IB Biology Paper 1 Practice

why is sweat a good coolant for the body?

breaking H bonds between water molecules in sweat requires energy from body heat

which is an effect of protein denaturation?

a. the order of amino acids is changed when the protein overheats

b. the bonds between amino acids are broken by condensation

c. parts of the protein become linked together by hydrolysis

d. the three-dimensional structure of the protein is altered.

d.

what usually distinguishes DNA from RNA?

DNA is double stranded while RNA is single stranded.

research has shown that the genetic code is not entirely universal. which research finding has shown this?

a. some amino acids are coded for by more than one codon.

b. there are differences between the base sequences of genes in different species.

c. in some organisms the genetic code for mitochondria differs from the genetic code for the nucleus.

d. some codons code for the addition of an amino acid and some code for the termination of translation.

b.

cells can only be formed by...

division of pre-existing cells

what event occurs only in meiosis?

a. fusion of gametes to promote genetic variation

b. random separation of chromatids

c. random separation of homologous chromosomes

d. replication of chromosomes

c.

what is the effect of dominant alleles?

I. they mask the effect of recessive alleles

II. they become more frequent than recessive alleles in a population

III. they have a joint effect with recessive alleles when characteristics are co-dominant

I. only

which technique separates proteins according to size?

a. treatment with restriction endonucleases

b. pcr

c. gel electrophoresis

d. DNA profiling

c.

what limits the length of food chains in an ecosystem?

a. the size of individual organisms

b. competition between organisms

c. the loss of energy between trophic levels

d. natural selection

c.

how can molluscs and platyhelminthes be distinguished?

a. molluscs are unsegmented but platyhelminthes are segmented.

b. molluscs have a mouth and an anus but platyhelminthes do not.

c. molluscs are smooth but platyhelminthes have bristles.

d. molluscs remain attached to rock but platyhelminthes move around in water.

b.

what is a feature of shorter wavelength visible radiation?

a. it includes violet light.

b. it has less energy per photon than longer wavelengths.

c. it is absorbed by greenhouse gases.

d. it is reflected by chlorophyll.

a.

which is a coniferophyte?

a. adansonia digitata, an african baobab tree with white flowers

b. cyathea australis, an australian tree fern producing spores

c. hypnum plumaeforme, a green plant with no vascular tisssue grown in japanese gardens

d. pinus strobus, a north american tree with ovules on scales not enclosed in an ovary

d.

which condition will always result in a change in allele frequency in a population?

a. mutation

b. crossing over

c. aging in a population

d. asexual reproduction

a.

what happens to starch in the small intestine?

a. endopeptidase secreted by the liver digests starch to enable absorption by the villi.

b. contraction of intestinal muscle mixes starch with enzymes to accelerate its conversion into amylose.

c. glycogen secreted by the pancreas hydrolyses starch into glucose, which is eventually transported to the liver.

d. amylase secreted by the pancreas digests starch to enable absorption by the villi.

d.

which discovery was an indication that the heart pumps blood to the body through arteries?

a. the amount of blood pumped exceeds that of blood produced

b. blood could easily be pushed up a limb vein, but not down

c. the observation that there were pores between the right and left atria

d. the heart swelled up when the arteries were tied in an animal experiment

d.

what is a valid comparison between arteries and veins?

a. arteries carry oxygenated blood, veins carry deoxygenated blood

b. arteries return blood to the atria of the heart, in veins blood flows from ventricles to body tissues

c. in arteries, blood flows at high pressure. in veins, blood flows at low pressure

d. arteries have thick walls, veins have permeable walls

c.

which statement is true for the antibiotic penicillin?

a. watson and crick developed the usage of penicillin.

b. penicillin blocks processes unique to eukaryotic cells.

c. viruses lack metabolism and penicillin has no effect on them.

d. florey and chain sequenced the genome of penicillium notatum.

c.

how can knowledge about the pineal gland function be applied?

a. to restore sleep time by the use of melatonin

b. to trigger ovulation during an IVF treatment

c. to reduce sperm production in male contraception

d. to regulate blood sugar in type I diabetes

a.

though a single nerve cell does not think, millions of them organized as a brain result in thinking. what kind of property does thinking represent?

a. anatomical

b. adaptive

c. extracellular

d. emergent

d.

the cell theory states that cells come from pre-existing cells. what biological process allows this to occur?

a. ovulation

b. differentiation

c. cytokinesis

d. exocytosis

c.

which structures have a phospholipid bilayer?

