CHAPTER 5 Life Processes KSEEB SSLC CLASS 10 SCIENCE PART 1 SOLUTIONS

CHAPTER 5 Life Processes KSEEB SSLC CLASS 10 SCIENCE PART 1 SOLUTIONS, English medium Karnataka state board,the Answers Are Prepared By Our Teachers Which Are Simple ,Pointwise,Easy To Read And Remember .

CHAPTER 5 Life Processes KSEEB SSLC CLASS 10 SCIENCE PART 1 SOLUTIONS

1.Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?

Diffusion alone cannot effectively transport oxygen to all cells in multicellular organisms.
As the body size and complexity increase, diffusion becomes inadequate to reach all cells efficiently.
Cells deeper within the organism may not receive sufficient oxygen through diffusion alone.

What criteria do we use to decide whether something is alive?

Visible movement, growth, and response to stimuli are considered.
Presence of life processes such as nutrition, respiration, and excretion.
Ability to maintain organized structures and carry out essential functions.

What are outside raw materials used for by an organism?

Outside raw materials, like food, are used for nutrition.
They provide energy and raw materials for growth and maintenance of living structures.

What processes would you consider essential for maintaining life?

Nutrition: Obtaining and processing food for energy and growth.
Respiration: Acquiring oxygen from the environment and breaking down food for energy.
Excretion: Removing waste products from the body.
Transport: Moving essential substances throughout the organism’s body.
Growth: Increasing in size and complexity.
Maintenance of structures: Repairing and maintaining organized living structures.

1.What are the differences between autotrophic nutrition and heterotrophic nutrition?

Autotrophic nutrition: Organisms produce their own food using simple substances like carbon dioxide and water, primarily through photosynthesis.
Heterotrophic nutrition: Organisms obtain their food from external sources, such as consuming other organisms or organic matter, as they cannot produce their own food.

2.Where do plants get each of the raw materials required for photosynthesis?

Carbon dioxide (CO2): Absorbed from the air through small pores called stomata on the surface of leaves.
Water (H2O): Absorbed from the soil through the roots and transported to the leaves through the xylem vessels.

What is the role of the acid in our stomach?

The acid (hydrochloric acid) creates an acidic environment in the stomach, which aids in the digestion of proteins.
It also helps to kill bacteria and other pathogens present in ingested food.

What is the function of digestive enzymes?

Digestive enzymes break down complex food molecules into simpler forms that can be absorbed and used by the body.
For example, amylase breaks down starch into simple sugars, protease breaks down proteins into amino acids, and lipase breaks down fats into fatty acids and glycerol.

5.How is the small intestine designed to absorb digested food?

The small intestine has finger-like projections called villi, which increase the surface area available for absorption.
Villi are richly supplied with blood vessels, allowing for efficient absorption of digested nutrients into the bloodstream.
Absorbed nutrients are then transported to every cell of the body for energy, tissue building, and repair.

What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?

Terrestrial organisms can directly breathe atmospheric oxygen, which is more abundant compared to dissolved oxygen in water.
They have specialized respiratory organs such as lungs, which provide a larger surface area for gas exchange compared to gills in aquatic organisms.
Terrestrial organisms do not have to constantly pump water over their respiratory surfaces like aquatic organisms, allowing for more efficient gas exchange.

What are the different ways in which glucose is oxidized to provide energy in various organisms?

Glucose can be oxidized through aerobic respiration, which occurs in the presence of oxygen and yields a large amount of energy in the form of ATP.
In anaerobic respiration, glucose can be partially oxidized without the use of oxygen, leading to the production of substances such as lactic acid or ethanol and carbon dioxide, depending on the organism.
Some organisms, like yeast, can ferment glucose, converting it into ethanol and carbon dioxide in the absence of oxygen.

How is oxygen and carbon dioxide transported in human beings?

