Biology 251-300 MCQs

Biology

251. Which of the following combinations is an example of self replicating organelles?

a. Mitochondria Ribosomes

b. Mitochondria Nucleus

c. Mitochondria Chloroplast

d. Mitochondria Vacuole

252. Which of the following is an autosomal disorder __________?

a. Down's syndrome

b. Klinefelter's syndrome

c. Turner's syndrome

d. Jacob's syndrome

253. Embryonic induction is caused by part developing from _________?

a. Endoderm

b. Ectoderm

c. Mesoderm

d. Extraembryonic layers

254. Sickle cell anemia is an example of _________?

a. Chromosomal aberration

b. Insertion of gene

c. Deletion of gene

d. Point mutation

255. The type of plastids which help in pollination is _________?

a. Chromoplasts

b. Leucoplasts

c. Chloroplasts

d. All of these

256. Purines and pyrimidines re in equal ratio in DNA. It was indicated by _________?

a. Friedrich Miescher

b. Chargaff

c. Watson & Crick

d. Hershey & Chase

257. Chlorophyll is a/an ________ molecule?

a. Inorganic

b. Cationic

c. Anionic

d. Organic

258. Ribonucleoprotein particles are the name of _________?

a. DNA

b. Nucleus

c. Eukaryotic ribosomes

d. RNA

259. Lock and Key model was proposed by _________?

a. Emil Fischer

b. Edward Koshland

c. Robin Williams

d. Rudolph Virchow

260. Which step causes activation of catalytic site of an enzyme __________?

a. Change in pH of the surroundings

b. Formation of Enzyme Substrate Complex

c. Change in the charge of the active site

d. Change in temperature

261. Amoeboid movements and movement of cyclosis is due to ________?

a. Microfilaments

b. Microtubules

c. Intermediate filaments

d. Cytoskeleton

262. Enzymes ________ the activation energy of a chemical reaction?

a. Increases

b. Decreases

c. Does not effect

d. Increases or decreases depending upon individual enzyme

263. Which one forms the raw material for coenzymes _________?

a. Vitamins

b. Carbohydrates

c. Proteins

d. Metals

264. Proteins and lipids are converted into glycolipids and glycoproteins by adding carbohydrates by _________?

a. Ribosomes

b. Cytoplasm

c. Golgi apparatus

d. Endoplasmic reticulum

265. Biological molecules (proteins) which catalyze a biochemical reaction and remain unchanged after completion of reaction are called _________?

a. Cofactor

b. Coenzyme

c. Activator

d. Enzymes

266. In which of the following location enzymes controlling cellular respiration are present ________?

a. Nucleus

b. Chloroplast

c. Mitochondria

d. Ribosome

267. In Golgi apparatus the maturing face is ________?

a. Biconcave

b. Convex

c. Spherical

d. Concave

268. A cofactor made of inorganic ion which is detachable is called _______?

a. Prosthetic group

b. Coenzyme

c. Activator

d. Cofactor

269. An activated enzyme consisting of polypeptide chain and a cofactor is called ________?

a. Apoenzyme

b. Holoenzyme

c. Activated enzyme

d. Both b & c

270. Centrioles are composed of ________ triplets of microtubules.

a. 3

b. 9

c. 10

d. 15

271. Which statement about enzyme is incorrect __________?

a. Some of them consist solely of protein with no non protein part

b. They catalyze a chemical reaction without being utilized

c. All enzymes are fibrous proteins

d. They without their cofactor are called apoenzyme

272. A three dimensional activity bearing a specific charge by which the enzyme reacts with its substrate is called ________?

a. Active site

b. Binding site

c. Catalytic site

d. Allosteric site

273. Cellular organelles related with H2O2 are _______?

a. Glyoxisomes

b. Lysosomes

c. Peroxisomes

d. Ribosomes

274. If more substrate to already occurring enzymatic reaction is added more enzyme activity is seen because ________?

a. There is probably more substrate present than there is enzyme

b. There is probably more enzyme available than there is substrate

c. There is probably more product present than there is either substrate or enzyme

d. The enzyme substrate complex is probably failing to form during the reaction

275. A group of ribosomes attached to mRNA is known as _________?

a. Polymer

b. Polypeptide

c. Polysomes

d. Monomer

276. The rate of reaction is directly proportional to the concentration of an enzyme which statement is incorrect in this respect _________?

