Class 10 Life Processes

Questions and Answers

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

Because all cells of the body need oxygen, and simple diffusion would not be able to deliver enough oxygen to meet the requirements of all cells.

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

Visible movement, growth over time, presence of organised structures, and molecular movements within cells are criteria used to determine if something is alive.

What are outside raw materials used for by an organism?

Outside raw materials are used for energy production, growth, repair, and maintenance of living structures in organisms.

What processes would you consider essential for maintaining life?

Essential processes for maintaining life include nutrition, respiration, transportation, and excretion. Signup and view all the answers

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

Terrestrial organisms have the advantage of breathing air directly from the environment, which contains a higher concentration of oxygen compared to water. Signup and view all the answers

How is oxygen and carbon dioxide transported in human beings?

Oxygen is primarily transported by the red blood corpuscles, while carbon dioxide is mostly transported in dissolved form in the blood. Signup and view all the answers

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

The lungs are designed with numerous alveoli that provide a large surface area for efficient gas exchange. Signup and view all the answers

What causes dental caries or tooth decay?

Bacteria acting on sugars produce acids that soften or demineralise the enamel. Signup and view all the answers

How does brushing teeth help prevent tooth decay?

Brushing teeth after eating removes plaque before bacteria can produce acids. Signup and view all the answers

What may happen if untreated dental decay allows microorganisms to invade the pulp?

Microorganisms may invade the pulp, causing inflammation and infection. Signup and view all the answers

In anaerobic respiration, what does pyruvate get converted into?

Ethanol and carbon dioxide. Signup and view all the answers

What is the primary function of ATP in cellular processes?

Providing energy for various life processes Signup and view all the answers

What are stomata and where are they present?

Stomata are tiny pores present on the surface of leaves. Signup and view all the answers

What causes the stomatal pore to open?

Swelling of guard cells Signup and view all the answers

What is the purpose of potassium hydroxide in the experiment described in Figure 5.4?

Potassium hydroxide is used to absorb carbon dioxide. Signup and view all the answers

Water used in photosynthesis is taken up by plants through their stems.

False Signup and view all the answers

In the experiment described, sunlight is essential for ________________.

photosynthesis Signup and view all the answers

Match the following organisms with their nutritive strategies:

Fungi like bread moulds, yeast, mushrooms = Break down food material outside the body and absorb it Cuscuta, ticks, lice, leeches, tape-worms = Derive nutrition from plants or animals without killing them Herbivores like cows = Take in stationary food sources like grass and digest inside their bodies Signup and view all the answers

What is the function of the enzyme salivary amylase?

Breaks down starch Signup and view all the answers

Describe the structure and functioning of nephrons.

Nephrons are the functional units of the kidneys responsible for filtering blood and producing urine. They consist of the glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct. The glomerulus filters blood and the tubules reabsorb necessary substances and excrete waste. Signup and view all the answers

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

Plants use various methods to get rid of excretory products, such as transpiration to remove excess water, storage in cell vacuoles, shedding of leaves, and excretion into the soil. Signup and view all the answers

How is the amount of urine produced regulated?

The amount of urine produced is regulated by factors like hydration levels, hormone levels (such as antidiuretic hormone), and kidney function. The body adjusts urine output to maintain water and electrolyte balance. Signup and view all the answers

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

The components of the transport system in human beings include the heart, blood vessels (arteries, veins, capillaries), and blood. The heart pumps blood, arteries carry oxygenated blood away from the heart, veins carry deoxygenated blood back to the heart, capillaries facilitate exchange of oxygen and nutrients with cells. Signup and view all the answers

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

It is necessary to separate oxygenated and deoxygenated blood in mammals and birds to ensure efficient transport of oxygen to body tissues and organs. This separation helps maintain a high oxygen concentration in oxygenated blood and prevents mixing of oxygen-rich blood with oxygen-poor blood. Signup and view all the answers

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

Highly organised plants have a transport system composed of xylem and phloem tissues. Xylem transports water and minerals from roots to other parts of the plant, while phloem transports sugars and nutrients produced in leaves to other plant parts. Signup and view all the answers

How are water and minerals transported in plants?

Water and minerals are transported in plants through the xylem tissue. The root cells actively take up ions from the soil, creating a concentration gradient that leads to the movement of water into the root xylem. This water is then transported upwards through the xylem to all parts of the plant. Signup and view all the answers

How is food transported in plants?

