Compare the functioning of alveoli in the lungs
[question] Question. Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning. [solution] solution: [/solution]...
What are the differences between the transport
[question] Question. What are the differences between the transport of materials in xylem and phloem? [/question] [solution] solution: [/solution]...
Describe double circulation of blood in human beings.
[question] Question. Describe double circulation of blood in human beings. Why is it necessary? [/question] [solution] solution: Double circulation In double circulation, the blood passes twice through the heart to supply once to the body (i) Systemic circulation In this, blood completes its circulation from left ventricle to right auricle through the body organs.(systemic organs) Oxygenated blood from lungs $\rightarrow$ heart $\rightarrow$ Systemic arteries $\rightarrow$ Body parts $\rightarro...
What would be the consequences of a deficiency
[question] Question. What would be the consequences of a deficiency of haemoglobin in our bodies? [/question] [solution] solution: Haemoglobin is the respiratory pigment that transports oxygen to the body cells for cellular respiration. Deficiency of haemoglobin in blood lead to deficiency of oxygen in the body cells which can lead to a disease called anaemia. [/solution]...
How are the alveoli designed to maximise
[question] Question. How are the alveoli designed to maximise the exchange of gases? [/question] [solution] solution: Alveoli are small pouches or sacs. Large number of alveoli occur inside each lung. The whole surface of an alveolus functions as respiratory surface. Due to large number of alveoli in each lung, a very large area of respiratory surface becomes available (about $80 \mathrm{~m}^{2}$ ) for exchange of gases. The walls of alveoli are very thin and they are surrounded by blood capilla...
What are the differences between aerobic and anaerobic respiration?
[question] Question. What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration. [/question] [solution] solution: Differences between aerobic and anaerobic respiration Yeast and most of bacteria use the anaerobic mode of respiration. [/solution]...
What are the necessary conditions for autotrophic
[question] Question. What are the necessary conditions for autotrophic nutrition and what are its by-products? [/question] [solution] solution: Requirements for photosynthesis (A) Sunlight (B) Photosynthetic pigment (C) Carbon dioxide (D) Water The sugar produced in photosynthesis is stored in the form of starch in plants and it is the source of reserved internal energy. [/solution]...
What is the role of saliva in the digestion of food?
[question] Question. What is the role of saliva in the digestion of food? [/question] [solution] solution: Salivary glands secrete saliva which contains a digestive enzyme called ptyalin or salivary amylase that breaks down starch. [/solution]...
How are fats digested in our bodies?
[question] Question. How are fats digested in our bodies? Where does this process take place? [/question] [solution] solution: The small intestine is the site of the complete digestion of carbohydrates,proteins and fats.Fats are present in the intestine in the form of large globules which makes it difficult for enzymes to act on them. Bile salts from Liver break them down into smaller globules increasing the efficiency of enzyme action. The pancreas secretes pancreatic juice which contains enzym...
The autotrophic mode of nutrition requires
[question] Question. The autotrophic mode of nutrition requires (A) carbon dioxide and water. (B) chlorophyll. (C) sunlight. (D) all of the above [/question] [solution] solution: (D) all of the above [/solution]...
The xylem in plants are responsible for
[question] Question. The xylem in plants are responsible for (A) transport of water. (B) transport of food. (C) transport of amino acids. (D) transport of oxygen. [/question] [solution] solution: (A) transport of water. [/solution]...
The kidneys in human beings are a part of the system for
[question] Question. The kidneys in human beings are a part of the system for (A) nutrition. (B) respiration. (C) excretion. (D) transportation. [/question] [solution] solution: (C) Excretion. [/solution]...
How is the amount of urine produced regulated ?
[question] Question. How is the amount of urine produced regulated ? [/question] [solution] solution: Amount of urine is regulated by volume of blood and amount of antidiuretic hormone $\mathrm{ADH}) \cdot \mathrm{ADH}$ is a hormone released by pituitary gland. Volume of blood is determined by resence or absence of extra water in the body. More blood volume will increase pressure in the glomerulus. It increases the amount of glomerular or nephric filtrate. ADH is not secreted. Dilute urine is al...