I. vesicle

II. nucleus

III. nucleoid

I & II only

what can be found in plant cells but not animal cells?

a. starch

b. mitochondria

c. golgi apparatus

d. rough ER

a.

which usually takes the most time in the cell cycle?

a. cytokinesis

b. interphase

c. telophase

d. anaphase

b.

which is a disaccharide?

a. fructose

b. galactose

c. lactose

d. ribose

c.

which process forms triglycerides?

a. evaporation

b. condensation

c. hydrolysis

d. glycolysis

b.

how much energy is stored in 1 kg of body fat compared to 1 kg of glycogen?

a. half as much

b. same amount

c. twice as much

d. one tenth as much

c.

which nucleic acids are directly involved in transcription?

a. mRNA and one DNA strand

b. mRNA and both DNA strands

c. tRNA and both DNA strands

d. tRNA and one DNA strand

a.

which substances are made during photosynthesis and store energy that can be used by cells?

a. carbon dioxide and glucose

b. ATP and water

c. water and glucose

d. glucose and ATP

d.

what occurs during gene mutation?

a. allele change

b. crossing over

c. non-disjunction

d. evolution

a.

what term describes identical organisms derived from a single parent?

a. species

b. clone

c. family

d. twins

d.

how is the polymerase chain reaction (PCR) used in research?

a. allows the separation of DNA fragments

b. tests expression of many genes simultaneously

c. permits identification of gene function

d. duplicates a selected DNA fragment

d.

what provides evidence for the universal nature of the genetic code?

a. uracil replaces thymine in RNA

b. the amount of A is equal to the amount of T and the amount of G is equal to the amount C

c. nucleic acids contain the same bases in all species

d. mRNA codons are assigned to the same amino acids in different species

c.

what might increase in arctic ecosystems as a result of rising global temperatures?

a. ozone

b. numbers of pest species

c. day length

d. chlorofluorocarbons

b.

what term describes similar structures found in animals with common ancestry?

a. homologous

b. inherent

c. characteristic

d. analogous

a.

what is the sequence of taxonomic groups from largest to smallest?

kingdom phylum class order family genus species

which structure directly absorbs nutrient molecules from the digestive tract?

a. esophagus

b. villus

c. liver

d. large intenstine

b.

which is/are involved in the control of heart rate?

I. heart pacemaker

II. hormone secretion

III. nerves

a. I only

b. III only

c. I and II only

d. I, II and III

d.

what describes antigens?

a. they catalyze immune reactions

b. they activate specific white blood cells

c. they destroy bacteria but not viruses

d. they are only produced by white blood cells

b.

what would allow inhalation to occur during ventilation?

a. diaphragm- contract, external intercostal muscle- contract, abdominal muscles- contract

b. diaphragm- relax, external intercostal muscle- relax, abdominal muscles- relax

c. diaphragm- contract, external intercostal muscle- contract, abdominal muscles- relax

d. diaphragm- relax, external intercostal muscle- relax, abdominal muscles- contract

c.

where could an action potential occur in a motor neuron?

a. anywhere on the cell membrane

b. dendrites only

c. cell body only

d. axon only

a.

what must be present for a human fetus to develop into a normal male?

I. X chromosome

II. Y chromosome

III. testosterone

I, II, and III

which property makes stem cells suitable for therapeutic use?

a. they can divide by meiosis to form gametes

b. they contain chemicals that can kill bacteria

c. their chromosomes are suitable for gene transfer and cloning

d. they can differentiate into specialized cells

d.

which features are present in prokaryotic cells?

a. DNA, plasma membrane, and mitochondria

b. DNA, cell wall, and pili

c. ribosomes, chloroplasts and cell wall

d. cytoplasm, ribosomes, and rough endoplasmic reticulum

b.

where in the cell do condensation reactions involving amino acids occur?

a. nucleus

b. Golgi apparatus

c. ribosomes

d. lysosome

c.

which process is possible due to the fluidity of cell membranes?

a. endocytosis

b. osmosis

c. ATP production

d. cell recognition

a.

between which atoms do hydrogen bonds form in water?

