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What does it mean to say that a gene is linked to a chromosome?
Wiki User
∙ 16y ago
This means that the gene is physically located on that particular chromosome.
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∙ 16y ago
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Does everyone have a recessive gene?
Yes. So do men. I believe it may be safe to say that any sexually reproducing individual will have at least some recessive genes. Women have 2 copys of the X chromosome, men have one copy of the Y chromosome and a single copy of the X chromosome. The Y chromosome contains much less information than the X chromosome. One of the genes on the Y chromosome is SRY this single gene prompts the body to develope into a male when the embyo is in the womb. In this case men have the gene and women don't have the gene, rather than women having a recessive copy of it. There are some XY women who have the SRY gene but lack a different gene which codes for the androgen receptors.
Why are males more likely to inherit sex-linked traits?
Females have XX chromosomes and males have XY chromosomes. Sex-linked traits are almost always carried on the X chromosome. Males are more likely to inherit sex-linked traits because they have only one chromosome that can carry a trait. If a male gets a recessive sex-linked trait, they will always acquire it because they have no other chromosome that will dominant over the recessive. In contrast, females have two X chromosomes which carry sex-linked traits. If they receive a recessive sex-linked trait, they always have one other chromosome that could be dominant over the other. For example: B - regular vision trait b - color blindness If a female has a colorblind father (XbY) and a mother with regular vision (XBXB), she will have XBXb. Even though the recessive colorblind trait was passed onto her, she will still have regular vision because of her other chromosome. Thus, she will be a carrier for colorblindness. Say the daughter above had children with a man with regular vision (XBY). If they have a son, there is a 50% chance he will be colorblind because of his mother who is a carrier. If they had a daughter, no matter what, she would always have regular vision with 50% chance that she will be a carrier.
Why do sex-linked traits follow different patterns of inheritence than other traits?
Sexlinked traits follow a different pattern of inheritance than a non-sex linked trait because of the size difference between the X and y chromosomes. Think about non-sex chormosomes as being the same size, each having the exact same number of genes in the same postions (loci). This means that a person has to have two copies of the recessive genes (one on each homolog of that chromosome) before the trait will be expressed. Lets say A is normal (dominant) and a is abnormal (recessive). People who are aa have the abnormal condition and people who are AA or Aa are normal. The normal ratio is 1 AA:2 Aa:1 aa if both parents are Aa. There is a 25% chance that a child will inherit two abnormal genes and the chance of any sex child will be so affected is exactly the same. When a recessive trait is located on the X chromosome only a female with two X chromosomes has the same number of genes on each X chromosome (the two X chromosomes have the same inheritance behavior as a homolog chromosome in females). In males who inherit the much smaller y chromosome there are many genes on the X chromosome that do not have a matching gene on the y chromosome. This means that recessive traits on the X chromosome that have no matching genetic material on the y chromosome will always be expressed. So, lets say that there is a family where the mother is Aa and the father (who only has one allele on the y chromosome is A. (A is normal and a is abnormal). None of the daughters produced can be aa, because the father will always pass A. Daughters will only be Aa or AA. Sons on the other hand, will get either A or a from the mother and, since the y chromosome has no genetic material at this gene locus the boys will be A normal or a affected at in a 1:1 ratio. If the father is a on his X chromosome, and the mother is AA 100% of the daughters will be carriers (Aa) and all the sons will be normal (A-).
What genetics are inherited by the father?
~uh... the father cannot inherit any genes, unless it's from his parents...but if you want to know what a father passes down to an offspring, I have that answer = Females are rarely affected by sex-linked traits because ______.? = a. female have one X chromosomeb. X-inactivation in malesc. X-inactivation in femalesd. X chromosomes in males generally have more mutations than X chromosomes in femalese. mutations on the X chromosome are not passed down to females, but are always passed down to malesMales are an "X" & a "Y" so I have no idea. I do know that Parkinson's Disease is passed from mother to son. My husband is concerned about that.*Female is XX and Male is XYIf the female is to suffer from a sex linked disease, she has to pick it up from the father's X chromosome. If the disease is "recessive", then it is masked over by the Mother's X chromosome that she passed down to the daughter. If the disease is on the father's X chromosome and is dominate in nature, that's a little different situation. The mother's X chromosome may carry a dominate allele for that same chromosomal location which may or may not mask over the diseased gene. In any case, it is the mother's X chromosome handed down to the daughter that reduces the likelihood of her experiencing a sex linked disease.The answer would d.)a.) almost seems right but females are XX not X0, generally. Though, after X chromosome inactivation, the female does have only one X chromosome, but ... she also has the X chromosome from the father. So, she does have XX chromosomes. d.) is your answer.See: Sex Linkagehttp:/en.wikipedia.org/wiki/Sex_linkage*Answer is probably C.A female is XX, but during development of the zygote, one of the X chromosomes is randomly turned off. This process is referred to as X-inactivation. If the sex linked trait is on the off X chromosome, then the female will not be affected.The answer is not D because the X chromosome carried by females that is "off" accumulates more mutations than the one in males since there is still one good copy of the chromosome left. The answer is definitely not A or B. Males need their one X chromosome to develop properly. E is partially right; mutations are not ALWAYS passed down to females, but a female can be a carrier for a genetic disease.Males have XY sex chromosomes while females have XX chromosomes & the fact is; These two chromosomes ( X & Y ) differ in shape. The X chromosome is larger than the Y chromosome & thus has a greater capacity of carrying genes. That is to say most genes are carried by the X chromosome whereas only a few genes are carried in the