Cell Biology Quiz-15

Cell Biology Quiz-15

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.   What is a genophore?

•  DNA in prokaryotes
•  DNA and RNA in prokaryotes
•  DNA and protein in prokaryotes
•  RNA in prokaryotes

Solution
(b) The characteristic feature of bacterial nucleus is absence of nuclear membrane, nucleolus and nuclear sap and such a nucleus is called nucleoid or genophore. It contains DNA and RNA.

Q2.   Lysosomes are reservoirs (store house) of

•  Hydrolytic enzymes
•  Secretory glycoproteins
•  RNA and protein
•  Fats or sugars or ATP

Solution
(a) Lysosomes were discovered by Christian de Duve (1955) from rat liver. Matile (1964) discovered lysosomes in plants. Generally, lysosomes are 0.2-0.8μ in size, irregular membranous vesicles filed with hydrolytic enzymes. They are polymorphic.

Q3.   Mesosomes are the infoldings of cells membrane, which I. helps in cell wall formation, DNA replication and respiration II. increases the surface area of plasma membrane III. are present in both prokaryotic and eukaryotic cells Choose the correct option

•  II and III
•  I and II
•  I and III
•  I, II and III

Solution
(b) A special membranous structure is the mesosome which is formed by the extensions of plasma membrane into the cell. There extensions are in the form of vesicles, tubules and lamellae They help in cell wall formation, DNA replication and distribution to daughter cell. They also help in respiration and secretion processes to increase the surface area of the plasma membrane and enzymatic content

Q4.   In a DNA, percentage of thymine is 20%. What is the percentage of guanine?

•  20%
•  40%
•  30%
•  60%

Solution
(c) Total DNA (100)=A+T+C+G A=20 % (given) A=T (Base pairing rule) 100=20+20+C+G C+G=100-40=60 C/G=30(C=G)

Q5.   In Neisseria gonorrhoeae, fimbriae takes part in …A…, while in Escherichia coli it helps in …B… Choose appropriate options for A and B to complete the given statement

•  A-conjugation; B-attachment
•  A-attachment; B-conjugation
•  A-movement only; B-conjugation
•  A-attachment; B-movement only

Solution
  (b) In Neisseria gonorrhoeae, fimbriae takes part in I. attachment, while in Escherichia coli it helps in II. conjugation

Q6.   Categorise the given statements as true and false I. Kingdom - Monera have eukaryotic organisation II. E.coli is a eukaryote III. Organised nucleus is present in eukaryotes IV. Paramecium is a prokaryote

•  T, T, F, F
•  F, F, T, T
•  F, F, T, F
•  T, T, T, F

Solution
(c) Kingdom-Monera have prokaryotic organisation, E. coli is a prokaryote and paramecium is a eukaryote

Q7.   In prokaryotic cells, an organelle like the one is eukaryotic cells is

•  Lysosomes
•  Golgi apparatus
•  Ribosomes
•  Plastids

Solution
(c) In prokaryotes, an organelle like the one in eukaryotic cells is ribosomes

Q8.   Thread like protoplasmic projections on the free surface of absorptive cells (such as intestinal cells) are called

•  Plasmodesmata
•  Microfilaments
•  Cilia
•  None of these

Solution
(b) The microfilaments are formed mainly of protein actin. They have a role in cell motion, intracellular movements, changes in cell shape, cleavage and muscle contraction.

Q9.   The number of hydrogen bonds between adenine and thymine in a DNA molecule is

•  Two
•  Three
•  Four
•  Eight

Solution
(a) Adenine (A) is complementary to thymine (T) and guanine (G) is complementary to cytosine (C). There are two hydrogen bonds between A and T while three hydrogen bonds between guanine (G) and cytosine (C).

Q10.   The factors which set the limit of cell size or volume are I. nucleo-cytoplasmic or kern-plasma ratio II. rate of metabolic activity III. ability of oxygen and other materials to reach every part of the cell IV. ability of waste products to pass to the outside V. ratio of surface area to the volume of the cell Identify the correct set of statements

•  III and IV
•  I and II
•  Only V
•  I, II, III and IV

Solution
(d) I, II, III and IV