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Encyclopedia > Human genetics
A karyotype of a human male, showing 46 chromosomes including XY sex chromosomes.

Human genetics describes the study of inheritance as it occurs in human beings. This article describes only basic features of human genetics; for the genetics of disorders please see: Medical genetics. Image File history File links Human_male_karyotpe. ... Image File history File links Human_male_karyotpe. ... Karyogram of human male using Giemsa staining. ... Medical Genetics is the application of genetics to medicine. ...

Contents

Chromosomes

Humans have 46 chromosomes, arranged in 23 pairs (i.e. they are diploid). 44 (22 pairs) of these chromosomes are autosomes, and 2 (1 pair) are sex chromosomes. Humans have an XY sex determination system, so that females have the sex chromosomes XX and the males XY. The Y chromosome is shorter than the X chromosome, so that males are hemizygous over this region. X-linked recessive genes are thus expressed more often in males. A Humans' gender is determined by the x and the y chromosomes. Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ... Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ... An autosome is a non-sex chromosome. ... A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. ... The XY sex-determination system is a well-known sex-determination system. ... Look up Female in Wiktionary, the free dictionary. ... This article is about the Male sex. ... It has been suggested that this article be split into multiple articles accessible from a disambiguation page. ...


Number of genes

Estimates of the number of genes humans have has been possible since DNA sequencing was first introduced. Estimates however have varied wildly, though the present best guess is 20,000-25,000, estimates of up to 40,000 have been in the past. Hey yall wats up? The term DNA sequencing encompasses biochemical methods for determining the order of the nucleotide bases, adenine, guanine, cytosine, and thymine, in a DNA oligonucleotide. ...


Mitochondrial DNA

In addition to nuclear DNA, humans (like almost all eukaryotes) have mitochondrial DNA. Mitochondria, the "power houses" of a cell, have their own DNA because they are descended from a proteobacterium that merged with eukaryotic cells over 2 billion years ago. Mitochondria are inherited from one's mother, and its DNA is frequently used to trace maternal lines of descent (see mitochondrial Eve). Nuclear DNA is DNA contained within a nucleus of eukaryotic organisms. ... Kingdoms Eukaryotes are organisms with complex cells, in which the genetic material is organized into membrane-bound nuclei. ... Mitochondrial DNA (some captions in German) Mitochondrial DNA (mtDNA) is the DNA located in organelles called mitochondria. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ... Orders Alpha Proteobacteria    Caulobacterales - e. ... Mitochondrial Eve (mt-mrca) is the name given by researchers to the woman who is the matrilineal most recent common ancestor (MRCA) for all living humans. ...


Genes and human characteristics

Genes have both minor and major effects on human characteristics. Human genes have become prominent in the nature versus nurture debate. The nature versus nurture debates concern the relative importance of an individuals innate qualities (nature) versus personal experiences (nurture) in determining or causing individual differences in physical and behavioral traits. ...


Genes and behavior

Genes have a strong influence on human behavior. IQ is largely heritable. However, this has been questioned. The stance that humans inherit substantial behavioral characteristics is called psychological nativism, compared to the stance that human behavior and culture are virtually entirely constructed (tabula rasa). IQ redirects here; for other uses of that term, see IQ (disambiguation). ... The subject of the inheritance of intelligence is the genetics of mental abilities. ... In the field of psychology, nativism is the view that certain skills or abilities are native or hard wired into the brain at birth. ... Tabula rasa (Latin: scraped tablet or clean slate) refers to the epistemological thesis that individual human beings are born with no innate or built-in mental content, in a word, blank, and that their entire resource of knowledge is built up gradually from their experiences and sensory perceptions of the...


In the early 20th century, eugenics was policy in parts of the United States and Europe. The goal was to reduce or eliminate people whose genes were considered inferior. One form of eugenics was compulsory sterilization of people deemed mentally unfit. Hitler's eugenics programs turned social consciousness against the practice, and psychological nativism became associated with racism and sexism. Eugenics is the self-direction of human evolution: Logo from the Second International Congress of Eugenics, 1921, depicting it as a tree which unites a variety of different fields. ... Compulsory sterilization programs are government policies which attempt to force people to undergo surgical sterilization. ... Adolf Hitler Adolf Hitler (April 20, 1889 – April 30, 1945, standard German pronunciation in the IPA) was the Führer (leader) of the National Socialist German Workers Party (Nazi Party) and of Nazi Germany from 1933 to 1945. ... A necessary part of society, social consciousness brings moral implications into all aspects of science. ...


Genes and gender

The biggest genetic difference among healthy humans is in gender. Scientists debate the extent to which genes and culture affect gender roles. The case of David Reimer was once a case in point for the tabula rasa camp, though recently that same case has become evidence for a strong genetic component to gender identity. David Reimer (August 22, 1965 – May 4, 2004) was a Canadian man who was born as a healthy boy, but was sexually reassigned and raised as female after his penis was inadvertently destroyed during circumcision. ...


