Answer:
A tan might indicate sun damage to the skin.
Explanation:
Tanning is the process by which the skin is exposed to the ultraviolet rays that comes from the sun with the purpose of producing a dark-brown coloration called a TAN.
A tan achieved by exposure to the sun can actually indicate that a person's skin is undergoing damage from the UV rays of the sun, hence, the skin responds by producing a protein called melanin, which protects the skin and later forms the dark coloration- tan. From this explanation, tan is got in response to a damaging signal received by the cell, hence, a tan might indicate sun damage to the skin.
The correct option is this: PLANTS CAN BE USED TO MAKE MATERIALS.
Plants are very important living organisms and they can be used in diverse ways. Some plants can be used as foods, some plants are used as raw materials for making pharmaceutical drugs and other herbal products. Plants, such as cotton are used to make clothing materials and dead and decaying plants serves as fertilizer that add nutrients to the soil.
The answer is c hope it helps
B. Cell wall and a central vacuole
The cell wall is a rigid structure that surrounds the cells and allows plants to stay upright. Animal cells are more fluid.
The central vacuole is a large region in the cell that stores nutrients and fluids. Many cells, including animal cells, contain vacuoles, but most are small, and only plant cells contain large central vacuoles.
Hope this helps!!
The denaturation step in the polymerase chain reaction will be affected. As a result the DNA strands will not unwind and the DNA will not become single stranded.
<u>Explanation:</u><u>
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Polymerase chain reaction is used to synthesize multiple copies of DNA. The technique in molecular biology uses thermal cycling which involves steps of heating and cooling. There are three important steps in PCR.
Nucleic acid denaturation is the first step. In this step the DNA is heated to about 90°c and this causes the denaturation of the DNA. Two strands of DNA get separated. The second step is annealing in which the strands are cooled to 55°c.
During annealing the primers stick to the complementary sites on the DNA to facilitate its replication. The third step is extension in which the temperature of the mixture is raised to 72°c. The tag polymerase will start working on the DNA strands and replicate them.
If the denaturation step is not performed the speration of double stranded DNA into single strands won’t take place.
