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Life Processes |
The metabolic processes that are vital for living
organisms to stay alive, grow and repair. They Include Digestion,
Respiration, Circulation, Excretion, Control, Coordination & Reproduction |
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Nutrition |
Intake of Food & its utilization by the body Types: Autotrophic & Heterotrophic Autotrophic: Photoautotrophic & Chemoautotrophic Heterotrophic: Holozoic, Saprotrophic, Parasitic |
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Photosynthesis |
Process by which green plants prepare their own food Reaction: 6CO2 + 6H2O -> C6H12O6 + 6O2 Steps: I. Absorption of Light energy by Pigment
systems II. Conversation of Light energy into chemical energy III. Split of Water into Hydrogen and Oxygen IV. Reduction of Carbon Dioxide to Glucose |
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Digestion in Human beings (Def: Breakdown of complex
molecules of food into simpler ones by the enzyme action) |
Digestive System: Mouth (Buccal Cavity) Oesophagus Stomach (J Shaped): Cardiac, Fundus, Pyloric Part Small Intestines: Duodenum, Jejunum, Ileum Large Intestines: Caesium, Colon, Rectum Digestive Glands: Salivary glands: Saliva (Ptyalin) Liver: Bile Pancreases: Pancreatic Juice Gastric glands: Gastric Juice Crypts of Lieberkühn: Succus entericus |
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Respiration (Def: Metabolic breakdown of Glucose to
release energy in the form of ATP) |
Types: Aerobic: Complete break down of Glucose to form CO2
& H2O Anaerobic: Incomplete breakdown of Glucose in Yeast,
Human muscle cells etc I. Yeast: Glucose forms Ethanol & CO2 II. Muscle cells: Glucose forms Lactic Acid |
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Respiratory System of Humans |
Tract: Nose>Nasal Chambers> Pharynx> Larynx>
Trachea> Bronchi> Lungs (Bronchioles> Alveoli) Breathing Steps: I. Inspiration II. Expiration |
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Transportation (Def: System for the distribution of
Food, Oxygen and Removal of Wastage, CO2 from the cells) |
Parts: Heart: Has 2 Auricles & 2 Ventricles Has blood vessels such as Vena Cava, Pulmonary Artery,
Pulmonary Vein, Aorta, Coronary Sinus Blood Vessels: Arteries, Veins and Capillaries Blood: RBSCs (Erythrocytes), WBCs (Leucocytes), Platelets
(Thrombocytes), Plasma |
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Blood Pressure |
Measured by instrument called Sphygmomanometer. Blood pressure of normal human being is 120/80 mmHg. |
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Transportation in Plants |
Water: Moves through Xylem due to Cohesion
between water molecules, Adhesion between water and xylem walls and Tension
due to transpiration. Food: Occurs through Phloem by translocation. Moves
from source to sink by Mass flow. |
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Excretory system (Def: System for the elimination of
nitrogenous wastes, salts and extra water) |
Excretory system: Pair of Kidneys> Ureters > Urinary Bladder > Urethra Nephron is the functional unit of kidney: Parts of Nephron: I. Renal Corpuscle (Malpighian body): Contains Glomerulus
and Bowmans Capsule II. Renal tubule: Contains PCT, Loop of Henle, DCT |
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Urine Formation |
Occurs in Three steps: I. Glomerular Filtration II. Tubular Reabsorption III. Tubular Secretion |
Q. Define Nutrition? What are different forms of Nutrition? Or
What is autotrophic nutrition and heterotrophic nutrition?
Ans: Nutrition means intake of food and its utilization by body.
Nutrition is of two types;
1. Autotrophic nutrition: It is also called self nutrition. In this type of nutrition, organisms prepare their own food from inorganic substances. E.g. green plants, euglena etc
Autotrophs are also called Producers.
2. Heterotrophic Nutrition: In this type of nutrition, organisms are directly or indirectly dependent on autotrophs for food. E.g. Animals
Heterotrophs are also called consumers.
Ans: Heterotrophic nutrition is of following types:
1. Holozoic: In this type of nutrition, food is directly ingested into body.
The digestion occurs inside the body. E.g Animals
2. Saprotrophic: In this type of nutrition, the organism feeds on dead and decaying matter.
The digestion takes place outside the body. E.g Fungi
3. Parasitic: In this type of nutrition, the organisms derives nutrition from other organisms.
Parasites are acto or endo. E.g. Tapworm.
Q. Differentiate between autotrophic and heterotrophic
nutrition.
Ans:
|
Autotrophic
Nutrition |
Heterotrophic
Nutrition |
|
In this type
of Nutrition, organisms prepare their own food |
In this type
of nutrition, Organisms depend on others for food |
|
It is of two
types: Photoautotrophic and Chemoautotrophic |
It is of many
types: Holozoic, Saprotrophic, Parasitic |
|
It includes
green plants, blue green algae, euglena, some bacteria |
It includes
animals, non-green plants, fungi, some bacteria |
Q. What is digestion? Eloborate the digestive system of human beings?
Ans: Digestion is the process of breakdown of complex food molecules into simple ones.
Digestion occurs by enzyme action.
Digestive system of human beings: Digestive system of human beings consist of
A. Alimentary canal
B. Digestive glands.
1. Mouth: It is also called buccal cavity. Mouth contains 32 teeth which help in mastication and a tounge which acts as a sense organ.
2. Oesophagus: It is also called food pipe. It is about 25 cm long and opens into stomach.
The food moves inside oesophagus by peristalsis.
3. Stomach: It is J shaped sac like structure. Stomach has three regions i.e cardaic, Fundus, Pylorus.
Stomach contains many gastic glands, which secrete gastric juices. It also contains HCl.
4. Small Intestines: It is longest part of digestive system. They are coiled and have villi to increase surface area.
Small intestines are divided into Duodenum, Jujenum and Illeum
5. Large Intestines: Large intestines consist of Caecum, Colon and Rectum.
Digestive Glands:
1. Salivary glands: They are located near mouth. They secrete about 1.5 litre saliva daily
Saliva contains salivary amylase and maltase.
2. Liver: It is bilobed, reddish brown organ.
It secretes about 1 litre of bile juice daily.
Bile helps to emulsify fats and absorb vitamins.
3. Pancreas: It is heterocrine, Pinkish gland. It secretes pancreatic juice. Pancreatic juice contains following enzymes;
Trypsin, Chemotrypsin, Amylase, Lipase, Sucrase, Nuclease.
Ans: In human beings, The digestion starts in mouth and ends in large intestines.
1. Digestion in mouth: In mouth, the food is masticated and mixed with saliva with the help of teeth and tongue.
Saliva contains salivary amylase and maltase.
Salivary amylase converts starch into maltose.
Maltase converts maltose into glucose.
The saliva also makes food moist, hence easy to swallow in form of bolus.
2. Digestion in stomach: Stomach contains HCl, Mucus and gastric juices such as pepsin, renin, lipase etc.
HCl forms acidic medium.
Pepsin converts proteins into peptides.
Renin converts milk into curd
Lipase converts fats into fatty acids.
The food is converted into semi solid form called chyme.
3. Digestion in small Intestines:In small intestines, the food mixes with bile from liver and pancreatic juices from pancreas.
Bile neutralizes effect of HCl and help in emulsify fats and absorb vitamins.
Pancreatic juices contain many enzymes which help in digestion of food.
Trypsin converts proteins into peptides.
Chemotrypsin converts proteins into aminoacids
Amylase converts starch into maltose.
Lipase converts fats into fatty acids.
In small intestines, the food is converted into diffusible form called chyle.
Q. Explain the process of Photosynthesis in Plants. List four factors which influence this process.
Ans: Photosynthesis is a process in which green plants, blue green algae and protozoans like euglena use solar energy and convert it into chemical energy. Such organisms are also called autotrophs.
Equation:
6CO2 + 6H2O —> C6H12O6 + 6O2
It occurs in the chloroplasts of cells.
