The reproductive organ of male animals, in which sperm and the sex hormones (androgens) are produced. Vertebrates have two testes, which in most animals are contained inside the body. In many mammals, they lie outside the body and are enclosed by the scrotum. ...
Maternal gametes always contain an X chromosome, so the sex of the animals’ offspring depends on whether a sex chromosome is present in the male gamete. 有時字母0表示缺少第二個X.母性配子總是包含X染色體,因此動物後代的性別取決於雄性配子中是否存在性染色體。 LASER-wikipedia2 Structure and ...
As male grasshoppers carry only a single X, the lack of a pair leads to two distinct gametes. Each carries either an X or no sex chromosome at all. At the same time, all female gametes are of the X type. Thus, fertilization by the male gamete with an X or no sex chromosome de...
While the organization and function of cilia have been studied in many somatic cell types, little is known about cilia´s role and presence in germ cells. Gametogenesis is the biological process that gives rise to gametes: oocytes in the case of female oogenesis and spermatozoa in the case ...
We also share information about your use of our site with our social media, advertising and analytics partners who may combine it with other information that you’ve provided to them or that they’ve collected from your use of their services. Show details Deny Allow all...
What are the two types of gametes? The two types of gametes are the male gamete and the female gamete. What is the male gamete? The sperm is the male gamete, taken from the male parent for sexual reproduction. The male gamete in plants is often found in the pollen of a plant, while...
This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebraf...
We did not find significant correlations between numbers of pollen grains and ovules (P = 0.5164), although negative correlations have often been reported in between-species comparisons, as expected on theoretical grounds owing to trade-offs in resource allocation to male versus female function...
Evolutionary theory predicts that the sex ratio of Plasmodium gametocytes will be determined by the number of gametes produced per male gametocyte (male fecundity), parasite clonal diversity and any factor that reduces male gametes' ability to find and combine with female gametes. Despite the import...
Importantly, the mechanisms of sexual selection do not operate in isolation; thus, it is important to consider both male–male competition and mate choice as well as their post-copulatory equivalents, sperm competition, and cryptic female choice....