The university of Bamenda Université de Bamenda

Faculty of Science Faculté des Sciences

Department of Biological Sciences Départment des Sciences

P.O. Box 39 Bambili Biologiques

Tell: (+237) 22 81 63 50

CELL BIOLOGY (BIOS 2101): CONTINOUS ASSESEMENT, FIRST SEMESTER 2013/2014

Tuesday 28

January 2014, 15h00-16h00, Course Instructor: Dr SALAH

and the wrong answer is -0.5 mark.

(1). Dehydration synthesis is the process in which ____

(a) water molecules are attracted to each other (b) water molecules are used as a source of raw materials to

break down polymers to monomers (c) water molecules are formed in the formation of polymers from

monomers. (d) water molecules are attracted to each other and water molecules are formed in the formation

of polymers from monomers (e) none of these choices is correct.

(2) Glucose plus fructose forms a disaccharide called ___

(a) maltose (b) sucrose (c) starch (d) amino acid (e) cellulose

___ and the coils or folds are held in place by ___.

(a) tertiary structure, ..covalent bonds (b) primary structure, ..hydrogen bonds (c) secondary structure,

..peptide bonds (d) tertiary structure, ..covalent bonds (e) secondary structure, ..hydrogen bonds.

(5) The building blocks of nucleic acid molecules is called ___

(a) polysaccharides (b) amino acids (c) fatty acids (d) nucleotides (e) DNA and RNA

(6) which of these is a source of lactose?

(a) sugar beets (b) milk (c) potatoes (d) sugar cane (e) starch

(9) Proteins are polymers of ___

(a)CH

2

(10) The secondary structure of a protein results from ___

(a) hydrogen bonds (b) ionic bonds (c) hydrophobic interactions (d) peptide bonds (e) bonds between

sulfur atoms

(11) The two strands of a DNA double helix are held together by ___ that form between pairs of nitrogenous

bases.

(a) hydrogen bonds (b) ionic bonds (c) hydrophobic interactions (d) S-S bonds (e) covalent bonds.

(12) Which of these is an amino group?

(a) R-COOH (b) R-COH (c) R-OH (d) R-NH

(13) The four main categories of macromolecules in a cell are ___

(a) proteins, DNA, RNA and steroids (b) monosaccharides, lipids, polysaccharides and proteins (c) proteins,

nucleotide is to a nucleic acid (e) an amino acid is to a nuclei acid.

(15) which of the following do nucleic acids and proteins have in common?

(a) they are both made of amino acids. (b) their structure contain sugars (c) they are hydrophobic (d) They

are large polymers. (e) they each consist of four basic kinds and of subunits.

(16) A typical human cell is about __ micrometers in diameter.

(a) 1 to 2 (b) 10 to 20 (c) 80 to 100 (d) 150 to 200 (e) 200 to 300

(17) Which of the following statements concerning cells is incorrect?

(18) The rough endoplasmic reticulum

(a) is studded with ribosomes (b)synthesizes proteins for export from the cell or to construction of a new

cellular membrane. (c) is continuous with the smooth endoplasmic reticulum. (d) is connected nucleus.

(e) All of these answers.

(19) Of the organelles below which occurs in the lowest numbers within a typical human cell?

(a) mitochondria (b) vault (c) peroxisomes (d) lysosomes (e) nuclei

(20) Delivery of ribosomes to the endoplasmic reticulum involves

(a) a signal recognition protein (b) a leader sequence ribophorins. (d) a leader sequence and ribophorins

(22) Select the incorrect statement about the smooth ER.

(a) it is abundant in most cell types. (b) it is found in liver cells (c) specializes in lipid metabolism (d) the

sarcoplasmic reticulum is a modified form of it. (e) this organelle does not e ribosomes.

(23) Which of the following does not apply to lysosomes?

(a) They contain powerful hydrolytic enzymes (b) they give hydrogen peroxide (c) They remove useless

parts of the cell. (d) They attack material engulfed by the cell by me endocytosis. (e) They play an important

(24) The form of endocytosis in which whole cells such as bacteria are brought in is

(a) exocytosis (b) pinocytosis (c) ree mediated endocytosis (d) phagocytosis (e) mitosis

(25) Select the element that is not a part of the cytoskeleton. (a) inclusion (b) intermediate filaments. (c)

microfilaments (d) microtubular lattice (e) microtubules

(26) Microtubules (a) serve as a mechanical stiffener for microvilli (b) are specialized to detect sound and

positional channel the ear. (c) form nonmuscle contractile assembles. (d) play a structural role in parts of the

cell subject to mechanical stress (e) none of these answers

(28) The molecule which associates with microtubules to provide transport of secretory vesicles is

(a) actin (b) Actomyostin (c) Kinesin (d) tubulin (e)xyulin

(29) Intermediate filaments

(a) comprised mitotic spindles. (b) are important in cell regions subject to mechanical stress comprise cilia.