Process:
The process of Photosynthesis occurs in two steps:
1. Light Reaction: This reaction occurs during the day in the thylakoid membrane. In this phase, the light energy is converted to ATP and NADPH, which are used in the second phase of photosynthesis.
2. Dark Reaction: This reaction does not require day light and occurs in the stroma. In this phase, Glucose is formed from CO2.
Water: Absorbed from the soil by the roots.
Carbon dioxide: Obtained from the atmosphere.
Sunlight: Absorbed by chlorophyll molecules to split water molecules into hydrogen and oxygen.
Light intensity: Maximum photosynthesis occurs in blue light, and minimum in green light.
Carbon dioxide concentration: The higher the concentration, the higher the rate until a certain point.
Temperature: Increasing the temperature to a certain level increases photosynthesis. However, increasing the temperature above 40 °C reduces photosynthesis.
Q. What is respiration? What are different types of respiration? Or
How is glucose oxidized in the body?
Ans: Respiration is the defined as metabolic breakdown of glucose to release energy.
Respiration is of two types:
1. Aerobic respiration: It occurs in presence of oxygen.
In aerobic respiration, complete oxidation of glucose takes place to release CO2 and H2O. It takes place in plants and animals.
C6H12O6 + 6O2 ----------> 6CO2 + 6 H2O
2. Anaerobic respiration: It occurs in absence of oxygen.
In anaerobic respiration, incomplete breakdown of glucose takes place . It takes place in yeast and muscle cells.
Yeast: In yeast, Glucose converts into ethanol
C6H12O6 ------> C2H5OH + CO2
Muscle cells: In muscle cells, Glucose converts into lactic acid.
C6H12O6 --------> C3H6O3
Q. Why is Respiration considered an exothermic reaction.
Ans: Respiration is considered an exothermic reaction because it releases energy. This process involves the breakdown of glucose and other organic molecules to produce energy in the form of ATP (adenosine triphosphate).
Q. Differentiate between aerobic and anaerobic
respiration. Name two organisms that use anaerobic mode of respiration.
Ans:
|
Aerobic Respiration |
Anaerobic Respiration |
|
It occurs in presence of Oxygen |
It occurs in absence of Oxygen |
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Complete breakdown of Glucose occurs |
Incomplete breakdown of Glucose occurs |
|
CO2 and H2O are formed as end product |
Ethanol or Lactic acid are formed as end product |
|
It releases more energy |
It releases less energy |
The two organisms in which anaerobic respiration occurs are yeast and some bacteria such as Lactobacillus, E.Coli.
Q. Describe the Respiratory system of human beings?
Ans: Respiratory system of human beings consist of respiratory tract and a pair of lungs.
A. Respiratory tract: It is a path via O2 reaches the lungs.
It has following parts,
1. Nose: Nose has two nostrils, divided by nasal septum.
2. Pharynx: The nose opens into pharynx. Pharynx has glottis covered by epiglottis.
3. Larynx: It is also called voice box.
4. Trachea: It is also called wind pipe. It is covered by C shaped cartilaginous rings. They prevent trachea from collapse
5. Bronchi: The trachea divide into two bronchi which enter into two lungs.
B. Lungs: There are two pink, hollow, elastic, thin walled lungs inside thoracic cavity.
They are protected by ribs and have double walled pleural sac.
Left lung has two lobes where as right lung has three lobes.
Inside the lungs, the bronchi further divide into bronchioles and alveoli.
Alveoli are functional unit of lungs where exchange of gases take place.
Alveoli also help to increase surface area of lungs.
Ans: Breathing is movement of air in and out of lungs.
Breathing involvs two steps:
1. Inspiration: Movement of air inside lungs is inspiration.
During inspiration, diaphragm and intercostal muscles contract.
2. Expiration: Movement of air out of lungs is expiration.
During expiration, diaphragm and intercostal muscles relax.
Ans: Heart is reddish brown muscular organ located inside thoracic cavity.
Heart is covered by pericardium having pericardial fluid.
Structure:
Human heart consists of 4 chambers i.e two auricles and two ventricles.
1. Auricles: There are two auricles i.e right auricle and left auricle. They are thin walled and are seperated by interauricular septum.
2. Ventricles: There are two ventricles i.e right ventricle and left ventricle. They are thick walled and are seperated by interventricular septum.
The left ventricle is thickest chamber of heart.
The blood from Right auricle enters right ventricle through Tricuspid valve.
The blood from left auricle enters left ventricle through bicuspid valve.
Heart contains many blood vessels:
1. Vena cava: It consists of superior vena cava and inferior vena cava. They bring deoxygenated blood from body into Right auricle.
2. Coronary sinus: It brings deoxygenated blood from heart itself into right auricle.
3. Pulmonary artery: It carries deoxygenated blood from right ventricle to lungs.
4. Pulmonary vein: It carries oxygenated blood from lungs to left auricle.
5. Aorta: It carries oxygenated blood from left ventricle to body.
How does circulation occur in human beings?
Ans: Humans undergo double circulation. It was first discovered by William Harvey.
The blood passes through the heart twice in following steps:
Step 1: The deoxygenated blood from body enter right auricle via superior and inferior vena cava.
Step 2: From right Auricle, blood enters into right ventricle via Tricuspid valve.
Step 3: From right ventricle, the deoxygenated blood flows into lungs via pulmonary artery. The blood is oxygenated in lungs.
Step 4: The oxygenated blood enters left auricle via pulmonary vein.
Step 5: From left auricle, the blood enters left ventricle via bicuspid valve.
Step6: From left ventricle, the oxygenated blood flows back to body via aorta.
Q. Write a note on different types of blood vessels?
Ans: Blood flows through three types of blood vessels.
1. Arteries: They carry oxygenated blood.
They are elastic and have thick walls.
They have narrow lumen and no valves.
2. Veins: They carry deoxygenated blood.
They are not elastic and have thin walls.
They have wide lumen and have valves.
3. Capillaries: They are formed near junction of arteries and veins.
They are very small.
Q, Write the function of each of the following components of transport system in human beings?
i. Blood Vessels ii. Blood Platelets
Ans: Blood Vessels: Blood vessels are of many types such as Arteries, Veins, Cappilaries. They carry blood from heart to the body and back.
Blood Platelets: Blood platelets are also called thrombocytes. They help in the clotting of blood.
Ans: Blood is red, connective tissue. Humans have around 5.5 litres of blood.
Blood has following components:
1. RBC's: They are called erythrocytes.
They are biconcave, anucleated cells.
They carry haemoglobin.
2. WBC's: They are called leukocytes.
They are round and show ameboid movement.
3. Platelets: They are called Thrombocytes.
They are non nucleated and help in blood clotting.
Ans: Lymph is colourless fluid in our bodies.
It is a connective tissueand contains antibodies.
It helps to fight infection.
It also transports fatty acids and glycerol in blood.
Ans: Blood pressure is the force that bloof exerts on walls of the blood vessels.
It consists of systolic pressure and diastolic pressure.
It is measured by sphygmomanometer. The blood pressure of normal human being is 120/80 mmhg.
Ans: Excretion means elimination of metabolic wastes, salts and extra water from body.
These wastes may lead to death of cells in body.
Excretory system of humans:
The excretory system of humans consist of:
1. Pair of Kidneys
2. Ureters
3. Urinary bladder
4. Urethra
They are protected by pair of floating ribs.
At the centre of concave side of kidney is a notch called hilus. The renal artery, renal vein enter kidney.
Outer part of kidney is called cortex, Inner part is called medulla.
Kidney also has renal pyramids. Each renal Pyramid contains nephrons.
Q. Discuss the structure of Nephron?
Ans: Nephron is functional unit of kidney and helps to remove wastes from body. There are about 1 million nephons in each kidney.
Each nephron is about 3 cm long.
Nephron consists of following parts:
A. Malphigian body
B. Renal tubule
C. Collecting duct
A. Malphigian body:
It contains glomerulus and bowmans capsule.
Glomerulus is bunch of capillaries.
Bowmans capsule is cup shaped having capsular space.
