If the number of chromosomes in an endosperm cell is 27, what will be the chromosome number in a definitive nucleus?
Endosperm is triploid in nature3n=27 thenn=9while definitive nucleus is diploid present in the centre of the embryosac i.e 2n hence it is 2*9 = 18 so the chromosome number in definitive nucleus is 18.
If an angiosperm has 24 chromosomes in its leaf cell. How many chromosomes will be there in its pollen grain, synergid, nucleolus and endosperm?
If there are 24Chromosome in angiosperm’s diploid cell ( as u mentioned leaf ) ,then calculations will be as follow .#. Pollen grains :- 12 ( it is a gametophyte and contains 2 or 3 haploid cells as 1 vegetative & 2 generative or 1 vegetative & 1 generative but chromosome no will be 12 in each ).#. Synergids :- 12 ( it is a most time vegetative type of cell in embryo sac which nearly function in guiding pollen tube to egg cell and large central cell ) .Well i think you are asking abaut nucellus instead of nucleous as its a cell orgennele onstead of a cell so im answering it considering nucellus .# .Nucellus :- 12 ( it is a mass of cell surrounding embryo sac it has cells containing single prominent nucleus and very dense cytoplasm and it ploidy is haploid .)#. Endosperm :- 36 ( cells pf this tissue are filled with reserved food materials and are used by developing embryo ).Well thanks for asking and ask more i will love to answer doubts and stuffs u dont understand in my answer ., Thanks
Maize plant cells have 20 chromosomes each. The number of chromosomes in a pollen grain sperm cell is ?
b.10 - the haploid number.
How many chromosomes are in endosperm?
Endosperm is triploid tissue in angiosperm contains 3 haploid (3n) sets of chromosomes .It is the product of secondary nucleus and a male gamet after fertilization Secondary nucleus is the fusion product of two polar nuclei Hence it is diploid it fuses with haploid male gamet results in triploid endospemIn gymnosperm it is haploid and formed from female gametophyte .it is pre -fertilization tissue hence haploid
What is the function of antipodal cells and synergids?
Synergids and Antipodals are present in the Female Gametophyte (embryo sac) in the majority of flowering plants.These are haploid in condition and formed as a result of free nuclear division. Synergids are present at the micropylar end and have special cellular thickenings at the tip called Filliform apparatus, which play an importnat role in guiding the pollen tubes into the synergid. These are two in number and along with one egg cell constitutes the egg apparatus. These cells are degenerated after the formation of Primary Endospore Nucleus which is formed as a result of fusion between Egg cell and male gamete.Antipodal cells are present at the chalazal end .Antipodals are nutritive in function; it nourishes the embryo sac.Substances produced by the antipodals helps in the growth and development of the endosperm.It contains large amount of starch, lipids and proteins which are used up by the developing embryo and the endosperm.In certain plants the antipodals also functions as haustoria.
What is an endosperm?
Endosperm is the tissue produced in the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. Endosperm is formed when the two sperm inside a pollen grain reach the interior of an embryo sac or female gametophyte. One sperm fertilizes the egg, forming a zygote, while the other sperm usually fuses with the two female nuclei at the center of the ovary, creating endosperm (double fertilization). Thus endosperm cells are usually triploid (containing three sets of chromosomes) but can vary widely from diploid (2n) to 15n. [1] In some species (e.g. grains) the endosperm persists to the mature seed stage as a storage tissue, and in others it is absorbed during embryo development (e.g. common bean, Phaseolus vulgaris) and the function of storage tissue is performed by enlarged seed leaves (cotyledons). In certain species (e.g. corn, Zea mays) the storage function is distributed between both endosperm and the embryo. Some mature endosperm tissues store fats (e.g. castor bean, Ricinis communis) and others (including grains, such as wheat and corn) store mainly starches. The dust-like seeds of orchids have no endosperm. Orchid seedlings are mycoheterotrophic in their early development. In some other species, such as coffee, the endosperm also does not develop.[2] Instead the nucellus produces a nutritive tissue termed perisperm. There are two different types of endosperm formation, the nuclear (or liquid endosperm) type, where formation of cell wall is delayed for a number of cell divisions and the cellular where cell wall formation is initiated instantly. The nuclear type is the most common one in angiosperms. Sweet corn is picked for eating at the tender liquid endosperm stage, before cell walls have formed and the sugars have been converted to starch. The 'milk' of the coconut is a liquid endosperm.
What are the four types of asexual reproduction? Examples for each please!?
Binary fission. Reproduction for a bacterium; simple cell splitting. Mitotic cell division. Reproduction for protists. Matching up of the chromosomes, followed by cell division. Parthenogenesis. A female animal gives birth to a female "clone." Vegetative reproduction. Many plants can grow from runners or cuttings.