Teachers recommend solving Kerala Syllabus 9th Standard Biology Question Paper Set 2 to improve time management during exams.
Kerala Syllabus Std 9 Biology Model Question Paper Set 2 English Medium
Time: 1½ Hours
Max Score: 40 Marks
Instructions:
• First 15 minutes is given as cool off time. This time is to be spend for reading and understanding the questions.
• Answer the questions according to the directions.
• Score and time to be considered while answering.
I. Answer any 4 from questions 1 to 5. Each carries 1 score (4 × 1 = 4)
Question 1.
What are the main components of the plasma membrane?
Answer:
The plasma membrane is primarily made up of phospholipid layers and proteins.
Question 2.
Name the biomolecules formed in cells to aid and regulate metabolism.
Answer:
Enzymes and hormones
Question 3.
Which are the major excretory substances in our body?
Answer:
The main excretory product generated by the human body is urea. The urea is excreted out of the body via urine. Sweat is another excretory substance from skin.
Question 4.
Name the membrane that covers the lungs.
Answer:
Pleura
Question 5.
Write any two services that plants provide to the living world.
Answer:
- Providefood.
- Provide oxygen.
II. Answer any 4 from questions 6 to 10. Each carries 2 score (4 × 2 = 8)
Question 6.
Give reason for the following:
a. Light phase takes place in grana.
b. Xanthophyll and Carotene are called accessory pigments.
Answer:
a. Pigments that absorb sunlight are found in the grana of chloroplast.
b. Pigments other than chlorophyll a, absorb light and transfer it to chlorophyll a. so, they are termed as accessory pigments.
Question 7.
Why doesn’t food enter trachea while swallowing it?
Answer:
Tongue compresses the food into balls with the help of palate. Uvula closes the nasal cavity that opens to the pharynx. Posterior part of the tongue allows food to move over the epiglottis into the oesophagus. Trachea rises up and is closed by the epiglottis. Thus, the food does not enter to trachea.
Question 8.
How does ammonia is converted into urea in liver?
Answer:
Synthesis of urea takes place in the liver. Amino acids are formed by the breakdown of proteins. As a result of the metabolic activities of amino acids, several nitrogenous by-products are formed. The most harmful among these is ammonia. The ammonia formed in tissues diffuses into blood through tissue fluids and blood transports it to the liver. In the liver with the help of certain enzymes, ammonia combines with carbon dioxide and water to form urea.
Question 9.
Mention the main excretory organs and the excretory products respectively of the following organisms.
a) Insects
b) Reptiles
c) Earthworms
d) Birds
Answer:
a) Insects – Malplghian tubules – Uric acid
b) Reptiles – Kidney – Uric acid
c) Earthworms – Nephridia – Urea
d) Birds – Kidney – Uric acid
Question 10.
What is the role of chemical digestion?
Answer:
Chemical digestion breaks down complex nutrients (like proteins, carbohydrates, and fats) into simpler absorbable forms (like amino acids, sugars, and fatty acids). This is achieved by enzymes present in digestive juices secreted by various organs along the digestive tract.
III. Answer any 4 from questions 11 to 15. Each carries 3 scores (4 × 3 = 12)
Question 11.
Kidney stone, nephritis, uremia etc. are some diseases affecting the kidneys. Prepare a table including the causes and symptoms of these diseases.
Answer:
| Diseases | Causes | Symptoms |
| Kidney stone | Not drinking enough water | Severe pain in your back or side, Blood in urine, A burning feeling when urinating. |
| Nephritis | Diabetes, genetic disorder link that affects the kidneys. | Decreased urine output, High blood pressure, urine appears dark, tea- coloured, or cloudy |
| Uraemia | Diabetes, High blood pressure | Nausea, Vomiting, Loss of appetite |
Question 12.
a) Define metabolism
b) What role do enzymes play in metabolism?
c) Why is homeostasis important for metabolism?
Answer:
a) Inside the cell, biomolecules and many other chemicals work together to show all signs of life. All such chemical reactions together taking place in an organism are called metabolism.
b) Enzymes act as biological catalysts, speeding up the countless chemical reactions that occur constantly within an organism.
c) Maintaining homeostasis, a stable internal environment, is crucial for the smooth functioning of metabolism.
Question 13.
