Search results
Results From The WOW.Com Content Network
The first fossilized evidence of sexual reproduction in eukaryotes is from the Stenian period, about 1.05 billion years old. [19] [20]Biologists studying evolution propose several explanations for the development of sexual reproduction and its maintenance.
Adolescent health creates a major global burden and has a great deal of additional and diverse complications compared to adult reproductive health such as early pregnancy and parenting issues, difficulties accessing contraception and safe abortions, lack of healthcare access, and high rates of HIV, sexually transmitted infections and mental health issues.
Gafrarium pectinatum, [2] [3] also known as Gafrarium tumidum, [4] [5] is a species of the genus Gafrarium in the family of Veneridae, order Veneroida in the bivalve class. They are edible clams. [5]
Labeled anatomy of the human vulva and nearby structures. The vulva is of all of the external parts and tissues and includes the following: [3] Clitoris: an organ located at the top of the vulva.
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction.It is initiated by hormonal signals from the brain to the gonads: the ovaries in a female, the testicles in a male.
Asexual reproduction in liverworts: a caducous phylloid germinating. Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes.
Sexual selection creates colourful differences between sexes in Goldie's bird-of-paradise.Male above; female below. Painting by John Gerrard Keulemans.. Sexual selection is a mechanism of evolution in which members of one sex choose mates of the other sex to mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual ...
A cercaria (plural cercariae) is a larval form of the trematode class of parasites. It develops within the germinal cells of the sporocyst or redia. [1] A cercaria has a tapering head with large penetration glands. [2]