Question

select all of the following that are true about chlorophyll a and b.

• ✓ they differ slightly in their chemical side groups.
• one absorbs red and orange light and the other reflects it.
• they capture photons with a magnesium ion.
• they have the same absorption spectrum.

Explanation:

1. For "They differ slightly in their chemical side groups": Chlorophyll a and b have similar structures but differ in their side - chain groups (e.g., chlorophyll a has a methyl group in a position where chlorophyll b has an aldehyde group), so this is true.
2. For "One absorbs red and orange light and the other reflects it": Both chlorophyll a and b absorb red - orange light (they mainly absorb blue - violet and red - orange light), and they reflect green light. So this statement is false.
3. For "They capture photons with a magnesium ion": The porphyrin ring of chlorophyll contains a magnesium ion at its center, and this magnesium ion is involved in capturing photons (as the photon energy can affect the electron in the porphyrin ring around the Mg²⁺), so this is true.
4. For "They have the same absorption spectrum": Chlorophyll a and b have slightly different absorption spectra. Chlorophyll a absorbs more red - orange light, and chlorophyll b absorbs more blue - green light. So this statement is false.

Answer:

• A. They differ slightly in their chemical side groups (True)
• C. They capture photons with a magnesium ion (True)