Related topics: females · sperm

Ancient DNA reveals the world's oldest family tree

Analysis of ancient DNA from one of the best-preserved Neolithic tombs in Britain has revealed that most of the people buried there were from five continuous generations of a single extended family.

Why males pack a powerful punch

Elk have antlers. Rams have horns. In the animal kingdom, males develop specialized weapons for competition when winning a fight is critical. Humans do too, according to new research from the University of Utah. Males' upper ...

Brazil mutant mosquitoes to breed out diseases

Scientists in Brazil are preparing to release millions of factory-bred mosquitoes in an attempt to wipe out their distant cousins that carry tropical diseases. The insects' method: have sex and then die.

Bolivian river dolphins observed playing with an anaconda

A trio of scientists, one with Universidade Federal do Rio Grande do Sul, another from Museo Historia Natural Noel Kempff Mercado and a third independent researcher, report evidence of several Bolivian river dolphins playing ...

Chimpanzees spontaneously dance to music

A pair of researchers at Kyoto University has found that chimpanzees will spontaneously dance to music. In their paper published in Proceedings of the National Academy of Sciences, Yuko Hattori and Masaki Tomonaga describe ...

NatGeo's 'Secrets of the Whales' surfaces little-known facts

When a killer whale slowly circled back toward wildlife photographer Brian Skerry in the middle of the ocean after discarding the giant sting ray it was devouring, panic is not what came to mind: "Part of my brain is thinking, ...

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Male

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.

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