What is the purpose of adding saliva to starch solution in the experiment?
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To observe the action of saliva on starch.
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What is the purpose of adding saliva to starch solution in the experiment?
To observe the action of saliva on starch.
What is the primary function of the alveoli?
To provide a surface for gas exchange.
What role do platelet cells play in the blood?
They help to clot the blood at points of injury to plug leaks.
What is lymph and how is it formed?
Lymph is a tissue fluid formed when plasma, proteins, and blood cells escape from capillaries into intercellular spaces.
What is reduced to carbohydrates during photosynthesis?
Carbon dioxide.
What role does root pressure play in water transport?
Root pressure is more important at night; during the day, transpiration pull is the major driving force.
What are life processes?
Processes that perform maintenance jobs in organisms.
What is the estimated surface area of the alveolar surface in human lungs?
About 80 m².
What role do guard cells play in the functioning of stomata?
Guard cells swell to open the stomatal pore when water flows into them and shrink to close the pore.
What is the role of peristaltic movements in the digestive system?
To push food forward through the digestive tract.
What secretions does the small intestine receive for digestion?
Secretions from the liver and pancreas.
What conclusion can be drawn if one plant shows more starch than the other in the experiment?
The plant that produced more starch likely had access to carbon dioxide and sunlight, indicating their importance in photosynthesis.
What is excretion?
The process of removing waste by-products from the body.
What happens to carbon dioxide-rich blood in the heart?
It is sent to the lungs for carbon dioxide removal.
How do we differentiate between living and non-living things?
We observe characteristics such as breathing, growth, and movement.
Why is there controversy about whether viruses are alive?
Viruses do not show molecular movement until they infect a cell.
What must living organisms do to maintain their structures?
They must keep repairing and maintaining their molecular structures.
What is the primary mechanism that helps move water upwards in plants?
Transpiration creates a suction that pulls water from the xylem cells of roots.
What is transpiration?
The loss of water in the form of vapor from the aerial parts of the plant.
What forms can nitrogen be taken up by organisms?
Inorganic nitrates or nitrites, or as organic compounds prepared by bacteria from atmospheric nitrogen.
What are the two types of nutrition discussed?
Autotrophic nutrition and heterotrophic nutrition.
What advantage do terrestrial organisms have over aquatic organisms in obtaining oxygen?
Terrestrial organisms can access oxygen directly from the air, which is more abundant than in water.
What is the function of Bowman’s capsule in the kidneys?
It collects the filtrate from the capillary clusters.
How does bile juice help in digestion?
It makes the food alkaline and acts on fats.
What raw materials do autotrophs need for photosynthesis?
Water, carbon dioxide, and minerals like nitrogen, phosphorus, iron, and magnesium.
What enzymes are found in pancreatic juice?
Trypsin for digesting proteins and lipase for breaking down emulsified fats.
What are villi and their function in the small intestine?
Finger-like projections that increase surface area for absorption.
Why do plants have lower energy needs compared to animals?
Plants do not move and have a large proportion of dead cells in many tissues.
How do aerobic organisms ensure sufficient intake of oxygen?
By exchanging gases through stomata.
Why are carbon-based molecules important for life on Earth?
Most food sources are carbon-based, necessary for growth and energy.
What are stomata?
Tiny pores present on the surface of leaves that facilitate gas exchange for photosynthesis.
What criteria do we use to determine if something is alive?
We assess characteristics such as growth, reproduction, response to stimuli, and metabolism.
What are outside raw materials used for by an organism?
They are used for growth, development, and synthesizing proteins and other necessary substances.
What is the role of specialized tissues in multi-cellular organisms?
To uptake food and oxygen efficiently.
What process breaks down the three-carbon pyruvate molecule to produce carbon dioxide and water?
Aerobic respiration.
How do autotrophs obtain their food?
They use simple inorganic materials like carbon dioxide and water to produce their own food through photosynthesis.
What does blood transport in the human body?
Food, oxygen, and waste materials.
What protects the inner lining of the stomach from acid?
Mucus.
How do autotrophic organisms fulfill their carbon and energy requirements?
Through the process of photosynthesis, converting carbon dioxide and water into carbohydrates.
