quiz 27 cell biology

cell biology Quiz-27

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 one of the following organisms is not an example of eukaryotic cells?

•   echerichia coli
•   euglena viridis
•   amoeba proteus
•   paramecium caudatum

Solution
(a) The bacterium E. coli is a prokaryote.

Q2. Find the correct combination, that can form a nucleotide of RNA.

•   Adenine + deoxyribose +phosphate
•   Thymine + ribose + phosphate
•   Uracil + deoxyribose + phosphate
•   Uracil + ribose + phosphate

Solution
(d) Uracil + ribose +phosphate can form a nucleotide of RNA. Each nucleotide consists of a nitrogenous base, a sugar and a phosphate group.

Q3.   Which of the following statements are correct? I. Human RBC is about 7.0µm in diameter II. Cytoplasm is the main arena of cellular activities III. The shape of the cells may vary with the function they perform IV. Various chemical reactions occur in cytoplasm to keep the cell in the living state Choose the correct option

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

Solution
(c) All statements are correct

Q4.  Omnis cellula-e-cellula (all cells arises from pre-existing cells). This concept was given by

•   Schleiden and Schwann
•   Virchow
•   Robert Brown
•   Leeuwenhoek

Solution
(b) Rudolf Virchow (1855) first explained that the cells gets divided and new cells are formed from pre-existing cells (omnis cellula-e-cellula)

Q5. The distance between two base pairs in DNA is

•  34Å
•   3.4Å
•   0.34Å
•   20Å

Solution
  (b) One turn of helix measures 34Å. It contains 10 base pairs placed at regular interval of 3.4Å.

Q6. F₁ particles present in mitochondria are

•   Episomes
•   Spherosomes
• Oxysomes
•   Microsomes

Solution
(c) F ₁ -particles or oxysomes are present on the cristae of mitochondria. Oxysomes involved in oxidative phosphorylation.

Q7. During endocytosis, the cell

•   Divides its cytoplasm during mitosis
•   Digests itself
•   Engulfs and internalises materials using its membrane
•  Enables the extracellular digestion of large molecules

Solution
(c) Endocytosis is the process by which materials enter a cell without passing through the plasma membrane. The membrane folds around material outside the cell, resulting in the formation of sac-like vesicle into which the material is incorporated. This vesicle is then pinched off from the cell surface so that is lies within the cell.

Q8. Which one of the following has its own DNA?

•   Mitochondria
•   Dictyosome
•   Lysosome
•   Peroxisome

Solution
(a) In mitochondria, the inner membrane space is filled with a matrix which contains dense granules along with ribosomes and mitochondrial DNA. The mitochondrial DNA is circular in nature.

Q9. Which of the following pairs is mismatched?

•  Pilli – involved in locomotion
•  Cell wall – protective, determines shape, prevents from bursting
•   Glycocalyx – may be capsule or slime layer
•  Flagella, pilli and fimbriae – surface structures of bacterial cell

Solution
(a) Pilli are not involved in locomotion. Actually, pilli are longer, fewer and thicker tubular outgrowths, which develop in response to or fertility factor in gram negative bacteria

Q10. 

•   It changes into RNA
•   It breaks into two fragments
•   It breaks into many fragments
• It uncoils and the two strands separate

Solution
270 (d) Heating of DNA strands at temperatures 80-90C results to breakage of hydrogen bonds between nitrogen bases of two strands (denaturation). The strands show reunion on cooling (renaturation/annealing).