Which group of organisms played an important role in shaping Earth’s atmosphere?
a. prokaryotes
b. eukaryotes
c. animals
d. cyanobacteria
D
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Answer the following statements true (T) or false (F)
1. The disease schistosomiasis is caused by a parasitic trematode. 2. Tagmata are segments of the body that represent two or more previous body segments fused together. 3. Scorpions do not lay eggs but rather give birth to live young. 4. Millipedes have a thousand legs whereas centipedes have only a hundred legs.
Suppose that the first part of a new polypeptide chain being produced in a eukaryotic cell does not
have a signal peptide. Which of the following would you associate with the location of translation to form that polypeptide?
a. cytoplasm only b. first cytoplasm, then rough ER c. Golgi apparatus only d. first rough ER, then Golgi apparatus e. rough ER only
Which group has a tentacle ringed mouth and a gastrovascular cavity?
a. sponges b. cnidarians c. flatworms d. annelids e. arthropods
Step 2 in Figure 41-3 is accomplished by:
a. an influx of Ca2+.
b. an influx of Na2+.
c. an influx of K+.
d. an efflux of Na2+.
e. an efflux of K+.