Question 1

According to mosaic model, plasma membrane is made up of

Accepted Answer

Singer and Nicolson proposed Fluid mosaic model in which the proteins are interspersed and floating like mosaic on a lipid bilayer made up of phospholipids having polar head made of phosphate and non-polar lipid tails. Some proteins called intrinsic proteins traverse through the entire width of membrane and cannot be separated easily from the membrane while some proteins called extrinsic proteins are present on the surface only and can be easily separated from the membrane.So, the correct answer is 'Phospholipid, extrinsic and intrinsic protein'

Question 2

Which is the latest model that is proposed to explain the structure of plasma membrane?

Accepted Answer

Fluid Mosaic model proposed by Singer and Nicolson in the year 1972, is the latest model to explain structure of plasma membrane.

Question 3

Pick up the correct statement regarding cell membrane from the choices given here.

Accepted Answer

According to the fluid mosaic model of Singer and Nicolson, cell membranes are quasi-fluid in nature with a viscous lipid bilayer having proteins at places (mosaic) both on the surface and inside. The arrangement of lipids in bilayer is also called as a head parallel arrangement because the polar heads of both the lipid layers are oriented on the surface and hydrophilic tails are embedded inside the membrane. The membrane does not allow free movement of ions like sodium and potassium because they are water soluble solutes and the membrane is essentially a lipid bilayer. Special carrier proteins are present in the membrane for the transport of ions.So, the correct answer is option B.

Question 4

Most abundant lipid in cell membrane is;

Accepted Answer

Correct Option: CExplanation: The cell membrane has a layer of hydrophobic tails of phospholipids which has a hydrophilic head.This hydrophilic head is present toward the outside of the membrane and interacts with water. it protects from an aqueous environment.The hydrophobic is a non-polar tail present towards the inside layer.this sandwich of layers of hydrophobic tails between two layers of hydrophilic heads makes the membrane trilaminar.The most abundant membrane lipids are phospholipids.These have polar head group and 2 hydrophobic hydrocarbon tails.Hence, phospholipid is most abundant in cell membrane.

Question 5

Solar energy is converted into chemical energy in

Accepted Answer

Chloroplasts are specialized subunits in plant and algal cells. Their main role is to conduct photosynthesis, where the photosynthetic pigment chlorophyll captures the energy from sunlight, and stores it in the energy storage molecules ATP and NADPH while freeing oxygen from water. They then use the ATP and NADPH to make organic molecules from carbon dioxide in a process known as Calvin cycle.So, the correct answer is option B.

Question 6

Name the plastid that is white in colour (pigment-free).

Accepted Answer

Plastids are the organelles found only in plant cells. These are of three types, namely, chloroplast, i.e., green plastid, non-green chromoplast, and leucoplasts. Leucoplasts are non-pigmented or colorless plastids that are used for the storage of starch and oils. Thus, the correct answer is option C.

Question 7

The bright colours of ripe fruits are due to

Accepted Answer

Plastids are organelles found in plant cells. These are involved in the synthesis and storage of food. Plastids are of different types- (1) chloroplasts, (2) chromoplasts, (3) leucoplasts. Chromoplasts are plastids that are coloured due to the pigments that are produced and stored inside them that is not chlorophyll.They are found in fruits, flowers, roots, and senescent leaves and are responsible for their different colours.So the correct answer is option D.

Question 8

Which of the following are the fat-storing leucoplasts?

Accepted Answer

Plastids develop from colourless precursors called proplastids. Leucoplasts are colourless plastids of various shapes; their function is storage. One type of leucoplasts is amyloplasts that store starch. Elaioplasts or oleosomes are fat-storing leucoplasts while aleuroplasts are protein-storing leucoplasts.

Question 9

Which of the following is mismatched?

Accepted Answer

Plastids are of three main types: leucoplasts (colourless plastids specialized for storage of food), chromoplasts (non-green plastids for attracting animals to flower and fruits) and chloroplasts (green plastids for photosynthesis).Leucoplasts may get specialized into amyloplasts (storage of starch), aleuroplasts (storage of proteins) and elaioplasts (storage of fats).

Question 10

........... determines the function and development of the cell.

Accepted Answer

The nucleus regulates all cellular activities by controlling the enzymes required for cellular processes. Enzymes are proteins and protein synthesis is controlled by the nucleus.The mRNA required for protein synthesis is made from DNA, which is situated in the nucleus. Hence the correct option is A.

