By the end of Gretas first month of pregnancy, her embryo __________.

By the end of Gretas first month of pregnancy, her embryo __________.
 
  A) can sense its world
  B) is about  inch long
  C) can suck its thumb
  D) can curl its toes

Question 2

The __________ folds over to form the __________, or primitive spinal cord.
 
  A) mesoderm; neuron tract
  B) ectoderm; neural tube
  C) endoderm; neural tube
  D) ectoderm; neuron tract

Question 3

Jalynn is in the last half of the first month of her pregnancy. Which of the following is developing the fastest?
 
  A) circulatory system
  B) endocrine system
  C) nervous system
  D) skin

Question 4

Answer: B
 
  A) mesoderm; nervous system, lungs, internal organs, and skin
  B) chorion; endocrine system, muscles, placenta, and skeleton
  C) ectoderm; circulatory system, skin, skeleton, and internal organs
  D) endoderm; digestive system, lungs, urinary tract, and glands

Question 5

The ectoderm becomes the __________.
 
  A) muscles and skeleton
  B) nervous system and skin
  C) circulatory system and other internal organs
  D) digestive system, lungs, urinary tract, and glands

Question 6

The most rapid prenatal changes take place in the period of the __________.
 
  A) zygote
  B) blastocyst
  C) embryo
  D) fetus