BioScience Dictionary

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Ot.

Found Sex chromosome 16 times.

Displaying results 1 to 10.

1. Autosome
A chromosome not involved in sex determination. The diploid human genome consists of 46 chromosomes, 22 pairs of autosome s, and 1 pair of sex chromosome s (the X and Y chromosomes).

2. Autosomes
The chromosomes other than the sex chromosomes . Each member of an autosome pair (in diploid organisms) is of similar length and in the genes it carries.

3. Bobbed
The name for a variety of Drosophila (a fruit fly) mutation where the bristles (mostly on the back of the head) are very short and thin compared to normal fruit fly bristles. Also, the number of copies of gene s encoding rRNA molecules are reduced.The mutant allele is located on the sex chromosome s and is recessive .

4. 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).

5. 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).

6. 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 .

7. 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 .

8. 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 .

9. Sex chromosomes
The chromosomes that determine the sex of an organism. In humans, females have two X chromosomes , and males have one X chromosome and one Y chromosome. Chromosome that determines the gender (sex) of the individual. Human males have a large X and a smaller Y sex chromosomes, while human females have two X sex chromosomes.

10. Sex linkage
The condition in which the inheritance of a sex chromosome is coupled with that of a given gene ; e.g., red-green color blindness and hemophilia in humans. Traits located on the X-chromosome .