Genes and race

Most genetic diversity occurs within races rather than between them. Common concepts of racial categories do not accurately match genetic characteristics. This article is about race as an intraspecies classification. ...


Evolutionary psychology

Evolutionary psychology explains many human behaviors as more or less moderated by genes that evolved in the hunter-gatherer stage of human cultural development. See for example Stockholm syndrome. This article includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... It has been suggested that this article or section be merged with Capture-bonding. ...


Genetic disorders

Main article: Genetic disorder

Humans have several genetic diseases, often caused by recessive genes. See List of genetic disorders. Genetic disorders happen everywhere and are very common in some places. A genetic disorder is a disease caused by abnormalities in genes or chromosomes. ... A genetic disorder, or genetic disease is a disease caused, at least in part, by the genes of the person with the disease. ... It has been suggested that this article or section be merged into Dominance relationship. ... // The following is a list of genetic disorders and their origins. ...


Human traits with simple inheritance patterns

Dominant Recessive References
Widow's Peak No Widow's Peak [1][2]
Facial Dimples No Facial Dimples [3][4]
Able to taste PTC Unable to taste PTC [5]
Unattached earlobe Attached earlobe [3][6][7]
Cleft chin No Cleft chin [8]
Freckles No Freckles [3][9]
Wet-type earwax Dry-type earwax [6][10]

Widows peak A widows peak is a descending V-shaped point in the middle of the hairline (above the forehead). ... Widows peak A widows peak is a descending V-shaped point in the middle of the hairline (above the forehead). ... For other uses, see Dimple (disambiguation). ... Phenylthiocarbamide, also known as PTC, or phenylthiourea, is a synthetic organic molecule. ... Phenylthiocarbamide, also known as PTC, or phenylthiourea, is a synthetic organic molecule. ... A cleft chin is unique trait resulting in a dimple on the chin. ... A cleft chin is unique trait resulting in a dimple on the chin. ... Freckles are small brownish spots of melanin on human skin in people of fair complexion, predominantly found on the face. ... Freckles are small brownish spots of melanin on human skin in people of fair complexion, predominantly found on the face. ... Wet-type human earwax on a cotton swab. ... Wet-type human earwax on a cotton swab. ...

See also

Human mitochondrial DNA (mtDNA) haplogroups Human evolutionary genetics studies how one human genome differs from the other, the evolutionary past that gave rise to it, and its current effects. ... A graphical representation of the normal human karyotype. ... Genetic genealogy is the application of genetics to traditional genealogy. ... A genealogical DNA test examines the nucleotides at specific locations on a persons DNA for genetic genealogy purposes. ... Hypothesized map of human migration based on mitochondrial DNA. In human genetics, Human mitochondrial DNA haplogroups are haplogroups defined by differences in human mitochondrial DNA. These haplogroups trace the matrilineal inheritance of modern humans back to human origins in Africa and the subsequent spread across the globe. ...

  most recent common mt-ancestor    
L0   L1  
L2 L3   L4 L5 L6 L7
  M N  
CZ D E G Q   A I O   R   S W X Y
C Z B F pre-HV   pre-JT P  UK
HV JT U K
H V J T

Human Y-chromosome DNA (Y-DNA) haplogroups Mitochondrial Eve (mt-mrca) is the name given by researchers to the woman who is the matrilineal most recent common ancestor (MRCA) for all living humans. ... In human genetics, Haplogroup L0 is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup L1 is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup L2 is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup L3 is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup L4 is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup L5 is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup L6 is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup L7 is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup M is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup N is a human mitochondrial DNA (mtDNA) haplogroup. ... In human mitochondrial genetics, Haplogroup CZ is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup D is a human mitochondrial DNA (mtDNA) haplogroup. ... In human mitochondrial genetics, Haplogroup E is a human mitochondrial DNA (mtDNA) haplogroup which can be used to define genetic populations. ... In human mitochondrial genetics, Haplogroup G is a human mitochondrial DNA (mtDNA) haplogroup. ... In human mitochondrial genetics, Haplogroup Q is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup A is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup I is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup O is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup R is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup S is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup W is a human mitochondrial DNA (mtDNA) haplogroup. ... // In human mitochondrial genetics, Haplogroup X is a human mitochondrial DNA (mtDNA) haplogroup which can be used to define genetic populations. ... In human mitochondrial genetics, Haplogroup Y is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup C is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup Z is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup B is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup F is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup pre-HV is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup pre-JT is a human mitochondrial DNA (mtDNA) haplogroup. ... In human mitochondrial genetics, Haplogroup P is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup HV is a human mitochondrial DNA (mtDNA) haplogroup. ... Haplogroup JT is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Haplogroup U is a human mitochondrial DNA (mtDNA) haplogroup. ... Haplogroup K is a human mitochondrial DNA (mtDNA) haplogroup. ... Haplogroup H is a mitochondrial DNA (or mtDNA) haplogroup. ... In human genetics, Haplogroup V is a human mitochondrial DNA (mtDNA) haplogroup. ... Haplogroup J is a human mitochondrial DNA (mtDNA) haplogroup. ... Haplogroup T is a human mitochondrial DNA (mtDNA) haplogroup. ... In human genetics, Human Y-chromosome DNA haplogroups are haplogroups defined by differences in the non-recombining portions of DNA from the Y chromosome (called Y-DNA). ...

