Hi Everyone!! This article will share Cell Structure and Functions Questions & Answers.
In my previous post, I have shared Cell Structure and Functions Objective Type Questions that includes multiple-choice, true/false, matching, fill-ups, assertion and reason, etc.So, make sure to check that post as well.
Question 1: Cell is called the structural and functional unit of life. Explain.
Answer: Every living thing is made up of cells and a cell represents the lowest level of organization at which life can exist. Hence, it is called the structural unit of life.
It is the single-cell that performs all the vital functions such as respiration, nutrition, transportation, excretion and reproduction for the whole organism. Hence, it is called the functional unit of life.
Question 2: What does Cell Theory state?
Answer: The Cell Theory states that:
i. All living organisms are made of cells.
ii. In all living things, the cell is the fundamental unit of structure and function.
iii. All cells arise from pre-existing cells.
Must Read:
Question 3: What is a gene?
Answer: A gene is a sequence of nucleotides that expresses a particular trait or a characteristic. It is responsible for the transmission of characteristics from parents to the next generation.
Question 4: Classify cells on the basis of presence or absence of organelles and arrangement of nucleus.
Answer: On the basis of presence or absence of organelles and arrangement of nucleus, cells can be of two types -Prokaryotic cells
Eukaryotic cells
Question 5: Classify organisms on the basis of number of cells present.
Answer: On the basis of number of cells present, organisms can be classified into two types –
Unicellular organisms
Multicellular organisms
Cell Structure and Functions Questions & Answers
Question 6: Give reasons:
(a) The cells found in an organism can come in a variety of different sizes and shapes.
Answer: The cells in an organism can come in a variety of different sizes and shapes to perform a specific function in the body. For example – Amoeba keeps changing its shape to move and engulf food.
(b) The white blood cells are irregular in shape.
Answer: White blood cells protect us from foreign invaders or pathogens like bacteria, viruses, etc. as they are a part of the immune system. They eliminate pathogens by ‘eating’ them (phagocytosis). WBCs keep circulating in the blood stream but are usually required at the site of infection inside tissues. So, for this to happen, they have to migrate through the walls of small blood vessels and find their way in tissues. This can only occur because they are able tochange their shape.
(c) The red blood cells are round and concave.
Answer: They are round and concave so that they can easily squeeze through the narrow blood capillaries.
(d) The nerve cells are elongated and highly branched.
Answer: The nerve cells are elongated and highly branched because the branches help in the passage of chemical and electrical messages throughout the body.
(e) Spikes are present on the pollen grains.
Answer: This is because, during pollination, the spikes help the pollen grains to stick to the body of the pollinating insect or animal.
Question 7: Why are bacteria classified as prokaryotic organisms?
Answer: Bacteria lack a membrane-bound nucleus and other internal organelles like mitochondria and Golgi bodies. Therefore, they are classified as prokaryotic organisms.
Question 8: Why are vacuoles of animal cells much smaller in comparison to those present in plant cells?
Answer: In animal cells, the vacuole helps in storing various substances such as food, enzymes and waste products for a short period of time. However, in plant cells, its main function is storage and maintaining the structure of the cell. Hence, plant cells have a large centralised vacuole.
Question 9: Why do muscle cells have a larger number of mitochondria compared to other cells of the body?
Answer: Mitochondria are the powerhouse of cells and are chiefly responsible for the synthesis of energy in the form of ATP. The number of mitochondria in a cell depends on how much energy the cell needs to produce. Since, physical activities and movement involve the use of muscles which will require a lot of energy, the number of mitochondria in muscle cells is higher.
Question 10: What would happen if there were no vacuoles in a plant cell?
Answer: Vacuoles are the sites where a cell stores its food and it maintains the structure of the plant cell. So in the absence of vacuoles, the cell won’t be able to store food and maintain its structure, it may not be able to survive.
Cell Structure and Functions Questions & Answers
Question 11: Where are chromosomes found in a cell? State their function.
Answer: They are found in the nucleus of the cell and each chromosome carries genes that are responsible for some trait or characteristic. These genes transfer these characters from the parents to the offspring.
Question 12: A nucleus to a cell is what a brain is to our body. Justify.
Answer: A nucleus controls all the activities of a cell just like a brain does for our body.
Question 13: Why are mitochondria considered as the powerhouse of the cell?
Answer: This is because Mitochondria are responsible for the synthesis of adenosine triphosphate or ATP, the main energy-rich molecule used by the cells.
Question 14: Why are lysosomes known as suicide bags?
Answer: Lysosomes contain substances that help in the digestion of foreign bodies and worn-out cell parts. Hence, when necessary they can digest the entire contents of the cell. In this process, the lysosomes also get destroyed. Hence, lysosomes are called suicidal bags.
Question 15: Write any three main functions of a cell wall.
Answer:
i. Provides shape and rigidity.
ii. Protects the protoplasm.
iii. Involved in the movement of materials in and out.
Question 16: Differentiate between prokaryotic cells and eukaryotic cells based on the following criteria:
i. Size
ii. Chromosome
iii. Membrane bound organelle
Answer:
| Criteria | Prokaryotic cells | Eukaryotic cells |
| i. Size | Size of cell is generally small. | Size of cell is generally large. |
| ii. Chromosome | It contains single chromosome. | It contains more than one chromosome. |
| iii. Membrane bound organelle | Membrane bound cell organelles are absent. | Membrane bound cell organelles such as mitochondria; plastids, endoplasmic reticulum, etc. are present. |
Question 17: Differentiate between plant cells and animal cells.
Answer:
| Plant cells | Animal cells |
| They are usually larger in size. | They are comparatively smaller in size. |
| They contain a rigid cell wall in addition to cell membrane. | They lack cell wall and only show presence of plasma membrane. |
| These cells show the presence of plastids like chloroplasts. | These do not have plastids. |
| Most of the plant cells show presence of single large vacuole. | A single large vacuole is absent in animal cells however, they often show presence of many small vacuoles. |
| Centrioles and centrosomes are absent. | Centrioles and centrosomes are present. |
Question 18: What is Cytoplasmic streaming? Give its importance.
Answer: The movement of the fluid part of the cytoplasm within a cell is known as cytoplasmic streaming. It helps in the transportation of proteins, nutrients and organelles within the cell.
Question 19: Write a short note on:
(a) Golgi Bodies
Found located near the nucleus, Golgi bodies modify the proteins made by the ribosomes. They also help in transporting them to various organelles and plasma membrane.
(b) Ribosomes
Made up of ribosomal RNA and ribosomal proteins, these are small round particles that are found either attached to the surface of the endoplasmic reticulum or scattered in the cytoplasm. They are associated with protein synthesis.
(c) Centrioles and Centrosomes
Present only in animal cells, they play an important role in cell division.
(d) Plasma Membrane
It is a flexible boundary of a cell that separates a cell from its surroundings. It is responsible for the shape of the cell. Made up of proteins and lipids, the plasma membrane is porous in nature and allows the movement of substances, both inward and outward. However, it is semi-permeable and the movement of substance is highly regulated. Only some molecules can pass through it. Other molecules are only admitted at certain times and in limited amounts. Others are not allowed in at all. So, a plasma membrane helps in maintaining the integrity of the cell.
So, these were Cell Structure and Functions Questions & Answers.
FAQs
What is cell structure and function Short answer? ›
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions.
What are the 7 functions of a cell? ›- Protects the cell from physical injury.
- Gives the cell a sense of organisation.
- Keeps osmotic bursting at bay.
- It maintains the shape of the cell.
- Regulates the flow of information between cells.
- It regulates the expansion of cells.
- Provides protection against pathogens.
- What is the smallest cell?
- What is the smallest human cell?
- What is the largest single cell and how big is it?
- How many different types of cells can be found inside the human body?
- Which living organism has the most cells?
- Do any cells have natural color?
- What color is a nucleus?
Although cells come in diverse shapes, all cells have certain parts in common. These parts include the cell membrane, cytoplasm, ribosomes, cytoskeleton, and DNA.
What are cells made of? ›Cells are composed of water, inorganic ions, and carbon-containing (organic) molecules. Water is the most abundant molecule in cells, accounting for 70% or more of total cell mass. Consequently, the interactions between water and the other constituents of cells are of central importance in biological chemistry.
What are the 4 types of cells? ›- Epithelial Cells. These cells are tightly attached to one another. ...
- Nerve Cells. These cells are specialized for communication. ...
- Muscle Cells. These cells are specialized for contraction. ...
- Connective Tissue Cells.
What limits cell sizes and growth rates? Cell growth is limited by rates of protein synthesis, by the folding rates of its slowest proteins, and—for large cells—by the rates of its protein diffusion.
What is importance of cell? ›Cells provide structure and function for all living things, from microorganisms to humans. Scientists consider them the smallest form of life. Cells house the biological machinery that makes the proteins, chemicals, and signals responsible for everything that happens inside our bodies.
Who discovered cell? ›Initially discovered by Robert Hooke in 1665, the cell has a rich and interesting history that has ultimately given way to many of today's scientific advancements.
What is the largest cell? ›- The largest cell present in the human body is the ovum.
- It is one millimeter in diameter.
- In animals, follicle cells produce eggs in the female ovary.
Which is the smallest cell? ›
Mycoplasma gallicepticum, a parasitic bacterium which lives in the primate bladder, waste disposal organs, genital, and respiratory tracts, is thought to be the smallest known organism capable of independent growth and reproduction. The cell in the work is known as mycoplasma. Its diameter is 0.0001 mm. Q.
What is the smallest human cell? ›The smallest cell in the human body is the sperm (male gamete). Size of the sperm is 4 micrometers. Sperm is 20 times smaller than the ovum.
Why is a cell called a cell? ›Robert Hooke suggested the name 'cell' in 1665, from the Latin cella meaning storeroom or chamber, after using a very early microscope to look at a piece of cork. It is also said that he thought that the rectangular chambers looked like the cells in some monasteries.
What are the 4 basic needs of a cell? ›Some living things consist of a single cell. Like familiar organisms, they need food, water, and air; a way to dispose of waste; and an environment they can live in.
What is the role of DNA? ›What does DNA do? DNA contains the instructions needed for an organism to develop, survive and reproduce. To carry out these functions, DNA sequences must be converted into messages that can be used to produce proteins, which are the complex molecules that do most of the work in our bodies.
What is inside a cell? ›A cell consists of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm. Within the cytoplasm lie intricate arrangements of fine fibers and hundreds or even thousands of miniscule but distinct structures called organelles.
What makes a cell alive? ›All living organisms (whether they are bacteria, archaea or eukaryote) share several key characteristics, properties or functions: order, sensitivity or response to the environment, reproduction, growth and development, regulation (including homeostasis), energy processing, and evolution with adaptation.
What are the cell types? ›There are two distinct types of cells: prokaryotic cells and eukaryotic cells.
Who is the father of cell? ›The legacy of a founding father of modern cell biology: George Emil Palade (1912-2008)
What are 2 main types of cells? ›There are two main types of cells: prokaryotic cells and eukaryotic cells. Prokaryotic cells include bacteria and archaea. Prokaryotes—organisms composed of a prokaryotic cell—are always single-celled (unicellular). Prokaryotic cells don't contain a nucleus.
What is the most common cell? ›
Red blood cells (RBCs) are by far the most abundant type of cell in the human body, accounting for over 80 percent of all cells.
What is the definition of structure and function? ›Structure refers to something's form, makeup, or arrangement. Function refers to something's job, role, task, or responsibility.
What is cell short answer class? ›The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms. Cells are the smallest unit of life that can replicate independently, and are often called the "building blocks of life".
What is cell short answer computer? ›A cell is the intersection where a row and a column meet on a spreadsheet that starts with cell A1. In the following example, a highlighted cell is shown in a Microsoft Excel spreadsheet. D8 (column D, row 8) is the highlighted cell that's also known as the cell address and cell reference.
What is cell and cell address short answer? ›A cell reference, or cell address, is an alphanumeric value used to identify a specific cell in a spreadsheet. Each cell reference contains one or more letters followed by a number. The letter or letters identify the column and the number represents the row.
What is another name for a cell structure? ›An organelle (think of it as a cell's internal organ) is a membrane bound structure found within a cell.
What are the 4 types of structures? ›- Frame: made of separate members (usually thin pieces) put together.
- Shell: encloses or contains its contents.
- Solid (mass): made almost entirely of matter.
- liquid (fluid): braking fluid making the brakes.
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as biological organisms, minerals and chemicals.
What is the main part of cell? ›A cell consists of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm. Within the cytoplasm lie intricate arrangements of fine fibers and hundreds or even thousands of miniscule but distinct structures called organelles.
Who discovered cell? ›Initially discovered by Robert Hooke in 1665, the cell has a rich and interesting history that has ultimately given way to many of today's scientific advancements.
What are the two types of cell? ›
There are two main types of cells: prokaryotic cells and eukaryotic cells. Prokaryotic cells include bacteria and archaea. Prokaryotes—organisms composed of a prokaryotic cell—are always single-celled (unicellular). Prokaryotic cells don't contain a nucleus.
Who called it cell? ›The Origins Of The Word 'Cell' In the 1660s, Robert Hooke looked through a primitive microscope at a thinly cut piece of cork. He saw a series of walled boxes that reminded him of the tiny rooms, or cellula, occupied by monks. Medical historian Dr. Howard Markel discusses Hooke's coining of the word "cell."
What is an active cell? ›The active cell is the selected cell in which data is entered when you begin typing. Only one cell is active at a time. The active cell is the cell surrounded by a black border. Data can only be entered into the active cell.
What is formula bar? ›Alternatively referred to as a formula box, the formula bar is a section in Microsoft Excel and other spreadsheet applications. It shows the contents of the current cell and lets you create and view formulas.
What is a cell address called? ›A reference is a cell's address. It identifies a cell or range of cells by referring to the column letter and row number of the cell(s). For example, A1 refers to the cell at the intersection of column A and row 1.
What is cell address formula? ›=ADDRESS(row_num, column_num, [abs_num], [a1], [sheet_text]) The formula uses the following arguments: Row_num (required argument) – This is a numeric value specifying the row number to be used in the cell reference.
What are the three types of cell address? ›Now there are three kinds of cell references that you can use in Excel: Relative Cell References. Absolute Cell References. Mixed Cell References.