In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.
Chromosomes are not visible in the cell’s nucleus—not even under a microscope—when the cell is not dividing. However, the DNA that makes up chromosomes becomes more tightly packed during cell division and is then visible under a microscope. Most of what researchers know about chromosomes was learned by observing chromosomes during cell division.
Answer:
<h3>Things NOT to Do in a Research Lab</h3>
Wearing open-toed shoes.
Keeping long hair down.
Eating or drinking.
Erasing data from your notebook.
Showing up late.
Forgetting to label samples or materials.
Incorrectly disposing of your materials.
Wearing shorts.
<span>Transport of the water from the roots to the leaves is driven through the vascular tissue called xylem. Water gets absorbed from the soil by osmosis and it must cross several cell layers (filtration system) before entering the xylem. The method used in the upward movement of water through the xylem is determined by the cohesion-tension theory (capilarity+transpiration). The transport is passive and it occures thanks to the primary force that creates the capillary action (adhesion between the water and the surface of the xylem and cohesion between individual water molecules) movement of water. Transpiration is also an important factor in the upward water movement. Transpiration in leaves creates tension (differential pressure) and because of this tension, water is being pulled up from the roots into the leaves.</span>
