Do all members of a species have the same number of UNIQUE genes?

Question

Do all members of a species have the same number of unique genes? I know that each gene is responsible for one or many traits in a species. Is it possible for one member to have a wholly unique gene that is not found in other members or does that imply that the member actually belongs to a different species.

Lets say member 1 in a species has the following UNIQUE genes: A,B,C,D

Is it possible for member 2 to have the following UNIQUE genes: A,B,C,D,E.

I have been told that all members of a species have the same total number of UNIQUE genes. For the case above, either 4 genes or 5 genes. I do not know if this is true.

When i say unique, i am not taling about alleles or damaged genes. I mean a gene that is totally not found in the chromosome of the other member. Would this imply that member 2 has a wholly new trait that is not found in member 1 and therefore, member 2 actually is of a different species from member 1?

Thanks

Thanks for the answers. For the case of Down syndrome, where do they get the extra gene from: I believe down syndrome has to do with a damaged gene and not a wholly new unique gene.

For one of the replies below, when you say lost a gene, I believe that you mean the gene is deactivated. On the otherhand, I am talking about a wholly new gene. I know about the Y chromosome but thats different since it deals with sex. For instance, we know that humans get a gene from each parent to make a pair. In my case, if one parent had the E gene, where would the offspring get the other one gene that makes a pair? Doesn't this imply that they are actually different species?

Answer 1

all members of a species have the same NUMBER of chromosomes or genes BUT DIFFERENT arrangement of the genes.

Answer 2

Yes, a majority of members of a species do have identical number of UNIQUE genes. In fact, plants and animals have two copies of every gene.

However, a minority group within the species will experience mutation which usually increase the number of genes causing birth defects, etc. This is natural selection, since only the most fit are supposed to survive to pass on its genetic material. (Mutants are not supposed to survive.)

Down syndrome is a genetic disorder caused by EXTRA genetic material (DNA) (ie, presence of an extra 21st chromosome). Chromosomes are present in every cell of the body except red blood cells, carry genes. Human cells normally have 46 chromosomes that can be arranged in 23 pairs. One set of 23 chromosomes comes from the mother (egg cell or ovum) and the other half of the 23 pairs comes from the father (sperm cell).

In Down syndrome, 95% of all cases are caused by either the sperm or the egg cell having two 21st chromosomes instead of one, so the resulting fertilized egg has three 21st chromosomes. Recent research has shown that in these cases, approximately 90% of the time the abnormal cells are the eggs. The cause of the extra chromosome isn't known, but there is definitely connection with the mother's age.

Answer 3

as what you have stated, UNIQUE gene...every specie therefore have unique gene (even twins or triplets). normal species with 46 chromosomes have the same total number of chromosomes but some, although not visible that they may happen to lack or excess in their chromosome number. each chromoses of a specie is different--unique---to other specie.

Answer 4

Anything is possible. However, a whole new gene is unlikely, so it would be more likely that an individual or sub-population LOST a gene.

New genes usually arise from gene duplication events and subsequent functional divergence of one or both of the genes.

Answer 5

The Y-chromosome in humans would be an example. Males have it. Females don't.

And there are some resultant "trait differences."

Aloha