A blastula is

a. the innermost germ layer.

b. a hollow ball of cells in an embryo.

c. a digestive organ.

d. a stage of development before a zygote.

4. Which is an autotroph - daisy, earthworm, mushroom, wolf?

Cattle egrets hitch a ride on domestic cows and eat insects that are stirred up by their activity. What term describes this relationship?

One of the foundations of vaccination is generating an antibody response against your virus. The antibody response is one part of the adaptive immune response. Which of the following are characteristics of an adaptive immune response? A.

Each trophic level has how much less energy

What are the two ways that organisms on the bottom of deep sea food chains acquire energy? a. photosynthesis and chemosynthesis b. chemosynthesis and marine snow c. marine snow and photosynthesis d. chemosynthesis and predation

What large peninsula is linked to the mainland of greece by the isthmus of corinth?

What is greek mitology

One of the first breakthroughs in biotechnology was the discovery of the gene that makes insulin. Part of this process involved scientists making DNA to match each possible sequence of insulin mRNA. What was the next step of this process? A.

If mollusks evolved before arthropods, where will their fossils be found?

Over time, a river cut through a field where some mice lived and some birds were nesting. Tell over time why the mice developed into 2 different species, but the birds did not