reproductive

Virus

...e virus during lysogenic and lytic cycles , the reproductive cycles. Contents showTocToggle("show","hide") 1 Etymology 2 Viruses: non-living or alive? 3 Study and applications of viruses 3.1 Viruses as tools for exploring basic cellular processes 3.2 Viruses as tools for genetic engi...

Stem cell

...s being in a category of unnaturalness shared with reproductive human cloning , in which cloned blastocysts would be allowed to grow into embryos and eventually infants. [10] Policy debate in the U.S. In 1995 , Congress passed the Dickey Amendment , prohibiting federal funding of research that involve...

Species

...then merged to form one united population. Without reproductive isolation, population differences cannot develop, and given reproductive isolation, gene flow between the populations cannot merge the differences. This is not to say that c...

Reproduction

... and spore formation . There are a wide range of reproductive strategies employed by different species. Some an...ty mother custody self-replication reproductive technology fertility issues External link http://www.microscopy-uk.org.uk/mag/article...

Semen

...en.This fluid is contributed by the accessory male reproductive organs . Some 60% of the volume of ejaculate is p...permatozoa during their journey through the female reproductive tract. The normal enviroment of the vagina is a hostile one for sperm cells, it is very acidic (from...

Secondary metabolite

...or interspecies competition, and to facilitate the reproductive processes. Contrary to primary metabolites these compounds are not ubiquitous in the living organisms who produce them nor are they necessarily expressed continuously.Although plants are better known as a source of secondary metabolites, bacteria...

Prophage

...ress in the host is detected, the phage enters its reproductive cycle....

Population

...dynamics , size, age and sex structure, mortality, reproductive behaviour, and growth of a population are studied. Demography is the study of human population dynamics. Other aspects are studied in sociology , economics , and geography . Plant and animal populations are studied in biology , in particula...

Plant

...e , from which they evolved, by having specialized reproductive organs protected by non-reproductive tissues. Bry...ooms are the most familiar, are actually only the reproductive structures of fungi. They are not related to any of the photosynthetic groups, but are close relativ...

Plant

...e , from which they evolved, by having specialized reproductive organs protected by non-reproductive tissues. Bry...ooms are the most familiar, are actually only the reproductive structures of fungi. They are not related to any of the photosynthetic groups, but are close relativ...

Alga

... algae stop is usually taken to be the presence of reproductive organs with protective cell layers, a characteristic not found in the other algal groups. Algal ecology Algae are a significant part of aquatic ecology. Larger algae, called seaweeds , grow mostly in shallow water and provide distinctive habi...

Phage

...ogenous phages become active again and start their reproductive cycle, resulting in the lysis of the host cell. An example is phage λ of E. coli . Sometimes, prophages even provide benefit to the host bacterium while they are dormant, by adding new functions to the bacterial genome , a phenomenon calle...

Patau syndrome

...but occur as random events during the formation of reproductive cells (eggs and sperm). An error in cell division called nondisjunction can result in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra co...

Parthenogenesis

...les, they still require sexual stimuli for maximum reproductive success. Gynogenesis A form of asexual reproduction related to parthenogensis is gynogenesis . In gynogenesis, offspring are produced by the same mechanism as in parthenogenesis, but with the requirement that the egg be stimulated by the presenc...

Molecular evolution

...y is the survival rate of individuals before their reproductive age. If they survive, they are then selected further by differential fertility – that is, their total genetic contribution to the next generation. In this way, the alleles that these surviving individuals contribute to the gene pool will incre...

Infertility

...ople in the U.S., equivalent to ten percent of the reproductive age population. Female infertility accounts for one third of infertility cases, male infertility for another third, combined male and female infertility for another 15%, and the remainder of cases are "unexplained" 2 . A Robertsonian translocatio...

Hormone

... of an organ or tissue. Hormones also control the reproductive cycle of virtually all multicellular organisms. Contents showTocToggle("show","hide") 1 Structure 2 Physiology of hormones 3 Pharmacology 4 Important human hormones 5 Spelling note 6 See also Structure Verteb...

Extinction

...s at lower toxicity levels by affecting life span, reproductive capacity, or competitiveness. DDT played such a role in killing off bald eagles and other birds by thinning the egg shell walls of affected birds, thus lowering the survivability of offspring. Since this effect was discovered, DDT has been ba...

Evolution

...y is the survival rate of individuals before their reproductive age. If they survive, they are then selected further by differential fertility — that is, their total genetic contribution to the next generation. Natural selection can be subdivided into two categories: Ecological selection occurs when o...

Eugenics

...e suggested that the new "eugenics" will come from reproductive technologies which allow parents to create " designer babies " (what the biologist Lee M. Silver prominently called " reprogenetics "). It has been argued that this "non-coercive" form of biological "improvement" will be motivated more by individual...

Common descent

...als lacking a mouth could not live; others lacking reproductive organs could not perpetuate themselves... The species we see today are but the smallest part of what blind destiny has produced..." In 1790 , Immanuel Kant (Knigsberg (Kaliningrad) 1724 - 1804), in his Kritik der Urtheilskraft , states that th...

Cloning

...any people believe that attempts to perform human reproductive cloning would be unethical , but some scientists...tural and social considerations in therapeutic and reproductive cloning...

Cancer

...ially or detrimentally) include certain sexual and reproductive practices, the use of exogenous estrogens, exposure to ionizing radiation and ultraviolet radiation, certain occupational and chemical exposures, and infectious agents. Food and nutrient intake have been examined in relation to many types of cancer....

Capacitation

...pically occurs after ejaculation , in the female reproductive tract . In vitro , capacitation can occur in sperm that have either undergone ejaculation or have been extracted from the epididymis .Non-mammalian spermatozoa do not require this capacitation step and are ready to fertilize an oocyte immediately ...

Reproduction

... and spore formation . There are a wide range of reproductive strategies employed by different species. Some an...ty mother custody self-replication reproductive technology fertility issues External link http://www.microscopy-uk.org.uk/mag/article...

Apoptosis

...iral infection and consequent damage to the cell's reproductive cycle. Cancer and defective apoptotic pathways Liling Yang et al. reported in the Feb. 15, 2003, issue of Cancer Research [13] the results of their work in the role played by a defective death signal in a type of lung cancer cells called ...

Alga

... algae stop is usually taken to be the presence of reproductive organs with protective cell layers, a characteristic not found in the other algal groups. Algal ecology Algae are a significant part of aquatic ecology. Larger algae, called seaweeds , grow mostly in shallow water and provide distinctive habi...