*Question*
Q: What is the lowest layer of the atmosphere called? Choices: - mesosphere - lithosphere - asthenosphere - troposphere A:
**Answer**
troposphere

*Question*
Q: Which phylum is made up of segmented worms such as earthworms? Choices: - chordata - arthropod - nematoda - annelida A:
**Answer**
annelida

*Question*
Q: Designed to exchange materials, what spongy structure consists of membranes and blood vessels from both mother and embryo? Choices: - endometrium - uterus - umbilicus - placenta A:
**Answer**
placenta

*Question*
Q: How many pairs of upper jaws do insects have? Choices: - four pairs - six pairs - three pairs - two pairs A:
**Answer**
two pairs