When creating developmental knockouts, scientists engineer mice lines in which

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.

Jellyfish sometimes squeeze in the sides of their bodies. this pushes a stream of water from the back end of their bodies. according to newton’s third law of motion, how will this behavior affect of the jellyfish ?

Apea plant that is heterozygous for the tall phenotype can produce short offspring when self pollinating. which of the following explains why this occurs? a. segregation of alleles b. condominance of traits c. polygenic expression of traits d. independent assortment of alleles