(d) comprise flagella. (e) form the basal bodies

(30) Glycolysis

(a) yields two molecules of ATP for each molecule of glucose processed. (b) requires oxygen (c) takes

B: if none of the answers is correct

C: if 1, 2 & 3 are correct

D: if 1, & 3 are correct

E: if 2, & 4 are correct.

(31) Plasma membranes: (1) Separate intracellular fluids from extracellular fluids. (2) Plays a dynamic role

in cellular activity, (3) Contains phospholipids and proteins. (4) Are not present in prokaryotes

(32) Fluid mosaic model indicates that the: (1) the cell membrane is a rigid structure, (2) is flexible without a

permanent form, (3) contain nuclei acids, (4) Proteins move freely in the Lipid bilayer

(35) Passive membrane transport systems are: (1) simple diffusion (2) Primary transport (3) Facilitated

diffusion (4) secondary transport

(36) Tonicity can be estimated as: (1) isotonic (2) hypertonic (3) hypotonic (4) osmotonic

(37) Active transport: (1) uses ATP, (2) Requires carrier proteins, (30 Can either be primary or secondary in

nature, (4) follows concentration gradient.

(39) Vesicular transport can be (1) Endocytosis (2) Antiport (3) Exocytosis (4) Symport

(40) G-protein acts: (1) Through a second messenger. (2) Through a first messenger. (3) Activates protein

kinase, (4) Deactivate protein kinase

Instructions: for questions 41 to 53, answer by selecting the letter that best answers the Question

(41) The organelles involved in protein transport:

a) ER and Golgi, b) ER and mitochondria, c) Golgi and mitochondria, d) lysosomes and Golgi

a) cell division, b) cell-cell recognition, c) assisting transport across cell membrane, d) cell storage reserve.

(44) Lipid bilayer is:

a) hydrophilic, b) hydrophobic, c) hydrophilic and hydrophobic, d) depends on the surrounding medium.

(45) In cell membrane, carbohydrates in glycoproteins or glycolipids are oriented:

a) towards outside, b) towards inside, c) towards outside and inside, d) randomly distributed.

(46) The plasma membrane is impermeable to all molecules except:

a) Glucose, b) ATP, c) urea, d) K

(49) Which of the following statements is false about enzyme kinetics

(a) An increase in the substrate concentration (at constant enzyme concentration) leads to proportional

increases in the rate of the reaction. (b) Most enzymes operating in the human body work best at a

temperature of 37

C. (c) An enzyme substrate complex can either form a product of dissociate back into the

enzyme and substrate. (d) maximal activity of human enzymes occurs around pis 7.2

(50) Some enzymes require the presence of non-protein molecule to behave catalytically. An enzyme devoid

of this molecule is can a(n)

a) holenzyme (b) apoenzyme (c) coenzyme (d) zymoenzyme

(a) decreasing the activation energy, (b) decreasing the overall free energy of the reaction. (c) both a and b

(d) none of the above

(53) Bonding between atoms within an enzyme such as trypsin is best described as

(a) glycosidic (b) saccaride (c) ionic (d) van der Waal’s.

Instructions: for question 54 to 60, answer by selecting the right letter that best answers the question, select:

A: if all the answers are correct

B: if none of the answers is correct

C: if 1, 2 & 3 are correct

D: if 1, & 3 are correct

E: if 2, & 4 are correct.

(54) Enzymes are: (1) Biological catalysts, (2) more than 40000 different types in the human cell, (3) were

first discovered by Buchiner in 1900 (4) Are unnatural proteins

(57) Cell signaling can use: (1) Endocrine (2) paracrine, (3) Autocrine, (4) Crozystrine

(58) G-protein coupled receptors are: (1) Transmembrane proteins, (20 Cytosolic, (3) Wind 7 times back and

forth, (4) Nuclear

(59) Steroid hormone receptors are: (1) Found within the nucleus, (2) Dinners of zinc-finger proteins, (3)

Are affecting the DNA functioning (4) Are transmembrane proteins.

(60) Metabolism involves: (1) Anabolism, (2) Endagonism, (3) Catabolism, (4) Exogonism