Chapter-5 The Fundamental Unit of Life Extra Questions

Explanation:

Since they are unable to metabolise or multiply on their own, viruses are seen as being in the middle of the two categories of life and death. A host is necessary for all of the virus's operations. Viruses can be stored as compounds that resemble crystals. Millions of viral cells are gathered together to form virus crystals.

Explanation:

Answer is A cell will swell up if  (b) The concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell.

Water from the surroundings enters the cell by osmosis and causes the cell to swell up when the concentration of water molecules in the surrounding medium is higher than the concentration of water molecules in the cell.

Explanation:

Chromosomes are made up of (c) DNA and protein

The thread-like components known as chromosomes are found in the nucleus of both animal and plant cells. Protein and a single molecule of deoxyribonucleic acid make up each chromosome (DNA). DNA is passed down from parents to children and contains the precise instructions that give each kind of living thing its individuality.

Explanation:

Answer is (c) (iii) and (iv) are not the fnctions of ribosomes.

Ribosomes are known as "protein factories" since they are where proteins are made. Proteins are enzymes. Option iii) and iv) are false statements because the ribosome does not make hormones or carbohydrates.

Explanation:

Answer is (c) ) it can provide energy
Mitochondria is known as “the powerhouse of the cells”. As the mitochondria are where energy is made, choice c has nothing to do with the endoplasmic reticulum.

Explanation:

Answer is (a) Movement of water molecules from a region of higher concentration to a region of lower concentration through a semipermeable membrane. This option is correct.
Water molecules travel through a semipermeable membrane during osmosis, a special type of diffusion, from an area of higher concentration to a region of lower concentration. Option b) Diffusion is the term for the movement of solvent molecules from a higher concentration to a lower concentration.

Explanation:

Answer is (b) the shrinkage of the cytoplasm in a hypertonic medium is known as Plasmolysis.
Osmosis causes water loss in living plant cells, which causes the contents of the cell to shrink or contract away from the cell wall. Plasmolysis is the name given to this process. Plant cells have a tendency to move water to their surroundings when they contain more water than the surrounding tissue, which causes plasmolysis and causes the cell to shrink.

Explanation:

Answer is (c) Lysosome is covered by a single membrane among the following options.
As double-layered membranes cover mitochondria, vacuoles, and plastids, the lysosome is the correct answer.

Explanation:

Answer is (d) Cytoplasm is referred to as protoplasm is the false sentence among the following options.

The protoplasm that covers the nucleus in a cell is known as cytoplasm. Thus, option d is a false sentence because cytoplasm is not referred to as protoplasm.

Explanation:

Answer is (a) Enzymes packed in Lysosomes are made through RER (rough endoplasmic reticulum) is the correct sentence among the following list of sentences.
Ribosomes, which are found on the surface of RER, are in charge of the creation of proteins, which are made up of enzymes. Hence, choice a) is right. No part in the synthesis of lipid is played by the rough endoplasmic reticulum. Similarly, the breakdown of the plasma membrane is unrelated to the endoplasmic reticulum. In prokaryotes, the nucleoid is an unidentified nuclear region.

Explanation:

Answer is (c) Smooth endoplasmic reticulum is the Which cell organelle plays a crucial role in detoxifying many poisons and drugs in a cell.

In the liver cells of vertebrates, SER is crucial for the detoxification of numerous toxins and medications.

Explanation:

Answer is The proteins and lipids, essential for building the cell membrane, are manufactured by  (a) rough endoplasmic reticulum
In the synthesis of lipids and proteins, the endoplasmic reticulum is crucial. RER creates proteins, while SER produces lipids

Explanation:

Answer is The undefined nuclear region of prokaryotes are also known as (d) nucleoid

A prokaryotic cell's nucleoid is defined as the area that houses most or all of the genetic material. The term "prokaryotic chromosome" refers to this substance. Both the nucleus and the nucleoid contain DNA. As a result, the nucleus' and nucleotide's functions are essentially identical.

Explanation:

Answer is (d) golgi apparatus
Proteins, lipids, and carbohydrates are only a few of the many macromolecules that are packaged and transported by the golgi apparatus.

