Q. What is the function of the enzyme ptyalin or amylase?
A: Ptyalin or amylase is an enzyme that digests carbohydrates. It is produced in small intestine. Thus, the carbohydrates are digested in small intestine.
Q. What is the function of stroma?
A: Stroma is a place for enzymatic reactions leading to the synthesis of glucose, which in turn join together to form starch.
Q. Explain about roughages.
A: Roughages are the fibres of either carbohydrates or proteins. The intestine works properly due to roughages. They help move the food quickly through the alimentary canal. They keep a person healthy.
Q. If we keep on increasing CO2 concentration in the air what will be the rate of photosynthesis?
A: The rate of photosynthesis increases as the concentration of CO2 increases in the air. Gradually the rate of photosynthesis falls and at a certain CO2 concentration the rate of photosynthesis stays constant. Here a rise in CO2 levels has no affect on the rate of photosynthesis as the other factors such as light intensity become limited.
Q. Raju said ‘stems also respire along with leaves in plants.’ Can you support this statement? Give your reasons.
A: Yes. I support the statement of Raju that stems also respire along with leaves in plants. The reasons are:
1. The stems of herbaceous plants have stomata. The exchange of gases in the stems takes place through stomata.
2. The oxygen from air diffuses into the stem through stomata and reaches all the cells for respiration.
3. The carbon dioxide released due to respiration diffuses out into the air through the stomata.
4. In woody stems the bark has lenticels for gaseous exchange. Through lenticels oxygen diffuses in and CO2 diffuses out
into the air.
Q. What happens if diaphragm is not there in the body?
A: As we know, diaphragm is the muscle that separates the thoracic and abdominal cavities. We need it for normal respiratory function.
If diaphragm is not there in the body, we would not be able to breath and all breathing movements would stop.
Q. Satish went on a trekking camp with his college team. He carried an oxygen cylinder on his back. When he reached high altitude, he
faced problem with the supply of oxygen through the cylinder due to some technical problem. He suffered a lot and felt suffocation. Can you explain why this happened?
A: At a height of 13 km above sea level, the concentration of oxygen is much lower about one fifth at sea level. Under these conditions, only about half as many molecules of oxygen combine with haemoglobin to form oxyhaemoglobin. Human life is impossible at such an altitude without a supplementary supply of oxygen. That is
the reason why satish felt out of breath.
Q. Show the process of respiration in a flow chart.
A: 2 Stages: Inspiration and expiration.
Inspiration: Air from outside → nostrils → nasal cavities → internal nares → pharynx → glottis → larynx → tracheae → bronchi → alveoli. Exchange of gases takes place in alveoli. Expiration: Air in lungs, under pressure rushes out of lungs.
Q. Write about single / double circuits.
A: Circuit : The path in which the blood flows is called a circuit. There are 2 circuits for the flow of blood. If blood flows through heart only once for completing one circulation it is called single circulation.
Single circuit heart : The heart that pumps blood into one circuit for one circulation of blood is called single circuit heart.
Double Circuit heart : The heart that pumps blood into two circuits is called a double circuit heart. The blood streams coming from these circuits are kept separate. If the blood flows through the heart twice
for completing one circulation it is called double circulation.
Q. Karuna’s uncle was admitted in hospital with a kidney problem. When Karuna went to see him, she saw that her uncle was undergoing a process that was filtering wastes in his kidney. If you were Karuna,
what questions would you ask the doctor about this process?
A: If I were Karuna, I would ask the doctor the following questions:
1. What is the process called as?
2. How is it performed?
3. Can all the wastes be removed by this process?
4. What is the name of the anticoagulant used here?
5. How much time does it take to finish this process?
6. Is there any long term solution for kidney failure patients?
Q. What is the result of the metabolic activities happening in our body?
A: A number of reactions take place during various metabolic activities. Many useful substances and energy are produced. At the same time many other things happen such as, toxic wastes may be produced, water content may increase, ionic balance in the body may be disturbed. The waste products include carbon dioxide, water,
nitrogenous compounds like Ammonia, Urea, Uric acid, bile pigments, excess salts etc. The most poisonous of all waste products
of metabolism is Ammonia.
Q. Write about the lymphatic system.
A: The lymphatic system is an accessory circulatory system which transports lymph from the intercellular spaces of tissues to the blood.
Lymph : It is a fluid similar to plasma. Lymphatic system is the one way route for the movement of interstitial fluid to blood. It carries proteins and large particle matter from the tissue spaces into the blood. We Lymphatic system would die within 24 hours if these proteins are not removed.
Q. Imagine yourself to be Galan, the Greek physiologist (A.D. 129 – 200). One day a patient came to you and told that he had fallen from his chariot and had a blow in the neck. He complained of loss of feeling in the arm while still retaining normal muscular control of its moment. What questions would arise in your mind to make any conclusions about the situation?
A: If I were Galan, I would think on following questions:
1. Is it the nervous system that is damaged?
2. Why is it that the blow in the neck resulted in the loss of feeling?
3. If the nervous system is affected, how is it that there is normalcy in muscular control of its movement?
4. Are there different types of nerves for feeling and muscular movement?
5. What should I do to the patient to normalize his situation?
Q. How can you avoid sexually transmitted diseases?
A: If we follow the simple life styles as cited below one could avoid many sexually transmitted diseases.
1. Avoid sex with unknown partners / multiple partners
2. Always use condoms during coitus.
3. In case of doubt, go to a qualified doctor for early detection and get complete treatment if diagnosed with disease.
Q. How would you appreciate the significance of placenta?
A: Placenta is a tissue formed by the cells from the embryo and the mother. It is formed around 12 weeks of pregnancy and becomes an important structure for nourishment of the embryo. Under normal conditions, there is never a direct blood flow between mother and young. The blood systems of the two, are separated by thin membranes made up of cells that allow an exchange, by diffusion, of oxygen, carbon dioxide, nutrients, and waste materials.
Q. How are taste and smell related?
A: Taste and smell are intimately related. This close relationship is most readily seen in how we perceive the flavours of food. Anyone with severe cough and cold cannot make out the difference in the taste of certain food items.
1. Actually, what is really being affected is the flavour of the food or the combination of taste and smell.
2. That is because not only the taste but also the food odours are being defected.
3. Taste itself is focused on distinguishing. chemicals that have a sweet, salty, sour, bitter or umami taste.
4. However interactions between the senses of taste and smell enhance our perceptions of the foods we eat.
Q. What is the difference between phenotype and genotype?
A: Phenotype : The character which can be seen is known as phenotype. We can’t determine the internal factors by phenotype. It tells only about the dominating characters which express externally.
The phenotype ratio in mono hybrid cross is 3 : 1.
Genotype : the genetic make up of an individual is known as genotype. Genotype itself is the indication of internal factors. It
tells about both dominant and recessive characters present within. The genotype ratio in mono-hybrid cross is 1 : 2 : 1.
Q. What does this picture denote?
A: It is a synapse. Dendrites of one nerve cell connect to the other or to the axons of the other nerve cell through connections called as a ‘synapse’. Synapse is the connections between neurons. Synapse is a functional region between two neurons where information from one neuron is transmitted or relayed to another neuron.