Cell Biology Quiz-20

Cell Biology Quiz-20

Dear Readers,

NEET is the most famous and important medical entrance examination held in our country. This exam is an objective type, an offline test which includes 4 sections namely– Physics, Chemistry, Botany, and Zoology. The maximum marks that can be scored are 720 marks and have 180 questions. About half of the paper consists of questions from Biology, as the NEET exam essentially focuses on capacitating students to go for seats in medical courses. One of the most significant and crucial sections in the NEET exam is of Biology. It comprises of theories, descriptions, discoveries, diagrams, definitions, explanations of differences, and relations. The majority of the topics covered in the NEET syllabus are from the NCERT syllabus of Class 11 & 12 and other related sources become part of the rest of the syllabus. Clear Exam curates a list of articles selected by professionals who recommend the highly vital topics for NEET exams. The table below takes you directly to the respective topic where the in-depth article and the MCQs are available for an easy and productive learning experience. Prior to solving NEET question papers or practicing mock tests, you must ensure to study the basic concepts in NEET and practice a few sample questions related to this exam. Students will be covered for all their studies as the topics are available from basics to even the most advanced. .

Q1.   Which of the following is not present in cell vacuoles?

•  Hydrolytic enzymes
•  Latex of the rubber plant
•  DNA
•  Anthocyanins of the flowers

Solution
(c) Vacuole is a single membrane bound space in plant cell. It contains cell sap. The cell sap have minerals dissolved in water. It also contains a water soluble pigment anthocyanin. DNA is absent here.

Q2.   DNA is present in

•  Chromosomes and dictyosomes
•  Chloroplasts and lysosomes
•  Mitochondria and chloroplasts
•  Mitochondria and endoplasmic reticulum

Solution
(c) In an eukaryotic cell, DNA is found mainly in nucleus but mitochondria and chloroplasts both also contain a single copy of double stranded, circular DNA molecules.

Q3.   The RNA primer is used in

•  Translation
•  Replication
•  Conjugation
•  Transformation

Solution
(b) The RNA primer is used in replication of DNA.

Q4.   In a hair pin model of RNA, which nitrogen base is present at the short end?

•  Adenine
•  Guanine
•  Thymine
•  Cytosine

Solution
(b) In a hair pin model of RNA, Guanine is present at the short end.

Q5.   Which of the following enzymes has/have haeme as a prosthetic group? I. Catalase II. Carboxypeptidase III. Succinic dehydrogenase IV. Peroxidase

•  I only
•  I and II
•  II and III
•  I and IV

Solution
  (d) Prosthetic groups are organic compounds and are distinguished from other co-factors (non-protein constituents bound to the enzymes) in that they are tightly bound to the apoenzyme (protein portion of the enzymes). For example, in peroxidase and catalase, which catalyze the breakdown of H_2 O_2 to H_2 O and O_2, haeme is the prosthetic group and it is the part of active site of the enzyme.

Q6.   Correlate the given features of animal cells (I to VII) with their respective parts (A to N)

I. The structure replicates during mitosis and generates the spindle II. Major site for synthesis of lipid III. Power house of the cell IV. store house of digestive enzyme V. Increase the surface are for the absorption of materials VI. Site of glycolysis VII. Site for active ribosomal RNA synthesis The correct option is I II III IV V VI VII

•  L G H J N F D
•  M G H J N F D
•  L B H J N F D
•  M A H J N F D

Solution
(c) (i) The structure replicates during mitosis and generates the spindle – L (ii) Major site for synthesis of lipid – B (iii) Power house of the cell – H (iv) Store house of digestive enzyme – J (v) Increase the surface area for the absorption materials – N (vi) Site of glycolysis – F (vii) Site for active ribosomal RNA synthesis – D

Q7.   Which one is the correct statement about the bacterial cell envelope?

•  The outermost cell wall is followed by glycocalyx and then the plasma membrane
•  Cell envelope is chemically very simple and consists of only plasma membrane
•  The outermost glycocalyx is followed by cell wall and plasma membrane
•  The outermost glycocalyx is followed by plasma membrane and then the cell wall

Solution
(c) Bacterial cell envelope consists of three components glycocalyx, cell wall and cell membrane Glycocalyx It is the outermert mucilage layer of the cell envelope Cell Wall It is rigid solid covering, which provides shape and structural support to the cell. Cell wall lies between plasma membrane and glycocalyx Plasma/Cell Membrane It is selectively permeable covering of the cytoplasm that forms the innermost components of cell envelope

Q8.   Main component of ribosome are

•  DNA and RNA
•  RNA and protein
•  DNA and protein
•  Protein and lipids

Solution
(b) Ribosomes are chemically composed of RNA and proteins (both occurring approximately in equal proportion). The RNA commonly formed ribosome is rRNA.

Q9.   The enzyme which helps to cut one strand of DNA duplex to release tension of coiling of two strands is

•  DNA ligase
•  DNA polymerase-I
•  Topoisomerase
•  Swielases (helicase or unwindases)

Solution
(c) The enzyme helicase unwinds the helix (by disrupting H bonds), while topoisomerase breaks and releases tension of strands of DNA. Topoisomerase also takes part in recombination.

Q10.   In the DNA molecule,

•  The total amount of purine nucleotides and pyrimidine nucleotides is not always equal
•  There are two strands, which run parallel in the 5’→3’ direction
•  The proportion of adenine in relation to thymine varies with the organism
•  There are two strands, which run antiparallel-one in 5’→3’ direction and other in 3’→5’

Solution
(d) The two strands run antiparallely, i.e., one strand has phosphodiester linkage in 3’→5’ direction, while other strands has phosphodiester linkage in 5’→3’ direction.