Answer

They convert carbon dioxide and water into carbohydrates in the absence of sunlight

Explanation

They need sunlight to convert carbon dioxide and water into carbohydrates.

Answer

(b) Yeast, mushroom, bread mould

Explanation

Yeast , mushroom and bread mould are saprophytes and Saprophytes break the food material outside their body and absorbed.

Answer

(a) Heterotrophs do not synthesise their own food

Explanation

Heterotrophs either dependent on Phototrophs or other organisms for their food.

Answer

(d) Mouth $\longrightarrow$ oesophagus $\longrightarrow$ stomach $\longrightarrow$ small intestine $\longrightarrow$ large intestine

Answer

(b) Starch breaking down into sugars

Explanation

Salivary Amylase enzyme present in the saliva breaks down Starch into simpler sugar and helps in digesting them. Hence the breakdown of starch will be affected if salivary amylase is lacking in the saliva.

Answer

(b) Mucus

Answer

(b) Small intestine

Explanation

Bile goes to small intestine from gall bladder through hepta pancreatic duct.

Answer

(d) starch

Explanation

Starch is made up of two components Amylose and Amylo pectin. When we add iodine to starch containg waqter Amylose reacts with iodine to form a blue colour complex. Here solution gives blue-black colour on adding Iodine which confirms the presence of starch in the rice water.

Answer

(d) Small intestine

Explanation

Although primary digestion process is conducted in mouth and stomach most of the digestion process occur in small intestine and in large intestine digestion process will not take place.

Answer

(d) trypsin digests proteins and lipase emulsified fats

Explanation

Trypsin breaks down proteins into polypeptides and Lipase digest emulsified fat molecules into fatty acids and glycerol.

Answer

(b) carbon dioxide

Explanation

Carbon dioxide reacts with lime water to convert it to milky.

Answer

d) $ \text{Glucose} \xrightarrow{\text{ Cytoplasm }} \text{Pyruvate} \xrightarrow{\text{ Cytoplasm } } \text{ Ethanol+ Carbon dioxide } $

Explanation

In Yeast cytoplasm Glucose is breakdown in anaerobic condition to produce Pyruvate which is further breakdown to Ethanol and carbon-di-oxide

Answer

(d) $\text{Glucose }\xrightarrow{\text{ cytoplasm }} \text{ Pyruvate + Energy } \xrightarrow{\text{mitochondria}} \mathrm{CO_2 + H_2O} + \text{ Energy}$

Explanation

In aerobic respiration breakdown of pyruvate takes place in mitochondria. $CO _2, H _2O$ and energy are released in the reaction.

Answer

(d) (ii) and (iv)

Explanation

Statement i) is wrong because ribs move outward and diaphragm is lowered during inhalation. Similarly Option iii) is wrong because Hemoglobin has greater affinity for Oxygen than $CO_2$.

Answer

(d) Nostrils $\longrightarrow$ pharynx $ \longrightarrow$ larynx $ \longrightarrow$ trachea $\longrightarrow$ alveoli

Explanation

Air enter respiratory system through nostrils through nostrils, passes to pharynx,larynx, trachea and then to alveoli. After inhalation diaphragm and intercoastal muscles contract along with expansion of thoracic muscles which creates enough space for the air to enter into the lungs.

Answer

(b) alveoli of lungs

Explanation

Trachea, Larynx provide a passage for the movement of air. Gas exchange takes place in Alveoli of lungs. From alveoli oxygen diffuses into blood and Carbon-di-oxide exhaled out of blood.

Answer

(c) (ii) and (iv)

Explanation

Oxygenated blood circulates through left part of the heart whereas deoxygenated blood circulates through right part of the heart. Atrium receives blood and ventricle pumps the blood out of the heart.

Answer

(a) Valves in heart

Explanation

Walls in the heart are responsible for only pumping of the blood and they are not responsible in blocking backflow of blood inside the heart during contraction.

Answer

(b) Hippocampus, Exocoetus, Anabas

Explanation

In Option a) Chameleon is a reptile and Salamander is an amphibian which are having 3 chambered hearts and show partial double circulation. In Option c) all are Amphibians and they show partial double circulation. In option d) Whale is a mammal but turtle is a reptile hence option d) is wrong.

Answer

(d) Pisces only

Explanation

This is because of single circulation where deoxygenated blood from all part of the body is pumped into heart. From heart it is pumped to gills where it gets oxygenated and gets transferred to all parts of the body. Hence it proves pisces will not receive oxygenated blood.

Answer

(d) They have thick elastic walls without valves inside, blood flows under high pressure and carry blood away from the heart to different parts of the body.

Answer

(d) nephrons

Explanation

Nephron is called as the functional unit of kidney. It helps in removing the waste products and excess substances from our body.

Answer

(a) water

Explanation

During photosynthesis water molecule splits to produce Oxygen and Hydrogen Ions. Oxygen is expelled out of plants and Hydrogen is used to reduce Carbon-di-oxide to produce carbohydrates.

Answer

(a) carbon dioxide

Explanation

Because of respiration Carbon-di-oxide gets accumulated in tissues. Hence blood leaving the tissues becomes richer in Carbon-di-oxide.

Answer

(c) Movement of molecules does not take place among cells

Explanation

Movement of molecule is a vital process. Movement of molecules in cells take place in active and passive modes such as Diffusion, osmosis, facilitated diffusion etc.

Answer

(c) starch

Explanation

Glycogen is the stored energy in animals, Plants stores energy in the form of Starch.

Answer

(c) $6 \mathrm{CO} _2+12 \mathrm{H} _2 \mathrm{O}+$ Chlorophyll + Sunlight $\rightarrow \mathrm{C}_6 \mathrm{H} _{12} \mathrm{O} _6+6 \mathrm{O} _2+6$ $\mathrm{H}_2 \mathrm{O}$

Explanation

Option a does not show the factors responsible for photosynthesis . Option b) is not a balanced equation. Option d) is wrong as it has $CO _2$ in the products.

Answer

(c) Oxidation of carbon to carbon dioxide

Answer

(c) water in guard cells

Explanation

Opening of guard cells is facilitated by the entry of water inside guard cells. This make the guard cell become turgid. Closing of guard cells is facilitated by water coming out of guard cells. This will make the guard cells flaccid.

Answer

(b) (ii) and (iii)

Explanation

Plants cannot absorb atmospheric Nitrogen. They can absorb the Nitrogen in the form of Nitrates,Nitrites and Urea present in the soil.

Answer

(c) Amylase

Explanation

Amylase is secreted in mouth and acts on the starch to convert into simpler molecules. Hence Amylase is the first enzyme to mix with food in the digestive tract.

Answer

Answer is(c) (i) and (iv)

Explanation

Fermentation is carried out by anaerobes in the cytoplasm. Hence option ii) and iii) are wrong.

Answer

(d) conversion of pyruvate to lactic acid

Explanation

Breakdown of Pyruvate in presence of oxygen takes place in mitochondria leading to the formation of Lactic acid. Due to workout oxygen is used for the production of energy leading to the lack of oxygen and production of lactic acid.

Answer

(c) kidney $\longrightarrow$ ureters $\longrightarrow$ urinary bladder $\longrightarrow$ urethra

Explanation

Urine from nephron is brought to the collecting duct of kidneys where the urine enters the ureters. There are 2 ureters, each opening from one kidney into the urinary bladder. The urinary bladder stores urine and it size increases as the amount of urine collected increases. When the CNS gives a voluntary message the muscles of bladder contract and the bladder sphincter relaxes thus excreting urine out through the urethra.

Answer

(a) cytoplasm

Explanation

When there is lack of oxygen Breakdown of Pyruvate takes place in cytoplasm of muscle cells leading to the formation of Lactic acid.

Answer

a) Photosynthesis

b) Autotrophs

c) Chloroplasts

d) Guard cells

e) Heterotrophs

f) Pepsin

Answer

The statement is wrong because plants respire every time and expel out Carbon-di-oxide every time but they give out oxygen only in the day time as photosynthesis process can take place only in the presence of sunlight.

Answer

Opening of guard cells is facilitated by the entry of water inside guard cells. This make the guard cell become turgid. Closing of guard cells is facilitated by water coming out of guard cells. This will make the guard cells flaccid.

Entry of water inside guard cells will make the cell turgid leading to the opening of stomata. Similarly cell become flaccid when water come out of guard cells, this leads to closing of the stomata.

Answer

A plant placed in constant light will live longer, because it will be able to produce the oxygen necessary for its respiration by the process of photosynthesis. A plant living in darkness will not be able to photosynthesize and hence will eventually die due to lack of oxygen availability.

Answer

If a plant is releasing carbon dioxide and taking in oxygen during the day means plant is respiring; it does not mean that there is no photosynthesis occurring in the plant. This is because Photosynthesis and respiration are two independent processes.

Answer

Fishes can respire only by using dissolved oxygen. When we take fish out of water it cannot respire due to lack of dissolved oxygen and they die.

Answer

Answer

Nutrition is an absolute necessity for the organisms because nutrition provides energy for carrying out metabolic activities.

Answer

Green plants are the sources of energy for all the heterotrophs on earth. Plants convert solar and chemical energy into viable food sources. If plants gets disappeared from the earth it lead to imbalance in the ecosystem and heterotrophs may die without food.

Answer

Coating Vaseline to the leaves of a healthy plants will clog its stomata pores and stops the respiration of plants and the plants dies.

Answer

Answer

Answer

Artery has thick walls whereas Veins has thin walls.

Arteries carries blood away from the heart but veins carry blood to the heart.

In arteries valves are absent and in veins they are present

In arteries blood flows under pressure but in veins there will be no pressure.

Answer

Adaptation of leaf for photosynthesis are as follows

a) Surface of leaf is flat to allow greater exposure of light.

b) Presence of chlorophyll to trap sunlight

c) Presence of stomata on the lower surface for easy transpiration

Answer

Food of herbivores contains mostly cellulose. To digest cellulose herbivores need help of certain bacteria. In order to accommodate the microbes and to facilitate digestion of food herbivores has longer small intestine than carnivores.

Answer

Mucus prevent inner lining of stomach from HCL. Mucus prevents drying of inner lining of the stomach. Mucus helps in easy movement of food particles through digestive system. If mucus is not secreted food will not easily moved through digestive system. HCL will damage the stomach lining and the digestion process will not take place.

Answer

Emulsification is a process of breakage of larger fats molecules into digestible fat globules. Emulsification aids action enzymes on fats by breaking larger fat molecules.

Answer

Peristalsis is the process that cause movement of food inside the alimentary canal.

Answer

Small intestine has specialized structures that facilitate absorption of digested food. Small intestine has number of folds that increase the area of absorption. Small intestine also has fingerlike projection called microvilli which are richly supplied by blood vessels.

Answer

Answer

Rate of breathing in aquatic organisms much faster than in terrestrial organisms because availability of oxygen is less in water than on land, hence in order to obtain required oxygen aquatic organisms has to work hard.

Answer

In Humans blood flow in two direction simultaneously in one cardiac cycle. Oxygenated blood comes to heart from lungs and at the same time de-oxygenated blood goes from Heart towards lungs. Because of this double movement is blood circulation in human heart called double circulation.

Answer

Four chambered heart has the following advantages

• Clear cut division of labors among different chambers
• Segregation of oxygenated and deoxygenated blood in the heart.
• Efficiency of the heart will increase.

Answer

Major events of Photosynthesis are

a) Absorption of light energy by chlorophyll

b) Conversion of light energy into chemical energy

c) Splitting of water molecules into Hydrogen and Oxygen

d) Reduction of $CO _2$ to from carbohydrates.

Answer

a) Rate of photosynthesis will reduce due to availability of sunlight.

b) Rainfall will not affect rate of Photosynthesis

c) Manuring will not affect rate of Photosynthesis

d) Blockage of stomata will reduce the rate of photosynthesis because blockage will affect availability pf Carbon-di-oxide.

Answer

Adenosine tri Phosphate (ATP) is the energy currency in the living organisms. It is produced in Mitochondria during respiration.

Answer

These all are parasite. They live on or inside another body to obtain food from the host. In obtaining food parasites always harm their host.

Answer

Role of mouth in digestion of food.

a) Ingestion of food

b) Breakage of food by Mastication

c) Saliva aids easy swallowing of food

d) Salivary amylase breaks starch into simpler carbohydrates.

Answer

Hydrochloric acid, pepsin and mucus are secreted by gastric gland present in the stomach. They have following functions.

HCL Kills germs present in the food and it decreases $P^{H}$ of the stomach which is essential for the working of digestive enzymes.

Pepsin digests protein.

Mucus protects stomach’s innerline from HCL.

Answer

Answer

a) Protein

b) Starch

c) Protein

d) Lipid

Answer

Blood flow through veins does not exert pressure on walls of veins hence they have thin walls. Blood flow in arteries exerts high pressure on arterial walls hence they need thick walls.

Answer

Platelets are responsible for the clotting of the blood. If platelets are absent bllod will not clot. In case of injuries blood flow cannot be stopped without clotting and this may prove fatal for the person.

Answer

Most of the transport in plants occur through passive transport which does not require energy and plants stand still at one place and they will not travel in search of food Hence Plants require low energy compared to animals.

Answer

Water should enter the root xylem continuously to assist the various process such as photosynthesis. Continuous flow of water into root xylem is due to transpiration pull.

Answer

Transpiration is important for plants because of the following reasons.

(a) It creates transpiration pull to facilitate ascent of sap.

(b) Ascent of sap is necessary to make water available for photosynthesis.

(c) It helps a plant to get rid of excess water.

Answer

Leaves plays an important role in excretion in plants because $CO_2$ is expelled out through pores of stomata present in the leaf. Plants shed leaves to get rid of excretory products deposited on them.

Answer

Amoeba shows holozoic nutrition which is comprised of Ingestion, Digestion, Absorption, Assimilation and Egestion.

Ingestion:

Ameoba traps food particles through fingerlike projections called as pseudopodia. Pseudopodia present outside its body and helps in taking food along with water

Digestion:

Food vacuoles are made after ingesting the food. Enzymes are released in the food vacuole for digestion.

Absorption:

After digestion, nutrients enter the cytoplasm through osmosis.

Assimilation:

Nutrients are utilized by the cell for various purposes.

Egestion:

Food vacuole goes near the cell membrane to empty its contents outside the cell. This results in expulsion of waste materials from the cell.

Answer

ALIMENTARY CANAL OF MAN

Human Ailmentary canal has the following parts

Buccal Cavity:

Generally called as mouth and it consists of tongue, teeth and salivary gland. It is the entry site for the food to digestive system. Food is breakdown into simpler molecules by mastication in buccal cavity and salivary amylase breaks Starch into simpler carbohydrates in the Buccal cavity.

Oesophagus:

Buccaql cavity is connected to long tube like structure called as Oesophagus. Oesophagus connects the buccal cavity to stomach and assists in flow of food towards stomach. Oesophagus has a valve to prevent backflow of food particles.

Stomach:

Stomach is a J Shaped organ which has gastric glands in it. Gastric glands secrets Hydrochloric acid, Pepsin and Mucus that helps in the digestion of food.

Small Intestine:

Small intestine is highly coiled long structure. Small intestine performs major of the food absorption. Small intestine has specialized structures that facilitate absorption of digested food. Small intestine has number of folds that increase the area of absorption. Small intestine also has fingerlike projection called microvilli which are richly supplied by blood vessels.

Large Intestine:

This is shorter than small intestine and its lumen is larger than that of Small intestine. The major function of the large intestine is to absorb water from the remaining indigestible food matter and transmit the useless waste material from the body.

Rectum:

Large Intestine open into rectum. Waste materials and undigested food are stored in rectum.

Anus:

It is the opening at the end of alimentary canal. Solid waste materials leave the body through Anus.

Answer

Breathing in Humans has two processes 1) Inhalation 2) Exhalation

Inhalation:

Inhalation is the process of taking oxygen. During this process, ribs come out and diaphragm moves down. This increases the volume of the lungs and decreases the pressure. This will make the air move towards the lungs.

