Answer:
unicellular life first
Explanation:
it arose billions of years ago while multicellular life forms around at least 600 million years ago
It is believed that this happens because some signals that regulate development are the same between different species and because <span>they share ancient genes. </span>These ancient genes are expressed during a middle "phylotypic stage" of embryonic development for all species.
For example, human and animal embryos go through very similar stages of early development and share similar features such as tails and gill-like structures. The major difference appears to be how long it takes to reach each of these same stages.
Answer:
Explanation:
Inbreeding results which can increase the chances of offspring being affected by deleterious or recessive traits. This usually leads to at least temporarily decreased biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce.
Answer:
I believe its option b. carbon dioxide.
