Human Reproduction -MG Flashcards
What are gametes? And what are the names of the male and female gametes?
It’s a reproductive cell used for the purpose of sexual reproduction. Ovum for females, and spermatozoon for males.
How many chromosomes are in a gamete and how is it different from a typical cell?
A gamete contains half the chromosomes compared to other cells in the body. This means a human gamete has 23 chromosomes (none are in pairs). A typical cell will have 46 chromosomes (23 pairs).
What are the 3 parts of a spermatozoon?
Head, mid piece, and tail
What is fertilization?
When spermatozoon and ovum meet.
What must unite in order to create a new individual?
The gametes (spermatozoa and ova)
How are fraternal twins formed?
Sometimes a woman has two ova the reach maturity and both get released during ovulation. If the two ova both become fertilized, this will result in fraternal twins.
What are fraternal twins?
Twins that do not have the same DNA since they were created from two different ova and two different spermatozoa.
What are identical twins?
Twins who share the same DNA since they were created from the same ovum and spermatozoon.
How are Indental twins formed?
If only one ovum is fertilized but then later splits into two during cell division at the start of pregnancy.
What is a zygote? And how many chromosomes
A single cell with 46 chromosomes (half are from ovum and other half from spermatozoon) that will undergo cell division (mitosis) and pregnancy begins.
What is pregnancy and when does it begin?
Pregnancy is when a woman Carrie’s an embryo (which will later become a fetus) in her uterus. It starts as soon as an ovum is fertilized by a spermatozoon and makes its way to the uterus.
Where is the zygote formed?
Fallopian tube
What is implantation?
Once a ball of 100 cells has been formed, it will attach to the endometrium.
What is an embryo and how’s it formed?
Once implantation occurs, the ball of 100 cells is now called an embryo and will keep its name until the 8th week of pregnancy.
What is a placenta? (And umbilical cord)
Organ that carries nutrients and oxygen from the mother to the fetus through the umbilical cord. It also helps remove wastes.
What is an amniotic sac (and fluid)?
It’s a fluid-filled pouch that surrounds the embryo. The sac is filled with clear, yellow fluid called “amniotic fluid”. They both are important to protect the developing embryo form outside dangers.