What are the methods used by plants to
[question] Question. What are the methods used by plants to get rid of excretory products ? [/question] [solution] solution: The method used by plants to get rid of excretory products are (i) The oxygen which is produced during the process of photo-synthesis gets removed through stomata. (ii) The carbon dioxide which is produced during the process of respiration also gets removed through stomata. (iii) The excess of water gets removed through transpiration. (iv) Some other wastes get removed alo...
Describe the structure and functions of nephron.
[question] Question. Describe the structure and functions of nephron. [/question] [solution] solution: The nephron is the functional unit of the kidney. A nephron consists of a twisted tubule closed at one end, open at the other with a network of associated blood vessels. Each kidney of man is formed of about one million nephrons. Each nephron has a length of about 3 cm. It is differentiated into 4 regions having different anatomical features and different physiological roles. Nephron : The 4 re...
How is food transported in plants.
[question] Question. How is food transported in plants. [/question] [solution] solution: Food is transported in dissolved form through phloem. This process is called as translocation. [/solution]...
How are water and minerals
[question] Question. How are water and minerals transported in plants ? [/question] [solution] solution: In xylem tissue, vessels and tracheids of the roots, stems and leaves are interconnected to form a continuous system of water-conducting channels reaching all parts of the plant. At the roots, cells in contact with the soil actively take up ions. This creates a difference in the concentration of these ions between the root and the soil. Water, therefore, moves into the root from the soil to e...
What are the components of the transport
[question] Question. What are the components of the transport system in highly organised plants ? [/question] [solution] solution: Transport system of highly organised plants consists of xylem and phloem. (i) Xylem. It is used in transport of water and minerals. Xylem is made of tracheids, vessels, xylem fibers and xylem parenchyma. Tracheids and vessels constitute the tracheary elements or channels for transport of water and minerals. (ii) Phloem. It is used for transport or translocation of or...
Why it is necessary to separate oxygenated and deoxygenated
[question] Question. Why it is necessary to separate oxygenated and deoxygenated blood in mammals and birds ? [/question] [solution] solution: Mammals and birds are warm blooded animals. They constantly use energy to maintain their body temperature. They have a higher energy needs and require more oxygenated blood for their cells. It is important that their oxygenated blood does not mix up with deoxygenated blood. [/solution]...
What are the components of the transport system in human beings ?
[question] Question. What are the components of the transport system in human beings ? What are the functions of these components ? [/question] [solution] solution: Human transport system has two components, blood vascular system and lymphatic system. Blood Vascular System. It consists of blood, blood vessels (tube) and heart. (1) Heart-It is pumping organ of blood vascular system. (2) Blood- It is made up of plasma and three types of cells – red blood corpuscles, white blood corpuscles and bloo...
How are the lungs designed in human
[question] Question. How are the lungs designed in human beings to maximize the area for exchange of gases. [/question] [solution] solution: Each lung has a highly branched respiratory tract called respiratory tree. A primary bronchus divides into secondary bronchi, secondary into segmental bronchi, segmental bronchus into bronchioles which divide into terminal bronchioles, respiratory bronchioles, alveolar sacs and alveoli. Alveoli are small rounded pouches which are extremely thin walled and p...
How is oxygen and carbon dioxide
[question] Question. How is oxygen and carbon dioxide transported in human beings? [/question] [solution] solution: Oxygen : (i) 97% in combined state with haemoglobin called oxyhaemoglobin. (ii) 3% dissolved in plasma. Carbon dioxide : (i) 5–7% as dissolved in plasma. (ii) 70% as sodium bicarbonate in plasma. (iii) 23% in combined state with haemoglobin called carbaminohaemoglobin. [/solution]...
