Fertilization, Gametes, Pregnancy Flashcards
(44 cards)
What is a gamete? Give two examples
A cell for the purpose of reproduction such as an ovum and a spermatozoon
When do women produce ovum and when do they stop?
Women produce ovum at puberty until middle age, female reproductive organs prepare for pregnancy every month
When do men produce spermatozoa and when do they stop?
Men start to produce spermatozoa at puberty and continue for the rest of their lives
What does ovum and spermatozoa carry?
Ovum carries half the mother’s genetic information and spermatozoa carries half the father’s genetic information
What is fertilization?
The union of two gametes (an ovum and a spermatozoon)
What is ovulation?
Every month one ovum is released fro, the overt towards a Fallopian tube
How is an ovum fertilized and what happens if it isn’t?
The ovum is fertilized if it meets a spermatozoon in a Fallopian tube, if not the female body will menstruated it 14 days later
How are fraternal twins produced?
A women produces two ova and both are fertilized
How are identical twins produced?
One ovum is fertilized and splits in two
When can an ovum be fertilized?
During her fertile period which lasts four days before ovulation to the day after ovulation
How long can ovum live? How long can spermatozoon live? How does this affect her fertile period?
Ovum can stay alive for 24 hours and spermatozoa can live for three to five days. Therefore a women’s fertile period lasts four days before ovulation to the day after ovulation.
What is menstruation?
When an unfertilized ovum is menstruated through blood flow
When does ovulation always occur?
14 days before the first day of menstruation
How much sperm does a man release in his semen?
A man releases millions of spermatozoa in his semen
What happens to other sperm after an ovum has been penetrated?
Once a spermatozoon penetrates the ovum, no other sperm can enter because the ovum is fertilized
How many spermatozoa reach the ovum?
One
What is pregnancy?
The time when a women carries an embryo, then a fetus in her uterus
When does pregnancy begin?
When a fertilized ovum is carried towards the uterus by millions of tiny hairs that mine the walls of the Fallopian tubes
What is a zygote?
An ovum that has been fertilized by a spermatozoon
What happens to a zygote on the first four days of fertilization?
It travels through the Fallopian tube to the uterus where it starts dividing to form a bundle of cells
What is implantation? How does this affect the zygote’s name?
When the zygote starts dividing, it’s cells attach to the endometrium and start to build a home. The zygote is now known as an embryo
How is the embryo connected to the placenta?
By the umbilical cord
What does the placenta allow the exchange and transfer of?
It allows for the exchange of respiratory gases such as oxygen and carbon dioxide and the transfer of nutrients & removal of waste
What is the embryo surrounded by and why?
It is surrounded by the amniotic save which is filled with amniotic fluid to protect it
