Glowing Jellyfish

Question

Jellyfish and comb jellies have existed in both cold and warm ocean water for more than 500 million years. These two types of organisms have many similar features even though jellyfish and comb jellies are not closely related. Some jellyfish and comb jellies can even produce and emit light, as shown in Photograph 1.

These organisms glow because of a process known as bioluminescence. During this process, a chemical reaction produces light energy that the organism can then emit. A substance known as a luciferase helps a luciferin molecule release this light energy as it reacts with oxygen. In some comb jellies, this chemical reaction is activated when calcium is present. The bioluminescence chemical reaction is shown in Figure 1.

Bioluminescence can occur in different ways, depending on the organism, but a few factors are common to all bioluminescent organisms. For example, oxygen is a reactant that is always needed. This element is absorbed through the thin cell membranes of the organism. Table 1 summarizes how bioluminescence can be used in different ways.

Scientists are studying the genes needed for bioluminescence in comb jellies. In one experiment, a researcher injected the DNA needed for bioluminescence into eight rabbit embryos. The embryos were then placed back inside the mother, where they developed normally. When the eight rabbits were born, it was found that two of them had the ability to bioluminesce. Scientists suggest that similar bioluminescent products will soon be possible for human use.

1
A population of comb jellies has members that show two distinct traits. One part of the population has male comb jellies that use a complex bioluminescence pattern to attract females. Another part of the population has male and female comb jellies that produce light in quick flashes. A new animal that preys on comb jellies enters the area.
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Using Table 1, which statement describes the most probable change in the comb jelly population over time due to the introduction of the new predator?
A
Only comb jellies whose genes mutate to no longer glow will survive and pass on this trait.
B
The comb jellies that have the most complicated patterns will survive to pass on this trait.
C
The comb jellies that are able to glow in quick flashes will survive and pass on this trait.
D
The two types of comb jellies will have an equal chance to survive and pass on their traits.

Answer 1

The most probable change in the comb jelly population over time due to the introduction of the new predator can be analyzed based on the given scenarios and the function of bioluminescence in attracting mates and possibly evading predators.

Considering the two distinct traits in the population:

1. Males using complex bioluminescence patterns to attract females.
2. Males and females producing light in quick flashes.

The introduction of a new predator means that the survival of the comb jellies may depend on their ability to evade detection. Quick flashes of light may be more effective in confusing or distracting predators than complex patterns, which might make the jellyfish more conspicuous.

Therefore, among the provided options, the most likely outcome would be:

C The comb jellies that are able to glow in quick flashes will survive and pass on this trait.

This option reflects the idea that the quick flashes could be a more advantageous trait in avoiding predation compared to the more complex bioluminescence patterns that might not offer the same level of evasion from predators.