Answer:
1. Ends of the respiratory branches are called alveoli.
2. C. To control blood flow to different areas of the body depending on activities
Explanation:
1. The trachea divides into left and right primary bronchi which in turn divide multiple times upon entering the lungs and make the bronchial tree.
The final branches of the bronchial tree are the terminal bronchioles that lead to alveoli. The alveoli are the balloon-shaped structures and serve as the site of gas exchange between the blood and inhaled air.
2. The opening and closing of sphincters of capillary beds regulate the direction of blood flow. The opening of sphincters allows the blood to flow into associated branches of capillary beds while closed sphincters direct the blood from arterioles to venules via thoroughfare channel.
This local change in blood flow is responsible for the autoregulation of blood flow to different tissues to match their respective metabolic demands. For example, during physical activity, more blood is directed to skeletal and cardiac muscles.
The answer is false
When the cells are differentiating in the embryo, they retain the same genetic material. However, certain genes in the differentiating cells are silenced using protein complexes called histones. This makes the genes inaccessible to RNA. Therefore, the process of transcription required in the expression of genes is restricted.
<span>Steroids are lipids and are made up of carbon, hydrogen, and oxygen, while enzymes are proteins and are made up of amino acids. </span>
Answer:
mutation or possible disease
