Q: Q: Blood from what organs enters the left atrium of the heart? A:

OPTIONS:
- Lymph nodes
- intestines
- Brain
- lungs

A: lungs

Q: Q: Many cancers, as well as autism, are thought to have what component, which is certainly a factor in asthma? A:

OPTIONS:
- emotional
- critical
- ecological
- environmental

A: environmental

Q: Q: How many pairs of chromosomes are there? A:

OPTIONS:
- 17
- 2
- 13
- 23

A: 23

Q: Q: The genome of an organism consists of one or more what? A:

OPTIONS:
- hemoglobin molecules
- require molecules
- rna molecules
- dna molecules

A:
dna molecules