3. What is a lever? Describe different classes of levers?
4. Draw a well labeled diagram to explain the human drain.
5. Discuss the layers of atmosphere in detail.
Section 11
Answers
Explanation:
3 = There are three types or classes of levers, according to where the load and effort are located with respect to the fulcrum. Class 1 has the fulcrum placed between the effort and load, Class 2 has the load in-between the effort and the fulcrum, and Class 3 has the effort between the load and the fulcrum.
4=
The human brain is the main coordinating center of the body, which enables an organism to think and make decisions.
Functions of different parts of the brain are:
Medulla oblongata: It controls involuntary actions and regulates reflex responses. It also controls blood pressure, salivation, and vomiting.
Cerebellum: It controls and coordinates different muscular actions. It is responsible for voluntary actions and maintains the equilibrium of the body during walking, drinking, catching, etc.
Forebrain: It has the following parts:
1. Cerebrum: Which performs thinking, reasoning, speech, intelligence and usage of information.
2. Olfactory: Where lobes are responsible for detecting the smell from different receptors.
3. Diencephalon: Which controls body temperature, the urge of eating, drinking, etc.
5=The atmosphere can be divided into layers based on its temperature, as shown in the figure below. These layers are the troposphere, the stratosphere, the mesosphere and the thermosphere. A further region, beginning about 500 km above the Earth's surface, is called the exosphere.
Answer:
Layers of atmosphere are troposphere, stratosphere,mesosphere , thermosphere and exosphere