Y chromosomes.Therefore it takes only one defective gene eg. that causing Colour blindness in males for it to have phenotypical impact on the individual whereas it would take two defective genes on both X chromosomes in females for it to have phenotypical impact on the individual. Only one defective gene on either of the two X chromosomes in females results to a carrier individual, a condition whereby the individual carrying the defective gene( usually recessive) is only affected genotypically but looks normal phenotypically, she only carries the gene in her chromosomes but due to its recessiveness, it does not show its effect phenotypically.Due to this simple reason more males are affected by sex linked defects than females since females, due to the nature of their sex chromosomes can either be normal, carriers or affected( they have 3 alternatives) while we male only have 2(normal or affected)PS. You should know that most sex linked defects are carried on recessive genes( this is a fact)With this little lecture I'm sure you can pick the right answer from your multiple choice.Good luck.*c.the gene is carried on the X chromosome, and a girl has the trait on ONE of her X chromosomes, then she will need it on the other for it to be expressed MOST OF THE TIME. for guys, if they get the mutation on their ONLY X chromosome, they're stuck with it because only the X can carry such mutations** *:there are 2 X chromosomes in male and only 1 X chromosome in female, and X is where all the stuff happens, so male are twice likely to have a mutation in their sex chromosomes than females.* I believe the answer is C. The X chromosome does not affect females. Males are affected by the XY, and females by YY. ** 3 weeks ago 0% 0 Votes** 0 Rating: Good Answer ** 4 Rating: Bad Answer ** Report Abuse~scrunnchy
Where does the chromosome of galactosemia is located on?
Some scientists say: -The insulin dependent DDM1, Diabtese mellitus is on chromosome 6 -Type 1 Diabetes was found on chromosome 1q42, and possibly 11 -Type 2 Diabetes on Chromosomes 12 and/or 20
What is the relation between DNA Gene Chromosome and Genome?
DNA is the smallest unit say a letter, then Gene it's like word, after that Chromosome it's like a sentence, Finally the biggest unit is Genome it's like a paragraph.
Which chromosome is connected with colorblindness?
There are many chromosomes linked to colour blindness. If you are reading a really old text book or your teacher is a fossil and hasn't done any work since the 60's then they will say that colour blindness is linked to the sex chromosomes. More men than women have Red-Green colour blindness as the "dodgy" copy of the gene is on the X chromosome which males only get one copy of. Females have two X chromosomes and so are more likely to get at least one "good" copy of the gene. Yawn, this is a lie, well its outdated science which is just as bad. Currently around half the human chromosomes linked to colour blindness in one way or another.
What do you call the genes that are located on the sex chromosomes?
genes located on sex chromosomes are called sex-linked genes. In humans, there are two types of sex chromosomes: X and Y chromosomes.Genes located on the X chromosome are called X-linked and genes located on the Y chromosome are called Y-linked chromosomes.
Does everyone have a recessive gene?
Yes. So do men. I believe it may be safe to say that any sexually reproducing individual will have at least some recessive genes. Women have 2 copys of the X chromosome, men have one copy of the Y chromosome and a single copy of the X chromosome. The Y chromosome contains much less information than the X chromosome. One of the genes on the Y chromosome is SRY this single gene prompts the body to develope into a male when the embyo is in the womb. In this case men have the gene and women don't have the gene, rather than women having a recessive copy of it. There are some XY women who have the SRY gene but lack a different gene which codes for the androgen receptors.
Why do sex-linked traits follow different patterns for inheritance than other traits?
Short Answer: There are just over a thousand genes on the X chromosome and about 26 on the Y. Of the 26 on the Y, 9 relate to sperm and one (SRY) relates to male anatomy, the others involved in general tasks. The fact that there are a hundred times more genes on the X chromosome means that traits related to the X, and variations in those traits, are far far more common. Sex-linked traits are those that can only be passed along from the father and not the mother or from the mother and not the father. Obviously, males do carry and pass on sex-linked traits, just not very many. Gender can only be passed along from the father, along with genes related to sperm. Females pass on to the male offspring a larger number of traits, (such as some color blindness and male pattern baldness) which have no counterpart in the Y chromosome. More: Males have an X and a Y chromosome and females have two X chromosomes. Because the Y chromosome is smaller than the X with far fewer genes, there are genes carried only on the X and only gotten from the mother. That does not mean that all males have Y chromosomes that are the same. Overwhelmingly though, the absence of the set of genes on the Y chromosome results in the corresponding genes on the X chromosome being expressed, in particular all of the X-linked disorders of a gene of an X chromosome in a male do not have a second X gene that can be expressed to compensate. Thus, there are a set of sex-linked traits that can only come from the mother. (Color blindness and male pattern baldness are the two most discussed examples.) A male offspring (son) has the same Y chromosome as the father and hence any traits influenced by that chromosome. A female offspring (daughter) has the same X chromosome as the father and hence any traits influenced by that chromosome. A recessive gene on the X from the father will not usually be expressed in a daughter, but a dominant gene on the X from the father will be expressed in the daughter. For a female to inherit a trait associated with an X-chromosome recessive gene, there must be two copies, one from each parent. Aside: The issue of gender-connected inherited traits has much more complexity than this simple discussion can address. For example, not all of the so-called male characteristics are carried on the male (Y) chromosome. The expression of genes on other chromosomes, from both the mother and father, is influenced by genes on the Y chromosome or simply by the absence of two X chromosomes. The reader should investigate further. Caveat: This discussion applies to humans and other mammals with the XX/XY sex determination system. See related links. Fun Fact: A woman discovered that the Y chromosome was male. While studying worms, in 1905, Nettie Stevens at Bryn Mawr College identified the Y chromosome as the determining factor in gender.
