Cell Biology Quiz-09

Cell Biology Quiz-09

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.   Most prokaryotic cells, mainly the bacterial cells, have

•  A chemically complex cell envelope
•  A chemically simple cell envelope
•  Cell envelope only in the form of a cell membrane
•  No cell envelope

Solution
(a) Most prokaryotic cells, particularly the bacterial cells, have a chemically complex cell envelope. The cell envelope consists of a tightly bound three layered structure, i.e., the outermost glycocalyx followed by the cell wall and the plasma membrane

Q2.   The Okazaki fragments in DNA chain growth

•  Results in transcription
•  Polymeries in the 3’ to 5’ direction and form replication fork
•  Prove semi-conservative nature of DNA replication
•  Polymerise in the 5’ to 3’ direction and explain 3’ to 5’ DNA replication

Solution
(a) The Okazaki fragments in DNA chain growth polymerise in the 5’-3’ direction and explain 3’→5’ DNA replication.

Q3.   If a DNA sequence is same as that of a mRNA copy that is translated into protein, it is called

•  Sense
•  Antisense
•  Intron
•  Exon

Solution
(a) A DNA sequence is sense, if its sequence is the same as that of mRNA copy that is translated into protein. The sequence on the opposite strands is called antisense sequence.

Q4.   An organelle with an internal cross section showing characteristic 9 +2 morphology is the

•  Microtubule
•  Microfilament
•  Cilium or flagellum
•  Cytoskeleton

Solution
(c) A eukaryotic flagellum is a bundle of 9 fused pairs of microtubule doublets, surrounding two central single microtubules The so called 9 + 2 structure is the characteristic of core of eukaryotic flagellum called an exoneme

Q5.   Channel proteins are involved in

•  Transport of enzymes
•  Water transport
•  Active transport of ions
•  Passive transport of ions

Solution
  (d) There are two major classes of membrane transport proteins carrier proteins and channel proteins. Carrier proteins involved with active as well as passive transport of ions or solutes while channel proteins are involved only with passive transport.

Q6.   The ATP synthase of chloroplasts is like that of

•  Peroxisomes
•  Golgi body
•  Microsomes
•  Mitochondria

Solution
(d) The function of ATP synthase in chloroplast and mitochondria is the same.

Q7.   Mechanical support, enzyme circulation, protein synthesis and detoxification of drugs are the functions of

•  ER
•  Ribosomes
•  Dictyosomes
•  Chloroplast

Solution
(a) Mechanical support and enzyme circulation are the functions of both RER and SER, while the protein is synthesised by RER and detoxification of drugs by SER.

Q8.   Which one of the following structures between two adjacent cells is an effective transport pathway?

•  Plasmodesmata
•  Plastoquinones
•  Endoplasmic reticulum
•  Plasmalemma

Solution
(a) The primary cell wall contains many small openings or pores situated in the primary pit fields. The cytoplasm of adjacent cells communicate through the pores by means of cytoplasmic bridges called plasmodesmata. The plasmodesmata permits circulation of fluids and passage of solutes between cells.

Q9.   Cell organelle responsible for autolysis is

•  Dictyosome
•  Lysosome
•  Peroxisome
•  Glyoxysome

Solution
(b) Lysosome is filled with digestive enzymes (like protease, nuclease, phosphatase, etc) which work at acidic pH. The lysosomes release hydrolases in the diseases or ageing cells digest them (autolysis). So, cell biologists called lysosomes as ‘suicidal bags’.

Q10.   The rough endoplasmic reticulum (RER) in the cells are because of the presence of

•  Mitochondria associated with ER
•  Ribosomes on the surface of ER
•  Volutin granules on the surface of ER
•  Sulphur granules on the surface of ER

Solution
(b) Endoplasmic reticulum consists of complex membranous system in the cytoplasm of eukaryotic cells. The ER having ribosomes on its surface is called Rough Endoplasmic Reticulum while the ER without ribosomes is called smooth ER.