Question

1. mud minnows are a type of fish found along the atlantic coast of the united states. these fish normally develop with two eyes. however, scientists have found that if eggs are placed in 100 ml of seawater mixed with 6 g of magnesium chloride, the fish embryos will only have one eye. what is a possible explanation for this phenomenon? this phenomenon is caused by gene expression regulated by chemicals. this phenomenon is caused by a change due to too high water temperature. this phenomenon is caused by having different dna nucleotides. this phenomenon is caused by a mutation caused by the saltwater. clear all

Explanation:

• The first option is correct. Gene expression can be regulated by chemicals in the environment. In this case, the magnesium chloride in the seawater could be affecting how genes related to eye development are expressed.
• The second option is incorrect as the problem does not mention anything about water temperature being a factor.
• The third option is incorrect because the fish embryos are from the same species (mud minnows) and would have the same basic DNA nucleotides; the change is likely due to gene - expression regulation, not a difference in nucleotides.
• The fourth option is incorrect. There is no indication that the saltwater (magnesium chloride in seawater) is causing a mutation. A mutation would imply a change in the DNA sequence, while the more likely scenario here is chemical - regulated gene expression.

Answer:

This phenomenon is caused by gene expression regulated by chemicals.