(Phys.org)—Males and females... Mars and Venus... XY and XX chromosomes—all are common memes. At the same time, the evolution of therian (placental and marsupial) sex chromosomes is less widely understood. More to the ...
Researchers of the Department of Ethology, Eötvös Loránd University (ELTE) have been investigating dogs' reactions to wolf howls. Are there dogs that are more prone to reply with howling? Are these dogs genetically closer ...
Ecology
Feb 6, 2023
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1671
If you happen to see termites engaging in courtship rituals, you'd be hard-pressed to spot the difference between opposite-sex and same-sex couples. That's because one of the termites in a same-sex couple changes its behavior ...
Plants & Animals
Nov 9, 2022
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109
Male and female mouse brains differ in important ways, according to a new study led by Stanford Medicine investigators.
Plants & Animals
Jan 21, 2022
10
298
Bearded dragon embryos can use two different sets of genes to become a female lizard—one activated by the sex chromosomes and the other activated by high temperatures during development. Sarah Whiteley and Arthur Georges ...
Plants & Animals
Apr 15, 2021
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154
We may take it for granted that the sex of an animal is established at birth and doesn't change.
Plants & Animals
Jul 10, 2019
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181
In a study published online today in Nature, researchers at Albert Einstein College of Medicine describe the first complete wiring diagram of the nervous system of an animal, the roundworm Caenorhabditis elegans, used by ...
Biotechnology
Jul 3, 2019
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4
Female fruit flies can feel when a sexual partner is a good fit. Scientists have long known that proteins in a male fly's ejaculate make female flies temporarily lose interest in other partners. It's a trick male flies use ...
Plants & Animals
May 6, 2019
0
114
A male mouse identifies the sex of an unfamiliar mouse because of hard-wired brain physiology, not previous experience, Stanford University School of Medicine investigators have found.
Plants & Animals
Jan 31, 2019
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103
A team of researchers from Japan, Brazil and Switzerland has found evidence that suggests female penis-like appendages in two types of cave insects evolved independently. In their paper published in the journal Biology Letters, ...
In biology, sex is a process of combining and mixing genetic traits, often resulting in the specialization of organisms into male and female types (or sexes). Sexual reproduction involves combining specialized cells (gametes) to form offspring that inherit traits from both parents. Gametes can be identical in form and function (known as isogametes), but in many cases an asymmetry has evolved such that two sex-specific types of gametes (heterogametes) exist: male gametes are small, motile, and optimized to transport their genetic information over a distance, while female gametes are large, non-motile and contain the nutrients necessary for the early development of the young organism.
An organism's sex is defined by the gametes it produces: males produce male gametes (spermatozoa, or sperm) while females produce female gametes (ova, or egg cells); individual organisms which produce both male and female gametes are termed hermaphroditic. Frequently, physical differences are associated with the different sexes of an organism; these sexual dimorphisms can reflect the different reproductive pressures the sexes experience.
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