Question 11

Nucleus is surrounded by a

Accepted Answer

In eukaryotic organisms, the nucleus has five parts - nuclear envelope, nucleoplasm, nuclear matrix, chromatin, and nucleolus. The nuclear envelope is also called as karyotheca. It is made up of two membranes, the outer membrane may have ribosomes and interconnections with the ER and the inner membrane is connected with the nucleoplasm.Hence the correct option is B.

Question 12

What is the function of nucleus in a cell?

Accepted Answer

The nucleus is the membrane-bound important structure of the eukaryotic cell.The nucleus regulates all cellular activities by controlling the enzymes required for cellular processes. It contains genetic information in the form of genes located in the chromosomes.It brings about the growth of the cell by directing the synthesis of structural proteins. It also controls all the metabolic activities of the cell. So, the correct answer is option D.

Question 13

Who discovered nucleus?

Accepted Answer

Solution&#10;&#10;Correct answer is option B.&#10;&#10;Explanation for correct&#10;option:&#10;&#10;A nucleus is a&#10;membrane-bound organelle that contains the cell's chromosomes.The nucleus controls and&#10;regulates the activities of the cell (e.g., growth and metabolism) and carries&#10;the genes, structures that contain the hereditary information.Robert Brown, Scottish&#10;botanist, discovered the nucleus of a cell in 1831.&#10;&#10;&#10;&#10;

Question 14

Nucleolus is made up of:

Accepted Answer

The nucleolus is the largest structure present in the nucleus of eukaryotic cells where it primarily serves as the site of ribosome synthesis and assembly. Nucleolus also has other important functions like the assembly of signal recognition particles and playing a role in the cell's response to stress. It is made of proteins and RNA and forms around the specific chromosomal regions.

Question 15

Basic structure of chromatin is composed of:

Accepted Answer

Chromatin is a fibrous heredity material formed by DNA-histone complex. Basically, the DNA-histone thread consists of nucleosome chains. The nucleosome chains are made of histone proteins forming charged cores around which DNA is wrapped.So, the correct answer is option D.

Question 16

Which of the following is a prokaryote?

Accepted Answer

Correct option: CExplanation:Bacteria are prokaryotic, single-celled organisms, which, belong to the kingdom Monera. The bacterial cell has coiled DNA in a region called nucleoid and is devoid of membrane-bounded organelles. Bacteria do not have an organized cellular structure.Amoeba is a unicellular eukaryote and belongs to the kingdom Protista.Spirogyra and Chlamydomonas are green algae and belong to the kingdom Plantae. They have a complex cellular structure with membrane-bounded organelles.So, the correct answer is option C.

Question 17

The prokaryotic cell does not have:

Accepted Answer

extbf{Correct option:D}   	extbf{Solution:} 	extbf{Option (A)} \bullet  Nucleolus is absent, rather the DNA that forms the major nuclear material is not membrane bound(naked) and coiled in the cytoplasm ,it is also known as genophore/nucleoid/prochromosone (single naked chromosome). \bullet  There is an additional circular DNA called plasmid which is a very important machinery for biotechnology , nitrogen fixation, resistance , fertility etc. 	extbf{Option (B)} \bullet  Membrane bound organelles are absent in prokaryotic cells such as mitochondria,endoplasmic reticulum,lysosomes,golgi apparatus, microtubules,microfilaments and centrioles. 	extbf{Option (C)} \bullet  Centrioles are minute microscopic microtubular cylindrical structures which can duplicate themselves ,producing astral poles and basal bodies without having DNA and a membranous converting . These structures are present in eukaryotic cells and plays a crucial role at the time of cell division. 	extbf{Option (D)} \bullet  All the above option are correct. 	extbf{Hence, the correct option is (D)}

Question 18

The only cell organelle seen in a prokaryotic cell is

Accepted Answer

Prokaryotes and eukaryotes are two different types of cells. Eukaryotic cells contain membrane-bound organelles, while prokaryotic cells do not. The ribosome is the only organelle that can be seen in both prokaryotic and eukaryotic cells, though the types of ribosomes in the two types of cells vary.Hence, the correct option is B.

Question 19

Which of the following statements is/are correct?

Accepted Answer

Prokaryotes lack a true nucleus with a well-defined nuclear membrane and other membrane-bound organelles. They have a simple structural organization. They are unicellular and division of labour is absent.So, the correct answer is option B.

Question 20

A bacterial flagellum is made up of:

Accepted Answer

The bacterial flagellum is made of a protein called flagellin.It has 3 parts, namely, basal body, hook and filament.So the correct answer is option A.

Question 21

Plasmids found in bacteria are:

Accepted Answer

A plasmid is an extrachromosomal, extranuclear DNA molecule occurring free in the cytoplasm and capable of autonomous replication. Most commonly found as small circular, double stranded DNA molecules in bacteria.

Question 22

The Golgi complex participates in:

Accepted Answer

Golgi complex is the double membrane-bounded organelle present in eukaryotic cells only. It takes part in the formation of secretory vesicles. It helps in transportation of material within or outside the cells. Whereas respiration in bacteria is done by mesosomes, activation of an amino acid is the part of protein synthesis occurs in ribosomes and breakdown of fatty acid by beta-oxidation occurs in mitochondria.

Question 23

Which type of membrane is most abundant within a cell?

Accepted Answer

The endoplasmic reticulum is a system of membrane-lined channels found in all eukaryotic cells. It constitutes around 30 to 60 percent of total cell membranes. Thus, the correct answer is option A.

Question 24

The main organelle involved in the modification and routing of newly synthesized proteins to their destinations is ________.

Accepted Answer

The main organelle involved in the modification and routing of newly synthesized proteins to their destination is the endoplasmic reticulum. ER divides the intracellular space into two distinct compartments, i.e., luminal (inside ER) and extraluminal (cytoplasm) compartments. The ER is of the following two types:1) Smooth ER (SER) - involved in the synthesis of lipids.2) Rough ER (RER) - involved in protein synthesis and secretion.So, the correct answer is 'Endoplasmic reticulum'.

Question 25

Lysosome arises from:

Accepted Answer

Lysosomes are formed by budding of the vesicles from Golgi bodies. It contains hydrolytic enzymes. The hydrolytic enzyme helps in the intracellular digestion. It helps in the removal of cell debris. They act as suicidal bags of the cell.So, the correct answer is option B.

Question 26

Lysosome arises from:

Accepted Answer

Lysosomes are formed by budding of the vesicles from Golgi bodies. It contains hydrolytic enzymes. The hydrolytic enzyme helps in the intracellular digestion. It helps in the removal of cell debris. They act as suicidal bags of the cell.So, the correct answer is option B.

Question 27

The terminal end of a chromosome is called:

Accepted Answer

A telomere is a region of repititive nucleotide sequences at each end of a chromatid, which protects the end of the chromosome from deterioration or from fusion with neighbouring chromosomes.So, the correct answer is 'Telomere'

Question 28

Centromere is a part of chromosome which helps in the:

Accepted Answer

The centromere is the part of a chromosome that links sister chromatids.  The primary function of the centromere is to serve as a place of attachment for spindle fibers during cell division which helps in the movement of daughter chromatids towards the poles.

Question 29

L-shaped chromosomes are called:

Accepted Answer

L-shaped or J-shaped chromosomes are called submetacentric chromosomes. Here, the centromere is placed just near the centre of the chromosome. It consists of two arms that are unequal in length; a shorter - 'p' arm and a longer - 'q' arm, these arms are joined together by the centromere. It occurs in the metaphase stage of cell division. Submetacentric chromosomes are bulky in appearance. So, the correct answer is 'Submetacentric'

Question 30

Four different types of chromosomes, but of the same size are:

Accepted Answer

Four types of chromosomes arranged serially according to the position of the centromere are - (a) Metacentric - centromere in middle.(b) Submetacentric - centromere is sub-median.(c) Acrocentric - centromere is sub terminal.(d) Telocentric - centromere is terminal.

Question 31

A chromosome, in which the centromere is situated close to its end so that one arm is very short and the other very long is:

Accepted Answer

Every chromosome has a primary constriction of the centromere on the sides of which disc-shaped structures called kinetochores are present.Based on the position of the centromere, the chromosomes can be classified into four types.The metacentric chromosome has a middle centromere forming two equal arms of the chromosome.The sub-metacentric chromosome has centromere slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm.In the case of acrocentric chromosome the centromere is situated close to its end forming one extremely short and one very long arm.Telocentric chromosome has a terminal centromere.So, the correct option is 'Acrocentric'.

Question 32

A normal metaphase chromosome with a centromere in the middle is ?

Accepted Answer

Metacentric chromosome: a chromosome having two equal arms because the centromere is in median position.So, the correct answer is 'Metacentric'

Cell : The Unit Of Life