Nutrients are essential for metabolism.
a) How do animals get nutrients?
b) How do plants get nutrients?
c) Which is known as the energy currency of the cell?
Answer:
a) Animals get their nutrients from their surroundings, and they depend on other organisms for their food. They are heterotrophic organisms.
b) Plants follow an autotrophic mode of nutrition. They can prepare their own food by photosynthesis.
c) ATP
Question 14.
Cellular respiration is the process of releasing energy from glucose inside the cells.
a) What are the two stages of cellular respiration?
b) Name the cell organelle in which the second phase of cellular respiration takes place.
c) What are the end products of cellular respiration?
Answer:
a) Glycolysis and Kreb’s cycle.
b) Mitochondrion.
c) CO2 and water
Question 15.
Find out the functions of different proteins in plasma.
Answer:
Albumin – Regulates blood pressure
Globulin – Helps in defence
Fibrinogen – Plays a major role in the coagulation of blood.
IV. Answer any 4 from questions 16 to 20. Each carries 4 scores (4 × 4 = 16)
Question 16.
Briefly explain the parts of the Human respiratory system and prepare a flowchart to illustrate the path of atmospheric air, entering the nostrils till it reaches the alveoli.
Answer:
The human respiratory system consists of a group of organs and tissues that help us to breathe. The major parts include:
A pair of external nostrils: To inhale and exhale air.
Nasal chamber: This is lined with hair and mucus to filter the air from dust and dirt.
Pharynx: It is a passage behind the nasal chamber and serves as the common passage for both air and food.
Larynx: It is the sound box
Trachea: A long tube passing through the mid-thoracic cavity also known as a windpipe. The walls of the trachea comprise C-shaped cartilaginous rings which give hardness to the trachea and maintain it by completely expanding. The trachea extends further down into the breastbone and splits into two bronchi, one for each lung
Bronchi: The trachea divides into left and right bronchi.
Bronchioles: Each bronchus is further divided into finer channels known as bronchioles.
Alveoli: The bronchioles terminate in balloon-like or sac-like structures known as the alveoli,Through which gaseous exchange takes place.
Lungs: Humans have a pair of lungs, which are sac-like structures and covered by a double-layered membrane known as pleura.
Question 17.
Though photosynthesis is ultimately anabolism, it also involves catabolism’. Analyze the statement.
Answer:
Photosynthesis is an anabolic process during which plants use energy from sunlight to convert carbon dioxide gas and water into sugar molecules. But during this anabolic process, some breaking down reactions have also happened. An example of a catabolic reaction during photosynthesis is the process of food digestion, where different enzymes break down food particles, so that they can be absorbed easily by the small intestine.
Question 18.
Chloroplasts are the cell organelles that are responsible for the photosynthetic process, in plants.
a) Which are the 3 types of plastids present in plant cells?
b) What is the role of carotenoid pigments?
c) Which is known as the colourless plastids?
d) Define thylakoids.
Answer:
a) Chloroplast, Chromoplast, and leucoplast
b) Carotenoid pigments are responsible for different colours like yellow, orange, and red colour imparted to fruits, flowers, old leaves, roots, etc.
c) Leucoplasts
d) Thylakoids are the numerous membranous sacs arranged like stacks of coins within the stroma of chloroplast.
Question 19.
Analyse the figure and answer the questions.
a) Write the names of the circulations X and Y.
b) Write the names of the blood vessels i, ii, iii, iv, v.
c) What is the role of these circulations in the exchange and transport of gases?
d) Explain the role of these circulations in the process of excretion.
Answer:
a) X-Alveolar exchange of gases (Pulmonary circulation), Y – Systemic exchange of gases (Systemic circulation).
b) (i) Inferior vena cava,
(ii) Superior vena cava,
(iii) Pulmonary artery,
(iv) Pulmonary vein,
(v) Aorta
c) Pulmonary circulation moves blood between the heart and the lungs. It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body.
d) The pulmonary veins by pulmonary circulation return oxygenated blood to the heart, which releases CO from the deoxygenated blood to the lungs for gaseous exchange. The release of CO2 is a kind of excretion. In systemic circulation, blood with oxygen, nutrients, and hormones travels from the heart to the rest of the body. In the veins, the blood picks up waste products as the body uses up oxygen, nutrients, and hormones.
Question 20.
Complete the given flow chart using the hints.
Answer:
