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.
3 position of the molecules.
The name of the tear collecting structure under the skin near the bridge of the nose is the lacrimal sac. The lacrimal sac is part of the lacrimal drainage system or the lacrimal apparatus. The tears are produced in the lacrimal gland and will drain through a hole near the lower palpebral conjuntiva called the puncta which serves as the entrance in the lacrimal system. The tears will now enter the canalicula which serves as the passage way from the puncta to the lacrimal sac. Lastly, the tears in the lacrimal sac will drain to the nasolacrimal duct and to the nose. This also explains why we get runny nose when we are crying.
Answer:
They are smaller than blood capillaries.
Explanation:
Lymphatic capillaries drains the extracellular fluid present between the cell spaces. The fluid is known as lymph as it enters the lymph capillaries. These capillaires drains into lymph vessels that drains to lymph nodes and lymph ultimately enters the venous circulation.
Lymphatic capillaries are slightly larger than blood vessels and these capillaries have close ends. The walls of lymph capillaries are made up of endothelial cells. The endothelial cells overlap in lymph vessels and when the pressure in ECF is greater these cells move and create a sort of gap for the movement of ECF inside the lymph capillary but when the pressure inside the capillary is greater these cells again overlap and does not allow the lymph to move outside of capillary. Thus lymph capillaries only allow the ECF to enter the capillary but does not allow the lymph to go out from capillary. Lymph capillaries have greater internal pressure than blood vessels.
