Answer:
b) spontaneous reverse mutation
Explanation:
Spontaneous mutations are produced by natural biological processes, while induced mutations are produced by mutagenic agents that trigger nucleotide errors in the DNA sequence. In the first phase of the experiment, Sally generated an induced mutation by using 5-bromouracil. The resulting strain required a constant supply of tryptophan to grow.
A reverse mutation restores the wild-type phenotype modified by a forward mutation, thereby reversing the phenotypic alteration to its original state. In a second step of the experiment, the colonies grew without the supply of tryptophan, thereby evidencing that the mutation was reversed in the original colony.
Animals can be classified into two main groups:vertebrates and invertebrates<span>. The main difference between </span>vertebrates and invertebrates<span> is that</span>invertebrates<span>, like insects and flatworms, </span>do<span> not</span>have<span> a backbone or a spinal column. Examples of</span>vertebrates<span> include humans, birds, and snakes. hope this helped</span>
Answer:
The answer is D) Fossil Evidence
Explanation:
Looking at creatures thousands of years old entrapped in fossils gives you the most solid evidence that things have changed greatly over time. Hope this helps :)
Answer:
bacterial cell
Explanation:
bacteria consists of a nucleus therfore it has simple body structure .
The answer would be C. tree roots split apart ricks in the ground
