Nutrition
Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans ?
Not in contact with Environment
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration ?
Aquatic organisms use oxygen dissolved in surrounding water. Since air dissolved in water has fairly low concentration of oxygen, the aquatic organisms have much faster rate of breathing.
Terrestrial organisms take oxygen from the oxygen-rich atmosphere through respiratory organs. Hence, they have much less breathing rate than aquatic organisms.
What are the components of the transport system in human beings ? What are the functions of these components ?
The transport system (circulatory system) in human beings mainly consists of heart, blood and blood vessels. Mention functions.
Name all the organs of the human excretory system. Mention the functional unit of excretion as well.
Kidneys, ureter, urinary bladder, urethra. Nephrons.
What is the difference between a reflex action and walking?
any three
Differences between autotrophic nutrition and heterotrophic nutrition ? All 4 types of heterotrophic nutrition?
2 differences(no eg allowed), holozoic, parasitic, symbiotic, saprotrophic
What are the different ways in which glucose is oxidised to provide energy in various organisms ?
Anaerobic, aerobic and lack of oxygen
Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds ?
Separation of oxygenated and deoxygenated blood allows good supply of oxygen to the body. This system is useful in animals that have high energy requirement. Mammals and birds constantly need oxygen to get energy to maintain their body temperature constant.
Describe the structure of nephrons.
Mention all parts.
What happens at the synapse between two neurons?
The small empty space between two nerve cells is called synapse. At synapse, a chemical substance is produced at the end of axon of one nerve cell that reaches to the other nerve cell through the dendrite. Thus, information is transmitted from one nerve cell to other nerve cell by synapse.
Where do plants get each of the raw materials required for photosynthesis ? Mention the raw material as well.
4 raw materials with plant parts
How is oxygen and carbon dioxide transported in human beings ?
i) Transport of oxygen : Haemoglobin present in the blood takes up the oxygen from the air in the lungs. It carries the oxygen to tissues which are deficient in oxygen before releasing it.
(ii) Transport of carbon dioxide : Carbon dioxide is more soluble in water. Therefore, it is mostly transported from body tissues in the dissolved form in our blood plasma to lungs. Here it diffuses from blood to air in the lungs.
How are water and minerals transport in plants ?
Answer with correct terms.
Describe the 3 steps of urine formation.
Filteration, reabsorption, Secretion.
How do we detect the smell of an agarbatti (incense stick) ?
Describe the pathway
How is the small intestine designed to absorb digested food ? Elaborate with specific characteristics.
The small intestine is designed to provide maximum area for absorption of digested food and its transfer into the blood for its circulation into the body. For this the inner lining of the small intestine has numerous finger-like projections called villi. The villi are richly supplied with blood vessels which take the absorbed food to each and every cell of the body.
How are the lungs designed in human beings to maximise the area for exchange of gases ?
Within the lungs, the air passage divides into smaller and smaller tubes, called bronchi which in turn form bronchioles. The bronchioles terminate in balloon-like structures, called alveoli. The alveoli present in the lungs provide maximum surface for exchange of gases. The alveoli have vary thin walls and contain an extensive network of blood vessels to facilitate exchange of gases.
How is food transported in plants ?
Ans with correct terms.
What are the methods used by plants to get rid of excretory products ?
(i) The plants get rid of gaseous products-through stomata in leaves and lenticels in stems.
(ii) The plants get rid of stored solid and liquid waste by the shedding off leaves, peeling off bark and felling off fruits.
(iii) The plants get rid of wastes by secreting them in the form of gums and resins.
(iv) Plants also excrete some waste substances into the soil around them.
Describe the parts of a human brain and give any two functions.
Correct terms
What is the function of digestive enzymes ? Name atleast 4 digestive enzymes and their functions.
Digestive enzymes break down these complex molecules into smaller simpler molecules so that they can be absorbed by the walls of the intestine. 4 examples and functions.
Name all plant parts which perform exchange of gases for plant respiration. Is there any other function which these parts perform? Name it.
Stomata, lenticels, root hair. Transpiration, Excretion.
Differentiate between single and double circulation. Define warm and cold blooded animals.
2 differences. Correct definitions.
How is the amount of urine regulated? Also, differentiate between natural and artificial kidney's function.
The amount of urine is regulated by kidney. It depends on the quantity of excess water and wastes dissolved in water.
(i) Quantity of water : When water is abundant in the body tissues, large quantities of dilute urine is excreted out. When water is less in quantity in the body tissues, a small quantity of concentrate urine is excreted.
(ii) Quantity of dissolved wastes : Dissolved wastes, especially nitrogenous wastes, like urea and uric acid and salts are excreted from the body. When there is more quantity of dissolved wastes in the body, more quantity of water is required to excrete them. Therefore, the amount of urine produced increases.
(iii) Hormones : The amount of urine produced is also regulated by certain hormones.
How is the human nervous system classified? Elaborate.
Correct terms.