Paper 2B Questions, IB Biology HL Exam, 1996 – 2014. Must answer 2 of the 4 choices.
Note: Each of these questions is worth 18 points for content. A student can earn up to 2 additional marks for quality of construction if s/he ‘Consistently expresses relevant ideas with clarity,’ AND, ‘Consistently links ideas (relevant or
irrelevant) in a logical sequence.’ Note also that the IB Bio course is periodically revised, so an older question might not exactly fit the current year’s objectives. Our course was last revised in 2009.
Year
1996
First choice
a) Draw a simple diagram of the
molecular structure of DNA. 5
b) Outline how protein combines with
DNA to form the eukaryotic
chromosome. 4
c) Compare the processes of DNA
replication & transcription. 9
1998
a) Draw a diagram of the human gas
exchange system. 4
b) Explain how & why breathing rate
varies with exercise. 8
c) Outline the role of oxygen in
providing cells w/ energy. 6
1999
a) Describe how replicated DNA
molecules are separated to form two
genetically ID nuclei during mitosis in
animal cells. 8
b) Explain the relationships between
tissues, organs & organ systems in
multicellular organisms such as
humans. 5
c) Discuss whether the light
microscope or the EM is more useful
for studying cells, tissues & organs. 5
a) List 4 functions of membrane
proteins. 4
b) Describe with examples the
secondary structures of proteins. 5
c) Explain how proteins act as
enzymes, including control by
feedback inhibition in allosteric
enzymes. 9
2000
Second choice
a) Draw the structure of the human
female reproductive system immediately
before ovulation. 6
b) Outline the levels of each of the
hormones that control the menstrual cycle
immediately before ovulation. 3
c) Explain the processes involved in human
oogenesis. 9
a) Outline the reasons for classifying
living organisms. 4
b) Describe the features used to
distinguish between plants and fungi. 6
c) Compare how a parasitic fungus & a
saprotrophic fungus obtain nutrients,
giving a named example of each. 8
Third choice
a) List the structures that are found in
angiospermophytes but not in
bryophytes. 4
b) Outline the gas exchange pathways in
the root of a plant growing in soil. 5
c) Explain how the root of a plant
carries out water uptake. 9
Fourth choice
a) Define, with examples, the term
homeostasis. 4
b) Outline ways in which the kidney helps
in homeostasis. 5
c) Discuss ways in which equilibrium is
maintained in the biosphere. 9
a) State, w/ examples, the main
features of metabolic pathways. 6
b) Explain how metabolic pathways in
cells are controlled by means of
negative feedback. 8
c) Outline the role of positive feedback
in the process of birth in humans. 4
a) Outline the light-independent reactions
of photosynthesis in C3 plants. 8
b) Explain why the light-independent
reactions of photosynthesis in C3 plants
can only continue for a short time in
darkness. 6
c) Compare the roles of carbon dioxide,
oxygen, light and heat in photosynthesis
with their effects on seed germination. 4
a) Outline how enzymes in the cytoplasm
of cells are produced. 8
b) Compare the induced fit model of
enzyme activity with the lock & key
model. 4
c) Explain, using one named example, the
effect of a competitive inhibitor on
enzyme activity. 6
a) Draw a generalized prokaryotic cell,
indicating its size, & illustrating the
structures that would be visible with an
EM. 5
b) Compare the structure of prokaryotes
w/ that of mitochondria & chloroplasts. 8
c) Outline one example of control of gene
expression in prokaryotes. 5
a) Describe the processes involved in
spermatogenesis. 8
b) Explain the hormonal control of puberty
in boys. 5
c) Discuss the ethical issues of
contraception. 5
a) Describe the structure of triglycerides
(fats). 6
b) Outline the use of fats in cell
respiration. 4
c) Explain how the structure of the
mitochondrion allows it to carry out its
function efficiently. 8
a) Draw a diagram to show the
structure of a motor neuron. 5
b) Outline the changes that lead to the
depolarization of an axon as an action
potential travels along a neuron. 5
c) Explain how a nerve impulse is
transmitted from a motor neuron to a
muscle. 8
a) Draw a diagram to show the distribution
of tissues in the root of a young dicot
plant. 5
b) Outline two adaptations of
hydrophytes. 4
c) Explain the process of water uptake by
roots. 9
2001
a) Describe the process of
fertilization in humans. 6
b) Outline the way in which a
pregnancy can be detected at a very
early stage. 4
c) Explain the factors that cause a
population to follow the sigmoid (Sshaped) growth curve. 8
a) Draw a diagram of a prokaryotic cell. 6
b) Outline the structure of the
nucleosomes in eukaryotic chromosomes.
4
c) Explain how DNA replication is carried
out by eukaryotes. 8
a) Draw a diagram to show the
structure of a cell membrane. 5
b) Outline the ways in which substances
move passively across membranes. 5
c) Explain how ATP is produced by
photophosphorylation in chloroplasts. 8
a) Compare the way in which autotrophic,
heterotrophic, and saprotrophic organisms
obtain energy. 6
b) Outline the international system used
for naming species of living things. 4
c) Discuss the definition of the term
species. 8
2002
a) Outline the general features used
to classify organisms into the
kingdoms Prokaryotae, Protoctista,
Fungi, Plantae & Animalia. 5
b) Outline a technique for
transferring genes between species.
5
c) Discuss the need to maintain the
biodiversity of organisms as a
reservoir of alleles. 8
a) Draw a diagram to show the distribution
of tissues in a cross-section of a root in a
dicot plant. 5
b) Describe the process of mineral ion
uptake into roots. 5
c) Explain the functions of the different
tissues in a leaf. 8
a) Draw the structure of a
mitochondrion as seen in an electron
micrograph. 5
b) Describe the central role of acetyl
CoA in carbohydrate and fat
metabolism. 5
c) Discuss the importance of a balanced
diet for people with varying energy
needs. 8
a) Discuss the ways in which proteins
within the cell are transported to the cell
surf. 4
b) Describe the roles of mRNA, tRNA, and
ribosomes in translation. 6
c) Discuss the theory that species evolve
by natural selection using two named
examples. 8
2003
a) Draw a diagram of the
ultrastructure of an animal cell as
seen in an EM. 6
b) Describe the process of active
transport. 4
c) Explain the process of aerobic
respiration including oxidative
phosphorylation. 8
a) Draw the structure of a dicot animalpollinated flower. 6
b) Compare the adaptations of xerophytes
& hydrophytes. 8
c) Describe how water is transported in a
plant. 4
a) Define the terms active, passive,
natural and artificial immunity. 4
b) Explain the role of antibody
production with regard to vaccinations.
8
c) Describe the roles of nerves,
muscles, and bones in producing
movement. 6
a) Outline the process of fertilization in
humans. 6
b) Describe how sexual reproduction
promotes genetic variation within a
species. 4
c) Explain how energy and nutrients enter,
move through, and exit a food chain in an
ecosystem. 8
2004
a) Outline enzyme-substrate
specificity. 5
b) Explain how allosteric control of
metabolic pathways by end-product
inhibition includes negative feedback
and non-competitive inhibition. 8
c) Distinguish between fibrous and
globular proteins, giving one example
of each. 5
a) State a role for each of four different
named enzymes in DNA replication. 6
b) Outline the differentiation of cells in a
multicellular organism. 4
c) Explain how meiosis results in great
genetic variety among gametes. 8
a) Outline locomotion in each of the
following: swimming in a bony fish;
flying in a bird. 5
b) Draw a labeled diagram of the human
elbow joint. 4
c) Explain how skeletal muscle
contracts. 9
a) Explain how the light-independent
reactions of photosynthesis rely on lightdependent reactions. 8
b) Outline the effect of temperature,
light intensity, and CO2 concentration on
the rate of photosynthesis. 6
c) Distinguish between xerophytes and
hydrophytes, giving one structural
adaptation for each type of plant. 4
2005
a) The process of translation involves
the use of transfer RNA (tRNA) and
amino acids. 5 Outline the structure
of tRNA.
b) Draw the basic structure of an
amino acid, and label the groups that
are used in peptide bond formation.
4
c) Explain the process of translation.
9
a) Plants are classified together in a
kingdom. Other organisms are classified
in other kingdoms. Outline the value of
classifying organisms. 4
b) Draw a labeled diagram to show the
external parts of a named dicotyledonous
plant. 5
c) Explain how roots absorb water and
then transport it to the xylem, noting any
special adaptations that help these
processes occur. 9
a) Outline the structure of DNA. 5
b) Describe the effects of polygenic
inheritance using two specific examples.
5
c) Explain the process of transcription in
eukaryotes. 8
a) Define the terms gene and allele and
explain how they differ. 4
b) Outline one example of inheritance
involving multiple alleles. 5
c) Using an example you have studied,
explain a cross between two linked
genes, including the way in which
recombinants are produced. 9
2006
a) Using a table, compare the
structures of prokaryotic and
eukaryotic cells. 5
b) Identify one specific disease in
humans caused by a prokaryotic
pathogen, name the pathogen and
outline its mode of transmission and
its possible effects. 5
c) Explain the production of
antibodies against a pathogen. 8
2007
a) The plasma membrane controls the
movement of substances into and out
of cells. Draw a labeled diagram to
show the structure of a biological
membrane such as the plasma
membrane. 5
b) Explain how ion movements cause a
nerve impulse to pass along a neuron.