Explanation:

Answer is (d) Locomotion
Vacuoles are in charge of storing things, keeping cells stiff and turgid, and excreting waste. Specialist organelles that are located outside of the cytoplasm are responsible for locomotion. Although vacuoles can be found inside the cytoplasm, option d) is false.

Explanation:

Response is Endocytosis (b) is the process through which amoebas obtain their food.

A live cell takes in material by the process of endocytosis, which involves penetrating its membrane to form a vacuole. The process by which substances are brought inside the cell from the outside is known as endocytosis. The process by which membrane-bound vesicles containing biological elements are transported to the cell membrane is known as exocytosis. The contraction of a plant cell's protoplast as a result of water loss is known as plastolysis.

Explanation:

Answer is (a) Bacteria has cell wall which is not made of cellulose.
As plants, hydilla, mango trees, and cacti all have cellulose in their cell walls. Bacteria have a polymer called peptidoglycan as part of their cell walls.

Explanation:

Answer is (b) golgi apparatus

 The Golgi body is visualised via the silver nitrate stain, which turns it black against a light yellow backdrop.

Explanation:

Answer is (c) mitochondria
The organelles with distinct DNA, known as mitochondrial DNA and chloroplast DNA, are mitochondria and chloroplasts.

Explanation:

Food in plants is produced inside Chloroplast hence Chloroplast is known as kitchen of the cell.

Explanation:

Lipid molecules in the cell are synthesized by (a) smooth endoplasmic reticulum

The smooth endoplasmic reticulum, often known as SER, plays a role in a number of metabolic activities. Steroids, phospholipids, and lipids are all synthesised by it. The testes, ovaries, and sebaceous glands are only a few examples of the cells that generate these substances and have a lot of smooth endoplasmic reticulum.

Explanation:

Answer is (b) Virchow

According to Virchow, who developed the Scheiden-Schwann cell theory, all cells develop from pre-existing cells, or omnis cellula-e-cellula.

Explanation:

Answer is (a) Schleiden and Schwann

The cell theory, which claimed that cells are the fundamental building block of life and that all plants and animals are composed of them, was first put forth by Schleiden and Schwann. The classical cell theory was proposed in 1839 by Theodor Schwann. There are three parts to this idea. According to the first section, cells make up all organisms. In the second section, it is said that cells are the fundamental components of life.

Explanation:

Answer is (b) ribosomes

The two different types of cells are prokaryotes and eukaryotes. Organelles that are attached to membranes are present in eukaryotic cells but not in bacterial cells.The only organelle that is present in both prokaryotic and eukaryotic cells is the ribosome.

Explanation:

Answer is (a) ribosome
Ribosomes are organelles without a membrane, whereas Golgi bodies, chloroplasts, and the nucleus are membrane-bound organelles.

Explanation:

Answer is (a) 10–6 m
103 millimetres in size 10-6 millimetres Nanometer: 10-9 m r.

Explanation:

Answer is ysosomes arise from (b) golgi apparatus
Secretion, packaging, and modification of proteins are the primary functions of the golgi apparatus. Moreover, it contributes to the creation of fresh membranes and lysosomes.

Explanation:

Answer is (c) Leeuwenhoek
The first person to observe cells was Robert Hook, but he did it with a dead cork cell; it was Leeuwenhoek who used a microscope to see a living cell.

Explanation:

Answer is (d) ) Plants' plasma membranes contain the sugar chitin is the odd one out.

The claim that sugar is present in plasma membrane is false, whereas the other claims are accurate. The plasma membrane of the plant contains cellulose.

Explanation:

Lysosomes are the organelles that house the digestive enzymes. The body's own cell digestion is started by the digestive enzymes that are released when lysosomes burst. This is why they are referred to as "suicidal sacks".

Explanation:

Absolutely, the basic unit of an organism is a cell. Similar-functioning cells combine to create tissues, which then develop into organs and organ systems. It creates an organism. Each life phase in a unicellular creature is carried out by a single cell.

