A thorough understanding of Kerala Syllabus 9th Standard Biology Textbook Solutions Chapter 1 To Life Processes Notes Questions and Answers English Medium can improve academic performance.
SCERT Class 9 Biology Chapter 1 Notes Questions and Answers To Life Processes
Std 9 Biology Chapter 1 Notes Pdf Kerala Syllabus English Medium Solutions Questions and Answers
Class 9 Biology Chapter 1 Let Us Assess Answers To Life Processes
Question 1.
Compare the outer membrane of raw egg and boiled egg using the indicators given below
- Permeability
- Possibility of osmosis
- Possibility of active transport
Answer:
| Raw egg | Boiled egg |
| Permeability is more | Permeability is less |
| Possibility of osmosis is more | Possibility of osmosis is less |
| Active transport is present | Active transport is not present |
Question 2.
Given below is an answer written by a child to the question ‘How is oxygen released in photosynthesis? ‘Evaluate and comment on it. ‘Carbon dioxide and water are the raw materials for photosynthesis. Both these breakdown and oxygen is released’
Answer:
The oxygen released during photosynthesis is from the water. The plants will absorb water as well as carbon dioxide during photosynthesis. Later these water molecules split and produce hydrogen and oxygen. Then this hydrogen is utilized for the dark phase of photosynthesis and is converted into sugar (Glucose). The oxygen is then released into the atmosphere whereas the sugar molecules are stored for energy.
Question 3.
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 they can be absorbed by the small intestine.
Extended Activities
Question 1.
There are so many people who have dedicated their lives for environmental activities. Collect information about them and prepare an album.
Answer:
(Hints: Given below is a list of some environmentalists and their achievements as a model for the preparation of your album).
Greta Thunberg: A Swedish climate activist who is famous for starting the Fridays for Future movement. Thunberg began by protesting in front of the Swedish parliament in 2018, and her lone strike inspired millions of students around the world to walk out of school and demand action on climate change.
Vandana Shiva: An Indian environmental activist, physicist, and author who has written extensively about the dangers of genetically modified organisms (GMOs) and the importance of biodiversity. Shiva is the founder of Navdanya, an organization that promotes organic farming and seed saving.
Question 2.
Complete the table given below by observing plants in the surroundings.
| Plants | Value added products | Consumption |
| Coconut tree | Coconut oil | For cooking |
| Medicine | ||
Answer:
| Plants | Value added products | Consumption |
| Coconut tree | Coconut oil | For cooking |
| Aloe vera | Medicine | Treating skin problems, wounds, cancers, diabetes, gastrointestinal problems, etc. |
| Rubber | Reclaimed rubber, rubber mats | Used in waterproof materials and works as an electrical insulator. |
| T urmeric | Cosmetics, Food | Ingredient in dietary supplements, cosmetics, flavouring for foods |
| Coffee plant | Coffee powder. Bio-oil | For cooking. To produce essential oils from coffee leaves |
| Palm trees | Toddy, Wine, Honey, Jaggery | To produce fresh juice (sweet toddy), fermented drinks (toddy, wine, and arak). |
To Life Processes Class 9 Notes Questions and Answers Kerala Syllabus
Question 1.
Complete the illustration given below to gain an understanding of metabolism.
Answer:
Question 2.
Find examples of enzymes and hormones.
Answer:
| Enzymes | Hormones |
| 1. Salivary amylase in saliva | 1. Sex hormone – Testosterone, Estrogen, Progesterone |
| 2. Pepsin in the gastric juice | 2. Thyroxine |
| 3. Sucrase | 3. Calcitonin |
| 4. Lipase | 4. Thymosin |
Question 3.
Many factors required for metabolism are obtained from their external environment. Which are they? List out.
Answer:
Air, water, temperature, etc.
Question 4.
Is there internal environment like external environment? Note down your guess.
Answer:
Yes, there is internal environment, like external environment. In animals the fluid found in the Ispace between the cells (extracellular fluid) serves as the internal environment. The internal environment of plants consists of cell walls and their components, extracellular fluid and air sacs between cells.
Question 5.
Why plasma membrane is known as selectively permeable membrane? Find out.
Answer:
The plasma membrane is called selectively permeable membrane, because, it allows only certaint molecules to pass in and out.
Question 6.
What happens to raisins placed in fresh water and why? Find out.
Answer:
The raisins will bulge, because high amount of water enter into it. This is because of the movement of water molecules from higher concentration to lower concentration.
Question 7.
Will diffusion take place through and without semi permeable membrane? Find out.
Answer:
Yes, diffusion will takes place through and without semi permeable membrane.
Ex: Diffusion of CO2 and O2.
Question 8.
Complete the work sheet by including processes involved in the exchange of materials.
| The nature of flow of molecule | Name of the process |
| from a region of higher to lower concentration | |
| From a region of low er to higher concentration | |
| Applicable to water only | |
| Energy required | |
| Energy not required | |
| Carrier protein not required | |
| Carrier protein required |
Answer:
| The nature of flow of molecule | Name of the process |
| from a region of higher to lower concentration | Diffusion |
| From a region of low er to higher concentration | Active transport |
| Applicable to water only | Osmosis |
| Energy required | Active transport |
| Energy not required | Facilitated diffusion |
| Carrier protein not required | Diffusion |
| Carrier protein required | Active transport |
Question 9.
Nutrients are essential for metabolism. How do animals get them? What about plants?
Answer:
Animals get their nutrients from their surroundings, and they depend on other organisms for their food. They are heterotrophic organisms. But Plants follow an autotrophic mode of nutrition. They can prepare their own food by photosynthesis.
Question 10.
Photosynthesis is the process by which plants make food. List the components required for photosynthesis.
Answer:
- Chlorophyll
- Sunlight
- Water
- Carbon dioxide
Question 11.
Observe the illustration and discuss the parts involved in photosynthesis based on the indicators and make a note.
Indicators:
- Structure of chloroplast.
- Position of chlorophyll.
- Thylakoid, grana and stroma.
Answer:
There are three types of plastids in plant cells: chloroplast, chromoplast, and leucoplast. Chloroplast is a green-coloured plastid mainly responsible for photosynthesis due to the presence of chlorophyll pigments.
Chromoplasts are plastids that contain carotenoid pigments. They lack chlorophyll. Carotenoid pigments are responsible for different colours like yellow, orange, and red colour imparted to fruits, flowers, old leaves, roots, etc. Chromoplasts may develop from green chloroplasts.
Leucoplasts are colourless plastids that generally occur in non-green plant cells near the nucleus and store starch, proteins, and oils.
Anatomically, leaves consist of an outer protective group of cells called epidermal cells, both upper and lower epidermis. The lower epidermis contains numerous openings called stomata for water and gaseous exchange. Mesophyll cells form the ground tissue, contains two types of cells: elongated palisade mesophyll and spherical spongy mesophyll. Numerous green-coloured, dot-like structures are seen in the mesophyll cells, the chioroplasts.
Chioroplast is a double-membrane bound cell organelle, consisting of an outer and an inner membrane. The fluid part inside the inner membrane is the stroma, in which the dark reaction of photosynthesis takes place. Thylakoids are the numerous membranous sacs arranged like stacks of coins within the stroma. The group of thylakoids are termed as grana. Each granum is interconnected by a bridge-like structure called the stroma lamellae. The light reaction of photosynthesis occurs inside the grana (Thylakoid).
Question 12.
Complete the given table by analyzing illustration and the informations given.
| Photosynthesis | ||
| Hints | Light phase | Dark phase |
| Place where reaction takes place | ||
| Reactions | ||
| Products | ||
Answer:
| Photosynthesis | ||
| Hints | Light phase | Dark phase |
| Place where the reaction takes place | Grana | Stroma |
| Reactions | Water splits into hydrogen and oxygen. | Glucose is formed by combining, hydrogen and carbon dioxide. |
| Products | Hydrogen, Oxygen, ATP | Glucose, Water |
Question 13.
Complete the illustration by including the reactants and products of photosynthesis.
Answer:
Question 14.
Is sunlight itself is required for photosynthesis? Can photosynthesis take place under the light of an LED bulb? Find out.
Answer:
Yes, photosynthesis can take place in artificial light if the plant is exposed to the correct wavelength of light. Photosynthesis is the natural process by which plants use chlorophyll to absorb atmospheric carbon dioxide and convert it to sugar in the presence of sunlight
Question 15.
Many substances are produced when starch undergoes metabolism. Observe the pictures given below and complete the illustration.
Answer:
Question 16.
You know about nutrition and nutrients. List the nutrients.
Answer:
- Carbohydrates
- Minerals
- Water
- Proteins
- Vitamins
Question 17.
Plants grow in water as well as on land. Who are the producers in the ocean and other water bodies?
Answer:
Aquatic plants include larger plants, or macrophytes, and microscopic algae, or phytoplankton. These are the primary producers in the ocean and other water bodies.
Question 18.
What are the steps to be taken to prevent ocean pollution? Discuss.
Answer:
- Reduce plastic production & waste
- Improve wastewater systems Use eco-friendly products
- Reduce chemical pollution
- Manage oil spills
- Beach & river cleanups
- Monitoring & measuring progress.
Question 19.
Are food and oxygen the only things that plants provide? Arrive at inferences by analyzing the illustration and the description.
Answer:
- The service rendered by plants for the sustenance of the living world is unique. Plants serve as the cheapest, most effective, and natural means for the purification of air.
- Mangroves are found where back waters meet the sea. Kerala has 43 species of mangrove plants that grow in salt water.
- Plants are the foundation stones of the biosphere. Depletion of plants will ultimately affect the survival of life itself.
- The concept of sustainable development is formulated by considering plants as well.
- Nature conservation should become part and parcel of everyone’s life. Nature should be used wisely and preserved for generations to come.
The nature and humans are receiving countless services from plants. Most plant parts have economic importance in one way or the other. A variety of value-added products are made from them. The processing and marketing of these resources open doors to a wide range of job opportunities. The service rendered by plants for the sustenance of the living world is unique.
Plants serve as the cheapest, effective, and natural means for the purification of air. By absorbing carbon dioxide from the atmosphere and releasing oxygen, plants provide invaluable service to the living world. Plants also have a major role in the mitigation of natural disasters. Mangrove forests help in controlling Tsunami to some extent. Bamboo forests, reed, vetiver, lemongrass, etc. protect the riverbanks from collapsing during floods. Trees and bushes in mountains and hills prevent soil erosion and landslide.