- Crop Variety Insect pests
(i) Flat bean Pusa sem 2 Jassids, aphids and
fruit borer
(ii) Okra (Lady’s
finger)
Pusa Sawani Shoot and fruit
borer
- (i) Rosie, was the first transgenic cow engineered in
1997. Several human genes are transferred in cows
which are expressed in mammary tissue; the protein is
secreted in milk from where it is easily harvested. Rosie
produced human protein- enriched milk (2.4 grams per
litre). The milk contained the human a-lactalbumin and
was nutritionally a more balanced product for human
babies than natural cow-milk.
(ii) The bacterium Agrobacterium tumefaciens is called
natural genetic engineer because its tumor inducing
(Ti) plasmid has natural capabilities to produce effect in
several parts of the plant by incorporating its gene into
host genome.
- The ovule inside the female reproductive part (gynoecium)
of the flower generally differentiate a single megaspore
mother cell (MMC) in the micropylar region of the
nucellus. The MMC undergoes meiotic division which
results in the production of four megaspores.
In a majority of flowering plants, one of the megaspores
is functional i.e., develops into the female gametophyte
(embryo sac), while the other three degenerate. The
nucleus of the functional megaspore divides mitotically
to form two nuclei which move to the opposite poles,
forming the 2-nucleate embryo sac. Two more sequential
mitotic nuclear divisions result in the formation of the
4-nucleate and later the 8-nucleate stages of the embryo
sac. Two of the nuclei from opposite poles migrate to
the centre and are called polar nuclei. They fuse to form
secondary nucleus (2n). Cell walls are laid down around
the 3 nuclei at each pole. Three antipodal cells are formed
at the chalazal end, while 3 celled egg apparatus (one
egg cell, two synergids) is formed at the micropylar
end. Thus, 7 celled 8 nucleate (7th cell is the central cell
which houses all these structures) female gametophyte
is formed.
Glands/stages Hormones involved Functions
- Hypothalamus Gonadotropin releasing hormone
(GnRH)
Stimulates the anterior pituitary to secrete luteinising hormone
(LH) and Follicle stimulating hormone (FSH).
- Pituitary LH and FSH LH stimulates the corpus luteum to secrete progesterone. FSH
stimulates the growth of the ovarian follicles and division of
primary oocyte within the follicle to form secondary oocyte. It
also stimulates the formation of oestrogen. - Ovary Oestrogen and progesterone Oestrogen stimulates the proliferation of endometrium of the
uterine wall. Progesterone is essential for the maintenance of
endometrium for implantation and other events of pregnancy. - Pregnancy Human chorionic gonadotropin
(hCG), human chorionic somato-
mammotropin (hCS), oestrogen,
progesterone, relaxin.
hCG stimulates the corpus luteum that continues to secrete
progesterone until the end of pregnancy. hCS stimulates growth
of breasts during pregnancy. Relaxin facilitates parturition.
- Hardy-Weinberg principle states that in a large, randomly
interbreeding population, the allelic frequencies in a
population remain stable and is constant from generation
to generation. This is called genetic equilibrium where
gene pool is constant and sum total of all the frequencies
is 1.
Hardy-Weinberg represented this using an algebraic
equations which as following:
p^2 + 2pq+ q^2 = 1
also, p + q = 1
where, p is frequency of dominant allele and q is
frequency of recessive allele. Hence, p^2 is the frequency
of individuals in the population that are homozygotic
dominant i.e., AA and q^2 is the frequency of individuals
in the population that are homozygotic recessive i.e., aa.
2pq represents frequency of individuals in the population
that are heterozygotic or carriers.
Now, we are given data about individuals showing
albinism.Albinism is due to autosomal recessive
disorder.
Therefore, number of individuals with albinism is:
q^2 = 1/10000 or 0.0001