BioScience Dictionary

 
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Found Heterogametic sex 10 times.

Displaying results 1 to 10.

1. Haldane's rule (Haldane's law)
If one of the two sexes is missing, sterile, or rare in a population of first-generation hybrid s between two different species , then that sex is the heterogametic sex (has two different sex chromosome s, such as XY as opposed to XX).

2. Hemizygous gene
Any gene which is present as only one copy in a diploid genome , when most other genes in the genome are present as two copies. The genes on the sex chromosome s of members of the heterogametic sex of a species are all hemizygous genes (for example, in humans, males have hemizygous genes on their X and Y chromosome s because they do not have two copies of either of those chromosomes).

3. Heterogametic sex
The gender which has two different sex chromosome s. For example: In humans, the male is heterogametic because he is XY (has an X chromosome and a Y chromosome ). In birds, the female is heterogametic because she is WZ (has a W chromosome and a Z chromosome ). Compare homogametic sex .

4. Heterogametic sex
The sex with two different chromosomes , such as males in humans and Drosophila.

5. Homogametic sex
The gender which has two copies of the same sex chromosome . For example: In humans, the female is homogametic because she is XX (has two copies of the X chromosome ). In birds, the male is homogametic because he is ZZ (has two copies of the Z chromosome ). Compare heterogametic sex .

6. Sex chromosomes
The chromosome s which determine the gender of the organism (for organisms whose gender is determined by gene s rather than by environment). In humans, fruit flies, and other animals where the male is the heterogametic sex , they are the X chromosome s and Y chromosome s. In birds, moths, and other animals where the female is the heterogametic sex, they are the W chromosome s and Z chromosome s. For humans, the sex chromosomes are the 23rd pair of all chromosomes. The sex chromosomes of most plants (when they exist) are also known as X and Y chromosomes; Ginkgo trees have a different system of sex chromosomes. Compare autosome .

7. W chromosome
A sex chromosome found in all birds and certain other animals where the female is the heterogametic sex . The W chromosome causes the individual to become female in bird species. It is part of the WZ set of sex chromosomes, where the female has one W chromosome and one Z chromosome , and the male has two Z chromosomes.

8. X chromosome
A sex chromosome found in humans, fruit flies, and certain other animals where the male is the heterogametic sex . In the XY set of sex chromosomes, the female has two X chromosomes and the male has only one (and usually also a Y chromosome ). In plants which use the XY system, this chromosome is female-determining.

9. Y chromosome
A sex chromosome found in humans, fruit flies, and certain other animals where the male is the heterogametic sex . The Y chromosome causes the individual to become male in most mammal species and carries few other gene s besides those dictating sperm development and triggering appropriate hormonal output. It is part of the XY set of sex chromosomes, where the male has only one X chromosome and usually a Y chromosome (fruit fly males can also have just one X and nothing else), and the female has two X chromosomes.

10. Z chromosome
A sex chromosome found in all birds and certain other animals where the female is the heterogametic sex . It is part of the WZ set of sex chromosomes, which are so designated to prevent confusion with the XY set of sex chromosomes for species where the male is the heterogametic sex. In the WZ system, the male has two Z chromosomes and the female has only one (and one W chromosome ).