Around the age of six or seven years, our teeth start to loosen, eventually falling right out. These are what we call milk teeth. Their termination is not a cause for alarm, but rather, a natural process. Soon new teeth replace the ones that are lost. In fact, the deciduous teeth help the permanent teeth erupt in their normal position. Certain of the lower vertebrates, such as sharks and mud puppies, continuously produce new teeth. But most mammals have only two sets. It seems that as you go up on evolutionary scale, there is loss in capacity to replace teeth, scientists say. On the other hand, the teeth become more specialized. For example, in lower organisms, teeth are designed primarily for grabbing and slashing, while in higher animals, they are also adapted for chewing and grinding.
It has been known that in humans the first set of teeth do more than just allow a child to chew. They play a role in stimulating and guiding the growth and development of jawbones and permanent teeth. One of the biggest fallacies is the belief that because deciduous teeth are temporary, they are not important. If a child loses milk teeth prematurely, by accident or because of decay, his jaw and permanent teeth are likely to develop improperly. Prolonged treatment may be needed to set them right.
Another reason for our two sets of teeth is that there is not enough room in a child’s small mouth for the full set of permanent teeth – there are only 20 deciduous teeth, compared with 28 or 32 permanent teeth present in adults.
Hope this helps
Answer:
We fear flying in a plane, nuclear power plants or being struck by lightning more because our risk perception isn't rational. We assess risks using a mixture of cognitive skills (weighing the evidence, using reasoning and logic to reach conclusions) and emotional appraisals. In this case, we believe that overheating or lack of exercise is something we can control. We believe we can feel the process taking place and we can react in time. We fear all the situations that we cannot control.
Explanation:
Yes, the human body is composed of approximately 60% of water. The given statement is true.
Water is essential for human health and for the survival of life on earth.
It keeps them alive, stale and healthy by providing oxygen and chief nutrients to the body.
It lubricates joints, knees and also removes waste materials from the kidney, and keeps them clean.
In adult humans, there is approximately 60% of water in their bodies.
The concentration of water is more in lean tissues than in fat tissues.
Women's bodies have more fats than men and water makes up only 55% of their bodies.
If you need to learn more about the water cycle click here:
brainly.com/question/2164391
#SPJ4
The reason behind S-waves' shadow being larger than P-waves' shadow zones is because S-waves cannot move through liquids or soft solids such as Earth's Core.
If you have any other questions I would be happy to answer them.
I believe the answer is b.
