Chapter 6 Life Process Solutions
Question - 11 : - What are the different ways in which glucose is oxidized to provide energy in various organisms?
Answer - 11 : - In cytoplasm Glucose is first broken down into two 3 carbon compounds called as pyruvate by the process known as Glycolysis. Further breakdown takes place in different organism by different processes.
Question - 12 : - How is oxygen and carbon dioxide transported in human beings?
Answer - 12 : - Oxygen and Carbon-di-oxide is transported in human being via blood stream. Oxygen is carried to the cells whereas carbon-di-oxide is carried away from the cells. Exchange of gases takes place between the alveoli of lungs and the surrounding blood capillaries. Oxygen is absorbed by the blood capillaries from the lungs alveoli by diffusion while carbon-dioxide is absorbed by the lungs alveoli from blood capillaries by diffusion.
Question - 13 : - How are the lungs designed in human beings to maximize the area for exchange of gases?
Answer - 13 : -
• The lungs is an important part of the body. The passage inside the lungs divides into smaller and smaller tubes, which finally terminate in balloon-like structures, called as alveoli.
• The alveoli provide a surface where the exchange of gases can take place. The walls of the alveoli usually contains an extensive network of blood vessels. We know that, when we breathe in, we lift our ribs, flatten our diaphragm and chest cavity becomes larger.
• Because of this action, air is sucked into the lungs and fills the expanded alveoli.
• The blood brings the essential carbon dioxide from rest of the body and supply it to alveoli; the oxygen in the alveolar air is taken up by the blood in the alveolar blood vessels to be transported to the all other cells of the body. During the normal breathing cycle, when air is taken in and let out, the lungs always contain a residual volume of air so that there is sufficient time for oxygen to be absorbed and carbon dioxide to be released.
Question - 14 : - What are the components of the transport system in human beings? What are the functions of these components?
Answer - 14 : - Heart, blood and blood vessels are the main components of transport system in human beings.
Functions of these components
Heart
Heart pumps oxygenated blood throughout the body. It receives deoxygenated blood from the various body parts and sends this impure blood to the lungs for oxygenation.
Blood
Blood transports oxygen, nutrients, CO2, and nitrogenous wastes.
Blood vessels
Blood vessels, arteries and veins carry blood to all parts of body.
Question - 15 : - Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Answer - 15 : - Mammals and birds are warm blooded animals which keep their body temperature constant irrespective of the environment they leave. This process require lot of oxygen for more cellular respiration so that warm blooded animals produce more energy to balance their body temperature. Hence it is very important for warm blooded animals to separate oxygenated and deoxygenated blood to keep their circulatory system efficient.
Question - 16 : - What are the components of the transport system in highly organized plants?
Answer - 16 : - There are two types of conducting tissues in highly organized plants that carry out transport system 1) Xylem 2) phloem. Xylem conduct water and minerals from roots to rest of the plant parts. Similarly Phloem transports food materials from leaf to other parts of the plant.
Question - 17 : - How are water and minerals transported in plants?
Answer - 17 : - Xylems parts tracheids and vessels of roots, stems and leaves are interconnected to form a continuous system of water-conducting channels that reaches all parts of the plant. Transpiration creates a suction pressure which forces water into xylem cells of roots. After this, there will be a steady movement of water from the root xylem to all parts of the plant connected through conducting interconnected water-conducting channels.
Question - 18 : - How is food transported in plants?
Answer - 18 : - Food is transported in plants by a special organ called as phloem. Phloem transports food materials from leaf to different parts of a plant. Transportation of food in phloem is achieved by the expenditure of ATP9 energy). This increases osmotic pressure in the tissue causing water to move. This pressure moves material in the Phloem to the tissues with less pressure. This is helping in transportation of food material as per the needs. Ex: Sucrose
Question - 19 : - Describe the structure and functioning of nephrons
Answer - 19 : -
Nephrons are the filtration units of the kidney which are large in numbers. Some substances in the initial filtrate, such as glucose, amino acids, salts and a major amount of water, are selectively re-absorbed as the urine flows along the tube.
Main components of Nephrons are
Glomerulus
Bowman’s capsule
Long renal Tube
Structure of Nephron
Functioning of Nephron
• The blood enters the kidney through the renal artery, which branches into many capillaries associated with glomerulus.
• The water and solute are transferred to the nephron at Bowman’s capsule.
• In the proximal tubule, some substances such as amino acids, glucose, and salts are selectively reabsorbed and unwanted molecules are added in the urine.
• The filtrate then moves down into the loop of Henle, where more water is absorbed. From here, the filtrate moves upwards into the distal tubule and finally to the collecting duct. Collecting duct collects urine from many nephrons.
• The urine formed in each kidney enters a long tube called ureter. From ureter, it gets transported to the urinary bladder and then into the urethra.
Question - 20 : - What are the methods used by plants to get rid of excretory products?
Answer - 20 : -
Plants can get rid of excess water by transpiration.
For other wastes, plants use the fact that many of their tissues consist of dead cells, and that they can even lose some parts such as leaves. Many plant waste products are stored in cellular vacuoles. Waste products may be stored in leaves that fall off.
Other waste products are stored as resins and gums, especially in old xylem. Plants also excrete some waste substances into the soil around them.