Oxygen is transported in human beings primarily by hemoglobin, a protein present in red blood cells. Hemoglobin binds to oxygen in the lungs and releases it in tissues where it is needed.
Carbon dioxide is transported in the blood mainly in the form of bicarbonate ions (HCO3-) and dissolved in plasma. Some carbon dioxide also binds to hemoglobin and is carried back to the lungs for exhalation.

How are the lungs designed in human beings to maximize the area for exchange of gases?

The lungs contain millions of tiny air sacs called alveoli, which provide a large surface area for gas exchange.
The walls of the alveoli are thin and surrounded by a dense network of capillaries, facilitating the diffusion of gases between air and blood.
The branching structure of the bronchial tree leading to the alveoli increases the overall surface area available for gas exchange.
The lungs expand and contract during breathing, ensuring fresh air reaches the alveoli for efficient exchange of gases.

What are the components of the transport system in human beings? What are the functions of these components?

Components: The transport system in human beings consists of the heart, blood vessels (arteries, veins, and capillaries), and blood.
Functions:
Heart: Acts as a pump to circulate blood throughout the body.
Arteries: Carry oxygenated blood away from the heart to various organs and tissues.
Veins: Return deoxygenated blood back to the heart.
Capillaries: Allow for the exchange of gases, nutrients, and waste products between blood and tissues.

Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?

It is necessary to separate oxygenated and deoxygenated blood to ensure efficient oxygen delivery to body tissues and organs.
Mammals and birds have high energy needs and require a constant and abundant supply of oxygen for cellular respiration.
Separating oxygenated and deoxygenated blood prevents mixing and ensures that oxygen-rich blood is efficiently delivered to body tissues, while deoxygenated blood is sent to the lungs for oxygenation.

What are the components of the transport system in highly organized plants?

Components: The transport system in highly organized plants includes xylem and phloem.

Functions:

Xylem: Transports water and minerals absorbed from the soil to the leaves and other parts of the plant.
Phloem: Transports organic nutrients, such as sugars and amino acids, synthesized in the leaves to other parts of the plant for growth and storage.

How are water and minerals transported in plants?

Water and minerals are transported in plants through the xylem tissue.
Water is absorbed by root hairs and moves through the xylem vessels via capillary action and transpiration pull.
Root pressure also aids in the upward movement of water in the xylem.

How is food transported in plants?

Food is transported in plants through the phloem tissue.
Organic nutrients, such as sugars and amino acids, synthesized in the leaves during photosynthesis are transported via the phloem to other parts of the plant for growth, storage, and metabolism.

Describe the structure and functioning of nephrons.

Structure and functioning of nephrons:

Nephrons are the basic filtration units in the kidneys.
Each nephron consists of a cluster of thin-walled blood capillaries (glomerulus) and a coiled tube called Bowman’s capsule.
Blood is filtered in the glomerulus, and the filtrate is collected in Bowman’s capsule.
The filtrate passes through the nephron tubule, where selective re-absorption of substances like glucose, amino acids, and water occurs.
The remaining filtrate forms urine, which flows into the ureter and then to the urinary bladder.

What are the methods used by plants to get rid of excretory products?

Methods used by plants to get rid of excretory products:

Plants release oxygen generated during photosynthesis.
Excess water is eliminated through transpiration.
Waste products are stored in cellular vacuoles, old xylem, or in leaves that fall off.
Some waste substances are excreted into the soil.

How is the amount of urine produced regulated?

. Regulation of urine production:

The amount of urine produced depends on the body’s water balance and the concentration of dissolved waste.
Excess water is re-absorbed in the kidney tubules if there is a deficit, resulting in concentrated urine.
Conversely, if there is excess water in the body, more water is excreted in the urine, resulting in dilute urine.

EXERCISES

The kidneys in human beings are a part of the system for

(a) nutrition.

(b) respiration.

(d) transportation.

The kidneys in human beings are a part of the system for (c) excretion.

Kidneys filter waste products from the blood.
They regulate water and electrolyte balance.
They help in maintaining blood pressure.
Kidneys also produce urine to remove waste from the body.

The xylem in plants are responsible for

(a) transport of water.

(b) transport of food.

(d) transport of oxygen.

