The transition of the early earth’s atmosphere from

one rich in hydrogen to one rich in oxygen may be
attributed to
a. photosystem II.
b. photosystem I.
c. the cyclic pathway of photosynthesis.
d. the light-independent reactions.
e. the activity of the electron transfer chain.


Answer: a

Biology & Microbiology

You might also like to view...

The Department of Energy is very interested in investigating which organisms compose the gut microbiome of cows, especially in the rumen. Why would the microbes within a cow's rumen be studied by scientists in the Department of Energy?

(Select all correct choices.) A. Scientists want to derive biofuels from cellulose. B. Scientists want to derive biofuels from methane. C. Scientists want to derive biofuels from the lactose in cow's milk.

Biology & Microbiology

Diseases such as ulcers and cardiovascular disease

A. have been shown to be, or may be due to, a bacterial infection. B. are solely due to lifestyle. C. are solely due to genetics. D. are due to new mutations in bacteria.

Biology & Microbiology

Are any of the offspring or parents affected?

a. Yes b. No

Biology & Microbiology

Bacterial agents of meningitis which can survive phagocytosis include

A) Neisseria meningitidis. B) Streptococcus pneumoniae. C) Mycobacterium leprae. D) both Neisseria meningitidis and Streptococcus pneumoniae. E) Neisseria meningitidis, Streptococcus pneumoniae and Mycobacterium leprae.

Biology & Microbiology