quiz 26 cell biology

cell biology Quiz-26

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.  Centrosome is not present in

•   Cell of higher plants
•   Cell of lower plants
•   Cell of higher animals
•   Cell of lower animals

Solution
Centrosome is an organelle containing two cylindrical structures called centrioles and occurs in most algal cells (except red algae) and most animal cells. They are absent in prokaryotes, red algae, yeast, gymnosperms and angiosperms and some non-flagellated or non-ciliated protozoans.

Q2. The non-membranous organelles are

•   Centrioles
•   Ribosomes
•   Nucleolus
•   All of these

Solution
Nucleolus, ribosomes and centrioles are non-membranous cell organelles.

Q3.   In which cell organelles, a lipoprotein covering is absent?

•   Ribosomes
•   Lysosomes
•   Mitochondria
•   Peroxisomes

Solution
Ribosomes are large non-membranous RNA protein complexes, which are necessary for protein synthesis.

Q4.  Three of the following statements regarding cell organelles are correct, while one is wrong. Which one is wrong?

•   Lysosomes are double membraned vesicles budded off from Golgi apparatus and contain digestive enzymes
•   Endoplasmic reticulum consists of a network of membranous tubule and helps in transport, synthesis and secretion
•  Leucoplasts are bound by two membranes, lack pigment but contain their own DNA
•  Sphaerosomes are single membrane bound and are associated with synthesis and storage of lipids

Solution
Double membranes are absent in lysosomes. They are enclosed by lipoproteinaceous unit membrane. Lysosome is called ‘suicidal bag’ of the cell due to presence of hydrolytic enzymes.

Q5. One turn of the helix in a B-form DNA is approximately

•  20 nm
•   0.34 nm
•  0.34 nm
•   2 nm

Solution
  B-DNA is helical structure with 20 Å diameter and the distance between the two base pairs is 3.4Å and there are 10 base in each turn or pitch (one round). Hence, one turn of the helix is approximately 34Å or 3.4 nm (10Å=1.0 nm).

Q6.  Go through the sectional view of a mitochondrion showing the different parts and identify the structures A to E

•  A-Outer membrane, B-Inner membrane, C-Matrix, D-Inter membrane space, E-Crista
•  A-Outer membrane, B-Inner membrane, C-Inter-membrane space, D-Matrix, E-Crista
• A-Outer membrane, B-Inner membrane, C-Matrix, D-Crista, E-Inter membrane space
•  A-Outer membrane, B-Inner membrane, C-Crista, D-Matrix, E-Inter-membrane space

Solution
A-Outer membrane, B-Inner membrane, C-Matrix, D-Inter-membrane space, E-Cristae

Q7. In DNA, which of the following is absent?

•   Adenine
•   Thymine
•  Guanine
•   Uracil

Solution
(d) In DNA molecule, instead of uracil, thymine is present. Uracil is present in RNA molecule.

Q8. Which one of the following is correctly matched?

•  Frederick Griffith - Discovered the phenomenon of transformation
•  Linus Pauling - Isolated DNA for the first time
•  Francis Crick - Proposed one gene-one polypeptide hypothesis
•  George Beadle - Proposed the concept of inborn errors

Solution
(a) F Griffith discovered the phenomenon of transformation.

Q9. Difference between prokaryote and eukaryote is in

•  Cell size
•   Cell shape
•   Chemical composition of protoplasm
•   Organisation of nuclear material

Solution
(d) Prokaryotic cells are differ from eukaryotic cells in organisation of nuclear material. In eukaryotes, nuclear material is present in nucleus, which is surrounded by nuclear membrane, while in prokaryotes nuclear material is dispersed in cytoplasm, there is no well organised nucleus in prokaryotes.

Q10.  The crystals of calcium carbonate deposit in the cell is called

•  Aleurone
•  Crystalloid
•   Globoid
• Core type

Solution
(b) Cystolith is a mass of calcium carbonate, occasionally of silica, formed on ingrowths of epidermal cell walls in some plants.