Answer:
Each of her parents must have one recessive gene for blond hair color
Explanation:
- Blond is a recessive trait
- Since Silvia is blond this means she has both copies of the recessive gene for hair color
- Therefore, both her parents have a recessive gene for blond hair and passed it down to her.
- The parents don't have blond hair because their dominant gene for browns masks the recessive gene for blond.
Answer:
The statement that accurately describes the aspects of plate tectonics that involve sub-duction and seafloor spreading is : Crust is created at the coastlines of continents.
Explanation:
i
In the absence of tryptophan, the genes trpA-E will not be transcribed.
If there were a mutation in the operator region of the trp operon, there would be a nucleotide change in the sequence of the operator. Mutations in the repressor that prevent its binding to the operator will lead to constitutive expression Mutations that prevent binding of the inducer without affecting the ability to bind to the operator lead to a non‑inducible phenotype.
The tryptophan binds to the trp repressor and causes it to change shape, converting into its active form. The trp repressor with the bound tryptophan attaches to the operator, blocking RNA polymerase from binding to the promoter and preventing transcription of the operon.
To learn more about tryptophan, here
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A) is a mussel
b) is a bone