a. Increase in enzyme molecule increases the available active sites

b. This relation is for unlimited time period with unlimited enzyme concentration

c. If the concentration is doubled the rate will become two fold

d. None of these

277. Which statement is incorrect about Lock and Key Model _________?

a. Specific enzyme can transform only a specific substrate

b. Active site of an enzyme is a non flexible structure

c. Active site does not change before during or even after the reaction

d. It explains the mechanism of every chemical reaction

278. If the concentration of enzyme is kept constant and amount of substrate is increased a point is reached where increase in substrates concentration does not affect the reaction rate because of __________?

a. Enzymes get denatured at higher substrate concentration

b. Rate of reaction is indirectly proportional to substrate concentration at this point

c. All the active sites on enzyme molecule are occupied

d. None of these

279. The active site of an enzyme _________?

a. Never changes

b. Forms no chemical bond with substrate

c. Determined by structure and the specificity of the enzyme

d. They are non specific in their action

280. Factory of Ribosomal synthesis is ________?

a. Cytoplasm

b. Nucleus

c. Nucleolus

d. Endoplasmic reticulum

281. If more substrate to already occurring enzymatic reaction is added and there is no effect on the rate of the reaction what is the form given to this situation ________?

a. Saturation

b. Denaturation

c. Composition

d. Inhibition

282. Who opposed the idea the cell is an empty space bounded by thick wall?

a. Lorenz Oken

b. Schwann

c. Robert Brown

d. Rudolph Virchow

283. Extreme change in pH results in ________?

a. Change in ionization of amino acids at the active site of the enzyme

b. Change in the ionization of the substrate

c. Denaturation of the enzyme

d. Increase in the reaction rate

284. Resolution power of a compound microscope is ________?

a. 2.0 micro m

b. 2-4 A

c. 24 micro m

d. 24 A

285. Excessive increase in temperature of medium causes the enzyme molecule to _________?

a. Activate

b. Unaffected

c. Denatured

d. None of these

286. If enzyme concentration is low than substrate pH and temperature values are equal to requirement then which of the following will increase rate of reaction _________?

a. increase in concentration of enzyme

b. increase in concentration of substrate

c. increase in pH

d. increase in temperature

287. In cell fractionation various components of cells including its organelles can be isolated in different layers depending upon _________?

a. Their physical properties like size & weight

b. Physical properties of the medium like its density

c. Their electrical properties like their charges

d. Both a & b

288. The structure of an enzyme is altered by _________?

a. Irreversible inhibitor

b. Reversible inhibitor

c. Competitive inhibitor

d. Non-competitive inhibitor

289. Malonic acid is an example of ________?

a. Irreversible inhibitor

b. Reversible inhibitor

c. Competitive inhibitor

d. Non-competitive inhibitor

290. Magnifying power of electron microscope as compared to eye is _________?

a. 500X

b. 250000X

c. 500000X

d. 250X

291. Inhibitors which block the enzyme by forming weak bond are called ________?

a. Competitive inhibitors

b. Non-competitive inhibitors

c. Irreversible inhibitors

d. Both a and b

292. Which of the statement about cell membrane is not true?

a. It contains protein molecules embedded in lipid bilayer

b. It is a differentially permeable membrane

c. It contains charged pores thus ions being charged particles cross cell membrane much easier than neutral particles

d. It may get unfolded to engulf solid or liquid material

293. A substance which binds at the active site of the enzyme but does not result in the formation of the products is called _________?

a. Irreversible inhibitor

b. Reversible inhibitor

c. Competitive inhibitors

d. Non-competitive inhibitors

294. A chemical substance which can react (in place of substrate) with the enzyme but is not transformed into product/s and thus blocks the active site temporarily or permanently is called ________?