B. Renal tubule:
Renal tubule consists of follwing parts:
Proximal convulated tubule,
Loop of henel
Distal convulated tubule
C. Collecting duct: The wastes, salts and extra water get collected in collecting duct.
Q. Explain the formation of Urine.
Ans: The urine formation occurs in nephrons.
It occurs in following steps;
1. Filteration
2. Reabsorption
3. Secretion
1. Filteration: It occurs in glomerulus.
Walls of glomerulus are thin so substances such as ions, water, creatinine, urea, glucose pass into bowmans capsule.
2. Reabsorption: It occurs in renal tubule
Some substances such as glucose, ions extra water enter back into blood.
3. Secretion: It occus in renal tubule.
Some substances such as creatinine, potassium ions, Ammonia are secreted from blood into urine.
Ans: When humans suffers from kidney failure, they undergo haemodialysis.
The blood is taken from artery and pumped into machine having isotonic salt solution.
Urea, uric acid, creatinine, diffuse out of blood.
The clean blood is then pumped back into body.
Q. What
is the function of excretory system in humans?
Ans: The
excretory system has many functions which include:
I. It helps
get rid of nitrogenous waste
II. It
helps get rid of extra water
III. It
helps get rid of excess salts
Textual Questions
Q. Why is diffusion insufficient to meet the O2 requirements of multicellular organisms?
Ans: Multicellular organisms have trillions of cells in form of tissues, organs and organ systems. O2 cannot reach every body cell by diffusion.
Q. What advantages over an aquatic animal does a terrestrial organism have with regard to obtain oxygen for respiration?
Ans: Terrestrial organisms take up oxygen from the atmosphere whereas aquatic animals obtain oxygen dissolved in water. Air contains more O2 as compared to water. Since the content of O2 in the air is high, terrestrial animals do not have to breathe faster to get more oxygen.
Q. What processes are essential for maintaining life?
Ans: The processes essential for maintaining life are digestion, respiration, circulation, excretion and reproduction.
Q. What is the role of acid in stomach?
Ans: The acid present in stomach is HCl.
The acid makes food acidic, activates enzymes and kills microbes.
Q. How are small intestines designed to absorb food?
Ans: Small intestines have folds called villi. They increase the surface area required to absorb food.
Ans: The oxygen and carbon dioxide are transported in human beings by haemoglobin.
The haemoglobin is present in RBS's.
Carbon dioxide is carried away from the cells.
Q. How lungs are designed in human beings designed to maximize the area for exchange of gases? Or
Ans: The lungs have alveoli which maximize the surface area for gaseous exchange.
The surface area of alveoli is about 70 sq. m which is much more than lungs.
Q. Why is it necessary to seperate oxygenated and deoxygenated blood in mammals and birds?
Ans: It is necessary to seperate oxygenated and deoxygenated blood in mammals and birds to ensure efficient supply to oxygen to all body parts.
Birds and mammals are warm blooded and need to maintain their body temperature.
What is ascent of sap?
Ans: Water and minerals are transported in plants through xylem.
The process is called ascent of sap.
The sap is absorbed by root hairs by osmosis. It is then transported into cortex cells and xylem.
The sap then moves up the plant by transpiration pull, cohesion amd adhesion.
Ans: The food is made in leaves of plants by the process of photosynthesis.
The food is then transported to other parts of plant through phloem and the process is called translocation.
Ans: The urine production is regulated by kidney by osmoregulation.
Antidiuretic harmone (ADH) also helps in regulation of urine produced.
Aldosterone harmone regulates amount of ions in urine.
Ans: Fats are mainly digested in duodenum. In duodenum, the food gets mixed with bile from liver and pancreatic juices from pancreas.
Bile helps to emulsify fats that break down large fat molecules into smaller droplets. This process is called Emulsification.
Pancreatic juices contain lipase which breaks down fats into fatty acids.
Ans: Saliva makes food moist which helps us to taste food and easy to swallow
It contains salivary amylase which convert starch to maltose.
It contains maltase, which convert maltose to glucose.
It leads to tiredness and weight loss.