Y-most recent common ancestor
|
A BR
B CR
C DE F
D E G H IJ K
I J L M NO P
N O Q R

In human genetics, Y-chromosomal Adam (Y-mrca) is the male counterpart to mitochondrial Eve: the most recent common ancestor from whom all male human Y chromosomes are descended. ... In human genetics, Haplogroup A (M91) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup BR, also known as Haplogroup YxA (SRY10831. ... In human genetics, Haplogroup B (M60) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup CR (M168, M294) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup C (RPS4Y=M130, M216) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup DE (M1, M145, M203) is a human Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup F (defining mutations M89, P14, and M213) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup D (M174) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup E (M96) is a human Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup G (M201) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup H (M52) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup IJ (S2, S22) is a human Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup K (M9) is a Human Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup I (M170) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup J (previously known as HG9 or Eu9/Eu10) is a Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup L (M20) is a Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup M (M4) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup NO (M214) is a human Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup P (M45) is a Y-chromosome haplogroup. ... In human genetics, Haplogroup N (LLY22G) is a Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup O (M175) is a Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup Q (M242) is a Y-chromosome DNA haplogroup. ... In human genetics, Haplogroup R is a Y-chromosome DNA haplogroup, a subgroup of haplogroup P, associated with the M207 mutation. ...

References

  1. ^ Campbell, Neil; Jane Reece (2005). Biology. San Francisco: Benjamin Cummings, pp. 265. 
  2. ^ Online Mendelian Inheritance in Man, ID=194000 [1]
  3. ^ a b c http://www.science.edu.sg/ssc/detailed.jsp?artid=4862&type=6&root=4&parent=4&cat=40
  4. ^ Online Mendelian Inheritance in Man, ID=126100 [2]
  5. ^ http://www.medicalnewstoday.com/articles/10009.php
  6. ^ a b Cruz-Gonzalez L., Lisker R. (1982). "Inheritance of ear wax types, ear lobe attachment and tongue rolling ability.". Acta Anthropogenet. 6 (4): 247-54. PMID 7187238. 
  7. ^ Online Mendelian Inheritance in Man, ID=128900 [3]
  8. ^ Online Mendelian Inheritance in Man, ID=119000 [4]
  9. ^ Xue-Jun Zhang et al. "A Gene for Freckles Maps to Chromosome 4q32–q34" Journal of Investigative Dermatology (2004) 122, 286–290 [5]
  10. ^ Online Mendelian Inheritance in Man, ID=117800 [6]

Neil A. Campbell (1946 – 2004) was an American scientist known best for his Biology textbook. ... Pearson Education is one of leading publishers of educational textbooks and other educational material, such as multimedia learning tools. ...

External links

  • Human Genome Project
  • How many Genes do humans have?

  Results from FactBites:
 
Human Genome Project Science (1855 words)
The human genome's gene-dense "urban centers" are predominantly composed of the DNA building blocks G and C. In contrast, the gene-poor "deserts" are rich in the DNA building blocks A and T. GC- and AT-rich regions usually can be seen through a microscope as light and dark bands on chromosomes.
Humans have on average three times as many kinds of proteins as the fly or worm because of mRNA transcript "alternative splicing" and chemical modifications to the proteins.
Humans share most of the same protein families with worms, flies, and plants, but the number of gene family members has expanded in humans, especially in proteins involved in development and immunity.
Human Genetics (1240 words)
Topics include an overview of human genetics in Mendelian genetics, cytogenetics, population genetics, molecular cytogenetics, oncocytogenetics, and clinical applications of principles, and the importance and implications of genetic disease at the levels of the population and individual families.
Covers basic genetic principles, with emphasis on biochemical and molecular approaches to the study of human health and metabolic disease; primary genetic defects underlying a diversity of disorders; molecular and biochemical genetics; immunogenetics; cancer genetics; neurogenetics and developmental genetics; and clinical applications of metabolic and molecular studies.
Topics include the application of genetic counseling to specific disorders; the psychosocial aspects of genetic disease; current topics in genetic counseling, such as cancer genetics and the genetics of psychiatric disorders; and ethical issues and the National Society of Genetic Counselors Code of Ethics.
  More results at FactBites »

 
 

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