RBSE Solutions Class 11 Biology Chapter 8 Protoplasm

Rajasthan Board RBSE Class 11 Biology Chapter 8 Protoplasm

RBSE Class 11 Biology Chapter 8 Multiple Choice Objective Questions

 

Question 1. Which of the following is not a property of protoplasm-
(a) Colloidal solution
(b) Viscosity
(c) Non living fluid
(d) Living matter
Answer: (c) Non living fluid
In simple words: Protoplasm is the living part of a cell. This means it cannot be a non-living fluid.

🎯 Exam Tip: Remember that protoplasm is fundamentally the 'living substance' of a cell; any characteristic that contradicts this fundamental nature is incorrect.

 

Question 2. Asafoctida is derived from-
(a) Roots of Ferula
(b) Leaves of Ferula
(c) Stem of Ferula
(d) Flowers of Ferula
Answer: (a) Roots of Ferula
In simple words: Asafoetida, also known as hing, comes from the roots of the Ferula plant. It is a type of gum collected from its tap roots.

🎯 Exam Tip: Knowing the botanical source of common plant products helps in answering such biology questions correctly.

 

Question 4. Most abundant organic compound of the protoplasm-
(a) Fat
(b) Proteins
(c) Carbohydrates
(d) Nucleic acids
Answer: (b) Proteins
In simple words: Among all the organic substances in protoplasm, proteins are found in the largest amount, making them the most common.

🎯 Exam Tip: Remember that proteins are essential building blocks and carry out many functions, hence their high abundance in living matter.

RBSE Class 11 Biology Chapter 8 Very Short Answer Questions

 

Question 1. Write the names of stored material in protoplasm.
Answer: The main stored materials found in protoplasm are carbohydrates, lipids, and proteins.
In simple words: Protoplasm stores carbohydrates, fats, and proteins for later use by the cell.

🎯 Exam Tip: List all three major macromolecules (carbohydrates, lipids, proteins) as they are the primary stored food materials in cells.

 

Question 2. Rubber is obtained from which plant ?
Answer: Rubber is primarily obtained from the plant known as Hevea brasilianis, also called the rubber tree.
In simple words: Natural rubber comes from the Hevea brasilianis tree.

🎯 Exam Tip: Ensure you spell botanical names correctly, especially the genus and species, for full marks.

 

Question 3. What is cystolith?
Answer: Cystoliths are crystals made of calcium carbonate. They are found as mineral growths inside the cells of some plants, often appearing like grape bunches or small granules.
In simple words: A cystolith is a special crystal made of calcium carbonate, found in some plant cells.

🎯 Exam Tip: Remember that cystoliths are calcium carbonate structures, distinct from other plant crystals like raphides (calcium oxalate).

 

Question 4. What is quinine ?
Answer: Quinine is a type of alkaloid. It is a natural compound found in the bark of the Cinchona tree and is well-known for its use in treating malaria.
In simple words: Quinine is an alkaloid drug from the Cinchona tree, used to treat malaria.

🎯 Exam Tip: When defining a substance, identify its chemical class (e.g., alkaloid) and its primary source or use.

 

Question 2. What is the importance of resins?
Answer: Resins are substances made from carbohydrates that have been oxidized from fragrant oils. They are important because they are used to make things like varnishes and paints. Examples include Canada balsam and Asafoetida, which is obtained from the tap roots of the Ferula assafoetida plant. Asafoetida is also used to enhance flavor in food (as a spice) and in various medicines.
In simple words: Resins are plant products used in paints, varnishes, and medicines. Asafoetida, a resin, comes from the Ferula plant and is used for flavor and in traditional remedies.

🎯 Exam Tip: When asked about importance, provide both the origin/nature of the substance and its practical applications or uses.

