Before photosynthesis evolved, _____ was a very small component of Earth's early atmosphere

a. carbon dioxide
b. nitrogen
c. water
d. oxygen
e. argon


d

Biology & Microbiology

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Which of the following is a muscle tissue that pumps blood throughout the body?

A. Skeletal muscle B. Cardiac muscle C. Smooth muscle D. Endocardium

Biology & Microbiology

The squid in this photograph contains a colony of Vibrio fischeri bacteria, which only luminesce while living within a squid. How is this behavior beneficial for V. fischeri bacteria?



a. Bioluminescent squid are more visible to free-floating V. fisheri bacteria, allowing them to join the colony.
b. Bioluminescent squid attract specific predators, allowing V. fischeri colonies to spread more rapidly.
c. Bioluminescent squid are less likely to be consumed by predators, protecting V. fischeri’s source of food.
d. Bioluminescence within squid provides ample light for V. fischeri to synthesize glucose via photosynthesis.

Biology & Microbiology

Tube feet of sea stars are used for feeding in addition to locomotion

Indicate whether the statement is true or false

Biology & Microbiology

What causes genital warts?

A. parasite B. fungi C. virus D. bacteria E. molds

Biology & Microbiology