What does the geologic time scale confirm about the cretaceous period? a. it ended during the cenozoic era. b. it ended during the mesozoic era. c. it started before precambrian time. d. it started before the cambrian period.

The correct answer is option B, that is, it ended during the Mesozoic era.  

The Cretaceous refers to a geological period, which persisted for 79 million years. It spans from the termination of the Jurassic period, that is, 145 million years ago, to the commencement of the Paleogene period, that is, 66 million years ago. It is the last period of the Mesozoic Era.  

The period exhibited comparatively warm climate, leading to the formation of high sea levels, which formed various shallow inland seas. These waters got populated with marine reptiles, while dinosaurs persisted on land.  

b

Explanation:

image result for describe the various types of gene mutationsghr.nlm.nih.gov

the types of mutations include: missense mutation: this type of mutation is a change in one dna base pair that results in the substitution of one amino acid for another in the protein made by a gene. nonsense mutation: a nonsense mutation is also a change in one dna base pair.

explanation:

a chair, a bed, and a toothbrush

explanation: