Sex Chromosomes
The nuclei of human cells contain 22 autosomes and 2 sex chromosomes. In females, the sex chromosomes are the 2 X chromosomes. Males have one X chromosome and one Y chromosome.
sex-influenced traits
those traits influenced or modified by the presence of a particular sex organ (and its secretions), such as the beard and voice of the male caused by hormones from the male testes ...
Sex-Linked Inheritance Problem Set
The study of inheritance of genes located on sex chromosomes was pioneered by T. H. Morgan and his students at the beginning of the 20th century.
sex pili
(Science: cell biology) fine filamentous projections (pili) on the surface of a bacterium that are important in conjugation.
The sex switch or testis-determining factor in human beings located on the Y chromosome. (Sry in mice.)
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 ...
Search for sex in these other databases too
Definition of sex :
1. One of the two classifications of living organisms that distinguish male and female.
2. activities associated with sexual intercourse ...
Sex Linked
Sex linked is a trait in which a gene is located on a sex chromosome. In humans, the term generally refers to traits that are influenced by genes on the X chromosome.
Sex and Disease
Sex is an important aspect of human identity, but it is also important in health. Women outlive men. In the United States at the start of the twenty-first century, a woman's life expectancy at birth is 79 years, and a man's is 72.
Sex Determination
The Y chromosome carries the gene for testis determination (SRY gene). In developing embryos, the gonads and external genitalia are undifferentiated until about 7 - 8 weeks gestation.
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.
sex-linked trait
An inherited trait, such as color discrimination, determined by a gene located on a sex chromosome and that therefore shows a different pattern of inheritance in males and females.
sexual dimorphism ...
Sex chromosomes: The X and Y chromosomes in human beings that determine the sex of an individual. Females have two X chromosomes; males have one X an d one Y. Single strand: One half of a DNA double helix.
Sex Chromosome One of the chromosomes which are present in different numbers in males and females. In humans this means the X and Y chromosomes, XX in females and XY in males.
Sex ratios
This is part 14 in my series called "evidence for evolution". For Bob's benefit, I'll explain what this is about. In this series I post summaries of recent scientific papers about evolution.
sex cells
gametes. In the male it is the sperm and in the female it is the egg.
Sex Chromosomes
Humans have 23 pairs of chromosomes (46 total) chromosomes. Two of these are called sex chromosomes, the other 44 are called autosomes.
Male Sex Hormones
The anterior pituitary produces follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Action of LH is controlled by the gonadotropin-releasing hormone (GnRH).
Mixed sex identical twins
In extremely rare cases, identical twins have been born with opposite sexes (one male, one female).
[edit] Sex determination
Main article: Sex-determination system
The sex of a particular organism may be determined by a number of factors. These may be genetic or environmental, or may naturally change during the course of an organism's life.
Sex chromosome
The X and Y chromosomes in organisms that determine the sex of an individual. In human beings females have two X chromosomes in diploid cells; males have an X and a Y chromosome.
sex chromosome one of a pair of chromosomes whose composition determines gender
sex hormone A hormone that controls the timing of reproduction and sexual characteristics in vertebrates.
A sex chromosome is one of the two chromosomes that specify an organism's genetic sex. Humans have two kinds of sex chromosomes, one called X and the other Y. Normal females possess two X-chromosomes and normal males one X and one Y.
A female sex hormone secreted by the corpus luteum that, in conjunction with estradiol, functions to prepare and maintain the uterine mucosa for the reception, implantation, and development of a fetus if fertilization occurs.
Genome -- all of the genes carried by a single gamete; the DNA content of an individual, which includes all 44 autosomes, 2 sex chromosomes, and the mitochondrial DNA. Genotype -- genetic constitution of an organism.
Terms Pertaining to Zoological Nomenclature Allotype A specimen designated from the type series that is the opposite sex of the holotype.
Of these, 22 are autosomes and 1 is a sex chromosome.
Clones A group of cells derived from a single ancestor.
Cloning The process of asexually producing a group of cells (clones), all genetically identical, from a single ancestor.
There has been discussion in the scientific community about the sex of DNA donors. A library prepared from a female donor will contain DNA from the X chromosome in an amount equivalent to the autosomes, but will completely lack Y chromosomal DNA.
The term coined by Farmer and Moore (1905) for the process of two consecutive cell divisions in the diploid progenitors of sex cells. Meiosis results in four rather than two daughter cells (gametes), each with a haploid set of each chromosome pair.
Fisher's Theorem of the Sex Ratio: In a population where individuals mate at random, the rarity of either sex will automatically set up selection pressure favoring production of the rarer sex.
1107- Enlarged view from the front of the left Wolffian body before the establishment of the distinction of sex. (From Farre, after Kobelt.) a, a, b, c, d. Tubular structure of the Wolffian body. e. Wolffian duct. f. Its upper extremity. g.
autosome - any chromosome not involved in sex determination.
cell cycle - the progression of a parent cell from creation through growth and development through DNA synthesis to cellular division to produce to daughter cells.
Hermaphroditic: Having both male and female sex organs in one individual.
Hindwings: The second pair of wings of an insect.
Honeydew: The sugary liquid discharge from the anus of certain insects (Homoptera) such as aphids and scales.
Androgens the collective name for male sex hormones‚ including testosterone
(andro = a man; gen = bear‚ produce)
Aneuploidy having an abnormal number of chromosomes
(aneu = without; ploid = set of chromosomes) ...
Autosome. A chromosome that is not involved in sex determination.
B
beta-DNA. The normal form of DNA found in biological systems, which exists as a right-handed helix.
pheromone. A substance secreted by an organism to affect the behavior or development of other members of the same species; sex pheromones that attract the opposite sex for mating are used in monitoring certain insects.
Recombination occurs naturally in plants and animals during the production of sex cells (sperm, eggs, pollen) and their subsequent joining in fertilization. In microbes, genetic material is recombined naturally during conjugation.
These hollow, hairlike structures made of protein allow bacteria to attach to other cells. A specialized pilus, the sex pilus, allows the transfer of plasmid DNA from one bacterial cell to another. Pili (sing., pilus) are also called fimbriae (sing.
Gamete: A mature reproductive cell that is capable of fusing with another gamete of the opposite sex to form a zygote. Male gametes are typically known as sperm and female gametes a typically known as eggs. See also fertilization, zygote.
pheromone - intraspecific interindividual chemical communication; a substance, such as a sex attractant, that is given off by one individual and causes a specific reaction in other individuals of the same species (Bio Control Glossary) ...
 See also: Human, Organ, Cells, Cell, Chromosome
|
