X,Y chromosomes in other species?

Question

you know how for humans, males are XY and females are XX, so the male contribution determines the sex of the child? is it the same way for all other animals (at least those that reproduce sexually), or are there examples where the situation is reversed?

also, if it's always the same way, is there some evolutionary explanation for it?

Answer 1

Here is an interesting situation in some birds it is different:

ITHACA, N.Y. -- In mammals, sperm from the male determines the sex of the offspring. In birds, however, it is the female's sex chromosome that determines offspring sex. Now, Cornell University researchers think they understand the mechanism that several bird species use to bias the sex ratios of their offspring toward female.

From:
http://www.news.cornell.edu/stories/May05/birds.gender.ssl.html


But in platypuses, XXXXXXXXXX creates a female, while XYXYXYXYXY creates a male. In other words, rather than a single chromosome pair, platypuses have a set of ten-chromosomes that determine their sex.

The researchers worked out the make-up of platypus sex chromosomes by using fluorescent markers to stain chromosomes in platypus cells before examining them under a microscope.

The researchers also found that when sperm is produced by male platypuses, the chromosomes are precisely distributed to form XXXXX-bearing sperm and YYYYY-bearing sperm. When an XXXXX-bearing sperm fertilises an egg it produces a female platypus. YYYYY-bearing sperm would produce a male.

From:
http://www.newscientist.com/article.ns?id=dn6568

Also, I remember learning in school that the sex of turtle hatchlings is determined by temperature and not by sex chromosomes.

Also, as mentioned by someone else, the fruit fly drosophila , and some other insects have a sex ratio that determines sex (ie, the number of x vs y).

Answer 2

A humans' sex is predetermined in the sperm gamete.

The egg gamete mother cell is said to be homo gametic, because all its cell possess the XX sex chromosomes. sperm gametes are deemed hetero gametic because around half of them contain the X chromosome and others possess the Y chromosome to compliment the first X chromosome.

In light of this, there are two possibilities that can occur during fertilization between male and female gametes, XX and XY. Since sperm are the variable factor (i.e. which sperm fertilizes the egg) they are responsible for determining sex.
There are exceptions, however. Among humans, some men have two X's and a Y ("XXY", see Klinefelter's syndrome), or one X and two Y's (see XYY syndrome), and some women have three Xs or a single X (and no Y, "X0", see Turner syndrome). There are other exceptions in which SRY is damaged (leading to an XY female), or copied to the X (leading to an XX male). For related phenomena see Androgen insensitivity syndrome and Intersex.

Many groups of organisms in addition to mammals have Y chromosomes, but these Y chromosomes do not share common ancestry with mammalian Y chromosomes. Such groups include fruit flies (Drosophila melanogaster and relatives), some other insects, some fish, some reptiles, and some plants. In fruit flies, the Y chromosome does not trigger male development. Instead, sex is determined by the number of X chromosomes. So XXY fruit flies are female, and fruit flies with a single X (X0), are male but sterile.

Answer 3

Your question refers to sexually reproducing organisms. There is a diversity of ways sex is determined genetically, even within vertebrates! For example, there is an analogous system in amphibians and birds (and some insects) to our XX/XY system: the ZZ/ZW system, which operates similarly. A number of reptiles have the ZZ/ZW system, but can also change their sex based on size (fish) or is determined in part by temperature during development (many reptiles).

In insects, there are ZZ/ZO and XX/XO systems, where a lack of a second sex chromosome determines the other gender. Organisms like grasshoppers and some butterflies and moths have this type of sex determination.

This is different to haplodiploidy. Haplodiploids have different genome sizes for genders (say 10 and 20 chromosomes; usually called n and 2n). This is common in social insects like bees, termites, and ants.

Answer 4

As I understand it sex is determined by the male in all mammals at least by contributing an X or Y chromosome. As for non-mammalians I am not sure since breeding in non mammalians can be very different.

As for evolutionary explanation: We all came from a common ancestor at one point and that reproductive trait was passed down.

Answer 5

there is relatively many a thank you to offer existence alongside with human beings.. it relatively is been completed with genetic cloning via our very own for the previous 60 yrs or so. i'm undecided precisely how the virgin beginning became into fertilized, yet there are a number of selections to copulation. additionally, yet another ingredient to evaluate is that for the period of accordance to mediums alongside with Edgar Cayce and another factors, Yeshua and his mom, Mary, have been of a similar soul, so particularly a similar individual in 2 bodies. i'm examining some thrilling ideas in 'Jesus and the Essenes' via Dolores Cannon. you are able to locate that thrilling.. i'm only getting into section 2 and the honestly existence of Jesus, so i haven't study too a lot yet. Pz

Answer 6

no the situation is different in some other animals,for example in butterflies ,the female has the XY.

Answer 7

I imagine so since we are also animals!