Exhalation:

Exhalation is a process of throwing out carbon-dioxide. During this process, ribs go down and diaphragm moves up. This decreases the volume of the lungs and increases the pressure. As a result air moves out of the lungs.

Answer

Soil is very important for the growth of the plant for the following reasons.

1 Soil provides the base for the growth of the plants and provides a platform for the penetration of roots.

2 It acts as a reservoir of the water.

3 Soil has different minerals essential for the growth of the plant. Soil is the only medium from which soil obtain nutrients.

4 Soil has organic materials essential for the growth of the plants.

5 Soil has microorganisms that has symbiotic relationship with the plant and these microbes assist plant in their growth and life processes.

Answer

ALIMENTARY CANAL OF MAN

Answer

Carbohydrate Digestion

Digestion of cabohydrates starts with buccal cavity where salivary enzymes breaks down the starch into simple sugar molecules. Other sugar molecules are breakdown to glucose in small intestine.

Protein digestion

Proteins are partially digested by pepsin secreted by gastric glands present in the stomach. Then Pancreatic juice secrets trypsin and chymotrypsin enzymes in small intestine where complete digestion of proteins takes place.

Fat Digestion

Fats are digested in small intestine. Bile juice present in the liver emulsifies the fat which breaks fats into small globules. These small fat globules are converted into glycerol and fatty acids by Lipase enzyme.

Answer

Photosynthesis is a process by which plants produce their own food by utilizing sunlight, CO2 and water. CO@ and water are converted to carbohydrates with the evolution of oxygen. Photosynthesis reaction can be given by following reaction.

$6 CO_2+6 H_2 O \xrightarrow{\text{ Sunlight energy }} C_6 H _{12} O_6+6 O_2$

Process of Photosynthesis is divided into 4 processes

1. Absorption of light energy by chlorophyll

2. Conversion of light energy into chemical energy

3. Splitting of water molecules into Hydrogen and Oxygen

4. Reduction of $CO _2$ to produce carbohydrates

Answer

Glucose is first broken down to 3 carbon molecule called as pyruvate. This process takes place in the cytoplasm of all organisms. Pyruvate is further broken down by the flowing steps.

In yeast:

Pyruvate is broken down in the absence of oxygen and the process is called as anaerobic respiration. In yeasts pyruvate is broken down to produce $CO_2$ and ethanol.

In Muscle Cells:

During rigorous physical activity energy demand of our muscles cells increases rapidly. This is compensated by anaerobic respiration in muscle cells. In muscle cells pyruvate is broken down into lactic acid.

In Mitochondria:

In case of aerobic respiration( in presence of oxygen) pyruvate is broken down in mitochondria. Here Pyruvate is broken down to produce $H_2 O$ and $CO_2$. Aerobic respiration is most common in most of the organisms.

Answer

• Deoxygenated blood from different organs comes to the right atrium through the vena cava.
• From the right atrium, blood goes to the right ventricle. The tricuspid valve between the right atrium and right ventricle prevents the backflow of blood.
• From the right ventricle, blood goes to the lungs through pulmonary artery. Inside the lungs, carbon dioxide is removed from the blood and oxygen enters the blood.
• From the lungs, blood goes to the left atrium through pulmonary vein.
• From the left atrium, blood goes to the left ventricle.
• From the left ventricle, blood is pumped into the aorta so that it can be supplied to different organs.

Answer

The basic filtration unit in the kidneys is a cluster of very thin-walled blood capillaries. Each capillary cluster in the kidney is associated with the cup-shaped end of a coiled tube called Bowman’s capsule that collects the filtrate (Fig. 6.14). Each kidney has large numbers of these filtration units called nephrons packed close together.

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. The amount of water re-absorbed depends on how much excess water is there in the body, and on how much of dissolved waste there is to be excreted. The urine forming in each kidney eventually enters a long tube, the ureter, which connects the kidneys with the urinary bladder.

Urine is stored in the urinary bladder until the pressure of the expanded bladder leads to the urge to pass it out through the urethra. The bladder is muscular, so it is under nervous control.