- A. Cell
- B. Protoplasm
- C. Cellulose
- D. Nucleus
(a) Cell
- A. Cell wall
- B. Nucleus
- C. Cell membrane
- D. Nuclear membrane
(c) Cell membrane
- A. Lysosome
- C. Mitochondria
- B. Ribosome
- D. Nucleus.
d) Nucleus
- A. Endoplasmic reticulum
- B. Golgi complex
- C. Centriole
- D. Nucleus
(c) Centriole
- A. Tissue
- B. Nucleus
- C. Cell
- D. Cell organelle
The suitable term for the various components of a cell is cell organelle. Cell organelles are specialized structures within the cell that perform specific functions necessary for the cell to survive and function properly. Examples of cell organelles include the nucleus, mitochondria, chloroplast, endoplasmic reticulum, Golgi apparatus, lysosomes, and ribosomes. Each organelle has a distinct structure and carries out particular tasks such as energy production, protein synthesis, storage, or transport of materials. The term organelle literally means a small organ, which reflects how these structures work like tiny organs within the cell to maintain life processes. Understanding cell organelles is fundamental to cell biology as they are the functional units that enable cells to perform all necessary activities for growth, metabolism, and reproduction.
False. Animal cells do not have a cell wall. Only plant cells have a cell wall. The cell wall is a rigid outer layer found in plant cells that provides structural support, protection, and maintains the shape of the plant cell. Animal cells lack this cell wall and instead have only a cell membrane, which is a flexible, selectively permeable layer that controls the movement of substances in and out of the cell. This is one of the key differences between plant and animal cells.
True. Salmonella is a unicellular bacterium. Bacteria are prokaryotic organisms that consist of a single cell, meaning they are unicellular. Salmonella is a genus of rod-shaped bacteria that can cause food poisoning and other infections in humans and animals. Despite being microscopic and consisting of only one cell, bacteria like Salmonella are capable of carrying out all life processes including nutrition, respiration, growth, and reproduction.
False. The cell membrane is not fully permeable. The cell membrane is selectively permeable, also called semi-permeable. This means that the cell membrane allows some substances to pass through it while preventing others from crossing. The cell membrane controls which molecules and ions can enter or exit the cell based on the cell's needs. This selective permeability is crucial for maintaining the internal environment of the cell and protecting it from harmful substances.
True. Only plant cells have chloroplasts. Chloroplasts are specialized organelles found exclusively in plant cells and some algae. These organelles contain the green pigment chlorophyll and are responsible for photosynthesis, the process by which plants convert light energy into chemical energy in the form of glucose. Animal cells do not have chloroplasts because they obtain their energy by consuming food rather than producing it through photosynthesis.
True. The human stomach is an organ. An organ is a structure made up of different types of tissues that work together to perform a specific function. The stomach is composed of muscle tissue, epithelial tissue, and connective tissue, all of which work together to store food and break it down through mechanical and chemical digestion. The stomach is therefore a true organ of the digestive system.
False. Ribosomes are small organelles without a membrane. Ribosomes are non-membrane-bound organelles found in all cells, both prokaryotic and eukaryotic. They are composed of ribosomal RNA and proteins and are responsible for protein synthesis. Because ribosomes lack a surrounding membrane, they are classified as non-membrane-bound organelles, unlike organelles such as the mitochondria or endoplasmic reticulum which have membranes.
Transporting channel – Endoplasmic reticulum. Suicidal bag – Lysosome. Control room – Nucleus. Power house – Mitochondria. Food producer – Chloroplast. These are the correct matches between the cell organelles and their functions. The endoplasmic reticulum transports materials throughout the cell, lysosomes contain digestive enzymes and are called suicidal bags because they can destroy the cell if they rupture, the nucleus controls all cell activities, mitochondria produce energy through cellular respiration, and chloroplasts produce food through photosynthesis in plant cells.
Macroorganism.
Organ
Animal cell.
Respiration.
- A. Both A and R are true
- B. Both A and R are false
- C. A is true but R is false
- D. A is false but R is true
(a) Both A and R are true
- A. Both A and R are true
- B. Both A and R are false
- C. A is true but R is false.
- D. A is false but R is true.
(a) Both A and R are true
The cell wall in plant cells has several important functions. It provides protection to the plant cell by acting as a protective framework that shields the delicate cell membrane and internal structures from damage. The cell wall maintains the shape and rigidity of the plant cell, giving plants their structural support and allowing them to stand upright. Additionally, the cell wall provides mechanical strength to the plant tissue, allowing plants to withstand external pressures and stresses. The cell wall is made of cellulose, a strong and rigid material that makes it much more durable than the cell membrane alone.
The chloroplast is the organelle that uses energy from sunlight to make starch. Chloroplasts are specialized organelles found in plant cells that contain the green pigment chlorophyll. During photosynthesis, chloroplasts capture light energy from the sun and use it to convert carbon dioxide and water into glucose, which is then converted into starch for storage. This process is essential for plants as it provides them with the energy and organic compounds needed for growth and survival.
The main components found inside a nucleus are the nuclear envelope, nucleolus, and chromatin body. The nuclear envelope is the double membrane that surrounds the nucleus and controls the movement of materials between the nucleus and the cytoplasm. The nucleolus is a dense region within the nucleus where ribosomal RNA is synthesized and ribosomal subunits are assembled. The chromatin body consists of DNA and proteins that are loosely arranged in the nucleus and contain the genetic information of the cell. During cell division, the chromatin condenses to form visible chromosomes.
The cell membrane acts as a boundary that separates the internal contents of the cell from the external environment. It protects the cell by controlling what enters and exits the cell. The cell membrane is selectively permeable, meaning it allows certain substances to pass through while preventing others from entering or leaving. This protective barrier is essential for maintaining the cell's integrity and allowing it to function properly.
Lysosomes are known as scavengers of the cell because they contain powerful digestive enzymes that break down and remove waste materials, damaged organelles, and dead cells. When a cell part becomes old or damaged, lysosomes engulf it and digest it completely, cleaning up the cell. This process of breaking down and removing cellular waste is similar to how scavengers clean up unwanted material, which is why lysosomes are called the scavengers of the cell. They play a crucial role in maintaining cell health and preventing the accumulation of harmful debris.
Yes, I agree with the statement that a virus is not an organism. A virus exhibits a unique characteristic where it behaves like a living thing inside the body of a host cell but acts like a non-living thing outside the host. This dual nature makes it difficult to classify as a true organism. Viruses lack the fundamental structures found in all living cells, including a cell wall, cell membrane, cytoplasm, and organelles. They cannot perform life processes independently and must rely on a host cell to reproduce. A virus consists only of genetic material (DNA or RNA) surrounded by a protein coat. Since viruses cannot carry out life functions on their own and lack the basic cellular structures that define organisms, they are not considered true living organisms but rather infectious particles that exist at the boundary between living and non-living matter.
Cell is the basic structural and functions unit of life.
It is the building unit of living organism.
A group of cells form a tissue which forms the organ and organ systems.
This helps a living organism to do its functions. Hence cell is very important for us.
Distinguish between the following pairs
Smooth ER and Rough ER
Cell wall and cell membrane
Chloroplast and mitochondria
Smooth ER (Endoplasmic Reticulum)
It is smooth due to absence of Ribosomes.
It helps in transport of steroids and lipids.
Rough ER (Endoplasmic Reticulum)
It is’rough due to presence of Ribosomes.
It helps in protein synthesis
Cell wall
It is seen only in plant cells.
It is made of cellulose.
Cell membrane
It is seen in plant and animal cells.
It is made of proteins and lipids.
Chloroplast
It is a organelle seen only in plant cells (green plants)
It helps in synthesis and storage of starch.
Mitochondria
It is a organelle seen in plant and animal cells.
It is the centre of respiration in a cell and produces energy.
The correct sequence from cell to organism is: Cell → Tissue → Organ → Organ System → Organism. This hierarchical organization shows how cells combine to form tissues, tissues organize into organs, organs work together in organ systems, and finally organ systems function together to create a complete living organism.
The nucleus is a membrane-bound organelle found in the cytoplasm of both plant and animal cells. It is surrounded by a double-layered nuclear envelope that controls the movement of materials between the nucleus and cytoplasm. Inside the nucleus, there are one or two nucleoli, which are sites of ribosome production, and a chromatin body composed of DNA and proteins. The chromatin body stores all the genetic information of the cell in the form of genes. The nucleus performs several critical functions in the cell. It controls all the metabolic processes and chemical reactions that occur inside the cell by regulating gene expression. The nucleus is responsible for the inheritance of characteristics from one generation to another through the transmission of genetic material during reproduction. During cell division, the chromatin condenses into visible chromosomes that carry genetic instructions. The nucleus essentially acts as the control center of the cell, directing all cellular activities and ensuring the continuity of life through heredity.
Cell
Tissue
Organ
Neuron
Xylem
Lungs
RBC
Adipose
Brain
WBC
Muscle
Leaf
Ovum
Squamous
Hand
Phloem
Heart
Cartilage
First, I'll start with understanding that the cell is the basic unit of all living organisms. All living things are made up of one or more cells. Based on the number of cells, organisms can be classified into two categories: unicellular organisms, which consist of a single cell, and multicellular organisms, which are composed of many cells working together. In multicellular organisms, cells organize into tissues, tissues combine to form organs, and organs work together in organ systems to help the organism function properly. I have learned that plant cells and animal cells have both similarities and differences. The cell wall is a rigid structure found only in plant cells that provides structural support, while the cell membrane is present in all cells and controls the movement of substances. Plant cells contain chloroplasts for photosynthesis, which animal cells lack. Various organelles within the cell, such as mitochondria for energy production, ribosomes for protein synthesis, endoplasmic reticulum for transport, Golgi bodies for packaging, and lysosomes for digestion, each perform specific functions that are essential for the cell to survive and carry out its activities. The nucleus serves as the controlling center of the cell, directing all cellular processes and storing genetic information that determines the characteristics of the organism.
The three organelles are as follows
Chloroplasts:
They are green organelles seen in plant cells only.
They can prepare food using sun is energy and photosynthesize since they contain the pigment chlorophyll.
They absorb the radiant energy of the sun and convert it to chemical energy to be used by plants and animals.
Golgi Complex:
They are cell organelles which consist of membrane bound sacs stacked on top of one another and have associated secretory vesicles.
Golgi complex helps in production of secretory substances, packaging and secretion.
Mitochondria:
It is a oral double membrane bounded organelle.
Aerobic respiration occurs in mitochondria and energy is released. Hence mitochondria is called as power house of the cell
The energy produced is used for metabolic activities of the cell.
This is an animal cell, which is the basic structural and functional unit of animal bodies. The animal cell is enclosed by a cell membrane that controls the passage of materials in and out of the cell. Unlike plant cells, animal cells lack a rigid cell wall, having only the flexible cell membrane as their outer boundary. Animal cells contain various organelles that perform specific functions necessary for cell survival and activity. These organelles include mitochondria, which produces energy for the cell; the Golgi apparatus, which packages and transports proteins; ribosomes, which synthesize proteins; and the endoplasmic reticulum, which aids in transport and synthesis. A significant difference between animal cells and plant cells is that animal cells contain centrioles, which are small cylindrical structures involved in cell division, whereas plant cells do not have centrioles. Animal cells also lack chloroplasts, which are present in plant cells and are responsible for photosynthesis. The nucleus is the controlling center of the animal cell, containing the genetic material that directs all cellular processes and activities.
A virus is called acellular because it lacks the fundamental structures and components that define a cell. A virus consists only of a protein coat on the outside and genetic material (DNA or RNA) on the inside. It does not possess a cell wall, cell membrane, cytoplasm, or any organelles that are characteristic of living cells. Since viruses lack these essential cellular components and cannot carry out life processes independently, they are classified as acellular entities. They can only reproduce and function inside a host cell by taking over the host's cellular machinery. This is why viruses are described as acellular rather than cellular organisms.
Living things: Living things use energy. They move or change shape.
Eg: Humans, insects, plants, animals etc.
Non-living things:
Do not move by themselves, grow or reproduce.
Eg: Rocks, car, pencils etc.
Some of the important functions of life that all living organisms display are reproduction, which is the ability to produce new individuals of the same species; response to stimuli, which is the ability to react to changes in the environment; growth, which is the increase in size and complexity; movement, which is the ability to change position or move parts of the body; and excretion, which is the removal of waste products from the body.
Yes, an individual cell is living. Cells are the basic units of life and are considered the smallest living things. A single cell can perform all the functions of life, including metabolism, growth, reproduction, response to stimuli, and excretion. Even unicellular organisms like bacteria and amoeba consist of just one cell and are living things. Cells are found in plants, animals, and bacteria, and they exhibit all the characteristics that define living organisms.
Various organelles found in cells include the vacuole, which stores water, nutrients, and waste materials; the lysosome, which contains digestive enzymes for breaking down waste; the endoplasmic reticulum, which is involved in protein and lipid synthesis and transport; the Golgi apparatus, which packages and modifies proteins; the mitochondria, which produces energy for the cell through cellular respiration; and the chloroplast, which is found in plant cells and is responsible for photosynthesis. Each of these organelles has specific functions that contribute to the overall functioning of the cell.
Organs
Heart (Cardiovascular)
Lungs (Pulmonary)
Blood vessels – Arteries
Blood vessels – Veins
Functions
Pumps oxygenated and deoxygenated blood on different sides.
In oxygen from incoming air enters the blood and carbon-di-oxide, a waste gas from the metabolism, leaves the blood.
Carry blood away from the heart.
Carry blood back to the heart.