Cell membranes are important because they protect the cell and control the materials that flow in and out of it. Lipids are needed in order to create the membranes in the cell.
Answer:
1. sperm cells: cell has a flagellum for movement
2. smooth muscle: cells have an elongated shape (tapered at each end)
3. Squamous epithelium: cells are close together
4. Human red blood cells: cells are circular
5. Squamous epithelium cells are thin and flat, with irregular borders
6. Human red blood cells: cells are anucleate (without a nucleus)
7. smooth muscle: longest cell
Explanation:
- <em>Sperm cells</em>: Active and morphologically specialized cells. They characterize as having an elliptic head mostly occupied by the nucleus, and a tail of about 55 micrometers that moves impulsed by a motor dynein protein that uses ATP energy.
- Smooth muscle cells: Fusiform cells. Long and tapered at the extremes. Located in organs and viscera, and in vessel walls, where involuntary maintained slow contractions are needed. Although they are the longest cells, their length depends on the organ where they are located. They might reach up to 500 microns.
- Squamous epithelium cells: The wide and length of the cells supere their height. Some of them suffer a process of keratinization from being exposed to dehydration and touch.
- Red blood cells: Red blood cells or erythrocytes are biconcave disks-shaped, with no nucleus, and very small. These are flexible cells that might move along in the smallest capillaries. Hemoglobin provides the typical red color. The red blood cell size and number vary among species.
