Answer: Although people have said that having a vertical posture is harmful and puts pressure on the spine, maintaining good posture is necessary exercise for your muscles. Sitting up straight requires the strength of the muscles in the back and the abdominal region, while slouching your shoulders or curving your back renders them weaker. Slouching often is also damaging to the position of many bones, especially the spine, and can cause a variety of problems later on, such as back or shoulder pain. Even though it is more tiring and uncomfortable than hunching your shoulders all the time, posture is essential to us modern humans. Back straight, shoulders down, chin up, eyes straight ahead, and ready to go!
Answer: Fats provide energy, form a protective cushion for your internal organs, build healthy cells (including brain!) and hormones, help the body use vitamins (such as A, D, E, and K), provide healthier skin and hair. Source: going-well.com
Answer: You can live without eating food for a long time but you can only live without drinking water for about two days. Water is need for digestion and to keep your body cool by sweating. It makes 60% of your body waight and makes most of the blood. It is also needed to keep the cells alive. Water is very important for living.
Answer: Lipids are essential to your health because they support a
number of your body’s functions. Lipids enable the fat-soluble vitamins A, D, E,
and K to be absorbed from food and regulate cholesterol metabolism. Lipids are
made up of several fatty acids (containing long chains of carbon and hydrogen
atoms), bonded to a glycerol. They are typically triglycerides, which have
three fatty acids attached to one glycerol.
Lipids have the highest caloric value of any nutrient. One
gram of lipids provides 9.3 k. cal. of energy. Lipids are insoluble in water. They
are stored in your body as reserve food, which you can use when you need it. Lipids
form an insulating layer that helps maintain body temperature. The myelin
sheaths around your nerves contain lipids that prevents the passage of nerve
impulses to adjacent nerve fibers. Lipids are also structural components of your
cells, and their presence is required for certain enzymes and hormones.
No. A sperm cell and an egg cell released from an ovary contain half the chromosomes as other cells until the sperm enters the egg cell and its chromosomes join that of the egg. At that point the egg cell becomes a new individual with a full complement of chromosomes. In humans a person gets 23 chromosomes from the mother and 23 from the father for a total of 46.