 

Question 3. What are secretory substances ?
Answer: Secretory substances are materials produced by certain cells that are not directly used for the plant's nutrition or growth. These substances are released by specialized gland cells. Examples include:
1. **Enzymes** – These are proteins that act as biological catalysts, speeding up various processes inside the plant. They help break down complex food into smaller, simpler molecules. Examples are amylase, maltase, and protease.
2. **Nectar** – This is a sweet, organic liquid secreted by nectar glands in flowers. It contains sugars like sucrose, glucose, and fructose. Nectar attracts insects, which then help in pollination.
In simple words: Secretory substances are things plants make but don't use for food or growing. Gland cells release them. Enzymes help with chemical reactions, and nectar attracts insects for pollination.

🎯 Exam Tip: Define secretory substances clearly and provide at least two distinct examples with their roles in plants.

RBSE Class 11 Biology Chapter 8 Essay Type Questions

 

Question 1. Explain the physical and chemical properties of the protoplasm.
Answer: Protoplasm, the living substance within cells, has distinct physical and chemical characteristics.
Physical Properties of Protoplasm:
Scientists have proposed several ideas about the physical nature of protoplasm. Two important theories are:
* **4. Fibrillar theory:** This theory, put forward by Flemming in 1894, suggests that protoplasm is made up of very small fibers.
* **5. Colloidal theory:** Proposed by Wilson Fisher in 1894, this widely accepted theory describes protoplasm as a special kind of solution called a crystallocolloidal solution and a polyphasic colloidal system. It means protoplasm has tiny particles spread out in a continuous fluid.
Protoplasm can react to things outside the cell, like changes in temperature, chemicals, and light. It also carries out several important life activities:
* Movement
* Nutrition
* Metabolism
* Respiration
* Growth
* Excretion
* Reproduction
Chemical Properties of Protoplasm:
The chemical makeup of protoplasm is very complex and difficult to study while it's alive. It contains around 50 different kinds of chemical compounds. The main ones and their typical amounts are:

The amount of water in protoplasm can vary a lot, for example, cells in aquatic plants and brain cells might have up to 95% water, while seed cells have 10-15%, and bone cells as little as 5%. Inorganic substances are found as charged particles (ions). Positive ions include calcium, potassium, magnesium, and iron, while negative ions include nitrate, sulfate, bicarbonate, and chloride.
In simple words: Protoplasm is the living part of a cell. Physically, it's like a jelly-like fluid with tiny particles, and it reacts to its surroundings and does all life activities. Chemically, it's mostly water, proteins, carbohydrates, and fats, plus tiny amounts of DNA, RNA, and other minerals that help it work.

🎯 Exam Tip: When describing protoplasm, always cover both its physical characteristics (like its colloidal nature and responsiveness) and its major chemical components (like water, proteins, and key ions).

 