a. oxygen and hydrogen atoms in the same water molecule

b. oxygen and hydrogen atoms in different water molecules

c. hydrogen atoms in the same water molecule

d. oxygen atoms of different water molecules

b.

which carbon compound produced by living organisms is inorganic?

a. DNA

b. cellulose

c. glucose

d. carbon dioxide

d.

what occurs during DNA replication?

a. DNA polymerase separates the two DNA strands

b. DNA molecules containing nucleotides from the original molecule are produced

c. adenine forms a base pair with either thymine or uracil.

d. new bases attach to the original sugar-phosphate backbone

b.

which chemical is produced during both aerobic and anaerobic respiration in humans?

a. carbon dioxide

b. pyruvate

c. water

d. lactate

b.

how is oxygen produced during photosynthesis?

a. water molecules are split with energy from ATP

b. water molecules are split with energy from light

c. carbon dioxide molecules are split with energy from ATP

d. carbon dioxide molecules are split with energy from light

b.

if there are 16 chromosomes in a cell that is about to divide, what will be the number of chromosomes in a daughter cell after division by mitosis or meiosis?

a. mitosis- 16, meiosis- 16

b. mitosis- 16, meiosis- 8

c. mitosis-8, meiosis- 16

d. mitosis- 8, meiosis- 8

b.

A man has hemophilia, a condition caused by a recessive sex-linked allele carried on the X chromosome. Which of his grandparents must be a carrier if none of them had the disease?

a. maternal grandmother, his mother's mother

b. maternal grandfather, his mother's father

c. paternal grandmother, his father's mother

d. paternal grandfather, his father's father

a.

what makes gene transfer between species possible?

a. all species use the same genetic code

b. all species have the same genetic material

c. all species produce the same polypeptides

d. all species transcribe genes using plasmids

a.

in a pond, two species of fish feed on insects and worms. the insects feed on the green plants that live in the water. what constitutes a population in this ecosystem?

a. all the living organisms

b. all the animals

c. all the fish

d. all the fish of one species

d.

what is recycled in an ecosystem?

a. nitrogen, carbon and energy are all recycled

b. nitrogen and carbon are recycled but not energy

c. nitrogen is recycled but not carbon or energy

d. nitrogen, carbon and energy are not recycled

b.

what characteristics describe homologous structures?

a. they have the same ancestral origin but may have different functions

b. they have the same ancestral origin and always have the same function

c. they have the same ancestral origin but may have different functions

d. they have different ancestral origins but always have the same function

a.

the atlantic cod (Gadus callarias) is a fish which lays about 5,000,000 eggs in its lifetime. on average, only two of these eggs survive to become adult cod. how does this promote evolution?

a. all offspring are genetically identical, so become better adapted

b. laying many eggs provides food for other species to survive and become better adapted

c. some young cod change to become adapted to the environment and survive and pass on their genes.

d. offspring with favourable variations survive and pass on their genes

d.

Based on binomial nomenclature, which two species are most closely related?

I. Common barberry (Berberis vulgaris)

II. Canadian bunchberry (Cornus canadensis)

III. Smooth blackberry (Rubus canadensis)

IV. Canadian barberry (Berberis canadensis)

I and IV.

what effect does HIV have on the immune system?

a. it prevents leucocytes from fighting bacteria by phagocytosis.

b. it causes excessive production of leucocytes in bone marrow

c. it destroys antibodies produced by leucocytes

d. it lowers the number of leucocytes, reducing antibody production

d.

what is a similarity between arteries and capillaries?

a. they both have elastic tissue

b. they both have smooth muscle cells

c. neither has collagen fibres in their walls

d. neither has valves

d.

what is a characteristic of axons in motor neurons?

a. when there is a resting potential, the outside of the axon is negative relative to the inside.

b. during an action potential Na + ions diffuse out of the axon.

c. K + ions diffusing out of the axon repolarizes it.

d. impulses in the axon travel towards the cell body.

c.

which response takes place when blood glucose levels are low?

a. glucagon is released from the a cells of the pancreatic islets.

b. glucagon is released from the B cells of the pancreatic islets.

c. insulin is released from the a cells of the pancreatic islets.

d. insulin is released from the B cells of the pancreatic islets.

a.

during the menstrual cycle, what occurs in response to a fall in the progesterone level?

a. growth of the uterus lining

b. growth of the follicle surrounding the egg

c. ovulation

d. menstruation

d.