a. Co-enzyme

b. Blocker

c. Inhibitor

d. Cofactor

295. Optimal temperature of enzymes present in human body is _________?

a. 27 degree C

b. 37 degree C

c. 47 degree C

d. 30 degree C

296. Strengthening material of prokaryotic cell wall is ________?

a. Cellulose

b. Chitin

c. Inorganic salts silica waxes and lignin

d. Peptidoglycan or Murein

297. Spherical or tubular membranes which separate the material present in endoplasmic reticulum from that of cytoplasmic material are called ________?

a. Cytosol

b. Cisternae

c. Polysomes

d. Cristae

298. Which is not the function of endoplasmic reticulum?

a. Nerve impulse conduction

b. Transport of material

c. Mechanical support

d. Synthesis of conjugated molecules

299. 60S and 40S subunit combine to form _________ particle.

a. 100 S

b. 90 S

c. 80 S

d. 70 S

300. Pancreas produces secretory granules that help in digestion. These granules after passing through endoplasmic reticulum are pinched off from _________ surface of Golgi apparatus:

a. Forming face

b. Maturating face

c. Any of them

d. None of these

Biology 201-250 MCQs

Biology

201. An antibody is made of ________ polypeptide chains?

a. 1

b. 2

c. 3

d. 4

202. 95% of the cytoplasm of RBCs is _________?

a. Hemoglobin

b. Enzymes

c. Salts

d. Other proteins

203. _________ cells of phloem are directly involved in transport of organic solutes?

a. Parenchyma

b. Companion cell

c. Tracheid

d. Sieve element

204. An infectious disorder of respiratory system is __________?

a. Cancer

b. Asthma

c. Tuberculosis

d. Emphysema

205. Cuticular transpiration is _________ of total transpiration?

a. 1-2%

b. 3-4%

c. 5-7%

d. 90%

206. According to cohesion-tension theory, tension is created by __________?

a. Hydrogen bonding

b. Transpiration

c. Adhesion

d. Root pressure

207. Deoxygenated blood first enters in _________ part in fishes?

a. Sinus venosus

b. Right atrium

c. Left atrium

d. Conus arteriosus

208. Ozone depletion occurs commonly due to _________?

a. Carbon dioxide

b. Chlorofluorocarbons

c. UV rays

d. Deforestation

209. Who coined the term CELL?

a. Schwann

b. Schleiden

c. Robert Hook

d. Both a & b

210. "lubb" sound is produced due to _________?

a. Opening of inlet valve

b. Closure of inlet valve

c. Opening of outlet valve

d. Closure of outlet valve

211. In condition of high temperature, following does not occur or occurs at low level ________?

a. Vasodilation

b. Activation of sweat glands

c. Thermogenesis

d. Evaporative cooling

212. Who first observed and thus hypothesized that new cells are formed from previously existing living cell?

a. Theodor Schwann and Schleiden

b. Rudolph Virchow's

c. Louis Pasteur

d. Both a & b

213. In Hardy-Weinberg formula P2 represents frequency of _________?

a. Recessive allele

b. Dominant allele

c. Homozygous dominant individual

d. Homozygous recessive individual

214. ________ supported theory of special creation?

a. Linnaeus

b. Aristotle

c. Mendel

d. Lamarck

215. Percentage of proteins in cell membrane is __________?

a. 20-40%

b. 40-60%

c. 60-80%

d. 80-100%

216. Which of the following is most constant abiotic component of ecosystem _________?

a. Air

b. Water

c. Land

d. Gravity

217. Ecosystem not found in Pakistan is ________?

a. Tropical rain forest

b. Temperate deciduous

c. Grassland

d. Tundra

218. Movement of the material across the cell membrane which does not requiring expenditure of metabolic energy is called _________?