How is sucrose transported into phloem tissue?
Using energy from ATP.
What happens during fermentation?
Pyruvate is converted into ethanol and carbon dioxide in the absence of air.
Why do arteries have thick, elastic walls?
Because blood emerges from the heart under high pressure.
How many chambers do amphibians and many reptiles have?
Three chambers.
What are the health risks associated with tobacco use?
It affects the tongue, lungs, heart, liver, and increases the risk of cancers and other diseases.
What is the source of energy needed for life processes?
Food, which comes from outside the body.
What does blood bring to the alveoli for release?
Carbon dioxide.
What instrument is used to measure blood pressure?
Sphygmomanometer.
What substances are released by the gastric glands in the stomach?
Hydrochloric acid, pepsin, and mucus.
What is the function of digestive enzymes?
To break down food into smaller, absorbable molecules.
What is the function of the different chambers in the heart?
To prevent oxygen-rich blood from mixing with carbon dioxide-rich blood.
What is plasma in the context of blood?
The fluid medium in which blood cells are suspended, transporting food, carbon dioxide, and nitrogenous wastes.
Which chamber of the heart receives oxygen-rich blood from the lungs?
The left atrium.
What causes muscle cramps during sudden activity?
The build-up of lactic acid in muscles.
What happens to unabsorbed food in the digestive system?
It is sent to the large intestine for water absorption and then removed via the anus.
Why do mammals and birds have a four-chambered heart?
To efficiently separate oxygenated and de-oxygenated blood for high energy needs.
Where are the kidneys located in human beings?
In the abdomen, one on either side of the backbone.
What structures help terrestrial organisms absorb oxygen?
Different organs that increase surface area for oxygen contact.
What is a common evidence for being alive?
Visible movement, either growth-related or not.
How does the form of nutrition differ among organisms?
It depends on the type and availability of food material and how it is obtained.
What is an example of an organism that breaks down food outside its body?
Fungi like bread moulds, yeast, and mushrooms.
How does saliva aid in the digestion process?
It moistens food and contains enzymes that break down complex molecules.
What happens to stomata when a plant does not need carbon dioxide?
The stomata close to prevent water loss.
How does transpiration assist in water movement?
It helps in the absorption and upward movement of water and minerals from roots to leaves.
How is carbon dioxide primarily transported in the blood?
In dissolved form.
What does lymph carry from the intestine?
Lymph carries digested and absorbed fat.
How is the small intestine designed to absorb digested food?
It has a large surface area with villi to increase absorption efficiency.
What is the force that blood exerts against the walls of a vessel called?
Blood pressure.
Which part of the vascular tissue is responsible for translocation?
Phloem.
What is stored in plants as an internal energy reserve?
Carbohydrates are stored in the form of starch.
How does translocation occur in the phloem?
It occurs in sieve tubes with the help of adjacent companion cells, in both upward and downward directions.
Why is the transport of materials in phloem important for plants?
It allows the phloem to move material according to the plant’s needs.
How do plants exchange carbon dioxide and oxygen?
Through diffusion in large inter-cellular spaces.
Can plants be considered alive if they are not visibly growing?
Yes, plants can still be alive even without visible growth.
What is the purpose of blowing air through lime water in the activity?
To observe how long it takes for the lime water to turn milky, indicating the presence of carbon dioxide.
What regulates the exit of food from the stomach?
A sphincter muscle.
What is a parasitic nutritive strategy?
Deriving nutrition from plants or animals without killing them.
How do single-celled organisms take in food?
Through the entire surface of the cell.
What is the purpose of potassium hydroxide in the experiment?
To absorb carbon dioxide from the environment.
How is oxygen transported in human beings?
Oxygen is carried by red blood corpuscles (hemoglobin).
What is the structure of the human digestive system?
A long tube extending from the mouth to the anus with specialized regions.
What role do bile salts play in fat digestion?
They break down large globules of fat into smaller ones, increasing enzyme efficiency.
What happens to food in the stomach?
It is mixed thoroughly with digestive juices and broken down further.
Why is nitrogen important for plants?
It is essential for the synthesis of proteins and other compounds.
What do arteries do?
Carry blood away from the heart to various organs.
What do veins do?
Collect blood from different organs and bring it back to the heart.
What are the main components of the human excretory system?
Kidneys, ureters, urinary bladder, and urethra.
What happens during the day regarding CO2 and oxygen in plants?
CO2 generated during respiration is used for photosynthesis, leading to oxygen release.
What are the balloon-like structures in the lungs called?
Alveoli (singular: alveolus).
What does the milky color of lime water indicate?
The presence of carbon dioxide in the air that we breathe out.
How long would it take for oxygen to diffuse from the lungs to the toes without haemoglobin?
Approximately 3 years.
What is the primary function of the small intestine?
Complete digestion of carbohydrates, proteins, and fats.
How does Amoeba obtain its food?
Using temporary finger-like extensions that form a food vacuole.
What are cilia and what is their function in the respiratory tract?
Hair-like structures that help remove germs, dust, and harmful particles from inhaled air.
What is translocation in plants?
The transport of soluble products of photosynthesis from leaves to other parts of the plant.
What is a common health risk associated with smoking?
Lung cancer.
What is the role of the left ventricle?
To pump oxygen-rich blood to the rest of the body.
How is urine stored before being excreted?
In the urinary bladder.
What is an artificial kidney used for?
To remove nitrogenous waste products from the blood through dialysis.
How do aquatic animals obtain oxygen?
They use the oxygen dissolved in water.
What type of movement is necessary for life at a molecular level?
Invisible molecular movement is necessary for life.
Why is the large surface area of alveoli important?
It allows for efficient gas exchange.
Why do herbivores have a longer small intestine?
To allow for the digestion of cellulose from grass.
What is the purpose of a transportation system in organisms?
To carry food and oxygen from one part of the body to another.
What is the main product of aerobic respiration besides carbon dioxide?
Water.
What is the role of enzymes in heterotrophic organisms?
Enzymes break down complex substances into simpler ones for growth and maintenance.
What happens to pyruvate in the absence of oxygen?
It is converted into lactic acid.
What does phloem transport?
Products of photosynthesis from the leaves to other parts of the plant.
How does de-oxygenated blood enter the heart?
It comes to the right atrium from the body.
How can dental plaque affect tooth health?
It covers teeth, preventing saliva from neutralizing acids, leading to decay.
What is the daily volume of initial filtrate produced in healthy kidneys?
About 180 liters.
How do terrestrial animals breathe?
They breathe oxygen from the atmosphere.
What is respiration?
The process of acquiring oxygen from outside the body to break down food for energy.
What happens to the chest cavity when we breathe in?
It becomes larger as ribs are lifted and the diaphragm is flattened.
What happens to the organized nature of living structures over time?
It is likely to break down due to environmental effects.
What are maintenance processes in living organisms?
Processes that continue even when the organism is not actively doing anything.
How does lymph drain back into the blood?
Lymph drains into lymphatic capillaries, which join to form larger lymph vessels that open into larger veins.
What is the function of hydrochloric acid in the stomach?
To create an acidic medium that facilitates the action of pepsin.
What are the filtration units in the kidneys called?
Nephrons.
How does smoking affect the respiratory system?
It destroys cilia, allowing harmful particles to enter the lungs.
What does xylem transport?
Water and minerals obtained from the soil.
What substances are transported by the phloem?
Products of photosynthesis, amino acids, and other substances.
What molecule is synthesized during cellular respiration to fuel cellular activities?
ATP (adenosine triphosphate).
What role does ATP play in cellular processes?
It acts as the energy currency for most cellular processes.
How does blood circulation differ in fish compared to other vertebrates?
Fish have two chambers and blood goes through the heart once per cycle, while other vertebrates have double circulation.
What is the purpose of urine production in humans?
To filter out waste products from the blood.
What is the major exchange activity occurring at night in plants?
CO2 elimination.
What does a color change after adding iodine indicate?
The presence or absence of starch in the test tubes.
What enzyme in saliva breaks down starch?
Salivary amylase.
What is the first step in the process of photosynthesis?
Absorption of light energy by chlorophyll.
What happens to water molecules during photosynthesis?
They are split into hydrogen and oxygen.