What are thedifferent ways in which glucose is oxidised
[question] Question. What are thedifferent ways in which glucose is oxidised to provide energy in various organisms? [/question] [solution] solution: The different ways in which glucose is oxidised to provide energy in various organisms 1. Aerobic respiration 2.Anaerobic respiration Fermentation [Alcohol fermentation] : Anaerobic respiration in muscle cells [Lactic acid fermentation]: [/solution]...
What advantage over an aquatic organism does a terrestrial organism
[question] Question. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration? [/question] [solution] solution: Air contains about $21 \%$ of oxygen while water has less than $1 \%$ oxygen in dissolved state. A terrestrial organism is able to get several times more oxygen than an aquatic organism. [/solution]...
How is small intestine designed to
[question] Question. How is small intestine designed to absorb digested food ? [/question] [solution] solution: Small intestine is lined by epithelium which is specialised to absorb. It has mechanism to increase its absorbing surface area several times. (i) Villi are transverse folds of intestine wall that not only increase surface area but also reach deep into the lumen of intestine for absorption of digested food. Villi possess blood capillaries and lacteals (lymph vessels) for quick transport...
What is the function of digestive
[question] Question. What is the function of digestive enzymes ? [/question] [solution] solution: Digestive enzymes are hydrolytic enzymes which bring about hydrolytic splitting of complex organic substances into simple, soluble and absorbable substances, e.g., Protein $\stackrel{\text { enzyme }}{\longrightarrow}$ Peptides $\stackrel{\text { enzyme }}{\longrightarrow}$ Amino acids. [/solution]...
What is the role of acid
[question] Question. What is the role of acid in our stomach ? [/question] [solution] solution: Hydrochloric acid (HCl) is component of gastric juice. It has five functions, (i) Softening of food, (ii) Conversion of pepsinogen and prorennin into active forms of pepsin and rennin (iii) Acidify the food for proper action of pepsin. (iv) Killing of microoganisms present in food. (v) Stoppage of action of salivary amylase. [/solution]...
Where does the plants get each of the
[question] Question. Where does the plants get each of the raw materials for photosynthesis ? [/question] [solution] solution: (i) Carbon Dioxide - Air through stomata. (ii) Water - Soil through roots. (iii) Minerals - Soil through roots [/solution]...
What are the difference between autotrophic
[question] Question. What are the difference between autotrophic nutrition and heterotrophic nutrition ? [solution] solution: Autotrophic nutrition : The process through which organisms are able to build up their own organic food from raw materials which are obtained from outside, in the form of carbon dioxide and water in the presence of chlorophyll and sunlight. The organisms having autotrophic mode of nutrition or can make their own food are called autotrophs or autotrophic organisms. e.g. Gr...
What processes would you consider
[question] Question. What processes would you consider essential for maintaining life ? [/question] [solution] solution: Life processes nutrition, metabolism, respiration, exchange of materials, transportation, excretion and awareness. [/solution]...
What are outside raw materials
[question] Question. What are outside raw materials used by an organism ? [/question] [solution] solution: Food by heterotrophic organisms ; carbon dioxide, minerals and water by autotrophic organisms ; oxygen by all aerobic organisms. [/solution]...
What criteria do we use to decide
[question] Question. What criteria do we use to decide whether something is alive ? [/question] [solution] solution: The major criterion which is used to decide whether something is alive is movements. Movements may be that of locomotion (e.g. running of dog), movement of a part (e.g. chewing cud by cow), breathing movements, growth movements (in plants) and movement of molecules in metabolic reactions, maintenance and repair of cellular structures. Besides movements, other criteria found in liv...
Why is diffusion insufficient to meet the oxygen requirements
[question] Question. Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans? [/question] [solution] solution: Every living cell requires oxygen for performing cellular respiration. In unicellular organisms (e.g., Amoeba), the single cell is in direct contact with environment. Oxygen passes into it through diffusion. In simple multicellular organisms (e.g. Hydra), every cell may also take oxygen through diffusion from environment. This is not possibl...