Gametes

Nitrous gases and zinc in the crosshairs

...ther or not a particular substance causes cancer, has a mutagenic effect on gametes or poses a risk to unborn children during pregnancy. Analyses of the substa...ccording to the new MAK and BAT Values List, chromium (VI) compounds damage gametes and cause skin sensitivity. They received an "H" warning, which means that ...

Human sperm created from embryonic stem cells

...spermatocytes) and post meiotic germ cells (spermatids and sperm). These results indicated maturation of the primordial germ cells to haploid male gametes called IVD sperm - characterised by containing half a chromosome set (23 chromosomes). ...

Octuplets Fiasco Could Have Been Prevented

...hniques, the highest quality embryos can be selected for transfer. Special environmental conditions, advanced culture media, and delicate handling of gametes and embryos are required; these efforts result in better embryos, with higher implantation and pregnancy rates. Growing these embryos to day 5, the b...

Researchers block transmission of malaria in animal tests

... complex life cycle The malaria parasite has an extremely complicated lifecycle, which starts with the fertilisation of the parasites male and female gametes and the formation of an oocyst, in the mosquito's stomach wall. The oocyst further de-velops into sporozoittes, which travel up the mosquito's salivar...

Penn researchers identify first sex chromosome gene involved in meiosis and male infertility

...on the X chromosome. Meiosis is the process of cell division that produces gametes in both sexes. During meiosis, homologous chromosomes undergo pairing, syna...terial between paternal and maternal genomes to produce genetically diverse gametes (sperm or eggs). Therefore, defects in meiosis are a leading cause of both...

Gametes in Medical Dictionary

Pollen

... Pollen is a fine to coarse powder consisting of microgametophytes ( pollen grains), which produce the male gametes (sperm cells) of seed plants. A hard coat covering the pollen grain protects the sperm cells during the process... pollen n. The fine powder...

Hypogonadism

...of the reproductive system that results in lack of function of the gonads . The gonads have two functions: to produce hormones, activin and to produce gametes (eggs or sperm). Deficiency of sex hormones can result in defective... Male hypogonadism — Comprehensive overview covers symptoms and treatment...

Gonad

... organ in animals that produces gametes, especially a testis or ovary. ... What is the male gonad of a flower? ... gonad a gland in which gametes (sex cells) are produced ... the relationship between gonad and gamete? Read ... The medulla of the gonad develope into the? ... Online Medi...

Conception

...Fertilisation (also known as conception , fecundation and syngamy), is the fusion ... Conception (biology) or fertilisation, the fusion of gametes to produce a new ... Conception (idea) or concept, an abstract idea or a mental symbol ... ... fertile, overcome infertility and even learn ...

Gametes in Biological News

Scripps scientists help decode mysterious green glow of the sea

...een mucuswhich often draws the attention of human seafarersbefore releasing gametes into the water. The bright glow attracts male fireworms, which also release gametes into the bright green cloud. The precisely timed bioluminescent displays...

Bitter-tasting nectar and floral odors optimize outcrossing for plants

...e in German . Animals "personally" bring their gametes together seeking out sexual partners, mating, fer...llows plants to optimize their ability to exchange gametes with each other. In a paper published in the lates...s optimize the tobacco plant's ability to exchange gametes and produce outcrossed seeds. Prior to these f...

Scientists demonstrate feasibility of preventing malaria parasite from becoming sexually mature

...s complex, and it is not yet known what triggers the production of parasite gametes or sex cells. These sexual forms of the parasite do not contribute to malar... parasite enzyme that is instrumental in triggering the emergence of mature gametes within the mosquito. Their findings are published today in the journal PLoS...

Smithsonian scientists working to save microscopic threatened species

... create a genome resource bank, which will help preserve the genetic diversity of coral. Hagedorn, Henley and the team captured spawning coral gametes in nets during night dives and transferred them back to their laboratory on the beach for research and artificial inseminationoften working until 3 a....

Multiple malaria infection inhibits spread of parasite

...d spread. The gametocyte is the developmental stage of the parasite that can be transmitted from people to the mosquito. In the mosquito's stomach the gametes are released and fertilisation takes place. The parasite develops further until the final stage (the sporozoite) in the salivary gland. The sporozoite...

Single molecular 'mark' seen as pivotal for genome compaction in spores and sperm

... has been duplicated and then halved on the way to the production of mature gametes or spores. Near the end of the process, the material ?called chromatin, the...ant to damage of all kinds. This is critical ?if the single-stranded DNA in gametes breaks, it can fall apart and possibly reassemble itself in devastating tra...

Sperm created in the laboratory from embryonic stem cells produce viable progeny

...ate into primordial germ cells that then give rise to cells resembling mature egg and sperm cells, known as gametes. However, the functionality of the gametes has not been thoroughly tested and many questions about the viability of these cells remain unanswered. Dr. Karim Nayernia and Dr. Wolfgang Engel from...

Human embryonic stem cells have the potential to develop into eggs and sperm in the laboratory

...ay have the ability to develop into PGCs and early gametes as has been shown previously for mouse embryonic s...hem to grow into gametes. "Producing functional gametes is much more difficult, because we have to recreat...ing as fertilisation would involve only one set of gametes produced in this way and therefore a unique embryo...

