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Camillo Golgi. 

(a) Robert Brown discovered the cell.

Bacillus (rod), coccus (spherical), vibrio (comma shaped) and spirillum (spiral). 

Egg of birds (Ostrich)

Chloroplasts, chromoplasts and leucoplasts.

(c) Waldeyer

The outer most layer of the cell envelope in bacteria is called glycocalyx.

Two types of glycocalyx are:- 

• Slime layer – which is a loose sheath
• Capsule – which is thick and tough.

Robert Brown

(c) In prokaryotes, there are no membrane-bound organelles.

Organisms that contain only a single cell in their body are called unicellular organisms

e.g. amoeba, euglena, etc.

Two layers are in nucleus.

Organisms that are made up of two or more cells are called multicellular organisms

eg: birds, fish, frog, etc.

Centrosome with Centrioles.

Fluid present inside the nucleus is called nucleoplasm. 

The types of cells based on nuclear characteristics:

1. Prokaryotes 

2. Mesokaryotes and 

3. Eukaryotes.

In a unicellular organism, a single cell is responsible for all the life processes. This is called cellular level of organization. This can be seen in some simple multicellular organisms as well. But in most of the multicellular organism, there are different groups of cells to carry different functions. Thus, formation of tissues paves the way for division of labour in multicellular organisms.

(c) Circular

(d) Golgi bodies

In plant cell, at few regions the secondary wall layer is laid unevenly, whereas the primary wall and middle lamellae are laid continuously such regions are called pits.

Schleiden and Schwann.

Hemicellulose binds the microfibrils with matrix and glycoproteins control the orientation of microfibrils while pectin serves as filling material of the matrix.

Mitochondria are inherited from parent Female.

Elaioplasts store Lipid.

In mammals, peroxisomes are seen in Liver cells.

Secondary wall is laid during maturation. It plays a key role in determining the shape of a cell.

(a) Fungi – Chitin and fungal cellulose. 

(b) Bacteria – Peptidoglycan 

(c) Algae – Cellulose, mannan and galactan.

Cell theory was proposed by schleiden and Schwann. Rudolf virchow modified the hypothesis and explained the theory as:

• All living organisms are composed of cells and products of cells.
• All cells arise from preexisting cells.

Cilia and flagella are hair-like outgrowths . of the cell membrane.

Cilia are small structures which work like oars causing the movement of either the cell or the surrounding fluid. Flagella are comparatively longer and responsible for cell movement Cilium and flagellum are covered by a plasma membrane. Their core called axoneme, pos-sesses a number of micro tubules running parallel to the long axis. The axoneme has nine pairs of doublets of radially arranged peripheral micro tubules and a pair of centrally located micro tubules.

The central tubules are connected by bridges and is enclosed by a central sheath, which is connected to one of the tubules of each peripheral doublets by a radial spoke. The peripheral doublets are also interconnected by linkers. Both cilium and flagellum emerge from centriole like structure called the basal bodies.

(d) Oxysomes

In plant, cell wall shows three distinct regions 

1. Primary wall 

2. Secondary wall and 

3. Middle lamellae.

Cellulose, hemicellulose, pectin, lignin, cutin, suberin and silica.

Membrane bound nucleus is absent in prokaryotic cell. Moreover, membrane bound organelles are also absent in prokaryotic cells. Bacteria are examples of prokaryotic cell. 

Reserve material in prokaryotic cells are stored in the cytoplasm in the form of inclusion bodies. These are not bounded by any membrane system and lie free in the cytoplasm.

Phosphate granules, cyanophycean granules, glycogen granules and gas vacuoles are the types of inclusion bodies. Gas vacuoles are found in blue green and purple and green photosynthetic bacteria.

Characteristics of Prokaryotic cell

• Prokaryotic cells are smaller and multiply more rapidly than eukaryotic cells.
• They have cell wall surrounding the cell membrane and the fluid matrix filling the cell is the cytoplasm. They don’t have a well defined nucleus. 
• Few prokaryotes like bacteria has additional small circular DNA called plasmids outside the genomic DNA. These plasmids confer unique phenotypic characters to such bacteria.
• Prokaryotic cell does not contain membrane bound organelles found in eukaryotes except ribosomes..
• A specialised differentiated form of cell membrane called mesosome are found in prokaryotes. These are membranous structure formed by the extensions of plasma membrane into the cell.
• Most prokaryotic cells like bacterial cells have chemically complex cell envelope consisting of tightly bound three layers viz. the outermost glycocalyx, the cell wall and the plasma membrane.
• Ribosomes, are made of two sub units 50s and 30s units which when present together form 70s prokaryotic ribosomes. 
• Reserve material in prokaryotic cells are stored in cytoplasm in the form of inclusion bodies which lie free in the cytoplasm.

(c) Antonie van Leeuwenhoek

Golgi complex plays a major role in post translational modification of proteins and glycosidation of lipids.

(d) Ribosomes

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Practice MCQ Questions for class 11 Biology Chapter-Wise

1. The cytoplasmic connections from cell to cell are known as

(a) middle lamella
(b) plasmodesmata
(c) cell membrane system
(d) endoplasmic reticulum

2.  Bacterial flagella is made up of

(a) tubulin
(b) flagellin
(c) chitin
(d) None of these

3. Plasmolysis occurs due to-

(a) Absorption
(b) Endosmosis
(c) Osmosis
(d) Exosmosis

4. Which is called Suicidal Bag?

(a) Centrosome
(b) Lysosome
(c) Mesosome
(d) Chromosome

5. Cell secretion is done by-

(a) Plastids
(b) ER
(c) Golgi apparatus
(d) Nucleolus

6. The outer layer of vacuole is called

(a) tonoplast
(b) leucoplast
(c) cell wall
(d) plasmalayer

7. Most abundant lipid in the cell membrane is

(a) phospholipids
(b) cerebrosides
(c) glycolipids
(d) None of these

8. Smooth endoplasmic reticulum is well developed in the cells which synthesize

(a) steorids
(b) carbohydrates
(c) proteins
(d) all of these

9. Quasi-fluid nature of membrane is due to

(a) Phospholipid
(b) Peripheral protein
(c) Integral protein
(d) Sugar moiety

10.Magnification of compound microscope is not connected with

(a) numerical aperture
(b) focal length of objective
(c) focal length of eye piece
(d) tube length

11. Binding of specific protein on regulatory DNA sequence can be studied by means of

(a) ultra centrifugation
(b) electron microscope
(c) light microscope
(d) X-rays crystallography

12. Gel electrophoresis is used for 

(a) cutting of DNA into fragments
(b) separation of DNA fragments according to their size
(c) construction of recombinant DNA by joining with cloning vectors
(d) isolation of DNA molecule

13. Peroxysomes contain:

(a) Hydrolytic enzyme
(b) Transferase
(c) Isomerase
(d) Oxidising enzyme (Oxidase)

14. The stacks of closely packed thylakoids is called

(a) Lumen
(b) Matrix
(c) Stroma
(d) Granum

15. Which of the following is present in both prokaryotic and eukaryotic cells?

(a) Mitochondria
(b) Endoplasmic reticulum
(c) Nucleus
(d) Ribosomes

16. Plastids which store fats and oils are called:-

(a) Aleuroplast
(b) Amyloplast
(c) Etioplast
(d) Elaioplast

17. If the centromere is situated close to the end of a chromosome, it is called as:

(a) Metacentric
(b) Submetacentric
(c) Acrocentric
(d) Telocentric

18. Prokaryotic cells have something unique in the form of:

(a) Inclusion bodies
(b) Plasmids
(c) Cell wall
(d) 70 S ribosomes

19. Gas vacuoles allow cyanobacteria to:

(a) Store carbon dioxide for assimilation
(b) Control their buoyancy
(c) Provide anaerobic conditions to nitrogenase
(d) Eliminate toxic ammonia

20. The lipid component of the plasma membrane mainly consists of:

(a) Triglycerides
(b) Cholesterol
(c) Phosphoglycerides
(d) Proteins

21. Microbodies, which help to convert stored lipids into carbohydrates so they can be used for plant growth, are known as:

(a) Peroxisomes
(b) Sphaerosomes
(c) Glyoxysomes
(d) Lysosomes

22. Which cell organelle is involved in apoptosis?

(a) Lysosome
(b) ER
(c) Golgi
(d) Mitochondria

23.  The rRNA is Synthesized by ..................

(a) Golgi body
(b) Nucleus
(c) Nucleolus
(d) Cytoplasm

24. The arrangement of outer and central microtubules in a cilium is called the:

(a) 9 + 1 pattern
(b) 9 + 0 pattern
(c) Flagellin pattern
(d) 9 + 2 pattern

25. Pigment-containing membranous extensions in some cyanobacteria are

(a) heterocysts
(b) basal bodies
(c) pneumatophores
(d) chromatophores

Answer

1. Answer: (b) plasmodesmata

Explanation: The cytoplasmic connection from cell to cell is known as plasmodesmata, while in animal cells it is known as gap junction.

2. Answer: (b) flagellin

Explanation:The bacterial flagellum is made up of the protein flagellin. Its shape is a 20-nanometer-thick hollow tube. It is helical and has a sharp bend just outside the outer membrane; this "hook" allows the axis of the helix to point directly away from the cell.

3. Answer: (d) Exosmosis

Explanation: Plasmolysis occurs due to Exosmosis in which the water molecules move from the region of higher concentration to the region of lower concentration of the cell around the surroundings through the cell membrane.

4. Answer: (b) Lysosome

Explanation:Lysosomes are called suicide sacks. They are produced by the Golgi body. They consist of a single membrane surrounding powerful digestive enzymes. It acts as the “garbage disposal” of the cell by breaking down cell components that are no longer needed as well as molecules or even bacteria that are ingested by the cell.

5. Answer: (c) Golgi apparatus

Explanation:Cell secretion is done by golgi apparatus. The external elimination of substances produced by the cell is known as cell secretion e.g., hormones, sweat, etc. Golgi apparatus is also known as the golgi complex.

6. Answer: (a) tonoplast

Explanation:The outermost covering of vacuole is called as tonoplast or vacuolar membrane. The tonoplast is the cytoplasmic membrane separating the vacuolar contents from the cell's cytoplasm.

7. Answer: (a) phospholipids

Explanation: The most abundant membrane lipids are the phospholipids. These have a polar head group and two hydrophobic hydrocarbon tails. The tails are usually fatty acids, and they can differ in length (they normally contain between 14 and 24 carbon atoms).

8. Answer: (a) steorids

Explanation:The smooth endoplasmic reticulum functions in many metabolic processes. It synthesizes lipids, phospholipids as in plasma membranes, and steroids. Cells that secrete these products, such as cells of the testes, ovaries, and skin oil glands, have an excess of smooth endoplasmic reticulum.

9. Answer: (a) Phospholipid

Explanation:It is a mosaic of molecules like lipids (primarily phospholipids), proteins, carbohydrate moiety and cholesterol.It suggests that the fluid nature of the plasma membrane is because of the phospholipids.Phospholipids of plasma membranes are amphipathic structures.

10. Answer: (a) numerical aperture

Explanation: Magnification of compound microscope is not connected with numerical aperature.

11. Answer: (d) X-rays crystallography

Explanation:X -rays crystallography is a technique which is used to study of binding protein on regulatory DNA sequence. In this technique, X-rays pass through a crystal of a substance and form a diffraction pattern.

12. Answer: (b) separation of DNA fragments according to their size

Explanation: Gel electrophoresis is a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores.

13. Answer: (d) Oxidising enzyme (Oxidase)

Explanation: Peroxisomes contain at least 50 different enzymes, which are involved in a variety of biochemical pathways in different types of cells. Peroxisomes originally were defined as organelles that carry out oxidation reactions leading to the production of hydrogen peroxide.

14. Answer: (d) Granum

Explanation:The stacks or closely packed thylakoids is called granum. Chlorophyll is present inside the thylakoidsto perform photosynthesis in plant cells.

15. Answer: (d) Ribosomes

Explanation: 'Ribosome is an organelle which is found in both the type of cells that are eukaryotic and prokaryotic cells'. Note: They are located in two areas of cytoplasm.

16. Answer: (d) Elaioplast

Explanation: Plastids which store fats and oils are called as elaioplast. Elaioplasts are a type of leucoplast that is specialized for the storage of lipids in plants. Elaioplasts house oil body deposits as rounded plastoglobuli, which are essentially fat droplets.

17. Answer: (c) Acrocentric

Explanation:The centromere which is located near the end of the chromosome is called the Acrocentric chromosome. There are 5 pairs of acrocentric chromosomes in the human body. It is a sub-terminal centromere. The shape of the acrocentric chromosome is rod or i-shaped.

18. Answer: (a) Inclusion bodies

Explanation: Prokaryotes store food particles and other necessary stuffs in the form of granules called the inclusion bodies In eukaryotes usually these substances are stored in vacuole But since prokaryotes lack vacuole they store it in the form of inclusion bodies.

19. Answer: (b) Control their buoyancy

Explanation: Gas vacuoles are aggregates of hollow cylindrical structures called gas vesicles. They are located inside some bacteria .The inflation and deflation of the vesicles provides buoyancy, allowing the bacterium to float at a desired depth in the water. Bacteria that are known as cyanobacteria contain gas vacuoles.

20. Answer: (c) Phosphoglycerides

Explanation: The lipid component of the cell membrane mainly consists of phosphoglycerides.

21. Answer: (c) Glyoxysomes

Explanation: Glyoxysomes are specialized peroxisomes found in plants and mold, which help to convert stored lipids into carbohydrates so they can be used for plant growth.

22. Answer: (d) Mitochondria

Explanation: Mitochondria are pivotal in the control of apoptosis, being involved not only in the intrinsic but also in the extrinsic pathway.

23. Answer:(c) Nucleolus

Explanation: Molecules of rRNA are synthesized in a specialized region of the cell nucleus called the nucleolus, which appears as a dense area within the nucleus and contains the genes that encode rRNA.

24. Answer: (d) 9 + 2 pattern

Explanation: The flagellum and the cilia are composed of the microtubules. In the cilium, 9 peripheral doublets of microtubules are found which are known as the outer microtubules. The number of central microtubules in a cilium is two. This arrangement of the microtubules is called as the 9 + 2 pattern.

25. Answer: (d) chromatophores

Explanation: A cyanobacterium is having membranous extensions that are containing pigments that are known as chromatophores that are responsible for photosynthesis. The correct option is B i.e. chromatophores.

Click to practice Cell the Unit of Life MCQ Questions for Class 11 

The largest organelle in plants is the central vacuole. Up to about 90% can be filled by a vacuole in a plant cell.

(b) Endoplasmic reticulum

The cytoplasmic connection between the cells is called Plasmodesmata 

Neutral solutes move across the plasma membrane through passive transport, i.e. by diffusion and osmosis. But polar molecules need a carrier protein of the membrane to be transported across against concentration gradient. This type of transport is dependent on energy and is called active transport.

(c) While lipids can rarely flip – flop proteins cannot

(b) Singer and Nicolson

S.J. Singer and G.Nicolson.

Lipids are arranged in the plasma membrane with the polar head towards the outer sides and the hydrophobic tails towards the inner part.