Question 2. What are excretory substances ? Explain two excretory products of plants.
Answer: Excretory substances in plants are by-products of metabolism that are not directly useful to the plant and are often stored in various parts of the plant. Plants do not have complex excretory systems like animals, so these substances accumulate. Some important excretory products of plants include:
1. **Alkaloids** - These are nitrogen-containing excretory substances that are insoluble in water but dissolve in alcohol. They are found in leaves, fruits, seeds, and bark. Many are bitter or poisonous, but some have medicinal uses. Examples include:
* **Quinine:** From Cinchona bark, used to treat malaria.
* **Morphine:** From opium poppy, used for pain relief and to induce sleep.
* **Nicotine:** From tobacco leaves, used to relieve pain and induce sleep.
* **Atropine:** From Atropa roots, used in eye medicine and to stimulate the nervous system.
* **Reserpine:** From Rauwolfia serpentina roots, used for high blood pressure and mental disorders.
* **Theine (caffeine/theophylline):** From tea leaves, acts as a stimulant.
* **Taxol:** From Taxus brevifolia, used as an anticancer drug.
2. **Gum** - Gums are formed when cellulose in plant cell walls breaks down. They are insoluble in alcohol but partly soluble in water. Gums are exuded as a sticky substance that hardens into a crystalline structure upon contact with air. Examples include gums from Acacia (babool or kikar) and Prosophis cineraria (Khejadee) stems.
3. **Resins** - These are carbohydrate derivatives formed by the oxidation of fragrant oils. They are used in making varnishes and paints. Canada balsam and Asafoetida are types of resins. Asafoetida is extracted from the tap roots (rhizome) of the Ferula assafoetida plant and is used as a flavor enhancer (spice) and in many medicines. The latex of some plants like Euphorbia, Oak, and Kaner (Thevetia) can also be used to produce petroleum.
4. **Tannins** - These substances have a bitter taste and are derived from cell walls, fibers, bark, leaves, and unripe fruits of many plants (gymnosperms and angiosperms). Tannins are used in medicines, and in the leather and ink industries.
5. **Latex** - This is a white to yellowish-brown, thick liquid exuded by many plants (around 200 species), notably Hevea brasiliensis (rubber tree) and Ficus elastica. Latex composition varies, being a mixture of resin, gum, stored food, and other carbohydrates. Plants that produce latex are also called petroplants, as their latex can be used to produce petroleum.
6. **Mineral Crystals** - Some plants store inorganic waste materials as crystals in their cell walls, vacuoles, or plant marrow. These commonly include crystals of silica, calcium carbonate, and calcium oxalate. Silica deposition occurs on the leaves of grasses. Calcium carbonate crystals, often appearing like grape bunches (cystoliths), are found in the cell walls of fig and rubber plants. Calcium oxalate crystals, which come in various shapes like needle-like raphides (e.g., in Pistia) and round spheriphides (e.g., in papaya), are found in the plant marrow of many plants like water hyacinth, Colocasia root, and Jimikand. In Atropa plants, these crystals appear as small granules on the leaves.
In simple words: Plants create waste products called excretory substances, which they store since they don't have a complex system to remove them. These include alkaloids (like quinine), sticky gums, resins (for paints), bitter tannins, milky latex (used for rubber), and mineral crystals (like calcium carbonate).

🎯 Exam Tip: Clearly define excretory substances and then provide detailed explanations for at least two main types, including examples and their uses.

 

Question 3. What are stored substances ? Give the detail account.
Answer: Stored substances, also known as reserve substances, are bioorganic compounds made in the cells through a process called polymerization. These are kept in either soluble or solid forms and are used as building materials or as stored food for the cell. Key stored substances include carbohydrates, lipids, and proteins.
(i) **Carbohydrates:** These are organic compounds made of carbon (C), hydrogen (H), and oxygen (O), with a general formula of \( (CH_2O)_n \). Based on their chemical structures, they are grouped into monosaccharides (simple sugars), oligosaccharides, and polysaccharides (complex sugars).
(ii) **Lipids:** Lipids are also organic compounds of C, H, and O, found as small droplets in the protoplasm. They do not dissolve in water but release energy when oxidized. Lipids are long, complex chains of hydrocarbons, which makes them hydrophobic (water-fearing) or non-polar. They are formed from fatty acids and glycerol.
(iii) **Proteins:** These are organic compounds containing C, H, O, and nitrogen (N). Proteins are built from amino acids; there are 20 different types of amino acids involved in protein formation. Each amino acid can act as both an acid and a base (amphoteric). During protein formation, a carboxylic group from one amino acid links with an amino group from another amino acid, forming a peptide bond (\( -CO-NH- \)) and releasing a water molecule. A protein chain, therefore, consists of many peptide bonds and is also called a polypeptide chain.
In simple words: Stored substances are important organic materials like carbohydrates, fats (lipids), and proteins that cells make and keep for energy or building blocks. Carbohydrates provide quick energy, lipids store a lot of energy, and proteins are essential for building and repairing cells.

🎯 Exam Tip: When detailing stored substances, define them generally, then explain each major type (carbohydrates, lipids, proteins) including their basic composition, structure, and function.

 

Question 4. Explain the importance of nectar & enzymes ?
Answer: Nectar and enzymes are both secretory substances in plants, meaning they are produced by cells but are not directly involved in the plant's nutrition or growth. They are secreted by specialized gland cells and play crucial roles:
1. **Enzymes:** These are proteins that act as biocatalysts, which means they speed up various chemical reactions (metabolic activities) in the plant. Enzymes break down large, complex food materials into smaller, simpler, and soluble molecules that the plant can use. Common examples include amylase, maltase, and protease.
2. **Nectar:** This is a sweet, sugary organic substance produced and released by nectar glands found in flowers. Nectar is rich in sugars such as sucrose, glucose, and fructose. Its primary importance is to attract insects and other animals, which then assist in the vital process of pollination, helping the plant reproduce.
In simple words: Enzymes are proteins that help plants break down food and carry out chemical jobs quickly. Nectar is a sweet liquid from flowers that attracts insects to help spread pollen, which is important for plant reproduction.

🎯 Exam Tip: When explaining the importance of biological substances, always describe their nature, origin, and specific function, providing examples where possible.

 

Question 5. What are alkaloids ? Write the source and importance of any five.
Answer: Alkaloids are nitrogen-containing excretory substances found in plants. They are typically insoluble in water but dissolve in alcohol. Often bitter or poisonous, many alkaloids have significant medicinal value.
The question asks to explain alkaloids and list the source and importance of any five excretory products. The various metabolic activities in plants produce substances not directly useful to them, which are stored in different plant parts. These include:
1. **Alkaloids:** These are nitrogenous excretory substances present in leaves, fruits, seeds, and bark. They can be bitter or poisonous and have medicinal importance.
* **Quinine:** Found in the bark of the Cinchona tree, it is used to treat malaria.
* **Morphine:** Derived from the opium poppy (Papaver somniferum), used to relieve pain and help with sleep.
* **Nicotine:** Found in the leaves of tobacco plants (Nicotiana tabacum), used to relieve pain and induce sleep.
* **Atropine:** Obtained from the roots of Atropa plants (Atropa belladonna), used in eye medicine and to stimulate the nervous system.
* **Reserpine:** From the roots of Rauwolfia serpentina, used as an antihypertensive and antipsychotic drug.
* **Theine (caffeine or theophylline):** Found in tea leaves (Camellia sinensis), acts as a stimulant.
* **Taxol:** From Taxus brevifolia (Gymnosperms), used as an anticancer agent.
2. **Gum:** Formed by the breakdown of cellulose in plant cell walls. It's a sticky substance that hardens into a crystalline structure when exposed to air. Gums from Acacia and Prosophis cineraria are common examples.
3. **Resins:** These are carbohydrate derivatives formed by the oxidation of fragrant oils. They are used in making varnishes and paints. Asafoetida, a resin from the tap roots of Ferula assafoetida, is used as a spice and in medicines.
4. **Tannins:** These bitter substances come from cell walls, fibers, bark, leaves, and unripe fruits of many plants. They are used in medicines, and in leather and ink production.
5. **Latex:** A white to yellowish-brown, dense liquid exuded by plants like Hevea brasiliensis. It's a mixture of resin, gum, stored food, and carbohydrates. Latex-yielding plants are called petroplants because their latex can be used to make petroleum.
6. **Mineral Crystals:** Inorganic waste products found in cell walls, vacuoles, or plant marrow. Examples include crystals of silica, calcium carbonate (cystoliths in fig and rubber plants), and calcium oxalate (raphides in Pistia, spheriphides in papaya).
In simple words: Alkaloids are special plant chemicals, often used in medicine, like quinine for malaria. Plants also make other useful products like gums, resins (for paints), tannins (for leather), and latex (for rubber). Some store mineral crystals as waste.

🎯 Exam Tip: When asked to explain a specific substance and then "any five" others, give a full explanation for the specific one, then list four more with their sources/importance. Ensure you provide examples for each where applicable.