Ans:
Alveoli are functional unit of lungs while nephrons are functional unit of kidneys.
Alveoli help to remove gases such as CO2 while nephrons help to remove solid and liqid wastes such as H2O, salts, ions etc
Both have thin walls with rich blood supply.
Q. What Criteria do we use to decide whether something is alive?
Ans: The criteria we use to decide whether something is living is that if it show Growth, Respiration, Nutrition, Excretion and Reproduction.
Q. Why do herbivores have longer whereas carnivores have shorter small intestines?
Ans: Herbivores have longer intestines than carnivores because they eat food which is rich in cellulose which takes longer time to digest.
Q. Write down the functions of salivary amylase and pepsin.
Ans: Salivary amylase converts starch into maltose
Pepsin converts proteins into peptides
Q. Do all the cells use oxygen to produce energy?
Ans: No all the cells do not use oxygen to produce energy.
Q. Name the organism that has parasitic mode of nutrition?
Ans: Ascaris, Tapworm, Lice show parasitic mode of nutrition.
Q. Name one organism that can live without oxygen?
Ans: Yeast
Q. What is another name of Food Pipe.
Ans: Oesophagus
Q. In which part of digestive system is water absorbed?
Ans: Large Intestines.
Q. Name the process by which plant parts like roots, stem and leaves get oxygen required for respiration?
Ans: Diffusion
Q. The kidney in human beings are a part of the system fora. Nutrition b. Respiration
c. Excretion d. Transportation
Ans: c. Excretion
Q. The Xylem in plants is responsible for transport of
a. water b.food c. amino acids d. Oxygen
Ans: Water
Q. Autotrophic mode of nutrition requires:
a. CO2 and H2O b. Chlorophyll
c. Sunlight d. All of above
Ans: All of Above
Q. The breakdown of pyruvate to give CO2 and water and energy takes place in:
a. Cytoplasm b. Mitochondria
c. Chloroplast d. Nucleus
Ans: b. Mitochondria
Q. Name organisms in which food is broken down outside the body and absorbed
Ans: Yeast, Mushroom, Bread mould
Q. A few drops of iodine were added to rice water. The solution turned black-blue. The rice water contains
a. Proteins b. Fats c. Starch d. Vitamins
Ans: C. Starch
Q. The opening and closing of stomatal pore depends upon:
a. Oxygen b. Temperature
c. Water d. Carbon dioxide
Ans: Water
Q. Which of follwing is first enzyme to mix with food in digestive tract?
A. Pepsin B. Cellulase
C. Amylase D. Trypsin
Ans: C. Amylase
Q. Hard work out leads to cramps in muscles. This is due to;
a. Convertion of Pyruvate to ethanol
b. Conversion of pyruvate to glucose
c. Non conversion of glucose to pyruvate
d. Conversion of pyruvate to lactic acid
Ans: D. Conversion of pyruvate to lactic acid.
Q. During deficieny of oxygen in tissue, the pyruvic acid is converted into lactic acid in the:
a. Cytoplasm b. Chloroplast
c. Mitochondria d. Golgi body
Ans: A. Cytoplasm
Q. The breakdown of pyruvate to give CO2, H2O and energy takes place in:
a. Cytoplasm b. Mitochondria
c. Chloroplast d. Nucleus
Ans: b. Mitochondria
Ans: Salivary glands secrete Saliva which moistens the food. It helps in swallowing and tasting of food.
Saliva also contains salivary amylase and maltase which help in digestion of food.
Q. Assertion: Autotrophs are also called as transducers
Reason: They change one form of energy into another.
Ans: Both A and R are true and R is correct explanation of A.
Q. Assertion(A): Anaerobic respiration, one of the end product is alcohol.
Reason (R): There is an incomplete breakdown of glucose.
Ans: Both A and Rare true and R is not correct explanation of A
Q. Autotrophic nutrition involves:
(A) Intake of simple inorganic material from the environment (B) Using external energy source like the sun(C) Intake of complex material prepared by other organisms (D) Both (A) and (B)
Ans: (D) Both (A) and (B)
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