Cell Biology Quiz-16

Cell Biology Quiz-16

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.   Cellular respiration is carried out by

•  Ribosome
•  Mitochondria
•  Chloroplast
•  Golgi bodies

Solution
(b) In 1850, Kolliker for the first time seen mitochondria. Later on, C Bends coined the term mitochondria. These are the sites of cellular respiration, oxidative phosphorylation, synthesis of haeme protein cytochrome, myoglobin, etc.

Q2.   Analyse the following pairs and identify the correct option given. I. Chromoplasts – Contain pigments other than chlorophyll II. Leucoplasts – Devoid of any pigments III. Amyloplasts – Store proteins IV. Aleuroplasts – Store oils and fats V. Elaioplasts – Store carbohydrates

•  II and III are correct
•  III and IV are correct
•  IV and V are correct
•  I and II are correct

Solution
(d) Plastids are mainly of two types: (i) Coloured (including chromoplasts containing pigments other than chlorophyll and chloroplast containing green pigment chlorophyll). (ii) Leucoplasts, which store reserve food material, these are devoid of any pigment and may be carbohydrate storing amyloplast, lipid storing elaioplast or protein storing proteinoplast (aleuroplast).

Q3.   The given diagram shows a chromosome.

Which of the following data refer correctly to the chromosome?
( No. of Centromere - No. of Kinetochore - No. of Arms )

•  2-1-4
•  1-2-4
•  2-2-4
•  1-2-2

Solution
(b) Every chromosome essentially has a primary constriction or 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 different types

Q4.   In eukaryotes, the cell wall constitutes

•  Primary and secondary walls
•  Primary walls only
•  Primary wall, middle lamella and secondary
•  None of the above

Solution
(c) In eukaryotic cell, a cell wall can have upto three parts-middle lamella, primary wall and secondary wall

Q5.   hnRNA undergoes two additional processing. Out of which, in one of them an unusual nucleotide (methyl guanosine triphosphate) is added to the 5’ – end of hnRNA. This is known as

•  Capping
•  Tailing
•  Splicing
•  Termination

Solution
  (a) Heterogenous nuclear RNA (hn RNA) undergo two additional processing known as capping and tailing. In capping an unusual nucleotide (methyl guanosine triphosphate) is added to the 5’ end of hnRNA. In tailing, adenylate residues (200-300) are added a 3’ end in template independent manner. In splicing, introns are removed and exons are joined in a definite order.

Q6.   Cell membrane was discovered by Schwann (1838) but it was named by

•  Nageli and Cramer
•  Schwann and Schleiden
•  Robert Brown
•  None of these

Solution
(a) Cell membrane was discovered by Schwann (1838) but it was named by Nageli and Cramer (1855)

Q7.   Cellular totipotency was first demonstrated by

•  F C Steward
•  Robert Hooke
•  T Schwann
•  A v Leeuwenhoek

Solution
(a) Concept of cellular totipotency was first given by Haberlandt (1902) but was proved by Steward (1965). Cellular totipotency is the ability of a somatic cell to produce the entire organism

Q8.   The cell as a basic unit of structure of living things was discovered by

•  Aristotle
•  Robert Hooke
•  Schleiden and Schwann
•  Gregor Mendel

Solution
(b) Robert Hook (1665) discovered hollow cavities like compartments in a thin slice of cork under his microscope. He coined the term cellula and wrote the book Micrographia. M Schleiden and T Schwann gave the cell theory.

Q9.   Which is not true about prokaryotes?

•  DNA is complexed with histones
•  Well developed nucleus absent
•  Mesosome present
•  Mitochondria absent

Solution
(a) In prokaryotic cell, the genetic material is not organised into nucleus and all the membrane bound organelles (mitochondria, chloroplast, Golgi body, endoplasmic reticulum, lysosomes) are absent. The histone proteins are absent and therefore, the genetic material is not organised into chromatin.

Q10.   Fluid mosaic model was given by

•  Beadle and Tatum
•  Jacob and Monod
•  Singer and Nicolson
•  Watson and Crick

Solution
(c) Singer and Nicolson proposed fluid mosaic model of cell membrane. According to this model cell membrane is composed of two type of protein, ie., integral and extrinsic, lipids and carbohydrate in form of glycolipid and glycoprotein.