Is blue eyes a birth defect?
Yes in fact colorblindness is related to genetics. Colorblindness is a sex (gender) linked disorder. In order to find out how colorblindness is inherited you must first know a little bit about sex linked genes. Every person has 2 sets of gene for each trait (one set comes from your mom and one set comes from your dad) except when it comes down to genes found on your 22 chromosome ( or sex chromosomes) The X sex chromosome is bigger than the Y chromosome and thus holds a few extra genes on it. In females because they have two X chromosomes they still have two of every gene. However, in males they only have one X and therefore they only have one set of the genes that are only found on the X chromosome and not the Y. Colorblindness is one of these genes. It is also a recessive gene found on the X chromosome. Because females have two X's they are not likely to become colorblind. This is because in most cases a female will inherit the gene for colorblindness in one X and a gene for normal vision on the other X. But because males only have one X, if they have the gene for colorblindness they do not have another gene to dominate this one and therefore become colorblind. In order for a male to become colorblind his mother should be either colorblind or a carrier for colorblindness, as a male gets his X chromosome from his mother.
Why a species has homologous chromosomes?
Basically we are all made up from 50% mum and 50% dad. Chromosomes are a condensed version of our DNA; these chromosomes (DNA) contain the genes that tell our body what to do during development and throughout our lives. We have 23 chromosome pairs in total we get one chromosome from the mother and one from the father. The chromosomes are called homologous since each chromosome pair will contain the same genes on it but the genes will not necessarily code for the same thing. For example a chromosome will have the genes for eye color on it and since we have one from the mother and father we will have a pair of chromosomes with the gene with eye color on it. This would be a homologous chromosome pair, however one gene may say blue eyes the other may say brown eyes. The genes are still the same however each color would be a different allele for the gene.
Is it linked to or linked with?
we can say both.
Why are X linked traits more common in mals then in females?
This is because males have one X chromosome while females have two. Example: Say a mother is homozygous for a certain recessive X-linked trait (ie x*x*) while the father does not have this x-linked trait (XY) If they have one boy and one girl: The girl will receive an x chromosome from each parent, and will be x*x: this means she will be a carrier only, and will not display this recessive trait. The boy will receive an x chromosome from his mom and a y chromosome from his dad, so he will have to be x*y. The boy will always display the trait. It works similarly if the mother is a carrier(ie x*x): the boy is more likely to display the trait because he gets only one x chromosome.
What is the difference between recessive disorders and dominant disorders?
A sex linked dominant trait could be on the X chromosome of either parent and the phenotype of any individual carrier would be that of the dominant trait. A father with the dominant characteristic on his single X chromosome would produce daughters that are 100% carriers and would not pass the characteristic on to his sons. A mother who is a dominant X linked carrier would pass the dominant characteristic on to half hersons and half her daughters all of which would show the trait phenotypically. A sex linked recessive father would produce 100% carrier daughters. His sons would not get the recessive allele from him. A sex linked recessive carrier (heterozygous) mother would pass the trait on to 50% of her children and 50% of her sons would show the recessive trait genetics.
Why are males more likely to inherit sex-linked traits?
Females have XX chromosomes and males have XY chromosomes. Sex-linked traits are almost always carried on the X chromosome. Males are more likely to inherit sex-linked traits because they have only one chromosome that can carry a trait. If a male gets a recessive sex-linked trait, they will always acquire it because they have no other chromosome that will dominant over the recessive. In contrast, females have two X chromosomes which carry sex-linked traits. If they receive a recessive sex-linked trait, they always have one other chromosome that could be dominant over the other. For example: B - regular vision trait b - color blindness If a female has a colorblind father (XbY) and a mother with regular vision (XBXB), she will have XBXb. Even though the recessive colorblind trait was passed onto her, she will still have regular vision because of her other chromosome. Thus, she will be a carrier for colorblindness. Say the daughter above had children with a man with regular vision (XBY). If they have a son, there is a 50% chance he will be colorblind because of his mother who is a carrier. If they had a daughter, no matter what, she would always have regular vision with 50% chance that she will be a carrier.
What does it mean when you say their gene poll is gone?
There's no other non-family specimens to mate with.