Food is transported in plants through the phloem tissue. The phloem transports sugars, amino acids, and other substances produced in the leaves to other parts of the plant, such as storage organs, fruits, and seeds. This process is known as translocation and relies on energy from ATP to move material according to the plant's needs. Signup and view all the answers

Study Notes

Life Processes

Life processes are the functions that living organisms perform to maintain their internal environment and respond to changes in their external environment.
These processes are essential for maintaining life and are necessary for growth, development, and survival.

Characteristics of Life

Living organisms exhibit certain characteristics, such as:
- Movement, either visible or invisible (e.g. molecular movement)
- Growth and development
- Reproduction
- Response to stimuli
- Energy conversion and utilization
- Maintenance of homeostasis

Molecular Movement

Molecular movement is necessary for life processes, as it allows for the exchange of materials and energy within the organism.
This movement is not always visible, but it is essential for the functioning of cells and tissues.

Life Processes in Organisms

Life processes are diverse and can vary depending on the type of organism, its environment, and its nutritional needs.
Examples of life processes include:
- Nutrition: the process of obtaining and utilizing nutrients and energy
- Respiration: the process of exchanging oxygen and carbon dioxide
- Transportation: the movement of materials and energy within the organism
- Excretion: the removal of waste products

Nutrition

Nutrition is the process of obtaining and utilizing nutrients and energy.
Autotrophic organisms, such as plants, produce their own food through photosynthesis.
Heterotrophic organisms, such as animals, obtain their food from external sources.

Photosynthesis

Photosynthesis is the process by which autotrophic organisms convert light energy into chemical energy.
The process requires:
- Light energy
- Carbon dioxide
- Water
- Chlorophyll
The products of photosynthesis are:
- Glucose (a type of sugar)
- Oxygen

Autotrophic Nutrition

Autotrophic organisms, such as plants, obtain their energy from sunlight and convert it into chemical energy through photosynthesis.
Plants use carbon dioxide and water to synthesize glucose and oxygen.

Heterotrophic Nutrition

Heterotrophic organisms, such as animals, obtain their food from external sources.
Examples of heterotrophic nutrition include:
- Herbivory: obtaining food from plants
- Carnivory: obtaining food from animals
- Omnivory: obtaining food from both plants and animals
- Parasitism: obtaining food from another organism without killing it

Human Nutrition

Human nutrition involves the process of obtaining and utilizing nutrients and energy from food.
The alimentary canal is a long tube that extends from the mouth to the anus and is responsible for the digestion and absorption of nutrients.
The digestive process involves:
- Mechanical digestion: breaking down food into smaller particles
- Chemical digestion: breaking down food into simpler molecules using enzymes
- Absorption: the uptake of nutrients into the bloodstream
- Assimilation: the use of nutrients by the body for energy and growth### Digestion and Absorption
Gastric glands in the stomach wall release hydrochloric acid, pepsin, and mucus to facilitate digestion.
Hydrochloric acid creates an acidic medium, which helps the enzyme pepsin break down proteins.
Mucus protects the inner lining of the stomach from the acid.

Small Intestine

The small intestine is the longest part of the alimentary canal, fitted into a compact space due to extensive coiling.
Its length differs in various animals, depending on the type of food they eat.
Herbivores, like those eating grass, need a longer small intestine to allow for cellulose digestion.
Carnivores, like tigers, have a shorter small intestine since meat is easier to digest.
The small intestine is the site of complete digestion of carbohydrates, proteins, and fats.
It receives secretions from the liver and pancreas for digestion.

Digestive Enzymes

Bile juice from the liver makes the food coming from the stomach alkaline, allowing pancreatic enzymes to act.
Bile salts break down fats into smaller globules, increasing the efficiency of enzyme action.
The pancreas secretes pancreatic juice containing enzymes like trypsin and lipase.
Intestinal juice from the walls of the small intestine contains enzymes that convert proteins into amino acids, carbohydrates into glucose, and fats into fatty acids and glycerol.

Absorption

The walls of the small intestine contain finger-like projections called villi, which increase the surface area for absorption.
Villi are richly supplied with blood vessels, which take absorbed food to every cell of the body.

Respiration

Respiration is the process of breaking down glucose to release energy.
The first step in respiration is the breakdown of glucose into a three-carbon molecule called pyruvate.
Pyruvate may be converted into ethanol and carbon dioxide in yeast during fermentation (anaerobic respiration).
In the presence of oxygen, pyruvate is broken down into carbon dioxide and water in the mitochondria (aerobic respiration).

ATP

ATP (adenosine triphosphate) is the energy currency for most cellular processes.
The energy released during respiration is used to synthesize ATP from ADP and inorganic phosphate.
ATP is broken down to release energy, which drives endothermic reactions in the cell.

Exchange of Gases

In terrestrial organisms, oxygen is absorbed from the atmosphere and carbon dioxide is released.
In aquatic organisms, oxygen is absorbed from the dissolved oxygen in water and carbon dioxide is released.
The rate of breathing is faster in aquatic organisms due to the lower amount of dissolved oxygen in water.

Human Respiratory System

The human respiratory system consists of nostrils, throat, lungs, and trachea.
Air passes through the nostrils, filtered by fine hairs, and enters the lungs.
The alveoli provide a large surface area for gas exchange.
The blood brings carbon dioxide from the rest of the body and takes up oxygen in the alveoli.

Transport of Oxygen and Carbon Dioxide

Oxygen is transported in the blood, bound to haemoglobin in red blood corpuscles.
Carbon dioxide is mostly transported in the dissolved form in the blood.
Haemoglobin has a high affinity for oxygen and releases it to tissues deficient in oxygen.

Heart and Circulatory System

The heart is a muscular organ that pumps blood around the body.
The blood transports food, oxygen, and waste materials to all the tissues.
A network of tubes (blood vessels) reaches all the tissues, and a system is in place to repair damaged blood vessels.### Human Circulatory System
The heart has different chambers to prevent oxygen-rich blood from mixing with carbon dioxide-rich blood.
The left atrium collects oxygen-rich blood from the lungs, and the left ventricle pumps it to the rest of the body.
The right atrium collects deoxygenated blood from the body, and the right ventricle pumps it to the lungs for oxygenation.
Valves ensure that blood does not flow backwards when the atria or ventricles contract.
The separation of the right and left sides of the heart allows for a highly efficient supply of oxygen to the body.

Double Circulation

In double circulation, blood goes through the heart twice during each cycle.
This is seen in vertebrates, including mammals and birds.
In contrast, fish have a single circulation, where blood goes through the heart only once during each cycle.

Blood Pressure

Blood pressure is the force exerted by blood against the walls of blood vessels.
It is higher in arteries than in veins.
Systolic pressure is the pressure in the arteries during ventricular contraction, while diastolic pressure is the pressure during ventricular relaxation.
Normal systolic pressure is around 120 mmHg, and normal diastolic pressure is around 80 mmHg.

Blood Vessels

Arteries carry blood away from the heart to various organs of the body.
They have thick, elastic walls to withstand high blood pressure.
Veins collect blood from different organs and bring it back to the heart.
They have valves to ensure that blood flows only in one direction.

Transportation of Oxygen and Carbon Dioxide

Oxygen-rich blood is pumped from the heart to the body.
Carbon dioxide-rich blood is pumped from the body to the lungs.
Oxygen is exchanged for carbon dioxide in the capillaries.

Lymphatic System

Lymph is a fluid that circulates around the body and helps to transport digested and absorbed fat from the intestine.
It drains excess fluid from the intercellular spaces back into the blood.
Lymphatic vessels join larger veins to return the fluid to the blood circulation.

Plant Transportation

Plants have a different transportation system than animals.
They have a low energy requirement, so they use relatively slow transport systems.
The xylem transports water and minerals from the roots to the leaves.
The phloem transports products of photosynthesis from the leaves to other parts of the plant.

Transportation of Water in Plants

Water is absorbed by the roots through a process called osmosis.
The water is then transported to the xylem vessels, where it is pushed upwards by root pressure.
Transpiration, the loss of water vapor from the leaves, helps to pull water up the xylem vessels.

Transportation of Food in Plants

The phloem transports products of photosynthesis, such as sucrose, from the leaves to other parts of the plant.
The phloem uses energy from ATP to transfer the sucrose into the phloem tissue.
The increased osmotic pressure of the phloem tissue causes water to move into it, which pushes the sucrose to tissues with lower pressure.

Excretion

Excretion is the process of removing waste products from the body.
In humans, the excretory system includes the kidneys, ureters, urinary bladder, and urethra.
The kidneys filter waste products from the blood, and the excess water is re-absorbed into the bloodstream.

Artificial Kidney (Hemodialysis)

In case of kidney failure, an artificial kidney can be used to remove nitrogenous waste products from the blood.
The artificial kidney contains tubes with a semi-permeable lining, suspended in a tank filled with dialysing fluid.
The patient's blood is passed through the tubes, and the waste products are removed through diffusion.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz is about identifying the characteristics of living beings, including plants and animals, and understanding the processes that occur in them.