The xylem in plants are responsible for (a) transport of water.

Xylem is a tissue responsible for transporting water and minerals from roots to stems and leaves.
It provides mechanical support to the plant.
Xylem consists of vessels, tracheids, fibers, and parenchyma cells.

The autotrophic mode of nutrition requires

(a) carbon dioxide and water.

(b) chlorophyll.

(d) all of the above.

. The autotrophic mode of nutrition requires (d) all of the above.

Autotrophic nutrition involves using carbon dioxide, water, and sunlight to synthesize food.
Chlorophyll is necessary for photosynthesis.
Sunlight provides energy for the process.

The breakdown of pyruvate to give carbon dioxide, water and energy takes place in

(a) cytoplasm.

(b) mitochondria.

(d) nucleus.

The breakdown of pyruvate to give carbon dioxide, water, and energy takes place in (b) mitochondria.

Pyruvate is further broken down through aerobic respiration in mitochondria.
This process generates energy in the form of ATP.

How are fats digested in our bodies? Where does this process take place?

Fats are digested in our bodies through the process of lipolysis, primarily in the small intestine.

Lipases break down fats into fatty acids and glycerol.
Bile salts emulsify fats to increase the surface area for enzymatic action.

What is the role of saliva in the digestion of food?

Saliva in the digestion of food:

Saliva contains enzymes like amylase, which begins the digestion of starch.
It moistens food to aid in swallowing.
Saliva helps in the formation of a bolus, making it easier to swallow

What are the necessary conditions for autotrophic nutrition and what are its byproducts?

Necessary conditions for autotrophic nutrition and its byproducts:

Carbon dioxide, water, and sunlight are essential.
Chlorophyll captures sunlight for photosynthesis.
Byproducts include oxygen released during photosynthesis.

What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.

. Differences between aerobic and anaerobic respiration:

Aerobic respiration occurs in the presence of oxygen, producing a large amount of energy (ATP), carbon dioxide, and water. Organisms like humans and most animals use aerobic respiration.
Anaerobic respiration occurs in the absence of oxygen, producing less energy (ATP) and byproducts such as lactic acid or ethanol. Organisms like yeast and bacteria undergo anaerobic respiration.

How are the alveoli designed to maximise the exchange of gases?

. Alveoli designed to maximize gas exchange:

Thin walls for easy diffusion of gases.
Large surface area for increased exchange.
Moist environment to facilitate gas exchange.

What would be the consequences of a deficiency of haemoglobin in our bodies?

Consequences of haemoglobin deficiency:

Reduced oxygen transport leading to fatigue and weakness.
Pale skin and shortness of breath.
Anemia and potential organ damage due to oxygen deprivation.

Describe double circulation of blood in human beings. Why is it necessary?

Double circulation of blood in human beings:

Oxygen-rich blood from the lungs (pulmonary circulation -between the heart and lungs) and oxygen-poor blood from the body (systemic circulation -between the heart and body ) are kept separate.

It ensures efficient oxygenation of blood and distribution to body tissues.
Prevents mixing of oxygen-rich and oxygen-poor blood.

What are the differences between the transport of materials in xylem and phloem?

Differences between transport in xylem and phloem:

Xylem transports water and minerals from roots to shoots, while phloem transports sugars and other organic nutrients from leaves to other parts.
Xylem consists of dead cells, while phloem consists of living cells.
Xylem transports unidirectionally (upwards), while phloem transports bidirectionally.

Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.

Functioning of alveoli and nephrons:

Alveoli: Facilitate gas exchange in the lungs, with thin walls and rich blood supply.
Nephrons: Filter blood and produce urine in the kidneys, with specialized structures like glomerulus and tubules.
Both involve exchange processes but serve different functions in the body.

– Both alveoli and nephrons have a highly specialized structure to perform their respective functions efficiently.

– Alveoli facilitate gas exchange by diffusion between air and blood, while nephrons filter blood to remove waste and regulate electrolyte balance through processes like filtration, reabsorption, and secretion