Answer:
The correct answer is option (D) there was a time in Pennsylvania history when dinosaur existed.
Explanation: A paleontologist discovers a rock slab on which the footprints of a Pennsylvania dinosaur are well preserved. This means that there was a time in Pennsylvania history when dinosaur existed in this area. Here fossil is a fragment of rock on which the footprints of dinosaur is present.
The animals who live in that area will become endangered because their habitat is being heated and they are made for cold only
Answer:
What causes genetic variation?
Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism’s offspring).
Explanation:
PLZ mark brainliest also I hope this helps
Answer:
D) a scientific journal about chemistry and a biography of a famous chemist