What is the role of acid in our stomach?
To aid in digestion by breaking down food.
What is the size of the human heart?
About the size of a fist.
What is the role of chloroplasts in photosynthesis?
They contain chlorophyll, which is essential for absorbing light energy.
What are the two main transport systems in plants?
Xylem and phloem.
What substances are selectively re-absorbed during urine formation?
Glucose, amino acids, salts, and a major amount of water.
What is necessary for blood to circulate throughout the body?
A pumping organ (heart) and a network of tubes (blood vessels).
What effect does the transport of sucrose have on osmotic pressure in phloem tissue?
It increases the osmotic pressure, causing water to move into the tissue.
What is the energy equivalent released when the terminal phosphate linkage in ATP is broken?
30.5 kJ/mol.
What are capillaries?
The smallest blood vessels with walls that are one-cell thick, where material exchange occurs.
What is the role of mucus in the respiratory system of humans?
It helps filter the air passing through the nostrils.
Why is diffusion insufficient for oxygen requirements in multi-cellular organisms?
Because diffusion alone cannot transport enough oxygen to meet the metabolic needs of larger, complex organisms.
How do single-celled organisms acquire nutrients and oxygen?
Through direct contact with the environment, without specialized organs.
What challenge do multi-cellular organisms face regarding nutrient and oxygen uptake?
Not all cells are in direct contact with the environment, requiring specialized tissues.
What is the role of haemoglobin in the human respiratory system?
To carry oxygen from the lungs to tissues.
What causes hypertension?
Constriction of arterioles, leading to increased resistance to blood flow.
What experiment can demonstrate the presence of starch in leaves?
The starch test using a variegated leaf and iodine solution.
What is anaerobic respiration?
The process of breaking down glucose without oxygen, producing ethanol and carbon dioxide.
What is the normal systolic pressure?
About 120 mm of Hg.
What is the normal diastolic pressure?
80 mm of Hg.
What happens to the material in the phloem due to increased osmotic pressure?
It moves to tissues with less pressure.
What is the biological process of removing harmful metabolic wastes called?
Excretion.
How much urine is actually excreted daily?
Only a liter or two, due to re-absorption.
Why do aquatic organisms have a faster breathing rate than terrestrial organisms?
Because the amount of dissolved oxygen in water is lower than in the air.
What processes are essential for maintaining life?
Processes such as nutrition, respiration, excretion, and reproduction.
What is high blood pressure also known as?
Hypertension.
What role do cilia play in Paramecium's nutrition?
They help move food to a specific spot for ingestion.
Where does the breakdown of pyruvate using oxygen occur?
In the mitochondria.
What connects the kidneys to the urinary bladder?
The ureter.
What causes dental caries?
Bacteria acting on sugars produce acids that soften the enamel.
How do unicellular organisms typically remove metabolic wastes?
By simple diffusion from the body surface into surrounding water.
What nitrogenous wastes are removed from the blood in the kidneys?
Urea or uric acid.
What is a major risk factor for oral cancer in India?
Chewing tobacco in the form of gutkha.
How does the energy release in aerobic respiration compare to anaerobic respiration?
The energy release in aerobic respiration is much greater.
Why do desert plants take up carbon dioxide at night?
To prepare an intermediate that is acted upon by energy absorbed during the day.
What determines the amount of water re-absorbed in the kidneys?
The excess water in the body and the amount of dissolved waste to be excreted.
How do humans store energy derived from food?
In the form of glycogen.
What is the purpose of heart valves?
To ensure that blood does not flow backwards.
How does an artificial kidney function?
It allows waste products to diffuse from the blood into a dialysing fluid, purifying the blood.
How do terrestrial plants obtain water for photosynthesis?
Through their roots from the soil.
What color change occurs in the leaf during the starch test?
The leaf turns blue-black in areas where starch is present after iodine treatment.
How do roots contribute to the transport of water in plants?
Roots actively take up ions, creating a concentration difference that facilitates water uptake.
What happens when the urinary bladder expands?
It leads to the urge to pass urine through the urethra.
What happens when there is a leak in the blood vessel system?
Blood loss occurs, which can reduce pressure and efficiency.