Explanation:

As you wash clothing for a long period, the hypertonic nature of soap solution causes the water to migrate out of the cells in your hand, which causes the fingers to shrink.

Explanation:

Animals are the only organisms that undergo endocytosis because they lack a cell wall. As a result, in animals as opposed to plants, the flow of chemicals within the cell is simpler.

Explanation:

Upon the consumption of salt solution Dehydration occurs as a result of the osmosis process. This is what causes someone who drinks salt solution to vomit.

Explanation:

Ribosomes are a non-membranous cell organelle. They are small, spherical structures composed of RNA and protein, and are responsible for synthesizing proteins in the cell. While they may associate with the endoplasmic reticulum, ribosomes themselves do not have a membrane-bound structure.

Explanation:

The absorption of digested food and water occurs primarily in the small intestine through a variety of mechanisms:

1.Passive Diffusion: Small, nonpolar molecules such as fatty acids and glycerol can diffuse across the membrane of the intestinal epithelial cells and into the bloodstream.

2.Facilitated Diffusion: Some larger molecules such as glucose and amino acids require the assistance of carrier proteins to cross the intestinal epithelial membrane.

3.Active Transport: Some molecules, such as sodium ions, are actively transported across the membrane by carrier proteins, which require energy in the form of ATP.

4.Endocytosis: Large molecules such as proteins are taken up into the intestinal epithelial cells through a process called endocytosis, in which the cell membrane surrounds the molecule and engulfs it.

Water is also absorbed primarily in the small intestine, through the process of osmosis, in which water moves from an area of low solute concentration (the intestinal lumen) to an area of high solute concentration (the bloodstream). The absorption of water is enhanced by the presence of electrolytes such as sodium and chloride ions, which create an osmotic gradient that drives the movement of water across the intestinal epithelium.

Once absorbed, nutrients and water are transported via the bloodstream to the liver, where they are processed and distributed to other organs and tissues throughout the body.

The process of osmosis allows water in swallowed food to be absorbed, and the process of diffusion allows digested food to flow into the blood vessels in the small intestinal wall.

Explanation:

Vegetables release water after being salted because of osmosis. The environment outside becomes hypertonic when salt is added. In comparison to the concentration of water inside the cell, the concentration of water outside is therefore lower. Exosmosis causes the veggies to lose water as a result of this.

Explanation:

(c) a and b both are correct.
When the medium around the cell is hypotonic, water flows inside. Cells swell as a result of this. RBCs easily enlarge and rupture because they lack a plasma membrane. Plant cells are protected from bursting by a cell wall.

Explanation:

Bacteria have tiny vesicles connected to their plasma membranes. The pigment in these vesicles can absorb sunlight to power photosynthesis.

Explanation:

(A) – (B) (a) Smooth endoplasmic reticulum – (iv) Detoxification (b) Lysosome – (v) Suicidal bag and nucleolus (c) Nucleoid – (iii) Bacteria (d) Food vacuoles -(i) Amoeba (e) Chromatin material – (ii) Nucleus

Explanation:

Chromoplasts, chloroplasts, and leucoplasts are different types of plastids, which are organelles found in plant cells.

Chromoplasts are responsible for giving color to different parts of plants, and are commonly found in fruits, flowers, and roots. Examples include the red color in tomatoes, the orange color in carrots, and the yellow color in daffodils.

Chloroplasts are responsible for photosynthesis, and are mainly found in the leaves of plants, as well as in green stems and unripe fruit.

Leucoplasts are involved in various metabolic processes, such as starch synthesis, and are mainly found in non-photosynthetic tissues, such as the roots, tubers, and seeds of plants.

Explanation:

(a) Transporting channels of the cell - Endoplasmic reticulum

(b) Power house of the cell - Mitochondria

(c) Packaging and dispatching unit of the cell - Golgi apparatus

(d) Digestive bag of the cell - Lysosomes

(e) Storage sacs of the cell - Vacuoles

(f) Kitchen of the cell - Chloroplasts (in plant cells only)

(g) Control room of the cell – Nucleus

Explanation:

Bacterial cells and onion peel cells are both types of cells but they have some significant differences:

1.Shape and size: Bacterial cells are usually much smaller and simpler in structure than onion peel cells. Bacteria are typically spherical, rod-shaped or spiral-shaped, and their size can range from 0.5 to 5 micrometers. Onion peel cells, on the other hand, are rectangular in shape and are larger than bacterial cells, typically measuring around 0.2-0.5 millimeters in length.

