Answer:
Smooth muscle is found in the walls of hollow organs like your intestines and stomach. They work automatically without you being aware of them. Smooth muscles are involved in many 'housekeeping' functions of the body. The muscular walls of your intestines contract to push food through your body.
Explanation:
<span>The correct answer is b.0.5 to 1 micrometre thick.</span>
Usually, the respiratory membrane is about 0.6 micrometres thick. This membrane consists of the alveolar epithelial cells, the capillary endothelial cell, and basement membranes which are formed by the alveolar and capillary cells.
Answer:
Calcium is a chemical element with the symbol Ca and atomic number 20.
Explanation:
<span>The four biological macromolecules are carbohydrates, lipids, proteins and nucleic acid. These macromolecules are known as polymers and are built when monomers join together by a process known as the dehydration reaction. The dehydration reaction is a chemical reaction that produces water (H2O) and the result is the covalent bonding of the two monomer molecules. The monomer molecules consist of nutrients found in the soil, as in the case of plants, and the intake of food as in the case of animals.
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