A new study from the University of Copenhagen reports that the prevalence of overweight dogs is markedly larger among overweight owners than among normal weight owners. Part of the explanation lies in whether treats are used ...
Veterinary medicine
Sep 19, 2019
0
4
We usually think of a species as being reproductively isolated—that is, not mating with other species in the wild. Occasionally, however, closely related species do interbreed. New research just published in The Auk: Ornithological ...
Ecology
Sep 17, 2019
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40
In 2008, a group of Chicago Public Schools students were on a leadership retreat for Black male students roughly 40 miles outside the city. Ignoring the cold of the fall night, 16 of those students left their bunks to take ...
Social Sciences
Sep 16, 2019
1
5
For male Trinidad Guppies applies: if you are hungry, seek female company. A recent study led by scientists of the the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) and the Leibniz Institute for Zoo and ...
Plants & Animals
Sep 13, 2019
0
6
If you've ever seen the Monterey Bay Aquarium's "Tentacles" exhibit, you know that cephalopods (squids, octopuses, and their kin) are awesome creatures. They can change the texture and color of their skin in the blink of ...
Plants & Animals
Sep 13, 2019
2
4
When a gorilla group's silverback is close to the end of his reproductive years, females face a dilemma: Should they stay with him until he dies or leave him for another male? A team of researchers from the Max Planck Institute ...
Plants & Animals
Sep 11, 2019
0
541
Transgenic mosquitoes released in Brazil in an effort to reduce the population of disease-bearing insects have successfully bred and passed on genes to the native mosquito population, a new Yale research study published Sept. ...
Plants & Animals
Sep 11, 2019
0
102
They say love is blind, but if you're a queen honeybee it could mean true loss of sight.
Plants & Animals
Sep 10, 2019
1
778
A tiny marsupial found only in northwest Australia mates so intensely that an entire generation of males can die off during a single breeding season, researchers reported on Friday.
Plants & Animals
Sep 06, 2019
0
13
A team of researchers from Universitat de les Illes Balears and Erasmus University Rotterdam, has found that female students score better than male students on tests over two hours long. In their paper published in the journal ...
Male (♂) refers to the sex of an organism, or part of an organism, which produces small mobile gametes, called spermatozoa. Each spermatozoon can fuse with a larger female gamete or ovum, in the process of fertilization. A male cannot reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and asexually.
Not all species share a common sex-determination system. In humans and most animals, sex is determined genetically but in other species it can be determined due to social, environmental, or other factors. The existence of two sexes seems to have been selected independently across different evolutionary lineages (see Convergent Evolution). Accordingly, sex is defined operationally across species by the type of gametes produced (ie: spermatozoa vs. ova) and differences between males and females in one lineage are not always predictive of differences in another.
Male/Female dimorphism between organisms or reproductive organs of different sexes is not limited to animals; male gametes are produced by chytrids, diatoms and land plants, among others. In land plants, female and male designate not only the female and male gamete-producing organisms and structures but also the structures of the sporophytes that give rise to male and female plants.
This text uses material from Wikipedia, licensed under CC BY-SA
