Search results
Results from the WOW.Com Content Network
In sociology, heterogamy refers to a marriage between two individuals that differ in a certain criterion, and is contrasted with homogamy for a marriage or union between partners that match according to that criterion. For example, ethnic heterogamy refers to marriages involving individuals of different ethnic groups.
For example, there are moths and butterflies that are ZW, but some have been found female with ZO, as well as female with ZZW. [22] Also, while mammals deactivate one of their extra X chromosomes when female, it appears that in the case of Lepidoptera , the males produce double the normal amount of enzymes, due to having two Z's. [ 22 ]
Offspring have two sex chromosomes: an offspring with two X chromosomes (XX) will develop female characteristics, and an offspring with an X and a Y chromosome (XY) will develop male characteristics, except in various exceptions such as individuals with Swyer syndrome, that have XY chromosomes and a female phenotype, and de la Chapelle Syndrome ...
Homozygous and heterozygous. Zygosity (the noun, zygote, is from the Greek zygotos "yoked," from zygon "yoke") (/ z aɪ ˈ ɡ ɒ s ɪ t i /) is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism.
A dominant allele can be inherited from a homozygous dominant parent with probability 1, or from a heterozygous parent with probability 0.5. To represent this reasoning in an equation, let A t {\displaystyle \textstyle A_{t}} represent inheritance of a dominant allele from a parent.
A study on guppies, Poecilia reticulata, revealed that the female preference was sufficient to tightly maintain polymorphism in male traits. [6] This type of mate choice shows that costly preferences can persist at higher frequencies if mate choice is hindered, which would allow the alleles to approach fixation.
It has been suggested that Haldane's rule simply reflects the fact that the male sex is more sensitive than the female when the sex-determining genes are included in a hybrid genome. But there are also organisms in which the heterozygous sex is the female: birds and butterflies and the law is followed in these organisms. Therefore, it is not a ...
In birds and some reptiles, by contrast, it is the female which is heterozygous and carries a Z and a W chromosome while the male carries two Z chromosomes. In mammals, females can have XXX or X. [30] [31] Mammalian females bear live young, with the exception of monotreme females, which lay eggs. [32]