Bio IB Exam review

Which of the following is a function of cellulose in plants?
A. Storage of fat
B. Formation of mitochondria
C. Storage of energy
D. Formation of cell walls

D. Formation of cell walls

What is the difference between galactose and lactose?
A. Lactose is a disaccharide and galactose is a monosaccharide.
B. Lactose is the product of anaerobic respiration in humans and galactose is the product of anaerobic respiration in yeast.
C. Lactose is an enzyme and galactose is a hormone.
D. Galactose is a sugar found in milk but lactose is not found in milk.

A. Lactose is a disaccharide and galactose is a monosaccharide.

What is a role of carbohydrates in animal cells?
A. As channels for passive transport
B. As enzymes
C. As energy storage
D. As components of the animal cell wall

C. As energy storage

Which is not a primary function of protein molecules?
A. Hormones
B. Energy storage
C. Transport
D. Structure

B. Energy storage

Which of the following reactions occurs when a dipeptide is formed from amino acids?
A. Hydrolysis
B. Denaturation
C. Condensation
D. Oxidation

C. Condensation

What is denaturation?

A. A structural change of a protein that results in the loss of its biological properties
B. A change in the genetic code of an organism
C. A change in the amino acid sequence of a protein causing a disruption of its 3D shape
D. The process by which amino acids are broken down and ammonia is released

A. A structural change of a protein that results in the loss of its biological properties

A red blood cell is 8 um in diameter. If drawn 100 times larger than its actual size, what diameter will the drawing be in mm?
A. 0.08 mm
B. 0.8 mm
C. 8 mm
D 80 mm

D 80 mm

In a cell, what is the effect of a large surface area to volume ratio?
A. Slower rate of exchange of waste materials
B. Faster heat loss
C. Faster rate of mitosis
D. Slower intake of food

A. Slower rate of exchange of waste materials

Which of the following characteristics found in a structure necessarily indicates that it is alive?

A. The presence of genetic material
B. The presence of a lipid bilayer
C. Metabolism
D. Movement

C. Metabolism

What does therapeutic cloning involve?
A. Developing genetically identical cultures of human cells for use in drug testing
B. Helping infertile couples to conceive by injecting the father's sperm into the mother's egg
C. Producing embryonic stem cells for medical use
D. Replacing a mutant allele in an embryo to prevent genetic disease

A. Developing genetically identical cultures of human cells for use in drug testing

A cell has cytoplasm, a cell wall, naked DNA and ribosomes. Based on this information, what type of cell could this be?
A. A cell from a pine tree
B. A grasshopper cell
C. A human red blood cell
D. A bacterium

D. A bacterium

Which of the following structures are found in all cells?

A.Mitochondria
B. Cell walls
C. Chloroplasts
D. Ribosomes

D. Ribosomes

How do prokaryotic cells divide?

A. By mitosis
B. By meiosis
C. By budding
D. By binary fission

D. By binary fission

The percentage of thymine in the DNA of an organism is approximately 30%. What is the
percentage of guanine?
A. 70%
B. 30%
C. 40%
D. 20%

D. 20%

What happens during the formation of Okazaki fragments?
A DNA polymerase III adds nucleotides in the 3°

\> 5' direction.
B. DNA polymerase IlI adds nucleotides in the 5'

What principle is necessary to preserve the sequence of DNA during replication?
A Base pairing is complementary.
B. One gene codes for one polypeptide.
C. Substrates are specific to enzymes
D. The genetic code is universal.

A Base pairing is complementary.

What does a nucleosome consist of?
A. DNA and histones
B. DNA and chromatin
C. Chromatin and nucleotides
D. Mature RNA and histones

A. DNA and histones

Which base is connected to its complementary base in a base pair by three hydrogen bonds?
A. Uracil
B. Thymine
C Guanine
D.Adenine

C Guanine

What is the distinction between highly repetitive DNA sequences and single

copy genes?
A. The highly repetitive sequences have greater amounts of guanine.
B. The highly repetitive sequences have greater amounts of cytosine.
C. The highly repetitive sequences are not translated.
D The highly repetitive sequences are not replicated.

