BLS 201_CAT 1_2023

SOKOINE UNIVERSITY OF AGRICULTURE
College of Veterinary Medicine and Biomedical Sciences

BLS 201: Cell and Tissue Culture techniques CAT 2 Total Marks: 68 Date: 23rd January 2023 Time: 30 minutes
General instructions: Answer all FOUR questions. One mark will be deducted for any wrong answer while the rubbed and cancelled answers will be given a zero mark.

1. Select the best answer among the alternative statements given for each question and circle it (Total 30 marks).

i. Which of the following is not the essential equipment for cell culture?
A) Cell culture hood B) Centrifuge
C) Spectrophotometer D) Incubator

ii. Which of the following is the purpose of using centrifuge for cell culture:
A) To separate proteins
B) To spin down cells
C) To extract DNA from cells
D) To remove culture medium

iii. Disaggregating of cells can be achieved by
A) physical disruption
B) enzymatic digestion
C) treating with chelating agents
D) all of the above
iv. Which of the following piece(s) of equipment is(are) required to count cells in cell culture?
I. Timer II. Hemocytometer III. Microscope
A) I and II B) II only
C) II and III D) All of the above

v. ________are anchorage-dependent and propagate as a monolayer attached to the cell culture vessel.
A) Autologous Cells B) Eukaryotic Cells
C) Prokaryotic Cells D) Adherent Cells

vi. What process does the following diagram represent?

A) Primary Cell Culture B) Cloning
C) Cell propagation D) Cell preservation

vii. Why is CO2 often used in an incubator to culture mammalian cells?
A) to control oxygen consumption
B) to control cell growth
C) to control the pH
D) to control or prevent viral/bacterial contamination

viii. pH of culture medium is initially controlled by
A) presence of CO2
B) presence of bicarbonate buffer
C) addition of bases
D) none of these

ix. In animal cell culture the CO2 levels in the incubators are usually maintained at:
A) 2% B) 1% C) 5% D) 10%

x. Sometimes cell lines can be cultured for such a long time that they apparently develop the potential to be sub cultured indefinitely in vitro. Such cells lines are called_________________
A) A) established cell lines B) primary cell lines
C) secondary cell lines D) propagated cell lines

xi. Viability of cells in animal cell culture can be determined by: 1. Bradford’s assay 2. Trypan Blue assay 3. Comet assay 4. MTT assay
A) 2 only B) 1 & 2 only
C) 2 & 4 only D) 1 & 3 only

xii. Which of the following is NOT the part of growth medium for animal culture?
A) Starch B) Serum
C) Carbon source D) Inorganic salts

xiii. Which of the following is NOT the major function of the serum?
A) Promotion of tuber and bulb formation
B) Stimulate cell growth
C) Enhance cell attachment
D) Provide transport proteins

xiv. Which of the following best describes adherent cells?
A) Cells that are scraped off a solid substrate
B) Cells that float in a solution
C) Cells that are dyed with trypan blue
D) Cells that travel
xv. Which of the following statements describes suspension cells?
A) They do not need to be dyed by trypan blue
B) They clump together.
C) They do not stick to a solid substrate.
D) Are anchorage-dependent.

2. Indicate whether the following statements are TRUE or FALSE (Total 14 marks).

i. In 1839, Matthias Schleiden and Theodor Schwann discovered that trypsin could be used for degradation of matrix proteins …………………………………………………………………………………………
ii. The use of the antibiotics (penicillin and streptomycin) in culture medium in 1940s decreased the problem of contamination in cell culture ……………………………………………………………………………
iii. Regenerative medicine is one of the tools under translational research which deals with replacing the diseased cells in order to restore normal cell function …………………………………………………….
iv. Glucose and Glutamine are the main constituents of culture for animal cell growth ………………………
v. When working with adherent or suspended cells it is important to consider confluence because cells cannot thrive and grow well when there’s confluence …………………………………………………….
vi. CO2 help in the cell metabolism during cell culture by participating in the de novo synthesis of purines and pyrimidines …………………………………………………………………………………………….
vii. The cell culture medium is always tested for sterility by placing it in a 37℃ CO2 incubator for 72 hours prior to utilization……………………………………………………………………………………………

 

3. Select the answer among the alternatives given in list B that best matches with the statement in list A, then write the letter of the correct response in spaces provided in list A (Total 14 marks).

LIST A

LIST B

i.      MEM, DMEM, RPMI-1640 and IMDM are examples of ……..………………… ii.    The most common supplement in animal cell culture media…….………………….. iii.  It maintains osmotic pressure and regulates membrane potential of the cell……… iv.  Constantly monitors the changes of pH in the culture media…………………….. v.    Precursors for numerous co-factors………………………………………………. vi.  Essential amino acid important for protein synthesis that is added in the media as a supplement………………………………………………………………………. vii.  Bicarbonate is added in the media in order to act as……………….……………..

A.   Vitamins B.   Hormones C.   Glutamine D.   Methionine E.   Inorganic salts F.    Organic salts G.   Phenol red H.   pH buffer I.     Natural media J.     Artificial media K.   Fetal bovine serum

4. Write a word or phrase that best fits in the blank spaces below (10 marks).
i. The pH indicator in animal cell culture medium is_____________________________________________
ii. The growth of animal cells in vitro in a suitable culture medium is called___________________________
iii. Name the type of culture which is prepared by inoculating directly from the tissue of an organism to culture media _________________________________________________________________________
iv. The type of cell obtained after sub culturing of a primary culture is called __________________________
v. The pH of the cell culture media is naturally maintained by_________________________ and chemically maintained by _________________________________________________________________________

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