2.Cell wall: Bacterial cells have a cell wall that is made up of peptidoglycan, which gives them protection from the outside environment. In contrast, onion peel cells have a cell wall made up of cellulose, which gives them rigidity and protection.

3.Nucleus: Bacterial cells do not have a true nucleus. Instead, their genetic material is contained within a region called the nucleoid. Onion peel cells have a distinct nucleus which contains the genetic material.

4.Membrane-bound organelles: Bacterial cells lack membrane-bound organelles, whereas onion peel cells contain various organelles like mitochondria, endoplasmic reticulum, Golgi apparatus, etc.

5.Reproduction: Bacterial cells reproduce by binary fission, where the cell divides into two identical daughter cells. Onion peel cells, on the other hand, reproduce by mitosis, where the parent cell divides into two daughter cells, each with a full set of genetic material.

Explanation:

Carbon dioxide (CO2) and water (H2O) move in and out of the cell through the process of diffusion. Diffusion is the movement of molecules or ions from an area of higher concentration to an area of lower concentration. The cell membrane, which is composed of a phospholipid bilayer, allows small, non-polar molecules such as CO2 and H2O to diffuse across it.

In the case of CO2, it diffuses from a region of high concentration (such as the atmosphere or the surrounding water) into the cell where the concentration is lower due to photosynthesis. Similarly, in the case of H2O, it can diffuse into and out of the cell depending on the concentration gradient, as well as other factors such as osmotic pressure.

In addition to diffusion, some substances like CO2 and H2O can also enter or exit the cell through specialized transport proteins in the cell membrane, such as aquaporins or carbonic anhydrases, which can facilitate their movement across the membrane in a specific direction and at a faster rate than simple diffusion.

Explanation:

Amoeba is a unicellular organism that obtains its food through a process called phagocytosis. Phagocytosis is the process of engulfing and ingesting food particles by forming a food vacuole around the particles.

When an amoeba senses the presence of food, it extends its pseudopodia (temporary projections of the cell membrane) towards the food particle. The pseudopodia surround the food particle and fuse together, forming a food vacuole inside the cell. The food vacuole then moves towards the center of the cell where it fuses with a lysosome (an organelle containing digestive enzymes). The digestive enzymes break down the food particle, and the resulting nutrients are absorbed by the cell for energy and growth.

Amoebas can feed on a variety of food sources, including bacteria, algae, and other small organisms.

Explanation:

The two organelles in a plant cell that contain their own genetic material and ribosomes are:

1.Chloroplasts: Chloroplasts are the organelles responsible for photosynthesis in plant cells. They contain their own genetic material in the form of circular DNA molecules, which are organized into nucleoids. Chloroplasts also have their own ribosomes, which are responsible for synthesizing some of the proteins required for photosynthesis.

2.Mitochondria: Mitochondria are the organelles responsible for cellular respiration in plant cells. They contain their own genetic material in the form of circular DNA molecules, which are organized into nucleoids. Mitochondria also have their own ribosomes, which are responsible for synthesizing some of the proteins required for respiration.

Explanation:

Lysosomes are also known as "scavengers of the cells" because they are responsible for breaking down and digesting unwanted or non-functional cellular components, such as old organelles, proteins, and cellular debris. They contain a variety of hydrolytic enzymes that are capable of breaking down these materials into simpler molecules that can be recycled or excreted by the cell.

Explanation:

The nucleus is the cell organelle that controls most of the activities of the cell. It contains the cell's genetic material, which is organized into chromosomes, and is responsible for regulating the expression of genes and controlling the cell's growth and reproduction.

The nucleus is surrounded by a double membrane called the nuclear envelope, which separates its contents from the rest of the cell. The nuclear envelope contains nuclear pores that allow the passage of molecules such as RNA and proteins in and out of the nucleus.