Which enzyme removes the RNA primer during replication?
A. RNA primase
B) DNA polymerase I
C. DNA ligase
D. Helicase

B) DNA polymerase I

The percentage of bacteria showing antibiotic resistance in Neisseria gonorrhoeae and other species of disease

causing bacteria has risen considerably since antibiotics were introduced. What has caused this increase?
A. When a bacterium detects an antibiotic, it changes its metabolism so that it becomes resistant.
B. When people do not complete courses of antibiotic, bacteria that were partly resistant become more resistant.
C. When a bacterium is treated with an antibiotic, it increases its resistance to the antibiotic and passes on increased resistance to its offspring.
(D. When an antibiotic is used, only bacteria that are resistant to it survive and these bacteria pass on resistance to their offspring.

What is evolution?
A. A measure of the relative survival and reproductive success of an individual
B. A cumulative change in the genetically controlled characteristics of a population
C. A physical change during an organism's life that is inherited by its offspring
D. A random change in the proportions of alleles from generation to generation

B. A cumulative change in the genetically controlled characteristics of a population

Which process tends to reduce variety within a population?
A. Natural selection
B. Random fertilization
C. Independent assortment
D. Crossing over

A. Natural selection

Charles Darwin used domesticated animals to provide evidence for evolution by natural selection.
What is this evidence?
A. Differences between breeds show that selection can cause species to change.
B. The ancestors of domesticated animals can be found in the fossil record.
C. Some domesticated animals die because the environment cannot support them all.
D. Variation in domesticated animals is due to sexual reproduction.

A. Differences between breeds show that selection can cause species to change.

What is responsible for the conservation of the base sequence during DNA replication?
A. DNA polymerase working on one strand at the same time.
B. Unpaired bases always attracting their complementary nucleotides.
C. DNA helicase and polymerase are complementary.
(D Both strands are identical to each other.

B

Which enzyme removes the RNA primer during replication?
A RNA primase
B. DNA polymerase I
C. DNA ligase
D. Helicase

B

What are Okazaki fragments?
A. Short lengths of RNA primase attached to the DNA during replication
B. Short sections of DNA formed during DNA replication
C. Nucleotides added by DNA polymerase I in the same direction as the replication fork
D. Sections of RNA removed by DNA polymerase III and replaced with DNA

B

What is the reason for Okazaki fragments being formed during DNA replication?
A. To enable replication of the 3'

› 5' (lagging) strand
B. To form the template for the RNA primers
C. To initiate replication on the 5'

A biochemist isolated and purified molecules needed for DNA replication. When some DNA was added replication occurred, but the DNA molecules formed were defective. Each consisted of a normal DNA strand paired with segments of DNA a few hundred nucleotides long. Which of the following had been left out of the mixture?
A. DNA ligase
B. Helicase
C. Nucleotides
D. DNA polymerase

A. DNA ligase

Where in the body are type I pneumocvtes found?
A. Alveoli
B. Nephrons
C. Capillaries
D. Trachea

A. Alveoli

Which process results in the exchange of gases across the membrane of pneumocytes?
A. Active transport
B. Simple diffusion
C. Facilitated diffusion
D. Mass flow

B.

Blood clotting involves a cascade of reactions. Which statement describes the blood

clotting process?
A. Red blood cells release clotting factors that result in the production of fibrin.
B. Clotting factors trigger the conversion of the inactive thrombin to prothrombin.
C. Insoluble fibrinogen is converted into soluble fibrin.
D. Fibrin forms a mesh that traps platelets and bload cells.

Some strains of the pathogenic bacterium Stanlvococcus aureus have developed mechanisms that protect them against foreign
DNA. What effect does this have on the evolution of antibiotic resistance in these strains of S. aureus?
A. Slower evolution, as bacteria with the antibiotic resistance gene will not reproduce
B. Slower evolution, as the antibiotic resistance gene from other species will not be accepted
C. Faster evolution, as mutations within a population are less likely to occur
D) Faster evolution, as antibiotic resistance genes can only be passed to individuals of the same species

B

Many blood

feeding insects inject an anticoagulant into their host in order to prevent blood from clotting. Female mosquitoes of the 11 mark] genus Anopheles inject the anticoagulant anophelin, which inhibits the action of the enzyme thrombin. Which statement explains how anophelin prevents blood clotting?
A. Platelets are no longer produced.
B. Platelets cannot produce fibrin.
C. Fibrinogen is not converted to fibrin.
D. Prothrombin is not converted to thrombin.

What is a property af arteries?
A. Arteries have elastic walls.
B. Arteries have valves.
C. All arteries carry oxygenated blood.
D. Arteries receive blood from the atria.

A

What is a feature of phagocytic white blood calls?
A. Stimulate blood clotting
B. Found only in the circulatory system
C. Form part of non

specific immunity
D. Produce antibodies

What is non

specific immunity to disease?
A. Blocking prokaryotic metabolism with antibiotics
B. Production of antibodies by lymphocytes
(C Endocytosis of pathogens by white blood cells
D. Production of cloned plasma cells

Which feature of capillaries distinguishes them from arteries and veins?
A. Narrow diameter
B) Valves to prevent backflow
C. Thick muscular walls
D. Elastic tissue

B

Which statement applies to HIV?
A. HIV infects red blood cells resulting in decreased production of hemoglobin.
B. HIV can be effectively treated using antibiotics.
C. HIV can only be transmitted by sexual intercourse.
(D) HIV causes a reduction in production of antibodies.

D

Florey and Chain injected four mice with Streptococcus bacteria and then penicillin and all four mice recovered from the infection.
What would be essential to show that penicillin caused their recovery?
(A) A control group that was infected but not treated with penicillin
B. Experiments to test for effects of penicillin on other bacteria
C. Experiments to test for effects of different dosages of penicillin in mice
D. Determination of the chemical structure of penicillin

A

What is a property af arteries?
A. Arteries have elastic walls.
B. Arteries have valves.
C. All arteries carry oxygenated blood.
D. Arteries receive blood from the atria.

A

What is a feature of phagocytic white blood calls?
A. Stimulate blood clotting
B. Found only in the circulatory system
C. Form part of non

specific immunity
D. Produce antibodies

Blood clotting involves a cascade of reactions. Which statement describes the blood

clotting process?

A. Red blood cells release clotting factors that result in the production of fibrin.
B. Clotting factors trigger the conversion of the inactive thrombin to prothrombin.
C. Insoluble fibrinogen is converted into soluble fibrin.
D. Fibrin forms a mesh that traps platelets and bload cells.

What type of enzyme could be used to cut a DNA molecule as indicated by the dotted line on the
diagram below?

Restriction enzyme

A small amount of a suspect's DNA is obtained from a crime scene. What techniques would be used to carry out DNA profiling?

Polymerase chain reaction (PCR) and gel electrophoresis

How are plasmids used in biotechnology?

For gene transfer

Which process is used in polymerase chain reaction (PCR)?

Replication

How are enzymes used during gene transfer involving plasmids?

To cut plasmids
To extract gene from DNA
To rejoin DNA

What was an aim of genetic modification of organisms?

To make crop plants resistant to herbicides

What could be achieved by DNA profiling using gel electrophoresis?

It could be shown that human tissue found at the site of a crime did not come from a person suspected of having committed the crime.

State two properties of the fragmented pieces of DNA which allow them to be separated in gel electrophoresis.

Charge and Size

Apart from determining family relationships, outline one other application for DNA profiling.

Identifying criminals

The sequence of nucleotides in a section of RNA is:
GCCAUACGAUCG

GCCATACGATCG

What is a codon?

A sequence of nucleotides on mRNA that corresponds to an amino acid

Which of the following reactions occurs when a dipeptide is formed from amino acids?

Condensation

A certain gene codes for a polypeptide that is 120 amino acids long. Approximately how many nucleotides long is the mRNA that codes for this polypeptide likely to be?

360

Which are the correct directions of the following processes?
Replication
Transcription
Translation

5' to 3'

A human organ is being prepared for transplant. In what type of solution must it be bathed?

A solution with the same osmolarity as the organ tissue

By which process do potassium ions move through potassium channels in axons?

Active transport

What feature of cell membranes allows endocytosis to occur?

Fluidity of phospholipid bilayer

Cells in the adrenal gland produce the hormone epinephrine and store it in vesicles. To release epinephrine these vesicles are
carried to the plasma membrane and fuse with it. What process is occurring?

Exocytosis

Which statement applies to cholesterol?
A. It is hydrophobic and found on the outside of the phospholipid bilayer.
B. It is hydrophilic and found inside the phospholipid bilayer.
C. It impacts membrane fluidity.
D. It is transported in association with glucose in the blood.

C

What special property of phospholipid molecules explains their ability to spontaneously assemble into a lipid bilaver?
A. They are hydrophobic.
B) They are amphipathic.
C. They are saturated.
D. They are hydrophilic

B

Which is an essential feature of the Davson

Danielli model of membrane structure?
A. A phospholipid monolayer with intrinsic and extrinsic proteins
B. A layer of protein sandwiched between two layers of lipid
C. A phospholipid bilayer with intrinsic and extrinsic proteins
D. A layer of lipid sandwiched between two layers of protein

The cell membrane model proposed by Davson

Danielli was falsified by the Singer

The giant alga Acetabularia has a feature that suggests it is an exception to the cell theory. What
feature is this?
A. It lacks a nucleus.
C. It has only one mitochondrion.
B. It lacks a cell wall.
D. It lacks subdivision into separate cells.

D

Which feature of striated muscle cells allows them to be considered as a possible exception to the
cell theorv?
A. They are found in multicellular organisms.
B. They contain more than one nucleus.
C. They are specialized for movement.
D. They do not carry out mitosis.

B

The statement relates to Pasteur's experiments.
In his experiments, Louis Pasteur demonstrated that
if broth was boiled to kill all organisms and was then kept in swan

necked flasks, preventing the entry of organisms, no organisms grew in the broth if the swan

What can be deduced about a striated muscle fibre from both of these statements?
"A eukaryotic cell has one nucleus."
"A striated muscle fibre has many nuclei."
A. It is prokaryotic.
B.It is an exception to cell theory.
C. It consists of aseptate hyphae.
D. It is preparing to divide.

B

Which functions of life are carried out by all unicellular organisms?
A. Response, homeostasis, growth and photosynthesis
B. Metabolism, ventilation, reproduction and nutrition
C Response, homeostasis, metabolism and growth
D. Reproduction, ventilation, response and nutrition

C

Which of the following will contribute to the cell theory?
I. Living organisms are composed of cells.
IL. All cells come from pre

existing cells by mitosis.
IlI. Cells are the smallest units of life.
A l only
B. Il only
C. I and IlI only
D. I, Il and IlI

Which of the following characteristics found in a structure necessarily indicates that it is alive?
A. The presence of genetic material
B. The presence of a lipid bilayer
C. Metabolism
D. Movement

C

Which of the following structures are found in all cells?
A. Mitochondria
B. Cell wall
C. Chloroplasts
D. Ribosomes

D

Which of the following structures are present in both plant and animal cells?
I. Cell wall
Il. Chloroplast
IlI. Mitochondrion
A. I only
B. I and Il only
C I and Ill only
D. Ill only

D

What route is used to export proteins from the cell?
A. Golgi apparatus

› rough endoplasmic reticulum

What is an example of binary fission?
Cell division in prokaryotes
B. Production of haploid gametes
C. Separation of chromatids in prokaryotic cells
D. Replication of prokaryotic DNA occurring simultaneously in two directions

Cell division in prokaryotes

An unknown cell is observed using a microscope. A cell wall, ribosomes and DNA are identified. What can
be concluded from these observations?

It could be a prokaryotic or eukaryotic cell.

If the amount of DNA in a haploid gamete is represented by x, what is the net quantity of DNA in a:
cell from the same organism at the start of meiosis?
A. 0.5x
B. x
C. 2x
D. 4x

D

What description is matched with the correct phase in meiosis I?
4×
A.
Prophase I Crossing over occurs only between sister chromatids
B
Metaphase I Homologous chromosomes join together at each end of the cell
C
Anaphase I Homologous chromosomes are pulled apart
D.
Telophase I Two diploid nuclei are produced

C

What are homologous chromosomes?
A. Two chromosomes with differing sets of genes, in the same sequence, with the same alleles.
B. Two chromosomes with the same set of genes, in a different sequence, with the same alleles.
C. Two chromosomes with a different set of genes, in the same sequence, with different alleles.
D. Two chromosomes with the same set of genes, in the same sequence, sometimes with

D

What does a karyotype show?
A. Gel electrophoresis bands from DNA
B. The number and appearance of chromosomes:
C. A pair of alleles controlling a specific character.
D. All the genes possessed by a living organism.

