Biology Questions and Answers
Sex Determination
and Sex-Linked
Inheritance
- How is the genetic
determination of sex
established in humans?
In the diploid genome of human beingsthere are 46 chromosomes, 44 of them (^)
are autosomes and two are sex
chromosomes. Tone of these chromosomhe individual ines from eachherits (^)
parent.
The human sex X chromosome and Y chromosomchromosomes are callede.
Individuals havi(44 + XX) are female. Ing two X chromosomndividuals es
having one X chromosome and one Y
chromosome (Individuals 44 (44 + XY) are + YY do not exist sincemale. (^)
the chromosome Y is exclusively from
paternal lineage.)
- What are the homologous
and the heterologous portions
of the human sex
chromosomes?
Homologous portion is that in which
there are genes having alleles in and X sex chromosomes. The both Y
homologous portions are situated more
in the central pchromosomes, nart of the sexear the centrom (^) ere.
Heterologous portion is that whose
genes do not have correspondent allelesin the other sex chromosome. These
genes are located more in the peripheral
regions of the arms of the Y and Xchromosomes.
- Concerning the sex
chromosomes of the XY
system which type of gamete
do the male and the female
individuals respectively
produce?
The individual of the male sex is XY so
he forms gX chromosome ametes coor the Y chromntaining eosome iither then (^)
a 1:1 proportion. The individual of the
female only gamsex is XXetes containin and thus shg an Xe forms
chromosome.
- Is it possible that an X
chromosome of a woman can
have come from her father?
It is not only possible that achromosome of a woman is from hern X (^)
father, it is certain. an X chromosome from her father andEvery woman has (^)
the other X chmother. romosome from her
In men however the X chromosomcomes always from his mother and thee (^)
Y chromosome is always from his
father.
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