Even though the business with international egg recipients is grounded in what Rose has called liberal eugenics, the everyday practices of those who select egg donors for the clinic's sex cell
banks are deeply shaped by (post-)colonial ideas of white desirability.
Evening the odds Female flower parts may be able to influence their mix of suitors by delaying the starting gun that sends pollen racing toward female sex cells
. Without this delay, the first pollen grains to land may sire most of the seeds.
Fertilize--the joining of a female sex cell
and male sex cell
to produce a new organism
To produce fertile offspring, scientists think chromosomes (cell structures that house all the genes) from both a mother and father may need to pair off evenly during meiosis, a process of cell division that produces sex cells
. For the hardy mule, for example, this is impossible, since its father--a donkey--has 62 chromosomes and its mother--a horse--has 64.
In some cases, the trisomy never occurs: DNA from a normal sex cell
may never even integrate into a newly fertilized cell that already has two copies of that DNA segment.
The process starts with a single human egg (female sex cell
THE SHELL EXPOSED: DEVELOPMENTAL STAGES OF A CHICKEN A chick's life begins when a rooster's sperm (male sex cell
) fertilizes an ovum (female reproductive egg) inside a hen to form a single cell called a zygote.
But other scientists like Wildt favor methods such as artificial insemination--in which sperm, a male sex cell
, is used to impregnate a female without sexual contact--recently used to successfully breed endangered ferrets.
However the consortium of international scientists known as BioRescue is also trying to create artificial sex cells
known as gametes via stem cell transformation from the frozen tissue of other, unrelated northern white rhinos, to diversify the gene pool.
Malaria parasites are dependent on female Anopheles mosquitoes to spread in a complex life cycle that begins when mosquitos eat male and female parasite sex cells
during a blood meal from an infected animal host.
Ageing is the result of DNA "tails", known as "telomeres", in chromosomes - of which every cell except red blood and sex cells
has 23 pairs - becoming shorter, and reversing ageing involves lengthening the telomeres.
- Alcohol is an opponent of potency, triggers dying of sex cells
, reduces the practicality of sperms and disrupts the bonds in between the mind and genitals.