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Haploid Cell

Biology  Haploid  Haploid gametophyte

haploid cell
(hap-loyd) [Gk. haploos, single + ploion, vessel]
A cell containing only one set of chromosomes (n).
Hardy-Weinberg equilibrium ...


Debec A: Haploid cell cultures of Drosophila melanogaster.
Nature 1978, 274:255-256.
Ui K, Nishihara S, Sakuma M, Togashi S, Ueda R, Miyata Y, Miyake T: Newly established cell lines from Drosophila larval CNS express neural specific characteristics. ...

Haploid cells can live indefinitely in the haploid condition. However, if two cells of opposite mating types meet, they can fuse and enter the diploid phase of the cell cycle.
This is not as rare event as you might expect.

Haploid cells possess only one set of a chromosome. For example, a diploid human cell possesses 46 chromosomes and a gamete created by a human is haploid possesses 23 chromosomes.
Tetraploid organisms possess more than 3 sets of a particular chromosome.
Reproduction ...

haploid cell a cell containing only one of each type of chromosome characteristic of its species
haptens Molecules of small molecular weight (usually) that are immunogenic only when attached to carrier molecules, usually proteins.

(D) ~s
Activated M-phase-promoting factor (MPF) signals entry into which of the following mitotic cell cycle phases?
(A) G1 ...

The human ~ is the gamete (egg cell and sperm cell). The human gamete has 22 autosomes and 1 allosome, i.e., 23 chromosomes. The diploid cell is the somatic cell and it has 44 autosomes and 2 allosomes, i.e., 46 chromosomes.

Gametes are ~s; that is, they contain one complete set of chromosomes (the actual number varies from species to species). When two gametes fuse (in animals typically involving a sperm and an egg), they form a zygote-a cell that has two complete sets of chromosomes and therefore is diploid.

Specialized ~ (in animals either a sperm or an egg) produced by meiosis of germ cells; in sexual reproduction, union of a sperm and an egg initiates the development of a new individual.

egg the ~ within the female ovary.
elements the fundamental building blocks of matter within all living things.
embryo forms when all the organs of the body have taken shape.

Gametes are ~s that carry reproductive functions produced through meiosis. Gametes carried by males are called sperms and gametes carried by females are called eggs. By joining during fertilization, gametes form a zygote, which is a diploid.
Transcript ...

The four ~s formed at the end of meiosis. The term was formerly used for the four chromatids making up a chromosome-pair at the first division of meiosis.
Related Terms:
Haploid ...

megaspores Four ~s produced by meiosis in the ovule of a þower. Usually, three of these cells degenerate, with the remaining cell becoming the female gametophyte phase of the plant's life cycle.

During syngamy, two ~s fuse. Cell fusion is followed by nuclear fusion, leading to the formation of a diploid cell. This diploid cell has two sets of chromosomes and so is 2N.

See ~. Directional cloning. DNA insert and vector molecules are digested with two different restriction enzymes to create noncomplementary sticky ends at either end of each restriction fragment.

Gamete -- an ~.gel electrophoresis the process by which nucleic acids (DNA or RNA) or proteins are separated by size according to movement of the charged molecules in an electrical field.

We [began to work] with yeast cells because they were susceptible to genetics; because they would grow as ~s. We couldn't do the same kind of genetics with human cells. We were looking for the things in common between yeast and human cells.

Meiosis I separates homologous chromosomes, producing two ~s (N chromosomes, 23 in humans), so meiosis I is referred to as a reductional division. A regular diploid human cell contains 46 chromosomes and is considered 2N because it contains 23 pairs of homologous chromosomes.

A ~ only has one set of chromosomes, and most of the time that refers to the so-called sex cells, either eggs or sperm.

A haplodiploid species is one in which one of the sexes has ~s and the other has diploid cells. Most commonly, the male is haploid and the female is diploid.

Each pollen grain has two ~s: a generative cell that divides to form two sperm and a tube cell that produces a pollen tube.
The ovule, which develops in the ovary, contains the female gametophyte, the embryo sac.
The embryo sac consists of only a few cells, one of which is the egg.

Most cells are diploid. Cells with only one set (23 in a human) are called ~s. Haploids are most often found in cells involved in sexual reproduction such as a sperm or an egg. ~s are created in cell division termed meiosis.

embryo sac A structure composed of eight ~s found in angiosperms. It forms by division of a megaspore and represents the female gametophyte stage of the plant's life cycle.
encephalitis Inflammation of the brain.
encyst To form a cyst.

Here the cell has divided into two daughter ~s however the process does not end here as these two cells immediately start to divide again. The spindle microtubules stretch out from each pole again and the nuclear membrane breaks down as in prophase I.

Meiosis
The process of nuclear division associated with the formation of gametes or of ~s from a diploid.
Merodiploid
A partially diploid bacterium, carrying both its own chromosome and a chromosome fragment introduced by conjugation, transformation or transduction.

in Dictyostelium discoideum, the solitary ~ of the vegetative life cycle that lives on bacteria and reproduces by binary fission until the food supply is exhausted.

spore
In the life cycle of a plant or alga undergoing alternation of generations, a meiotically produced ~ that divides mitotically, generating a multicellular individual, the gametophyte, without fusing with another cell.
Covered in BIOL1020 Lab 6 Mitosis & Meiosis ...

GROWTH of daughter cells from mitotic divisions
Products of the growth phase divide by MEIOSIS producing ~s (46→23)
MATURATION of haploid daughter cells into gametes (eggs, sperm)
Heads are embedded in Sertoil cells ...

spermatid [Gr. spermatos - seed, semen]. ~ in male testes, formed from spermatocyte by meiosis and will differentiate into a spermatozoon.
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Telophase
One of the steps of normal cell division, mitosis. Telophase is the last step. There is also a telophase during meiosis, the cell division leading to the formation of ~s in the formation of gametes.
View Dr Chromo's lecture on 'Mitosis'.
Pronounce:
Related Links ...

However, surprisingly little is known about the histone fraction, which was previously presumed to be a 'leftover' from remodeling during spermiogenesis (the last stages of spermatogenesis when the cell is transformed from a round ~ to a motile cell).

In instances of sexual reproduction, the cellular process of meiosis is first necessary so that haploid daughter cells, or gametes, can be produced. Two ~s then fuse to form a diploid zygote, which develops into a new organism as its cells divide and multiply.

See also: See also: What is the meaning of Haploid, Cells, Cell, Meiosis, Diploid?

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