y chromosome and they are phenotypically express only in the male sex.

A group of genes that together determine a characteristic of an organism.

Individuals formed by asexual reproductive methods are morphologically and genetically identical and are called clones.

Ramapithecus\(\rightarrow \) Austrolopithecus \(\rightarrow \) Homo habilis \(\rightarrow \)  Homo sapiens

The method I suggest is Artificial lnsemination Technique (AI)
1. In AI, the semen is collected either from the husband or a healthy donor and then artificially introduced into the vagina or into the uterus (IUI- Intra Uterine Insemination) of the female.
2. It is commonly used in cases where male partner are unable to inseminate the female due to very low sperm counts in the ejaculate.

Human Ovum
a - Vitelline membrane
b - Nucleus
c - Zona Pellucida
d - Corona radiata

Intersexes: 
1. Intersexes refers to the individuals having the characteristics of both female and male sexes and their sexual anatomy does not seem to fit the typical definition of male or female.
Supersexes: 
1. Supersexes ar formed as a result of abnormal combination of sex chromosomes. 
2. Example : Super males in humans human beings have 44+XYY

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).

Supplies nutrition to the developing microspores contributes sporopollenin through, ubisch bodies. This plays an important role in pollen wall formation. The pollen kit material is contributed by tapetal cells, and is later, transferred to the pollen surface. Exine protein responsible for rejection reaction are derived from tapetal cells.

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.