Gametes in Biological Definition

Bacterial conjugation

...n regarded as the bacterial equivalent of sexual reproduction or mating ; however it is not actually sexual as it does not involve the fusing of gametes and the creation of a zygote , it is merely the exchange of genetic information. In order to perform conjugation, one of the bacteria has to carry a...

Cell division

...ion of the cell, called cytokinesis . A diploid cell may also undergo meiosis to produce haploid cells, usually four. Haploid cells serve as gametes in multicellular organisms, fusing to form new diploid cells. Multicellular organisms replace worn-out cells through cell division. However, in so...

Cell growth

...osomes as the parental cell. Meiosis is used for a special cell reproduction process of diploid organisms. It produces four special daughter cells ( gametes ) which have half the normal cellular amount of DNA. A male and a female gamete can then combine to produce a zygote , a cell which again has the...

Chromosome

...m the father) or polyploid [Xn] (more than two sets of chromosomes), and gametes (reproductive cells) which are haploid [n] (they have only one set of chromosomes). gametes are produced by meiosis of a diploid germ line cell. During meiosis, th...

Ploidy

...iploid organisms produce haploid sex cells that can combine to form a diploid zygote , for example animals are primarily diploid but produce haploid gametes . During meiosis , germ cell precursors have their number of chromosomes halved by randomly "choosing" one homologue, resulting in haploid germ cell...

Ewens's sampling formula

...that under certain conditions (specified below), if a random sample of n gametes is taken from a population and classified according to the gene at a par...njoys the property that if after the sample of n is taken, m of the n gametes are chosen without replacement, then the resulting probability distribution...

Gamete

... gametes (in Greek : γαμέτε...ts is called a pollen grain . Organs that produce gametes are called gonads in animals , and archegonia or antheridia in plants . gametes are haploid cells; that is, they contain one c...

Ploidy

...iploid organisms produce haploid sex cells that can combine to form a diploid zygote , for example animals are primarily diploid but produce haploid gametes . During meiosis , germ cell precursors have their number of chromosomes halved by randomly "choosing" one homologue, resulting in haploid germ cell...

Meiosis

...animals and plants are normally diploid, and use meiosis to produce sexual gametes , which fuse to form zygotes that develop into new organisms. In most an...es. Significance of meiosis If meiosis did not occur, fusion of the gametes would not result in a diploid condition (2n) but 4n. Meiosis also provides...

Nondisjunction

... In biology , nondisjunction is the failure of a chromosome to split correctly during meiosis . This results in the production of gametes which have either more or less of the usual amount of genetic material, and is a common mechanism for trisomy or monosomy . Nondisjunction can o...

Gametes in Biological Dictionary

Gametes

A gamete is a cell that fuses with another gamete during fertilization (conception) in organisms that reproduce sexually. In species that produce two morphologically distinct types of gametes , and in which each individual... Gametogenesis is a process by which diploid or haploid ...

Zygospore

...pore . The spore of certain fungi and algae formed by the union ... zygospore . ... zygospore . n. cell formed by joining of two similar gametes (Biology) ... A zygospore remains dormant while it waits for environmental cues, such as ... Zygospore information including symptoms, causes,...

Syngamy

...eiosis and syngamy . ... Meiosis and Syngamy | gametes | Evolution of Life Cycles ... Sexual reproduc...each ovule. ... syngamy n. The fusion of two gametes in fertilization. syngamic syngam ' ic or syn ' g...yngamy , ... syngamy The union of nuclei of two gametes to produce a zygote nucleus, ... Pronunciati...

Spermatogenesis

... Spermatogenesis is the process by all males spermatogonia develop into mature spermatozoa. Spermatozoa are the mature male gametes in many sexually reproducing organisms. Thus, spermatogenesis is the male version of... spermatogenesis n. Formation and development of sperma...

Somatic cells

... which... The term somatic refers to cells of the body, rather than gametes (eggs or sperm). In humans, somatic cells contain two copies of each chromosome (diploid), whereas gametes only contain one copy of each chromosome (haploid). Although all somati...

Somatic

... The term somatic refers to cells of the body, rather than gametes (eggs or sperm). In humans, somatic cells contain two copies of each chromosome (diploid), whereas gametes only contain one copy of each chromosome (haploid). Although all somati...

Sex cells

...ex of any resulting zygote, as the genotype of the sex -determining ... gametes are haploid cells ; that is, they contain half(n) of a complete set of ....d die, ... Meiosis, a type of cell division, results in production of gametes (eggs & sperm). Genetically unique sex cells combine at fertiliza...

Self-pollination

...the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains, which contain the male gametes (sperm) to where the female gamete(s) are contained... Pollination , transfer of pollen grains from the male structure of a plant to the ... Th...

Reproduction

... introduction to the mechanisms of sexual reproduction in animals. ... In animals, sexual reproduction encompasses the fusion of two distinct gametes to form ... In biology, reproduction is the process by which new individual organisms are produced. Reproduction is a fundamental feature of a...

Random mating

... mating model is. are ... Random mating with singly mated females is not equiva ... Random mating means that alleles (as carried by the gametes -- eggs or sperm) ... Situations where the random mating assumption does not hold include: ... NetPets - Your Complete Internet Pet Connection...