Answer:
a) Teeth arose from the rough scales of ancestral sharks.
b) Skeletal developments leading to the amphibian movement onto land probably evolved from lobe-finned fishes.
d) The anterior gill arch formed the basis for the evolution of the vertebrate jaw.
Explanation:
The animals we know today have physical characteristics that are evolutionary adaptations of characteristics of their ancestors, which have undergone a series of evolutions and modifications over the years giving rise to new species that have resulted in the species we know today. This process of evolutions and adaptations also happened with the ancestral species of fish, which allowed that today, they had characteristics such as teeth and jaws. Many of these evolutions occurred even in different species, such as the evolution that allowed the amphibians to have a skeleton, which evolved from the spine fins of fish.
On number one you could say dirt seeing as dirt is another word for earth because it makes up earth
Both breathe air. Both can be herbivores, omnivores, or carnivores. Both are warm blooded. Both are animals. Both have an interior skeleton. Both have four limbs. Both have two eyes. Both have large central nervous systems.