Geologist finds four layers of sedimentary rock. she determines that no geologic events have shifted the layers. she labels the layers a, b, c, and d from the top to the bottom. which statement about these layers is accurate? a is older than b. b is older than c. c is younger than a. b is younger than d.

The answer is; B is younger than D

In sedimentary rocks, the bottom layers are older that overlaying layers. This is because sediments are placed on top of each other by surface runoffs to ocean beds. Therefore, the first sediments to be deposited will always be towards the bottom as more and newer ones are brought in and deposited.

B is younger than D.

a: the sheep and waste material both release carbon into the atmosphere.

the answer to the blank provided is “an autosomal gene that is required for the expression of genes on the x chromosome”.

testis-determining factor, abbreviated as td, which is more popularly known as sex-determining region y or sry protein, is a dna-binding protein or  gene-regulatory protein/transcription factor, encoded by the  sry gene. it is the gene responsible for the initiation of male gender determination in humans.