8
c) Outline the process of water
uptake by root epidermal cells. 5
a) The activity of enzymes determines
the rate at which chemical reactions
occur in living organisms. Outline the
effects of two factors that can both
increase and decrease enzyme activity. 6
b) Explain how end product inhibition is
used to control the rate of chemical
reactions in cells. Include an example in
your answer with the names of both the
enzyme and the inhibitor. 8
c) Outline the process of blood clotting. 4
a) The carbon cycle involves both the
production and the fixation of carbon
dioxide. Draw a labeled diagram to
show the processes involved in the
carbon cycle. 5
b) Explain the light-independent
reactions of photosynthesis. 8
c) Outline the consequences of rising
carbon dioxide concentrations in the
Earth's atmosphere. 5
2008
a) Draw and label a diagram of a
dicot animal-pollinated flower as seen
with the naked eye and a hand lens. 5
b) Describe how meiosis results in an
enormous genetic variety in the
production of pollen. 5
c) Using the theory of natural
selection, explain how new species of
dicotyledonous plants develop. 8
a) Outline the various means of transfer
of different types of molecules through
the plasma membrane. 4
b) Describe the transport of water
through an angiosperm root system. 6
c) Explain the homeostatic control of
water balance in the human body. 8
a) Outline the first three levels of
protein structure, including the types
of bonding within each and the
significance of each level. 5
b) Using a table, compare competitive
and noncompetitive inhibition and give
one named example of each. 5
c) Explain the production of antibodies.
8
a) Outline the formation of
carbohydrate molecules in
photosynthesis starting from the
absorption of light energy. 6
b) Describe the metabolic events during
germination of an angiosperm seed that
is rich in starch. 4
c) Explain the formation of ATP by
chemiosmosis in cellular respiration. 8
a) Blood vessels carry blood to and from
the kidney. Draw a labeled diagram to
show the internal structure of the kidney,
including the vessels that are connected to
it. 5
b) Compare the composition of blood
arriving at the kidney with the composition
of blood carried away from it. 4
c) Explain the relationship between the
structure and functions of arteries,
capillaries, and veins. 9
a) Outline the regulation of pregnancy by
two named hormones. 4
b) Describe the principles of synaptic
transmission in the nervous system. 6
c) Explain homeostasis giving two specific
examples that show the role of the
endocrine or the nervous system. 8
a) The male reproductive system produces
huge numbers of sperm, each of which is
genetically different. Draw a labeled
diagram of the male reproductive system.
5
b) Explain the events in meiosis that lead
to the genetic diversity of sperm. 8
c) Outline the events after meiosis in the
male reproductive system that result in
the production of semen. 5
a) Describe a pyramid of energy and the
reasons for its shape. 4
b) Outline the conversion of light energy
to chemical energy in photosynthesis. 6
c) Explain the conversion of the chemical
energy of organic compounds into ATP in
aerobic cell respiration. 8
2009
MOST
RECENT
curriculum
revision
2010
2011
2012
a)
a) Draw a labeled diagram of the
structure of a chloroplast as seen
with an electron microscope. 4
b) Describe how water is carried by
the transpiration stream. 7
c) Explain how flowering is controlled
in long-day and short-day plants. 7
a) Outline a possible cause of Down
syndrome. 4
b) Outline the processes involved in
oogenesis within the human ovary. 8
c) Discuss the ethical issues surrounding
in vitro fertilization. 6
a) Distinguish between RNA and DNA.
3
b) Explain the process of DNA
replication. 8
c) Outline how enzymes catalyze
reactions. 7
a) Outline how antibiotic resistance in
bacteria can arise in response to
environmental change. 5
b) Outline the principle of immunity. 6
c) Discuss the benefits and dangers of
vaccination. 7
a) Blood is a liquid tissue containing
glucose, urea, plasma proteins and
other components. List the other
components of blood. 5
b) Outline how the human body
prevents blood glucose concentration
from rising excessively. 5
c) Blood plasma, glomerular filtrate,
and urine have different
concentrations of solutes, such as
glucose, protein and urea. Explain the
processes occurring in the kidney
that cause differences in the
concentrations of these solutes
between blood plasma, glomerular
filtrate, and urine.
a) The main parts of growing plants are
roots, stems and leaves. Draw a plan
diagram to show the arrangement of
tissues in the stem of a dicot plant. 5
b) Outline the adaptations of plant roots
for absorption of mineral ions from the
soil. 5
c) Photosynthesis and transpiration occur
in leaves. Explain how temperature
affects those processes. 8
a) Eukaryotic cells have intracellular and
extracellular components. State the
functions of one named extracellular
component. 4
b) Outline, with an example, the process
of exocytosis. 5
c) Translation occurs in living cells.
