Unit 9: Fetal Development

Question 1

fertilization

Answer 1

The union of one egg and one sperm to create an embryo. Happens in the Fallopian tubes. Only possible within 24 hours of ovulation.

Question 2

Embryo

Answer 2

The fertilized egg. This term is used for the first few months of development. After that the embryo is referred to as the fetus.

Question 3

Implantation

Answer 3

When the embryo makes its home in the lining of the uterus. Happens about a week after fertilization.

Question 4

Why is the egg so much bigger than the sperm?

Answer 4

So that it can go through cell division many times, making hundreds of cells. The egg cell skips the G1 and G2 phases of the cell cycle because it is already so big. honors: also because it got all the goods during meiosis

Question 5

Gastrulation

Answer 5

The formation of the gut (donut hole) The first major development of the embryo.

Question 6

Which organs develop first? Why?

Answer 6

The placenta and umbilical cord, to nourish the fetus. The heart, to pump nutrients around the body. The liver, to manage any toxins.

Question 7

What is undeveloped in premature babies? Why? (premature babies are born after 6-8 months instead of 9 months)

Answer 7

lungs: the fetus shouldn’t need to breathe yet, so they are undeveloped. fat: the fetus should be warm inside mom, so it has not put on a layer of insulating fat under the skin yet. Premies will be kept in an incubator to keep them warm and will be given pure oxygen to breathe.

Question 8

Identical twins

Answer 8

One egg and one sperm made one embryo. During cell division, the embryo split into two bunches of cells and each developed into a baby. Same DNA, so same bodies.

Question 9

Fraternal twins

Answer 9

two eggs are ovulated (usually one from each ovary), both are fertilized, both implant. Results in non-identical twins.

Question 10

miscarriage

Answer 10

When an embryo or fetus dies before the 20th week of pregnancy. This is usually due to abnormalities of the embryo or fetus.

Question 11

placenta

Answer 11

The organ which allows the fetus’s blood to exchange nutrients and wastes with the mother’s blood The placenta is directly attached to the uterus. A tiny piece is taken to do CVS.

Question 12

amniotic sac

Answer 12

The bubble the baby is floating in. Contains fluid to cushion the fetus. The fetus practices breathing, swallowing and excreting this fluid.

Question 13

amniocentesis

Answer 13

A medical procedure used to get fetal skin cells. Some of the amniotic fluid is extracted using a needle.

Question 14

CVS (chorion villi sampling)

Answer 14

A medical procedure used to get cells from the placenta (which contain the fetus’s DNA). The sample is taken using a tool which goes up the vagina, through the cervix, and into the uterus.

Question 15

NIPT (Non-Invasive Prenatal Test)

Answer 15

is a method of determining the risk that the fetus will be born with certain genetic abnormalities. This testing analyzes small fragments of fetal DNA that are circulating in a pregnant woman’s blood

Question 16

conjoined twins

Answer 16

identical twins (always!) which did not fully separate. Must be born surgically, by a C section.

Question 17

umbilical cord

Answer 17

the cord that connects the fetus to the placenta

Question 18

the afterbirth

Answer 18

The placenta It is expelled a few minutes after the baby is born. Usually it is thrown away by humans. Animal mothers eat the placenta, umbilical chord, and amniotic sac to regain nutrients and energy after giving birth.

Question 19

the birth canal

Answer 19

The vagina

Question 20

Is it ok to have sex when pregnant?

Answer 20

Yes. The baby is contained in the amniotic sac, so the sperm could not touch it. A woman does not ovulate while pregnant, so there is no egg cell for the sperm to fertilize. The movement will not hurt the baby.

Question 21

Which of the 5 senses develops first for a fetus?

Answer 21

Hearing develops first. The fetus can’t see, smell, taste, or touch, but it can hear voices and begins to learn language.

Question 22

Why do babies (and humans of all ages) calm down when they hear loud shushing and/or the sound of flowing water?

Answer 22

It is the sound of the blood moving though the mother’s body. It reminds us of safety and warmth.

Question 23

Why do babies (and humans of all ages) calm down with slow rhythms and get excited with fast rhythms?

Answer 23

The rhythms are similar to the sound of the mother’s heart beat. A slow heart beat is calm, while a racing heart is excited.

Question 24

lacatation

Answer 24

The production of milk by the breasts. Happens a few days after birth. Breast milk is healthier for babies than formula.

Question 25

C-section

Answer 25

A surgery in which doctors cut through the abdomen and uterus and remove the baby. sections can cause scarring of the uterus which might prevent the mother from having more babies. Natural birth healthier for babies.

Question 26

Ultrasound

Answer 26

The use of sound waves to gain an image of the fetus. By bouncing the sound waves off of the fetus, doctors can determine the sex of the baby (they look for a penis) Ultrasound is also used in CVS and amniocentesis to ensure that the doctor’s tools do not harm the fetus.