Question

part a - required conditions for conception
specific conditions have to be present for a pregnancy to result from vaginal intercourse. conception occurs when a sperm fertilizes an egg, usually in the fallopian tube. if no birth control or contraception is used, 85% of women having sex will become pregnant in 1 year.
choose the answer which best describes that the conditions required for conception have been met.
view available hint(s)
vaginal intercourse occurs 3 - 5 days after ovulation without the use of any form of birth control.
a couple has unprotected sex 5 days before the egg is present in the fallopian tube.
unprotected sex occurs 9 days before ovulation, and approximately 300 million sperm are ejaculated.
unprotected sex occurs 15 days after ovulation, and 80% of the sperm are destroyed during the journey to the fallopian tube.

Explanation:

Conception occurs when sperm fertilizes an egg in the fallopian tube. Sperm can survive in the female reproductive tract for about 5 days, and an egg is viable for about 24 hours after ovulation. For conception to occur, sperm must be present when the egg is available. In the first option, 3 - 5 days after ovulation, the egg is likely no longer viable. In the second option, having sex 5 days before the egg is in the fallopian tube means sperm may still be present when the egg arrives. In the third option, 9 days before ovulation is too early for sperm to survive until egg release. In the fourth option, 15 days after ovulation, the egg is not present.

Answer:

A couple has unprotected sex 5 days before the egg is present in the fallopian tube.