Explanation:

(a) The most common type of plastid in roots of the plant is leucoplasts. Leucoplasts are responsible for storing starch, oils, and proteins in the root cells.

(b) The most common type of plastid in leaves of the plant is chloroplasts. Chloroplasts contain the pigment chlorophyll and are responsible for photosynthesis in the plant.

(c) The most common type of plastid in flowers and fruits of the plant is chromoplasts. Chromoplasts contain pigments other than chlorophyll, such as carotenoids and anthocyanins, which give flowers and fruits their bright colors.

Explanation:

Plant cells possess a large-sized vacuole for several reasons:

1.Storage of water and nutrients: The vacuole in plant cells can occupy up to 90% of the cell volume and is used to store water and nutrients such as ions, sugars, and amino acids. This storage function helps plants survive periods of drought or nutrient scarcity.

2.Maintenance of turgor pressure: The vacuole helps maintain turgor pressure in plant cells, which is important for the rigidity and support of plant tissues. When the vacuole is filled with water, it exerts pressure on the cell wall, which helps keep the cell rigid and maintain the overall shape of the plant.

3.Storage of waste products: The vacuole can also store waste products and toxic compounds, which helps protect the rest of the cell from damage. By storing these compounds in the vacuole, plant cells can avoid the harmful effects that would occur if they were allowed to accumulate in other parts of the cell.

Explanation:

Chromatin, chromatid, and chromosomes are all related to each other as follows:

1.Chromatin: The genetic material of a eukaryotic cell is composed of a complex of DNA, histone proteins, and other proteins called chromatin. During interphase, the time between cell divisions, when DNA is present in its uncondensed state in the nucleus.

2.Chromatid: A chromatid is one of two identical copies of a chromosome that are joined at a region called the centromere. Chromatids are formed during the S phase of the cell cycle when DNA replication occurs, and they remain joined until they are separated during cell division.

3.Chromosome: A chromosome is a structure composed of DNA and proteins that carries genetic information. A chromosome is formed from two identical sister chromatids that are joined together at the centromere. During cell division, the two sister chromatids separate from each other and become individual chromosomes that are distributed to the daughter cells.

So, chromatin is the uncondensed form of DNA, which condenses to form a chromosome. A chromosome is composed of two identical sister chromatids joined together at the centromere. The sister chromatids separate during cell division and become individual chromosomes.

Explanation:

The consequences of the following conditions are:

(a) A cell containing higher water concentration than the surrounding medium:

If a cell contains a higher water concentration than its surrounding medium, it is said to be in a hypotonic solution. Water molecules will move from the surrounding medium to the cell to equalize the concentration gradient. As a result, the cell will swell up and may eventually burst or lyse due to excessive water intake. This phenomenon is known as osmotic lysis.

(b) A cell having low water concentration than the surrounding medium:

If a cell has a lower water concentration than its surrounding medium, it is said to be in a hypertonic solution. Water molecules will move from the cell to the surrounding medium to equalize the concentration gradient. As a result, the cell will shrink or crenate due to loss of water. In extreme cases, the cell may die due to dehydration.

(c) A cell having equal water concentration to its surrounding medium:

If a cell has the same water concentration as its surrounding medium, it is said to be in an isotonic solution. There will be no net movement of water molecules between the cell and the surrounding medium. The cell will remain in its normal state without any changes in shape or size. Isotonic conditions are important for maintaining the normal functioning of cells, as they ensure a balance between water uptake and loss.

Explanation:

(A) The nucleus controls the cell's development and function.

(b) The endoplasmic reticulum's materials are packaged in the Golgi apparatus.

(c) Microbes can survive hypotonic external media without bursting thanks to the cell wall's resilience.

(d) The cytoplasm is the site of a variety of biochemical processes required for the maintenance of life.

(e) The fluid residing inside the nucleus is known as the nucleoplasm.

Explanation:

Plant cells and animal cells have many similarities, but there are also some key differences between the two:

1.Cell Wall: The cellulose-based stiff cell wall that surrounds the cell membrane in plant cells acts as both a structural support and a layer of protection. Cell walls are absent from animal cells.

