DEVELOPMENT & AGING (2)

Question 1

ovulation

Answer 1

ovaries release eggs (erupt) once a month

-birth control and being pregnant stops it from cycling

Question 2

zygote

Answer 2

fertilized egg and sperm

Question 3

embryo

Answer 3

implanted zygote (pregnant)

Question 4

fetus

Answer 4

after 3 months embryo turns into this

Question 5

cleavage

Answer 5

zygote divides into 2 cells, then 4, then 8, then 16, and 32 cells

Question 6

growth

Answer 6

cells increase in size

Question 7

morphogenesis

Answer 7

cells move or migrate to shape the embryo

Question 8

differentiation

Answer 8

cells take on specific structure and function

Question 9

extraembryonic membranes

Answer 9

1. chorion
   - develops in the fetal half of the endometrium (placenta)
2. yolk sac
   - little yolk and is the the first site of RBC formation
3. allantosis
   - gives rise to the bladder; the allantosis blood vessels become the umbilical blood vessels
4. amnion
   - contains amniotic fluid to cushion and protect the embryo

Question 10

pre-embryonic

Answer 10

encompasses the events of first week of development after fertilization

• cleavage
• morula
• blastocyst
• implantation

Question 11

cleavage

Answer 11

cell division that increases the number of cells

Question 12

morula

Answer 12

solid mass of cells

a zygote that is cleaving

Question 13

blastocyst

Answer 13

inner cell mass becomes the embryo surrounded by the trophoblast that becomes the chorion

Question 14

implantation

Answer 14

usually occurs on the 6th day

Question 15

embryonic development

Answer 15

begins in the 2nd week and lasts until the end of the 2nd month of development

• pregnancy begins after implantation
• nervous system becomes evident
• heart begins development the 3rd week and begins beating the 4th week
• all organ systems have been established by the end of this development stage

Question 16

fetal development

Answer 16

includes the 3rd thru the 9th months of development

• fetus has visible human characteristics
• cartilage begins to be replaced by bone
• 3rd month can distinguish sex of it
• 4th month heartbeat is loud enough to hear with a stethoscope
• 5th-7th month fetal movement can be felt, fetal position, eyelids can open
• fetus is about 201/2 in long and weighs about 71/2 pounds at the end of this stage of development

Question 17

stages of life

Answer 17

• infancy
• childhood
• adolescence
• adulthood