FRHD 2110 Lecture Notes - Lecture 8: Ovulation, Asphyxia, Condom
11 Jan 2018
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Document Summary
Unions a sperm cell and an ovum. Ova carry x sex chromosomes sperm carry either x or y sex chromosomes. Girls are conceived from the union of an ovum and x-bearing seem. Girls are conceived from the union of an ovum and a y-bearing sperm. Sperm bearing y chromosomes swim faster than those bearing x this is why 120-150 boys are conceived for every 100 girls. However, female fetuses more likely to be favoured in survival male more likely to be lost in spontaneous abortions (women doesn"t realize she"s pregnant) Boys still outnumber girls at birth, but suffer a higher incidence of infant mortality. Average 200-400 sperm in ejaculation only 1 in 1000 will ever arrive in the vicinity of an ovum. Many flow out of women"s body due to gravity or vaginal acidity kills more. Surviving sperm swim through the os into the uterus may reach fallopian tubes 60-90 minutes after ejaculation.
