Question

plant species: base your answers to questions 14 and 15 on the diagram below and on your knowledge of biology. the diagram represents the results of paper chromatography performed on extracts from five organisms. cyanobacteria red algae brown algae green algae spinach 14. identify one pigment molecule common to all five organisms. 15. which two organisms are most closely related? a) cyanobacteria and green algae b) red algae and spinach c) brown algae and red algae d) red algae and cyanobacteria

Explanation:

Question 14

Looking at the chromatograms, cyanobacteria, red algae, green algae, and spinach all have a pigment band that matches the position (and likely identity) of chlorophyll a or a similar core pigment. Chlorophyll a is common in photosynthetic organisms, so a pigment like chlorophyll a (or the xanthophyll - like band common? Wait, re - examining: Cyanobacteria has a mixture, red algae has a similar band to cyanobacteria, green algae and spinach have more, but the common pigment across most (cyanobacteria, red, green, spinach) is likely chlorophyll a or xanthophyll? Wait, no, the key is that chlorophyll a (or a similar photosynthetic pigment) is common. Alternatively, looking at the bands: the faint yellow xanthophyll - like in cyanobacteria, red algae also has a similar band, green algae and spinach have xanthophylls. But more accurately, chlorophyll a is a core pigment in photosynthetic organisms. However, from the diagram, the band that is present in cyanobacteria, red algae, green algae, and spinach (maybe chlorophyll a or xanthophyll). But the most common pigment across all five? Wait, cyanobacteria, red algae, green algae, spinach – brown algae has different. Wait, the pigment common to most: chlorophyll a (blue - green) or xanthophyll (yellow). But the answer is likely chlorophyll a or xanthophyll, but more precisely, chlorophyll a is a primary pigment in photosynthetic organisms. However, from the chromatogram, the band that is present in cyanobacteria, red algae, green algae, and spinach (and maybe brown algae? No, brown algae has chlorophyll c). Wait, the correct common pigment is chlorophyll a (or xanthophyll, but chlorophyll a is more fundamental). But the answer is likely chlorophyll a (or xanthophyll, but let's check the bands. Cyanobacteria: mixture (faint yellow xanthophyll), red algae: similar, green algae: xanthophylls, spinach: xanthophylls. Brown algae: fucoxanthin, chlorophyll c. So the common pigment across cyanobacteria, red algae, green algae, spinach is xanthophyll (faint yellow in cyanobacteria, yellow in green algae and spinach, similar in red algae). So one pigment common to all five? Wait, no, brown algae has different. Wait, the question is "one pigment molecule common to all five organisms". Wait, maybe chlorophyll a? No, brown algae has chlorophyll c. Wait, maybe xanthophyll. Alternatively, the pigment that is in cyanobacteria, red algae, green algae, spinach (and maybe brown algae? No, brown algae's xanthophyll is fucoxanthin (orange - brown), not the faint yellow. Wait, maybe the answer is chlorophyll a (but brown algae has chlorophyll c). Wait, perhaps the question has a typo, but looking at the options, the common pigment is likely chlorophyll a or xanthophyll. But the standard answer for such a chromatogram question is that chlorophyll a (or xanthophyll) is common, but more accurately, the pigment common to cyanobacteria, red algae, green algae, and spinach (and maybe brown algae? No). Wait, maybe the answer is chlorophyll a (blue - green band) or xanthophyll (yellow band). But the correct answer is likely chlorophyll a (or xanthophyll, but let's go with chlorophyll a as a core photosynthetic pigment.

To determine which two organisms are most closely related, we compare their chromatograms (pigment profiles). Green algae and spinach have very similar pigment bands (number, position, intensity). Red algae and cyanobacteria have fewer bands in common. Brown algae has a different profile. So green algae and spinach (option B) have the most similar pigment profiles, indicating a closer evolutionary relationship as they share more photosynthetic pigments.

Answer:

Chlorophyll a (or xanthophyll, depending on the chromatogram, but typically chlorophyll a is a common photosynthetic pigment in these organisms)

Question 15