Karnataka Board Class 8 Science Chapter 19 Nutrition and Respiration
KSEEB Class 8 Science Chapter 19 Textual Questions & Answers
I. Four alternatives are given to each of the following incomplete statement/ question. Choose the right answer.
The process of obtaining food and utilizing it in the body is ……………
One of these is a product of photosynthesis …………….
Insectivorous plants commonly grow in areas where soil is deficient in
A person applies hydrogen peroxide on his wound This is to kill
a) anaerobic bacteria
b) aerobic bacteria
Amylase Converts Starch to
II. Answer the Following.
What are life processes?
The processes such as respiration, nutrition, growth, movement, response to stimuli, excretion and reproduction that help to support and sustain life are called as life processes.
Explain the method of testing a leaf for starch.
Collect a Few leaves From a plant put it in water For Some time and the take out, It is then dipped in spirit and then in Iodine Solution. Observe that the leaf turns blue-black Showing the presence of Starch.
Explain an experiment to demonstrate that oxygen is released during photosynthesis.
Take two troughs Filled with water Add a few Crystals of Sodium bicarbonate to both. Place Hydrilla plants in both the troughs and invert large Funnels over them Take two test tubes, place Small pieces of Steel wool into their bottoms.
Fill the test tubes with water and invert them over the narrow ends of each of the Funnel, place one of the troughs in a bright Sunny area Whereas the other trough in dark Cupboard For about by introduced Splinters.
The Splinter burns brightly in the gas collected in the test tube which is kept outside, but not which is kept in the Cupboard. From this experiment, we can show that the gas released during photosynthesis is oxygen.
Differentiate between the two phases of photosynthesis
|Light reaction||Dark reaction|
|1. Light reaction takes place in the presence of sunlight.||1. Dark reaction takes place in the absence of sunlight (night)|
|2. It takes place in the grana region||2. It takes place in the stroma region|
What are parasites? Give two examples.
The organism which obtains Food from other organism is called a parasite. There are two types of parasites.
- Semi parasite
- Total parasite
Eg: Cuscuta, intestinal worms like tapeworm, roundworm, etc.
Amoeba Cannot digest Fats Why?
Amoeba has no enzyme to digest Fats Therefore amoeba Cannot digest Fats.
Explain the respiration in the cockroach.
The tracheal system of a cockroach includes stigmata, Trachea, and Tracheoles. Stigmata are the respiratory openings in a cockroach. These are present on the lateral sides of the body. Trachea and Tracheoles carry oxygen from the diffused air to all parts of the body.
Cells take in oxygen and give out carbon dioxide to the tracheole. Haemolymph the blood of cockroach is involved in the gaseous exchange. between the cells, The carbon dioxide is diffused out through the spiracle openings.
Explain respiration in human beings.
Air enters into the nasal cavity through the nostrils. Dust particles present in the air are prevented from entering the lungs. Air passes to the pharynx and then into the trachea. It has ‘C’ shaped rings which prevent it from collapsing.
The trachea is divided into bronchi and into bronchioles and a number of alveoli. Blood circulating around the alveoli gives out CO2. This oxygenated blood reaches the cells and gives oxygen to the cells and is used for oxidizing glucose. CO2 formed as a product is carried by the blood to the alveoli and exhaled along the same pathway.
Draw a diagram of the human digestive system label the parts.
KSEEB Class 8 Science Chapter 19 Additional Questions & Answers
What are autotrophs?
The organisms which prepare their own food are called autotrophs.
Example: Green plants
What is photosynthesis?
The process by which the green plants manufacture Organic Compound by using CO2 and H2O in the presence of sunlight and Chlorophyll.
What are Stomata?
The minute Opening on the leaf Surface is called Stomata.
Draw a neat diagram of the cross-section of the leaf.
Mention the two phases of photosynthesis
The two phases of photosynthesis are
- Light reaction
- Dark reaction (Light independent reaction)
Draw a neat labelled diagram of Chloroplast
What arc insectivorous plants? Give example.
photo Synthetic plants which are growing in the soil, poor in nitrogen content try to obtain nitrogen by trapping and digesting insects are Called insectivorous plants.
Example: Rosecrans, Nepenthes.
What are epiphytes? Give example.
Some plants Capable of photosynthesis take shelter in the host tree Such plants are Called epiphytes
What are Saprophytes? Give example.
The organism which obtains Food From dead and decaying organic matter by decomposing the Same is Called as Saprophytes
Example: bacteria, Fungi
What is the benefit of E-Coli bacteria in a man?
