he first photosynthetic organisms to oxygenate the Earths at

he first photosynthetic organisms to oxygenate the Earth’s atmosphere and trigger a mass extinction were:

Select one:

a. Land plants

b. Green algae

c. Cyanobacteria

d. Purple sulfur bacteria

e. Methanogens

Which of the following is absent in some kinds of living cells?

Select one:

a. cytoplasm

b. cell membrane

c. ribosomes

d. nucleus

e. phospholipids

Observations used as scientific evidence should NOT include

Select one:

a. peer-reviewed scientific literature.

b. previous data generated.

c. observations about past work.

d. anecdotal evidence.

e. other people’s data.

Solution

The cyanobacteria is responsible for the great oxygenation events

the red blood cells lack nucleus

anecdotal evidence little stories or hearsay would not be qualified as scientific evidence