Q 01/05

What pigment gives most plants their green color?

A) Carotene

B) Xanthophyll

C) Anthocyanin

D) Chlorophyll

Answer · why

D) Chlorophyll

Chlorophyll looks green because it soaks up red and blue light for energy and reflects the green wavelengths it barely uses.

Q 02/05

What gas do plants absorb from the atmosphere during photosynthesis?

A) Oxygen

B) Nitrogen

C) Carbon dioxide

D) Carbon monoxide

Answer · why

C) Carbon dioxide

Carbon dioxide is the raw material of wood, which is about half carbon by weight; that is why van Helmont's potted tree could grow heavy in the 1600s ...

Q 03/05

In which part of a plant cell does photosynthesis primarily occur?

A) Mitochondria

B) Nucleus

C) Ribosome

D) Chloroplast

Answer · why

D) Chloroplast

Chloroplasts began as free-living cyanobacteria engulfed by an ancestral cell, which is why they still carry their own DNA and multiply by dividing in...

Q 04/05

What is the main product plants create through photosynthesis?

A) Protein

B) Fat

C) Glucose

D) Cellulose

Answer · why

C) Glucose

Glucose rarely stays as glucose: the plant ships it around as sucrose, stores it as starch and strings it into cellulose, the stuff of cotton and wood...

Q 05/05

What are the tiny pores on the surface of leaves called that allow gas exchange?

A) Trichomes

B) Lenticels

C) Plasmodesmata

D) Stomata

Answer · why

D) Stomata

Stomata are each flanked by two guard cells that swell with water to open the pore and go limp to shut it, which lets a thirsty plant seal its leaves.