Problem:OPTIONS:
- tubes
- Veins
- Aorta
- arteries

Q: What is the name of muscular blood vessels that carry blood away from the heart? A:
****
A: arteries

Problem:OPTIONS:
- lipids sheath
- nerve sheath
- layer sheath
- myelin sheath

Q: What is the outer layer of an axon that acts like a layer of insulation, similar to the plastic that encases an electrical cord? A:
****
A: myelin sheath

Problem:OPTIONS:
- the orbit
- the earth
- jupiter
- the sun

Q: What is the largest object in the solar system? A:
****
A: the sun

Problem:OPTIONS:
- the vagina
- the cervix
- the ovaries
- the placenta

Q: What allows for a large and mature fetus before birth, resulting from a long period of fetal growth in the uterus? A:
****
A:
the placenta