Ploidy
... , and a few algae exist as haploid organisms,
male bees, wasps and ants are also haploid. For ... the other has diploid cells. Most commonly, the
male is haploid and the female is diploid. In such species, the
male develops from unfertilized eggs, while the female ...
Ploidy
... , and a few algae exist as haploid organisms,
male bees, wasps and ants are also haploid. For ... the other has diploid cells. Most commonly, the
male is haploid and the female is diploid. In such species, the
male develops from unfertilized eggs, while the female ...
Hermaphrodite
... hermaphrodite is a species that contains both
male and female sexual organs at some point ... up of primarily groupers. Since even a small
male can produce more than enough sperm to fertilize ... is causing a change in when the switch from
male to female occurs, since fishermen naturally ...
Infertility
...
2 Causes
2.1 Female infertility
2.2
male infertility
2.3 Combined infertility
3 ... accounts for one third of infertility cases,
male infertility for another third, combined
male and female infertility for another 15%, and the ...
Parthenogenesis
... embryo or seed without fertilization by a
male .
Parthenogenesis occurs naturally in some ... In sexual populations half the individuals are
male and cannot themselves produce offspring. This ... entirely female. One female plays the role of a
male lizard and mounts the female that is about to ...
Y chromosome
... of the genes on this chromosome are involved in
male sexual determination and development.
... a person has the sexual characteristics of a
male or a female), sexual development, and the ability ... of bases contain functioning genes important for
male fertility. Most of the sequence pairs are greater ...
Chromatin
... chromatin is an exception to the above. During spermiogenesis , the
male germ cell 's chromatin is remodelled into a more tightly packaged, ...
Sperm chromatin is an exception to the above. During spermiogenesis, the
male germ cell's chromatin is remodelled into a more tightly packaged, compact ...
Human
... at conception . An egg is usually fertilized inside the female by the
male through sexual intercourse , though in vitro fertilization methods ... male, while in Botswana , due largely to AIDS , it is 30.99 years for a
male and 30.53 years for a female. One in five Europeans , but one in twenty ...
Semen
... the fluid portion of semen.This fluid is contributed by the accessory
male reproductive organs . Some 60% of the volume of ejaculate is produced by ... fetish pornography.
References
Mann T, Lutwak-Mann C. 1981 .
male Reproductive Function and Semen . Berlin : Springer-Verlag . ISBN ...
Sociobiology
... successful example was a quantitative description of infanticide by
male harem-mating animals when the alpha
male is displaced. Female infanticide and fetal resorption are active areas ...
Sperm
... : sperm = semen and zoon = alive), is the haploid cell that is the
male gamete . It is carried in fluid called semen , and is capable of ... through the chromosomal pair "XX" (for a female ) or "XY" (for a
male ). Sperm cells were first observed by Antoni van Leeuwenhoek in 1679 .
...
X chromosome
... male's cells. Extra genetic material from the X chromosome interferes with
male sexual development, preventing the testicles from functioning normally and ... sex determination (whether a person has the sexual characteristics of a
male or a female), sexual development, and the ability to have children ...
Reproduction
... process by which organisms create descendants through the combination of genetic material. These organisms have two different adult sexes,
male and female.
Asexual reproduction is a biological process by which an organism creates a genetically similar copy of itself without the ...
Barr body
... two X-chromosomes are present. The provision of an extra artificial Xic in early embryogenisis can induce inactivation of the single X found in
male cells.
The roles of Xist and Tsix appear to be antagonistic. The loss of Tsix expression on the future inactive X chromosome results in an ...
Cancer
... of life. Neuroblastoma is the most common infant malignancy, followed by the leukemias and the central nervous system cancers. Female infants and
male infants have essentially the same overall cancer incidence rates, but white infants have substantially higher cancer rates than black infants for ...
Carolus Linnaeus
... Uppsala .
He originated the practice of using the ♂ - (shield and arrow) Mars and ♀ - (hand mirror) Venus glyphs as the symbol for
male and female .
Linnaeus was instrumental in the development of the Celsius (then called Centigrade ) temperature scale, inverting the scale that ...
Cell growth
... 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 normal amount of chromosomes.
For details see the ...
Chromosome
... mother can exchange small parts of themselves ( crossover ), and thus create new chromosomes that are not inherited solely from either parent. When a
male and a female gamete merge ( fertilization ), a new diploid organism is formed.
Figure 3 : Karyogram of human female
Karyotype ...
Drosophila
... approximately from 3.2 mm to 4.2 mm in length. Most species have red eyes. The feathered arista is characteristic of the family.
male (left) and female fruit flies.
Drosophila is part of the phylum Arthropoda , a phylum of segmented animals with paired, jointed appendages and ...
Hardy-Weinberg principle
... 250 women (0.004).
If a population is brought together with males and females with different allele frequencies, then the allele frequency of the
male population follows that of the female population because each receives its X chromosome from its mother. The population converges on equilibrium, ...
Insulin
... mg/dl to perhaps 110 mg/dl (3.9 to 6.1 mmol /litre) except shortly after eating when the blood glucose level rises temporarily. In a healthy adult
male of 75 kg with a blood volume of 5 litre , a blood glucose level of 100 mg/dl or 5.5 mmol/l corresponds to about 5 g (1/5 ounce) of glucose in ...
Klinefelter's syndrome
... males usually have an XY karyotype . The XXY chromosome arrangement is one of the most common genetic abnormalities, occurring in about 1 in 1,000
male births, but the symptoms that may result from having the extra chromosome are less common. Because of this extra chromosome, individuals with the ...
Life
... cell membrane .)
Stars could be considered living beings (with an extraordinary life span and size scales compared to other known life forms).
male mules are not alive as they are sterile and cannot reproduce.
viruses are not alive as they do not grow and cannot reproduce outside of a ...
Malaria
... in Plasmodium falciparum malaria and this is the main factor giving rise to hemorrhagic complications of malaria.
Some merozoites turn into
male and female gametocytes . If a mosquito bites the infected person and picks up gametocytes with the blood, fertilization occurs in the mosquito's ...
Olfaction
... and well-developed sense of taste . The lack of olfaction is called anosmia . In many species olfaction is highly tuned to pheromones ; a
male silkworm moth, for example, can smell a single molecule of bombykol.
Insects primarily use their antennae for olfaction. Sensory neurons in the ...
Reproduction
... process by which organisms create descendants through the combination of genetic material. These organisms have two different adult sexes,
male and female.
Asexual reproduction is a biological process by which an organism creates a genetically similar copy of itself without the ...
Spermatid
... The term spermatid refers to the haploid
male germ cell that results from secondary spermatocyte division. As a result of meiosis , each spermatid contains only half of the genetic material ...
Spermatogenesis
... Spermatogenesis refers to the creation, or genesis, of sperm cells, which occurs in the
male gonads or testes . Sperm cells develop initially from germ stem cells known as spermatogonia . As these differentiate they become spermatocytes ...
Thermoregulation
... curves obtained from rabbit, guinea pig and dog were quite similar to those from man. The mean temperature of the female was higher than that of the
male in all the species examined whose sex had been determined.
Meals sometimes cause a slight elevation, sometimes a slight depression—alcohol ...
Thomas Hunt Morgan
... theories in animals. He began cross-breeding Drosophila , but had no success for two years. Finally in 1910, he noticed a white-eyed mutant
male among the red-eyed wild types . He bred this white-eyed fly with a red-eyed female. Their progeny were all red-eyed, suggesting that the white eye ...
Twin
... process, one twin loses a Y chromosome (boys have chromosome type XY while girls have XX). Without a Y chromosome to trigger the production of
male sex hormones , this fetus develops as a girl by default, but a girl with only one X chromosome (chromosome type XO). The co-twin is unaffected, ...
Zygote
... ) is a cell that is the result of fertilization . That is, two haploid cells—usually (but not always) a sperm cell from a
male and an ovum from a female —merge into a single diploid cell called the zygote .
Animal zygotes undergo mitotic cell divisions to ...