E – Coli bacteria present in the intestine of man provide the Vital B – Complex Vitamins.
Define the term Symbiosis/ mutual-ism.
The mode of nutrition in which two organisms live together and are mutually benefited is called mutual-ism or Symbiosis.
Mention the steps involved in Horologic nutrition.
The Horologic nutrition involves Five steps namely
- assimilation and
Define the following terms.
- Ingestion: The process of taking the Food is called ingestion.
- Digestion: Conversion of Complex larger molecules into simple smaller molecules by the action of enzymes for easy absorption is called digestion.
- Absorption: Taking in of Soluble digested nutrients into the blood is called absorption.
- Assimilation: The process of converting the digested food into protoplasm I.e storing or utilizing in the ells is called assimilation.
- Egestion: Elimination of undigested Food From the animal body is called egestion.
Explain the nutrition in Amoeba.
Amoeba feeds on bacteria, diatoms, unicellular algae, minute protozoa, and even dead organic matter The pseudopodia help in surrounding and ingesting the prey into Food vacuole Digestive enzymes amylase and pro-tease Secreted in the Food Vacuole digest the carbohydrates and proteins respectively into Simple Forms.
The digested Food is diffused into the cytoplasm and circulates so that all the parts of the receives the nutrients, It is used For all the life activities. The undigested Food is egested with the help of pseudopodia.
What are antennae? Write its Functions.
The pair of Feelers in the head region of Cockroach is called antennae. It senses the Food and pushes the Food into the mouth.
Draw a neat labeled diagram to show the digestive System of Cockroach
Name the parts of alimentary canal of man.
The alimentary Canal in eludes the mouth pharynx esophagus stomach Small intestine, large intestine and anus.
Mention the acid present in the gastric juice Mention its Function.
The gastric juice contains hydrochloric acid, It kills the microbes that enters in to the stomach through Food and water.
Name the enzymes present in gastric juice and mention its Function.
Enzymes present in gastric Juice are
- pepsin : convert proteins in to polypeptides
- Rennin : converts the soluble milk proteins insoluble curds.
Mention the juice produced by the liver and where is, it stored?
Bile juice is produced by the liver and it is stored in the gall bladder. Bile juice emulsifies Fats.
Mention the enzymes present in pancreatic juice mention its Function.
The pancreatic juice contains two enzymes are
- Amylase: diverts Starch into maltose
- Lipase: Converts fats into simple fats
Mention the enzymes present in intestinal juice, mention its Functions.
- Enzymes present in intestinal juice are Maltose – Converts Maltose into glucose.
- Sucrose – Converts Cane sugar into glucose
- Lactate – Converts Milk sugar into glucose
- Peptidase – Converts Peptidase into amino acids
- Lipase – converts Fats into fatty acids and glycerol
What are villi?
The Finger-like projection of the Small intestine which absorbs the digested Food are called villi
What is respiration? Name the two types of Respiration.
Respiration is a process by which energy is liberated by oxidation of Food.
- Aerobic respiration
- Anaerobic respiration
Differentiate between aerobic and anaerobic respiration.
- Aerobic respiration:
- oxygen is used to break down organic CO2 and H2O
- A large amount of energy is liberated
- Occurs in higher Forms of organisms
- Glucose + Oxygen + Carbon dioxide + water + energy.
- C6H2O6 + O2 → 6CO2+ 6H2O+ H2O + Energy.
- Anaerobic respiration
- organic compounds are broken in the absence of oxygen, producing alcohol and CO2
- Small amount of energy is liberated.
- occurs in lower Forms of organisms.
- Glucose + Ethos Alcohol + Carbon dioxide + Energy
- C6H2O6 → 2C2H5OH + 2CO2 + Energy.
What are spiracles?
The respiratory openings in Cockroach are called spiracles.
Draw a neat labelled diagram of the Respiratory System of Cockroach.
Draw a neat labeled diagram of human Respiratory System.
Define the Following.
- bronchi: Trachea is divided into two branches called the bronchi
- bronchioles: The bronchi are Further branched, inf to bronchioles.
- Air sacs: are present at the terminals of bronchioles. These are called alveoli
Green plants are called as auto tropes? Give reason
Green plants can prepare their won Food. Hence, they are called autotrophs.
Amoeba is called as an omnivore.
Amoeba feeds on bacteria, diatoms, unicellular algae, minute protozoa, and even dead organic matter, there Fore, Amoeba is called an omnivore.
Parasites have haustoria, Give reason.
parasites have haustoria to absorb water and minerals From the host plant.