Development

Question 1

first-trimester development

Answer 1

Zygote: united sperm cell and ovum
Blastocyst: multiple cells that implant
Heartbeat can be heard by 10 weeks after last menstrual period
Second month: spinal canal, arms, and legs form
Third month: internal organs form

Question 2

full term time

Answer 2

40 weeks

Question 3

second-trimester development

Answer 3

Begins with fourth month of pregnancy
Sex of fetus can be distinguished
External body parts develop
Skin is covered by fine down-like
hair
Growth in size and feature refinement occurs
Fetal movements felt by the end of fourth month
By the trimester end, the fetus has opened its eyes

Question 4

third-trimester development

Answer 4

Size and strength continues to develop
Down-like hair disappears
Skin becomes smoother
Protective, creamy, waxy substance, called vernix caseosa, covers
the fetus