If a repressor protein attaches to the operator, RNA polymerase cannot proceed to transcribe key enzymes needed by the organism. This can be seen in the trp operon in E .coli bacteria.
Answer:
Explanation:
The two lower, larger chambers of the heart are called _ventricles._
Answer:
Alpha-1
Explanation:
Adrenergic receptors are the integral proteins present in the postsynaptic plasma membranes. These receptors are activated when the neurotransmitter norepinephrine and the hormones norepinephrine and epinephrine bind to them. The alpha 1 adrenergic receptors are found in the smooth muscle fibers of blood vessels that serve the salivary glands, skin, and kidneys. These receptors are also found in the radial muscle of iris of the eye as well as in the sphincter muscles of the stomach and urinary bladder.
They exert excitatory effect and lead to contraction of smooth muscles of the blood vessels, dilation of pupil, and closure of sphincters of the bladder.
Answer: Layer a is 500 million years old.
Explanation:
Trilobite is a member of the group of extinct arthropods found as fossils and they can be identified by the three-lobed as well as three segmented forms. These were the marine animals. These were appeared initially in the Cambrian Period. They used to live 542 million years ago so the fossils can be estimated to be aged of 500 above years old. These animals used to dominate in the sea area.
Answer:
meiosis is for reproduction and mitosis is for growth and repair
Explanation:
