Females with Triple X syndrome 47,XXX or males with 47,XYY tend to be taller than average, but usually show few other physical differences Table 4 and have normal fertility, thus can go undiagnosed. Whereas human females possess a pair of homologous X chromosomes, males have a single, largely unpaired X and non-homologous Y, whose unpaired status is not recognized by checkpoint machinery .
Sharat There is also a potential conflict between the needs of the developing foetus and the continued health of the mother.
It is thus the male's sperm that determines the sex of each offspring in mammals. Purine French : purine A nitrogen- containing, single-ring, basic compound that occurs in nucleic acids. A recent study in mice provides compelling evidence for the importance of MSCI in male fertility  ; however, as perturbation of both transcriptional silencing and checkpoint signaling results in elevated apoptosis it is difficult to determine the relative contributions of these processes to ensuring the formation of gametes from the heterogametic sex.
Questions 69 -
So, if your question is about humans, the answer is: The Cell in Development and HeredityEd. Maize diploid or palaeotetraploid . When a male and a female gamete merge fertilizationa new diploid organism is formed.
How many genes are there in the human genome? Contig is the abbreviation for contiguous. Chromosomal anomaly French : anomalie chromosomique A chromosome anomaly can be constitutional, acquired, homogenous, mosaic, numerical, structural. We will consider it in more detail when we look at organelle genomes in Chapter 2.
Brenner S The genetics of Caenorhabditis elegans.