10th Biology Practice Questions – Page 9

One mark questions
1. What is irritability?
A: The property of responding to changes in the environment is called irritability.

2. What are reflex actions?
A: Reflex actions are fast, immediate, automatic and involuntary responses of the body and occur without our thinking. They save
us from painful or dangerous stimuli.

3. What is epiglottis?
A: The cartilaginous flap which acts as a lid over the glottis preventing the food from entering the larynx is called the epiglottis.

4. How is trachea prevented from collapsing?
A: The walls of trachea are supported by several ‘C’ shaped cartilaginous rings which prevent the trachea from collapsing and
closing.

5. Why is spleen called the graveyard of R.B.C?
A: Spleen is called the graveyard of RBC because old red blood cells are destroyed in spleen.

Two marks questions
1. What are gyri and sulci? What is advantage of these structures?
A: Gyri: The several ridges or elevations in the cerebral cortex are gyri.
Sulci: The grooves in the cerebral cortex are sulci. They increase the surface area of the cortex so that it can accommodate more number of neurons.

2. Give an account of Tetany.
A: If the parathormone secretes in large quantities, the muscles become very active and remain the contracted state. This condition
is called Tetany.

3. What is a reaction centre?
A: In chloroplasts, the chlorophyll and other accessory pigment molecules are situated in the thylakoid membranes. These are organized to form the reaction centres called photosystem-I and photosystem-II.

4. What is an electron acceptor? Give some examples.
A: The acceptors which accept electrons are called electron acceptors.
e.g.: NAD, NADP, Cytochromes, ferredoxins.

5. What is systole and diastole?
A: Systole: The contraction phase of heart. This pumps blood into arteries.
Diastole: The relaxation phase of heart. This brings the blood vessels, chambers return to their normalcy.
Four marks questions

Four marks questions
Q. Plant growth substances act together and against each other. Give suitable examples in support of the statement.
A: Growth regulating substances act in a different manner. In many cases they act together and produce same action and sometimes they act opposite to each other.
Examples of their combined actions are given below:
1. Interaction of auxins and cytokinins together controls the differentiation of roots and shoots in tissue culture experiments.
2. Dormancy of buds and seeds is broken by gibberellins and cytokinins.
3. ABA and gibberellins regulate bud dormancy and seed germination.
4. Root growth is influenced by the levels of auxin and ethylene.
5. Cytokinins are synthesized usually in the roots and they move to
shoots through xylem and act along with auxins for promoting bud growth.

The following are the examples for the growth regulating substances which act against each other:
1. Dormancy induced by ABA in buds, tubers and many seeds can be broken by using gibberellins and cytokinins.
2. ABA and ethylene induce senescence and abscission of leaves and flowers.
3. These two processes can be delayed by the action of auxins and cytokinins.

Q. Write the differences between Red blood cells and White Blood Cells (RBC and WBC) or Erythrocytes and Leucocytes.

Redblood corpuscles
1. The cells are red in colour because of the presence of a red pigment called haemoglobin.
2. Cells are circular or biconcave in shape.
3.They are more numerous in the blood.There are about 4.5 to 5.5 ×
109cells per ml of blood.
4. They are produced in the bone marrow of long bones.
5. Life span is about 120 days.
6. They carry oxygen and carbondioxide to different tissues.
7. They cannot kill the foreign germs.
8. Only one type of cells is present.
9. Old cells are destroyed in spleen and liver

Whitebloodcorpuscles
1. They are colourless.
2. They do not have any fixed shape.
3. They are less numerous than RBC.
4. There are about 5 to 9 × 106
5. They are produced in the lymph nodes, spleen and thymus.
Life period is only 12 to 13 days.
6. They cannot carry oxygen and carbon dioxide to different tissues.
7. They can kill the foreign germs, which cause diseases.
8. Different types of cells like Eosinophils, Neutrophils and Basophils. Lymphocyte s and monocytes are present.
9. Old cells are destroyed in the blood, liver and lymph.

Essay Type Questions (Each question carries 4 Marks)
Q. What are the rules to be followed while giving first aid?
A. The following rules and principles are necessary for success in first aid and to save the victim from danger.
1. Organise the activities in orderly fashion without panic and confusion.
2. Firstly, treat for breathing. Every second is important for the survival of the victim.
3. If the victim is bleeding, immediately make efforts to stop bleeding.
4. Treat for the shock by moving the victim as little as possible and handling gently.
5. Do first aid as much as required to prevent the deterioration of the condition.
6. Do not allow people to crowd around the victim. Allow fresh air to the victim.
7. Do not create fear in the victim or people around him. Assure him that he is in safe hands and medical help will be coming soon.
8. Do not move or remove clothes from the victim unnecessarily.
9. See the proper medical help is available to the victim at the earliest by sending message to a doctor or to an ambulance.

Q. What are the different types of fractures seen in the limbs of a person?
A. The term fracture is used to indicate that the bone is broken due to an accident. Fractures can occur in any part of the body, but usually they occur in the limbs. The following are the different types of fractures.
1. Simple fracture: This is also called closed fracture. Only the bone is broken and there will not be wounds at the site of fracture. The bone may be broken completely or partially.
2. Compound fracture: This is called open fracture. Along with the fracture of the bone, wound is also seen at the site of the fracture. One or both the broken ends of the bone pierce through the skin and protrude out. This may damage the surface tissue and cause bleeding.
3. Complicated fracture: This type of fracture is associated with damages to important internal organs such as liver, brain, intestines, spleen and major blood vessels.
4. Communicated fracture: In this type bone is broken at several places.
5. Impact fracture: The broken ends of fractured bone are driven into one another.
6. Green Stick Fracture: The bone bends but does not break. This is usually seen in children.

Q. Mention the symptoms of a fracture.
A. The following are the symptoms of a fracture.
1. There will be pain at the site of fracture.
2. Swelling appears at that site.
3. The affected area will be tender to touch and cannot bear even small pressure.
4. Injured part cannot be moved normally.
5. The limbs may be deformed. When the bones break, the muscles attached to the bones contract and pull the broken ends of the bones one over the other. This usually results in shortening of the bones (or) limbs.
6. There will be unnatural movement at the site of fracture.
7. Grating sound can be heard at the site of fracture.
8. Symptoms depend on the extent of bone damage. The extent of damage can be known by comparing the unbroken side with the broken side.

Short Type Questions (Each question carries 2 Marks)
Q. What first aid do you render for fractures?
A. 1. Treat the fractures at the site of accident, victim should not be moved unnecessarily.
2. First attend to wounds which are bleeding. Clean the wounds and make efforts to stop bleeding.
3. Clean the injured part with cotton and give support to the fractured limb with splints of wood.
4. This will stop bleeding and prevents damage to the blood vessels, nerves and muscles.
Q. What is first aid? Mention its purpose.
A. It is an immediate and temporary care given to a person who had met with an accident or suddenly falls sick. The purpose of the first
aid is to:
1. Keep the victim alive.
2. Relieve pain or distress
3. Prevent the condition going bad until a doctor attends on the patient or the patient is taken to a hospital.
Q. Who was the pioneer in the first aid and who made significant contributions in popularising it?
A. A German called Esmarch was the originator of first aid. However, first aid was made popular by St. Johns Ambulance Service (England) in 1879. British Red Cross Society and St. Andrew’s Ambulance service
also made significant contributions in popularising first aid. Even today, these three organisations are giving training to the people in first aid.

AP 10th Biology Practice Questions and Answers

10th Biology Important Questions and Answers