2. Chloroplasts: Organelles in plant cells called chloroplasts are in charge of photosynthesis. Chlorophyll, a pigment that gives plants their green hue, is found in chloroplasts. Chloroplasts do not exist in animal cells..

3. Plant cells have a sizable central vacuole that houses waste materials, nutrients, and water. Vacuoles in animal cells may be tiny or less noticeable than those in plant cells.

4.Shape: Plant cells tend to be rectangular or box-like in shape, whereas animal cells are more irregular in shape.

5.Size: Plant cells are generally larger than animal cells.

6.Mitosis: Plant cells undergo cell division through a process called mitosis, which involves the formation of a cell plate during cytokinesis. Animal cells undergo cytokinesis by forming a cleavage furrow.

Explanation:

Explanation:

The genetic makeup of the cell is housed in an organelle called a eukaryotic nucleus, which is membrane-bound. The nuclear envelope, a bilayer membrane surrounding it, has nuclear pores that permit molecules to enter and exit the nucleus..

The eukaryotic nucleus contains several structures, including:

1. The membrane that encloses the nucleus is known as the nuclear membrane..

2.Nuclear pores: protein-lined channels that allow molecules to move in and out of the nucleus.

3.Nucleolus: a dense structure within the nucleus that is responsible for the production of ribosomes.

4.Chromatin: a complex of DNA and proteins that makes up the chromosomes.

5.Nucleoplasm: the fluid-like substance within the nucleus.

In contrast, a nucleoid is a region within a prokaryotic cell that contains the genetic material but is not surrounded by a membrane. The nucleoid is less organized than the eukaryotic nucleus and lacks many of the structures found in the nucleus, such as the nuclear membrane and nucleolus.

Explanation:

1. In eukaryotic cells, a network of membranes known as the endoplasmic reticulum (ER) is in charge of various functions, including the synthesis and modification of proteins and lipids as well as the transport of these molecules within the cell. The two types of ER are rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER).Rough endoplasmic reticulum (RER):

The RER appears "rough" under a microscope because ribosomes are adhered to its surface. The synthesis of proteins intended for secretion or for insertion into the cell membrane is carried out by these ribosomes. The folding and modification of proteins as well as the construction of protein complexes depend on the RER..

2.Smooth endoplasmic reticulum (SER):

Under a microscope, the SER is "smooth" and devoid of ribosomes. Steroids and phospholipids, among other lipids, are synthesised by the SER. Moreover, it helps the cell detoxify medications and other toxic compounds.

The endoplasmic reticulum is crucial to membrane biogenesis. The ER is related to other organelles, such as the Golgi apparatus and the plasma membrane, and its membrane is continuous with the outer membrane of the nucleus. In the ER, proteins and lipids are created and changed before being packaged and transported to various areas of the cell. Vesicles from the ER membrane burst during this process, and they are subsequently moved to their intended organelles. Hence, the synthesis, modification, and transport of membrane proteins and lipids, which are necessary for the healthy operation of the cell, are carried out by the ER.

Explanation:

(a) Dry apricots will swell and become plump when placed in pure water for a period of time. Osmosis is the mechanism through which water is absorbed. They will osmotically lose water when put in a sugar solution, which will cause them to wrinkle and dry out once more.

(b) Water will osmotically exit a red blood cell when it is held in a concentrated saline solution, causing the cell to contract and become crenated. 

(c) When a cell's plasma membrane degrades, the cell is unable to regulate how chemicals enter and leave the cell. This may result in cell death or the expulsion of the contents of the cell into the environment.

(d) When sugar syrup is added to rheo leaves after they have been boiled in water, the sugar syrup is absorbed by the leaves through the process of osmosis, making the leaves swollen and turgid..

(e) The cell's capacity to alter and package proteins and lipids for transport to other sections of the cell or for secretion will be impacted when the golgi apparatus is eliminated. This could result in the buildup of misfolded proteins in the endoplasmic reticulum, which can stress and dysfunctional cells.

Explanation: