Thermoregulation is an energy-expensive phenomenon; considering the cost and benefit, many animals have not evolved thermo-regulation.

Tt and tt.

Conventional taxonomic methods are not suitable for the identification of prokaryotic species.

Cellular onco genes or proto onco genes are present in normal cells which ,when activated under certain conditions,could lead to oncogenic transformation of the cells.

Easily available , create gap, inhibit ovulation and implantation, less side effect

Curd / Whey is more nutritious, have vitamin B_12, synthesized by LAB (absent in milk).

Spleen. It acts as the filter of the blood by trapping blood borne micro-organism.

Diagrammatic representation of stabilizing, directional and disruption factors.

i) Theory of Natural Selection
ii) Main points of the theory i.e. built in variation in characters, over reproduction, struggle for existence, survival of the fittest through natural selection as a mechanism of evolution.
iii) Alfred Wallace, a Naturalist.

The conversion of non-pathogenic living R-strain into living pathogenic S-strain indicates that some thing( transforming factors) have been passed from S- to R- strain.

GIFT (gamete intra fallopian transfer )

Hormonal stimulus – obtained from pituitary gland.

Artificial hybridization involving emasculation and bagging.

Potato has small eyes bearing buds which grow to form daughter plants.

Binary fission: Irregular in Amoeba, longitudinal in Euglena.

Diet deficient in micronutrient is not good for health as it increases the risk of disease, reduces lifespan and also reduces mental abilities.

An oral pill prevents pregnancy in the following ways
(i) It inhibits ovulation and implantation.
(ii) It alters the quality of cervical mucus and retards the entry of sperms into cervix.

Lactation or breast-feeding the baby delays the onset or return of menstruation and ovulation cycle, due to interference of hormones. Therefore, the chances of conception are nilduring this period, i.e. upto six months. Hence, breast-feeding baby may act as a natural contraceptive for mother.

Cow dung contains
(i) Celluosic materials and 
(ii) Methanoges, i.e, the raw material and the microbes needed for production of biogas.

1. Plant cells retain the power of division for comparavely longer periods than animal cells.
2. Animal cells become mature just after the embryonic stage and hence cannot be cultured.

1.Meiosis occurs during gametogenesis;it leads to reduction in  the number of chromosomes and haploid (n) gametes are formed.
2.During fertilisation,when two haploid gametes fuse,a diploid (2n) zygote is formed.

1. In yeast, the cell division is unequal; the small cell grows into a bud, which remains attached to the large cell in the initial stages, but gets separated later.
2. In Amoeba, the cell reproduces by binary fission, where the cell divides into two halves and each one grows into an adult.

Banana produces fruits without fertilization of ovary; the process is known as parthenocarpy.
Since, parthenocarpic fruits are seedless, banana is propagated by vegetative means.

Banana fruit develops without fertilisation of the ovary; hence it is considered parthenocarpic.