Explain how translation is carried out,
from the initiation stage onwards. 9
a) Most of the DNA of a human cell is
contained in the nucleus. Distinguish
between unique and highly repetitive
sequences in nuclear DNA. 5
b) Draw a labeled diagram to show four
DNA nucleotides, each with a different
base, linked together in two strands. 5
c) Explain the methods and aims of DNA
profiling. 8
a) Membrane proteins vary in their
positions within the membrane and in
their functions. Outline the positions
and functions of proteins in
membranes. 8
b) Explain how polar and non-polar
amino acids help channel proteins and
enzymes carry out their functions. 5
c) Compare competitive and noncompetitive inhibition of enzymes. 5
a) During a period of physical exercise,
the rate of urine production falls, but the
ventilation rate and the body temperature
rise. Explain the mechanisms that are
used to cool the body when it is
overheated. 5
b) Explain how the collecting ducts can
alter the volume of urine produced by the
kidney. 5
c) Describe the structure of the
ventilation system, including the alveoli. 8
a) Describe the characteristics of stem
cells that make them potentially useful in
medicine. 5
b) Outline a technique of gene transfer
resulting in genetically modified
organisms. 5
c) Explain the use of karyotyping in human
genetics. 8
a) Gametes are produced in humans by
spermatogenesis and oogenesis.
Compare spermatogenesis and
oogenesis. 5
b) Explain the processes that result in
genetic variation in the sperm produced
by an adult male. 5
c) Outline the process of in vitro
fertilization. 8
a) All organisms in an ecosystem are
involved in the carbon cycle. Outline the
roles of living organisms in the carbon
cycle. 8
b) Explain how triose phosphate is
produced and used in the chloroplasts of a
plant. 5
c) Explain the conditions that are needed
to allow a seed to germinate. 5
a) Describe how plants carry out gas
exchange in the leaves. 5
b) Outline the causes and consequences
of the enhanced greenhouse effect. 5
c) Explain the role of limiting factors in
photosynthesis. 8
a) Outline what is meant by homeostasis.
4
b) Describe how body temperature is
maintained in humans. 6
c) Explain the processes occurring in the
kidney that contribute to osmoregulation.
8
a) Outline, with examples, the types
of carbohydrates found in living
organisms. 4
b) Describe the importance of
hydrolysis in digestion. 6
c) Explain the effect of inhibitors on
the activity of enzymes. 8
2013
c)
d)
e)
2014
f)
g)
h)
a) Draw a labeled plan diagram to
show the distribution of tissues in
the leaf of a dicotyledonous plant. 4
b) Outline the metabolic processes
that occur in starchy seeds during
germination. 6
c) Explain the light-independent
processes of photosynthesis in plants.
8
a) Draw a labeled diagram to show
the structure of a motor neuron. 4
b) Explain how nerve impulses pass
from one neuron to another neuron. 8
c) Outline how the rate at which the
heart beats is controlled. 6
a) Describe the process of blood clotting.4
b) Factor IX is a blood clotting protein
that some hemophiliacs lack. In the
future, hemophilia could be treated using
clotting factors synthesized by genetically
modified bacteria. Outline the basic
technique used for this gene transfer. 6
c) Explain how males inherit hemophilia
and how females can become carriers for
this condition. 8
a) Draw a simple labeled diagram to show
the structure of a double stranded DNA
molecule, comprising four nucleotides. 6
b) Describe the use of DNA profiling in
forensic investigations. 4
c) Using a named example, discuss the
effects of genetically modifying an
organism. 8
a) Outline the types of evidence that
can be used to support the theory of
evolution. 4
b) Outline the relationship between
Mendel’s law of independent assortment
and meiosis. 6
c) Explain two examples of evolution in
response to environmental change. 8
a) Draw a labeled diagram of the kidney
and associated vessels. 5
b) Outline type II diabetes. 5
c) Explain the presence of glucose in
the urine of a diabetic person and its
absence in the urine of a person with
type I diabetes that is being
successfully treated. 8
a) Draw a labeled diagram of a
mitochondrion as seen in an electron
micrograph. 4
b) A supply of oxygen is needed for
aerobic respiration in mitochondria.
Describe the features of alveoli in human
lungs that adapt them for efficient
absorption of oxygen. 6
c) Explain the mechanism of ventilation of
human lungs. 8
a) Draw a labeled diagram of the carbon
cycle. 6
b) Outline the effect of carbon dioxide on
the rate of photosynthesis and how this
can be measured by oxygen release. 4
c) Carbon dioxide is released during
cellular respiration. Explain anaerobic and
aerobic respiration. 8