What is a key characteristic of index fossils

Q: a pair of homologous chromosomesa) always has the same genes and the same allows b)always has the same genes c)always has the same alleles d)never has the same genes

List two limitations of natural selection

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.