a. Active transport

b. Passive transport

c. Co-transport

d. Counter transport

219. The productivity of aquatic ecosystem is basically determined by light and _______?

a. CO2

b. O2

c. Water

d. Nutrients

220. The first layer of cell wall which is formed is _________?

a. Primary wall

b. Secondary wall

c. Middle lamella

d. All of these

221. Annual rainfall is grassland is about _________?

a. More than 2500 mm

b. 750-1500 mm

c. 250-750 mm

d. Less than 250 mm

222. Conversion of ammonia or ammonium ion into nitrites during nitrogen cycle occurs due _________?

a. Rhizobium

b. Nitrosomonas

c. Nitrobacter

d. Pseudomonas

223. Cellulose is the major component of ________?

a. Primary wall

b. Secondary wall

c. Middle lamella

d. All of above

224. Humming bird is an example of ________?

a. Cold blooded animal

b. Ectotherm

c. Endotherm

d. Heterotherm

225. Number of cervical vertebrae is _________?

a. 5

b. 7

c. 9

d. 12

226. Autophagosomes are _________?

a. Those lysosomes which eat parts of their own cells to generate energy

b. Those lysosomes which eat old and worn out cellular organelles

c. Lysosomes which help in extracellular digestion

d. Both an & b

227. Sapwood is formed from ________?

a. Primary xylem

b. Secondary xylem

c. Primary phloem

d. Secondary phloem

228. Which of the following cytoskeletal fiber contain tubulin protein?

a. One which help in assembly of spindles during mitosis

b. One involved in internal cell motion

c. One involved in maintenance of cell shape

d. Both a & b

229. Only myosin is present in _________?

a. A band

b. I band

c. H zone

d. Sarcomere

230. Joints present in skull are example of __________?

a. Fibrous joints

b. Cartilaginous joints

c. Synovial joints

d. Slightly moveable joints

231. The human naked eye can differentiate between two points which are ______ apart?

a. 1.0 mm

b. 0.1 mm

c. 1.0 cm

d. 1.0 dm

232. ________ is a nervous disorder characterized by involuntary tremors, diminished motor power and rigidity?

a. Epilepsy

b. Meningitis

c. Alzheimer's disease

d. Parkinson's disease

233. Of the following which one is not the characteristic of mitochondria?

a. It contains F1 particles

b. It is involved in the synthesis of protein

c. It is a self replicating organelle

d. Number of mitochondria is constant

234. In human female, fertilization commonly occurs at __________?

a. Proximal part of oviduct

b. Distal part of oviduct

c. Uterus

d. Cervix

235. The part of chloroplast where CO2 is fixed to manufacture sugar is ________?

a. Stroma

b. Grana

c. Thylakoid

d. Outer membrane

236. Highest form of learning is _________?

a. Latent learning

b. Insight learning

c. Operant conditioning

d. Instinct

237. Which of the following hormone is polypeptide in nature _________?

a. Insulin

b. Thyroxine

c. ADH

d. Cortisone

238. Ribosomes are assembled in _________?

a. Nucleolus

b. Nucleus

c. DNA

d. RNA

239. Far-red light promotes flowering in _________?

a. Short day plant

b. Long day plant

c. Day neutral plant

d. None of these

240. Which of the following is not present in mitochondria?

a. Enzymes

b. Co-enzymes

c. Ribosomes

d. Thylakoids

241. Secretin inhibits production of ________?

a. Gastric juice

b. Pancreatic juice

c. Bile

d. All of these

242. Yellowish glandular structure which produces progesterone is _________?

a. Graafian follicle

b. Ovary

c. Corpus luteum

d. Placenta

243. The stent energy in the form of ADP is regenerated by mitochondria into ________?

a. AMP

b. ADP

c. ATP

d. All of these

244. On which of the following component of chloroplast chlorophyll is arranged?

a. Cell membrane

b. Matrix

c. Thylakoids

d. Stroma

245. An example of codominance is ________?

a. A' blood group

b. B' blood group

c. O' blood group

d. AB' blood group

246. Test cross is used to find _________?

a. Trait

b. Phenotype

c. Genotype

d. Ratios

247. Number of nuclear pores/nucleus in an RBC are _________?

a. 1/3

b. 3/4

c. 10000

d. 30000

248. Yellow cytoplasm in ascidian gives rise to _________?

a. Epidermis

b. Muscle cells

c. Gut

d. Notochord

249. Chlorophyll molecule contains __________ as central metal ion.

a. Fe2+

b. Mg2+

c. Zn2+

d. Cu2+

250. Okazaki fragments are connected together through action of __________?

a. Primase

b. Polymerase

c. Helicase

d. Ligase

Biology 151-200 MCQs

Biology

151. Which character differentiates living things from non-living organisms __________ ?

a. They live in the same ecosystem

b. They are acted upon by the same environment

c. They are highly organized and complex made of one or more cells and contain genetic material