B

Which of the following statements relate(s) to Down syndrome (trisomy 21)?
I. It can be detected in chorionic villus samples.
If. It results from non

disiunction in meiosis.
Ill. It is caused by gene mutation.
(A. I and Il only
B. I. and Ili only
C. Il only
D. Ill only

What happens in crossing over?
A. Exchange of genetic material between homologous chromosomes
B) Exchange of genes during metaphase of mitosis
E. Random distribution of chromosomes during meiosis
D. Homologous chromosomes fail to separate during meiosis

A

Colchicine is a chemical substance that prevents the formation of microtubules. What stage of mitosis would
be prevented, if dividing cells were treated with colchicine?
A. Breaking down of the nuclear membrane
B. Replication of DNA
C, Separation of chromatids
D. Supercoiling of chromosomes

C

What ensures that mitosis produces two genetically identical nuclei?
A. One of each of the twenty

three types of chromosome is pulled to each pole of the cell by spindle
microtubules.
B. Half of the chromosomes are pulled to each centriole by mesosomes.
C,., Identical chromatids are pulled to opposite poles by spindle microtubules.
D. DNA molecules are moved to the equator of the cell where they are replicated.

What is a difference between a cell in the G1 phase and a cell in the G, phase of the cell cycle?
A. A cell in the G2 phase would be smaller than a cell in the G1 phase.
B. A cell in the G2 phase would have more mitochondria than a cell in the G1 phase.
C. A cell in the G1 phase would have more DNA in its chromosomes than a cell in the G2 phase.
D. DNA replication occurs in the G1 phase but not in the G2 phase.

B

Which statement about water is correct?
A. The atoms within a molecule of water are held together by hydrogen bonds.
B. Water has a low heat capacity allowing enzymatic reactions to happen at a wide range of temperatures.
C. Water molecules are polar, therefore fatty acids do not dissolve.
D. Ice has a higher density than liquid water, therefore some organisms can live under the ice.

C

Blood is a water

based transport medium. Which property of water makes it a good transport medium?
A) High specific heat
C. Versatility as a solvent
B. Transparency
D. It has its greatest density at 4°C

d. Which of the following features are correct for hydrogen bonding?
I. It is involved in the cohesion of water.
II. It results in the thermal properties of water.
Ill. It is a bond within the water molecule.
A. I and Il only
B. Il and Ill only
C. I and Ill only
D. I. Il and IlI

A

What is the maximum number of fatty acids that can be condensed with glycerol?
A. One
B. Two
C. Three
D. Four

C

Olive oil may reduce the risk of coronary heart disease. What is/are the compound(s) responsible for the
health benefits of olive oil?
I.Cis unsaturated fatty acids
I. Trans unsaturated fatty acids
IlI. Saturated fatty acids
A. I only
B. I and Il only
C. Il and III only
D. I, Il and III

A

Which of the following is TRUE regarding saturated fatty acids?
A. They are the predominant fatty acid in corn oil.
B. They have double bonds between carbon atoms of the fatty acids.
C. They are the principal molecules in lard and butter.
D. They are usually liquid at room temperature.

C

Which of the following best summarizes the relationship between condensation reactions and
hydrolysis?
A. Condensation reactions assembly polymers, and hydrolysis reactions break down polymers.
B. Macromolecular synthesis occurs through the removal of water and digestion occurs through the addition of water.
C. Condensation reactions can occur only after hydrolysis.
D. Hydrolysis creates monomers, and condensation reactions break down polymers.
E. A and B are correct

E

Which type of metabolic reaction occurs when a dipeptide is formed from amino avids?
A. anabolism
B. denaturation
C. catabolism
D. oxidation

A

4. How many molecules of water are required to completely hydrolyse a poly peptide made up ot
amino acids?
A. 11
B. 22
C 23
D 44

B

What is a proteome?
A. The genes that code for all the proteins in the ribosome
B. The group of proteins that generate a proton gradient in mitochondria
C. The entire genome ol a prokaryote
D) The entire set of proteins expressed by an organism at a certain time

D

Which variable has the least effect on enzyme activity?
A. Temperature
B. light intensity
C. pH
D. Substrate concentration

B

Which of the following could cause denaturation of an enzyme?
A. substrate concentration
B. low salt concentration
C. high temperature
D. increasing speed of enzyme

C

What occurs in the induced fit model for enzyme catalysed reactions?
A. There is an exact fit between a specific substrate and a specific enzyme.
B. The enzyme can change shape to accommodate the substrate.
C. The substrate can change its shape to fit a number of enzymes.
D. Other substrates can bind away from the active site.

B

The function of each protein is a consequence of its specific shape. What is the term used for a change
in a protein's three

dimensional shape or conformation due to disruption of hydrogen bonds, disulfide
bridges, or ionic bonds?
A. hydrolysis
B. stabilization
C denaturation
D. destabilization