Study of formation, growth and development of new individual from an egg is
Embryology is the study of an individual's life cycle after the fertilization takes place and till it develops into a new organism.
Ovule is straight with funiculus, embryo sac, chalaza and micropyle lying on one straight line. It is
It is a Polygonum type ovule in which the body of ovule is straight i.e. funiculus, chalaza, embryo sac & micropyle lie in the same vertical axis.
Double fertilization is characteristic of
Double fer tilization in a characteristic feature of angiosperms in which one male gamete fuses with egg (called syngamy) and other male gamete fuses with 2 polar nuclei (called triple fusion) to form endosperm.
Number of meiotic divisions required to produce 200/400 seeds of Pea would be
200 seeds of pea would be produced from 200 pollen grains and 200 embryo sac. 200 pollen grains will be formed by 50 microspore mother cell while 200 embryo sac will be formed by 200 megaspore mother cell (because 3 will degenerate) so 250/500.
Haploid plant cultures are got from
All other are diploid. Best method of haploid plant culture is pollen grain culture.
Chief pollinators of agricultural crops are
Pollination by insect is known as Entomophily. Among insects bees are the most common pollinators which pollinate about 80% of the total insect pollinated flowers.
Transfer of pollen to the stigma of another flower of the same plant is
Autogamy = Self Pollination Geitanogamy - (geiton = neighbour, gamos = marriage.) i.e. when pollen grains are transferred to the stigma of other flower of the same plant (i.e. neighboring flower).
Allogamy = Xenogamy – Cross pollination.
Fer tilization involving car r ying of male gametes by pollen tube is
In angiosper ms the male gametes are carried by the pollen tube was discovered by Strasburger in 1884. The process is called Siphonogamy.
One of the most resistant biological material is
Each pollen has two layered wall. The outer layer is thick, tough, cuticularised called exine which is composed of a material called "sporopollenin". It is highly resistant to biological and physical decomposition, due to which pollens are preserved for a long time in fossils.
In an angiosperm, how many microspore mother cells are required to produce 100 pollen grains
Each microspore mother cells undergoes meiosis to produce four pollen grains.
Thus, 25 microspore mother cells are required to produce 100 pollen grains
The polyembryony commonly occurs in
Polyembryony refers to the formation of more than one embryo within a seed of a flowering plant. e.g. Citrus.
Reproducing new plants by cells instead of seeds is known as
Culture is the ter m generally used for artificial growth. The plant tissue culture actually refers to the growth of plant cells, tissues and organs on artificial nutrient media.
How many pollen grains will be formed after meiotic division in ten microspore mother cells?
Each microspore mother cell gives rise to 4 microspores which develop into pollen grains.
In angiosperms, triple fusion is required for the formation of
In angiosperms, one male gamete fuses with the egg resulting in the formation of a diploid zygote. The other male gamete fuses with the two polar nuclei forming the primary endosperm nucleus . Thus type of fertilization is called double fertilization.
If an angiospermic male plant is diploid and female plant tetraploid, the ploidy level of endosperm will be
The male gamete will be haploid (n). 2 polar nuclei will be diploid (2n). Endosperm formed by fusion of male gamete with two polar nuclei will be pentaploid.
The endosperm of gymnosperm is
In gymnosperms the female gametophyte forming archegonia provides nourishment to the developing embryo. It later gets transformed into food-laden endosperm inside the seed. Endosperm provides nourishment for growth of seed at the time of seed germination. Triploid endosperm occurs in angiosperms.
Flowers showing or nithophily show few characteristic like 
Transfer of pollen grains by birds is known as ornithophily. They usually have bright coloured flowers, tubular or cup shaped and having a large quantity of nectar.
Double fertilisation leading to initiation of endosperm in Angiosperms require
The second male gamete entering the ovary fuses with two haploid polar nuclei to form triploid primary endosperm nucleus which develops into endosperm. This fusion of two male gametes with two different structures (egg and secondary nucleus) in the same female gametophyte is called double fertilization.
Eight nucleate embryo sacs are
Megapore is a haploid structure which divides and gives rise to embryo sac which is also called as female gametophyte. Eight-nucleate embryo sacs may be monosporic (e.g.. Polygonum); or bisporic (e.g., Allium); or tetrasporic (e.g., Adoxa).
Anemophily type of pollination is found in
Vallisneria exhibits hydrophily and Salvia is pollinated by honey bee. In bottle brush pollination is carried out by birds.
Adventive polyembryony in citrus is due to
The embryos arising from the maternal sporophyte tissues are called adventive embryos. In polyembryonate species the adventive embryo arises by the proliferation of the nucellus cells.
In angiosperms pollen tubes liberate their male gametes into the
Antipodal cells occur at the chalazal end of the ovule. Synergids are the helping cells.
What is the direction of micropyle in anatropous ovule ?
In orthotropous ovule micropyle is upward. This is the presentive type of ovule.
Which type of association is found in between entomophilous flower and pollinating agent
Commensalism is interaction between two individuals in which one is benefitted while the other is unaffected. In mutualism both individuals are beneficial for each other. The pollinating insect gets nectar from flower and in turn helps in pollination of flowers.
In angiosperms all the four microspores of tetrad are covered by a layer which is formed by
The deposition of callose starts in pollen mother cell as it enters meiosis and is complete by the end of first meiotic division. By the time tetrad are formed, the common callose wall dissolves; even then all the four micro-spores lie within a common callose wall.