The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary (K–T) extinction) was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago.
True aka pollution from machines smoke carbon emissions etc
A.) Veins in the pulmonary circuit carry oxygen-rich blood
red blood cells are used to circulate oxygen through out the body, thus it is true.
Answer:
d. RNA polymerase II.
Explanation:
The main enzyme responsible for RNA synthesis is RNA polymerase, which <em>catalyzes the polymerization of 5'-triphosphate ribonucleosides (NTP) </em>directed by a DNA mold.
Eukaryotic cells contain <u>three types of nuclear RNA polymerases</u> that transcribe different types of genes. Protein-encoding genes are transcribed by RNA polymerase II to give mRNA.