d. Both a & b

152. The study of fossils is called _______?

a. Environmental

b. Historical biology

c. Paleontology

d. Social biology

153. A chemical substance that reacts with enzyme but is not transformed into product and thus blocking active site is called ________?

a. Substrate

b. Co-factor

c. Inhibitor

d. Promotor

154. The experiments on DNA molecules in chromosomes for knowing the basis of inherited diseases are conducted by _________?

a. Molecular biologists

b. Microbiologists

c. Freshwater biologists

d. Social biologists

155. Percentage of water in brain cells is ________?

a. 20%

b. 65%

c. 85%

d. 89%

156. The atoms of different elements combine with each other through ionic or covalent bonding to produce compounds this stable form is called ________?

a. An organ

b. A molecule

c. Tissue

d. Both a and c

157. Different species of plants and animals living in the same habitat is called _______?

a. Population

b. Community

c. Biome

d. Habitat

158. In animals coordination is achieved by means of ________?

a. Respiratory system

b. Nervous system

c. Endocrine system

d. Both b and c

159. _________ is the potential source of chemical energy for cellular activities?

a. C-H bond

b. C-O bond

c. C-N bond

d. P-O-C bond

160. The branch of biology which deals with the study of social behavior and communal life of human beings living in any environment is called ________?

a. Environmental biology

b. Social biology

c. Human biology

d. Both b and c

161. The concept that various organisms dominated this planet during various geological time period and thus placing organisms in a time sequence came from the studies by _________?

a. Environmental biologist

b. Paleontologist

c. Marine biologist

d. Social biologist

162. Group of living organisms of same species living in the same place at the same time is called ________?

a. Community

b. Population

c. Ecosystem

d. Biome

163. Control of organisms by using living organisms is called _________?

a. Bioremediation

b. Integrated disease management

c. Antisepsis

d. Biological control

164. Which one is a micro molecule ________?

a. Polysaccharide

b. Protein

c. Hemoglobin

d. ATP

165. Unbroken series of organisms arranged from ancestor to descendant sequence is _________?

a. Biodiversity

b. Phyletic lineage

c. Connecting link

d. Evolutionary line

166. Out of 92 naturally occurring chemical elements how many are considered as bio-elements ________?

a. 6

b. 16

c. 26

d. 15

167. A large regional community primarily determined by climate is called ________?

a. Population

b. Community

c. Biome

d. Habitat

168. Branch of biology which deals with the study of chemical components and chemical processes in living organisms is called _________?

a. Molecular biology

b. Physiology

c. Biochemistry

d. Atomic biology

169. A structure formed by groups of similar cells organized into loose sheets or bundles performing similar functions is called as ________?

a. An organ

b. An organism

c. A tissue

d. A cell

170. Oxygen accounts for ________ percent of totals human body mass?

a. 65%

b. 18%

c. 10%

d. 3%

171. Out of total organisms on earth, _________ are vascular plants?

a. 53.10%

b. 19.90%

c. 17.60%

d. 9.40%

172. Breakdown of large molecules into smaller ones utilizing water molecules is _________?

a. Hydration

b. Hydrolysis

c. Dehydration synthesis

d. Dehydration synthesis

e. Electrolysis

173. Intake of liquid material by cell membrane is called _________?

a. Endocytosis

b. Exocytosis

c. Phagocytosis

d. Pinocytosis

174. Which one is not correct for a productive theory _________?

a. It is predictive

b. It has explanatory power

c. It discourages suggestion of different hypothesis

d. None of these

175. _______ is concerned with cell secretions?

