Describe the mechanism of gaseous exchange in mammals

What are the types of mutations, and how does each alter the encoded protein? college level answer

What is the farthest destination to date for a human spaceflight mission?

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.