1) Scientists believe that the ancient ancestors of all animals were <span>single-celled eukaryotes that sometimes grew in colonies.
</span>Eukaryotic cells have membrane-bound organelles such asmitochondria<span> and the Golgi apparatus.
</span>The best answer is :
<span>B) single-celled eukaryotes that sometimes grew in colonies</span>
Answer: A protein domain is a region of the protein's polypeptide chain that is self-stabilizing and that folds
independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of several domains.
One domain may appear in a variety of different proteins. Molecular evolution uses domains as building blocks and these may be recombined in different arrangements to create proteins with different functions.
In general, domains vary in length from between about 50 amino acids up to 250 amino acids in length.
The shortest domains, such as zinc fingers, are stabilized by metal ions or disulfide bridges. Domains often form functional units, such as the calcium binding EF-hand domain of calmodulin.
Because they are independently stable, domains can be "swapped" by genetic engineering between one protein and another to make chimeric proteins.
This is false. Carbon dioxide is taken in, and oxygen out. Oxygen is not converted to carbon dioxide. It is a waste of the chemical reaction taking place, just like carbon dioxide is a waste in the respiratory process for us.
I hope this helps!
~kaikers
Answer:
Oocyte: A cell in a ovary which may undergo meiotic division to form an ovum
