What structure protects and cushions the fetus throughout its prenatal development?

• amniotic sac and fluid

• placenta

• umbilical cord

• vagina

When the blastocyst attaches to the lining of the uterus, this is known as

• fertilization
• ovulation
• implantation
• mitosis

What is the "lifeline" between the fetus and the placenta?

• amniotic sac
• umbilical cord
• placenta
• vagina

Following implantation, and until the 9th week of pregnancy, this would be called a(n)

• blastocyst
• zona
• embryo
• fetus

Tags

NGSS.HS-LS1-2

NGSS.HS-LS1-4

In the embryo, heartbeat can first be heard at around 

• 8 days
• 3 weeks
• 6 weeks
• 12 weeks

Twins can result from

• a fertilized egg dividing into two blastocysts
• two eggs being released at the same time, and both are fertilized
• two embryos implanted in the uterus through invitro fertilization
• all of these can result in twins

A female egg that has been fertilized.

• Amniotic Sac

• Placenta

• Infant

• Zygote

Tags

NGSS.HS-LS1-4

A membranous vascular organ that develops in female mammals during pregnancy, lining the uterine wall and partially enveloping the fetus, to which it is attached by the umbilical cord.

• Fetus Amniotic Sac

• Umbilical Cord

• Placenta

• Yolk

Which system develops first in the embryo?  

• reproductive 
• circulatory 
• nervous 
• respiratory 

Pregnancy is divided into three_________.

• Trimesters
• Periods
• Months