a. Endoplasmic reticulum

b. Golgi complex

c. Lysosomes

d. Cell membrane

176. Synthetic insulin from pork was formed by which technique _________?

a. Parasitology

b. Social biology technique

c. Biotechnology

d. Both a and c

177. Cytoskeleton involved in assembly and disassembly of the spindle during mitosis is of ________ ?

a. Microtubules

b. Microfilaments

c. Intermediate filaments

d. None of these

178. _________ is used to relieve one kind of headache, migraine?

a. Penicillin

b. Lovastatin

c. Cyclosporine

d. Ergotin

179. Bacteria which grow either in the presence or absence of oxygen ________?

a. Aerobic bacteria

b. Anaerobic bacteria

c. Facultative bacteria

d. Microaerophilic

180. It is possible to date the rocks by comparing the amount of specific radioactive isotopes they contain. Which of the statement is correct in this respect:

a. Older sediment layers have equal amount of these radioactive isotopes as that of the young ones

b. Older sediment layers have less amount of these radioactive isotopes as that of the young ones

c. Older sediment layers have greater amount of these radioactive isotopes as that of the young ones

d. Older sediment layers did not have these radioactive isotopes

181. Reverse transcriptase is present in ________?

a. All RNA viruses

b. All DNA viruses

c. All retroviruses

d. All viruses

182. Destruction of all life forms is called ________?

a. Sterilization

b. Disinfection

c. Antisepsis

d. Preservation

183. Pox viruses are ________?

a. RNA non-enveloped

b. RNA enveloped

c. DNA non-enveloped

d. DNA enveloped

184. Pollen grains in Pinus have ________ for dispersal through wind?

a. Flagella

b. Cilia

c. Wings

d. Feathers

185. The single healthy megaspore retained within the megasporangium germinates to form an egg containing female gametophyte called _______?

a. Ovule

b. Seed

c. Fruit

d. Embryo sac

186. Alternation of generation is absent in _________?

a. Hydration

b. Obelia

c. Jelly fish

d. Physalia

187. Double fertilization is feature of ________?

a. Ferns

b. Whisk ferns

c. Gymnosperms

d. Angiosperms

188. If bile pigments are prevented from leaving digestive tract, then they cause ________?

a. Hepatitis

b. Jaundice

c. Gall stones

d. Blockage

189. Initial pH of food vacuole during digestion in amoeba is ________?

a. 5.3

b. 5.6

c. 7.3

d. 7.6

190. The arrangement of _______ speaks of the division of labour within cell?

a. Molecule

b. Subatomic particles

c. Atoms

d. Organelles

191. NADH is oxidized by ________?

a. Coenzyme

b. Cytochrome

c. Oxygen

d. Glycolysis

192. Salivary glands present in the front of ear are ________?

a Sublingual

b. Submaxillary

c. Submandibular

d. Parotid

193. How many spiracles are present in cockroach _______?

a. 5

b. 10

c. 20

d. 40

194. Which of the following is the correct sequence n the biological method?

a. Observation-Hypothesis-Law-Theory

b. Observation-Hypothesis-Deduction-Testing of deduction

c. Hypothesis-Observation-Deduction-Testing of deduction

d. Law-Theory-Deduction-Observation

195. Amphibians are considered to be evolved from _______?

a. Newts

b. Varanope

c. Dipnoi

d. Hagfishes

196. Enterobius vermicularis is commonly known as ________?

a. Flatworm

b. Pinworm

c. Hook worm

d. Tapeworm

197. Red to orange pigments are ________?

a. Carotenes

b. Carotenoids

c. Xanthophylls

d. Chlorophyll

198. Animals of which class of arthropoda are present everywhere _______?

a. Crustacean

b. Insecta

c. Arachnida

d. Myriapoda

199. Gaseous exchange in birds occurs at level of _________?

a. Alveoli

b. Air sacs

c. Bronchi

d. Parabronchi

200. ________ of earth surface is covered with water?

a. 10%

b. 30%

c. 75%

d. 90%