Zadanie 1
A nucleotide contains one of the pentose structures shown. Which structure can provide the sugar component of a DNA nucleotide? A. Structure A B. Structure B C. Structure C D. Structure D
- Materiał graficzny
Biology SL Paper 1A, May 2026, TZ1
Zadania wzorowane na pytaniach z tego arkusza: te same umiejętności, format i punktacja, inne dane i kontekst. Treści arkusza IB nie publikujemy.
W bazie 30 zadań z tego arkusza, razem 30 punktów, każde z kluczem i schematem punktowania.
Rozwiąż arkuszCały arkusz po kolei. Wynik na końcu.
Dodaj cały arkusz do zestawuZadanie 2
A digestive enzyme breaks the chain shown into smaller units. What does water contribute to the hydrolysis reaction? A. It provides an H and an OH that become attached to the separated products B. It supplies ATP directly from its oxygen atom C. It permanently…
- Materiał graficzny
Zadanie 3
Two purified triglyceride mixtures have fatty acid chains of similar length. Mixture X contains many cis double bonds and melts below mixture Y. Which explanation is consistent with this result? A. The double bonds make X a polymer of glycerol B. Kinks in the…
Zadanie 4
An enzyme catalyses the assembly of a larger molecule from smaller reactants. Which energy profile is consistent with an anabolic reaction that still has an activation barrier? R and P indicate the reactant and product ends of each curve. A. Profile A B.…
- Materiał graficzny
Zadanie 5
A model exercise test records the curve shown. Which process explains the rapid lactate rise at higher workloads? A. Lactate is consumed faster than it is produced at every workload B. Muscle converts increasing amounts of glucose-derived material to lactate…
- Materiał graficzny
Zadanie 6
A thermocycler follows the temperature programme shown. What is the purpose of holding the mixture at stage X? A. To expose the templates by melting hydrogen bonds B. To permit primers to anneal at the lowest temperature C. To allow the thermostable polymerase…
- Materiał graficzny
Zadanie 7
Three mRNA codons for alanine are 5′-GCU-3′, 5′-GCC-3′ and 5′-GCA-3′. Which anticodon could belong to an alanine-carrying tRNA? A. 3′-CGA-5′ B. 3′-GCU-5′ C. 3′-CGT-5′ D. 3′-AAA-5′
Zadanie 8
A researcher freezes a cell sample and splits membranes before electron imaging. Which feature is this technique particularly useful for examining? A. The nucleotide sequence of a chromosome B. The distribution of structures embedded within the lipid bilayer…
Zadanie 9
A sodium ion cannot readily cross the hydrophobic core of a lipid bilayer. Which pair of mechanisms can move it across a cell membrane? A. Osmosis and simple diffusion through lipid tails B. Channel-mediated diffusion and active transport through a pump C.…
Zadanie 10
Which list consists entirely of cell organelles? A. Cell wall, chromosome and cellulose fibre B. Ribosome, lysosome and Golgi apparatus C. Microtubule, plasma membrane and cell wall D. Collagen fibre, nucleus and chitin sheet
Zadanie 11
How does an axon maintain the ion gradients needed for its resting potential? A. ATP-driven pumps transport sodium outward and potassium inward B. Every sodium and potassium ion diffuses outward until none remains C. ATP pumps both sodium and potassium inward…
Zadanie 12
Which observation supports the identification of a dividing cell as entering mitotic metaphase? A. Homologous chromosomes form paired bivalents B. Sister chromatids have already reached opposite poles C. Spindle microtubules position chromosomes towards the…
Zadanie 13
A survey records Betula pendula, Quercus robur, Betula pubescens and Quercus petraea. What can be deduced from these names? A. All four plants belong to one species B. Betula pendula and Betula pubescens share a genus C. Quercus robur and Betula pendula share…
Zadanie 14
The trace includes quiet breathing followed by maximal inspiration and expiration. Which labelled interval represents expiratory reserve volume? A. A B. B C. C D. D
- Materiał graficzny
Zadanie 15
Which statement reliably distinguishes a vein from an artery? A. A vein carries blood towards the heart B. Every vein carries oxygen-rich blood C. Veins are the only vessels containing smooth muscle D. Veins must have thicker walls than the arteries beside…
Zadanie 16
Which description is compatible with a peripheral nerve supplying the skin and nearby skeletal muscle? A. A bundle that may contain sensory and motor axons, some insulated by myelin B. A chain of interneuron cell bodies joined by synapses along its entire…
Zadanie 17
Which sequence can correctly link a chemical change in the blood to a change in heart rate? A. Lower pH → chemoreceptors → nervous signalling via the medulla → faster heart rate B. Lower pH → pressure-only receptors → secretion of antibodies → slower heart…
Zadanie 18
Three statements describe possible immune responses. I. Recognition of features shared by many pathogens II. A much stronger antigen-specific response after a second exposure III. Rapid engulfment of microbes by phagocytes Which statements describe innate…
Zadanie 19
During much of the follicular phase, which response illustrates negative feedback in the menstrual cycle? A. Moderate rising oestradiol suppresses further FSH secretion B. Falling progesterone directly produces a permanent LH surge C. FSH secretion forces the…
Zadanie 20
In a plant species, flower pigment shows incomplete dominance. A true-breeding dark-magenta plant is crossed with a true-breeding white plant. What flower phenotype is expected in the first generation? A. All flowers have an intermediate pale-magenta colour B.…
Zadanie 21
A class measures the heights of students of the same age. The distribution is shown below. Which combination best explains this continuous variation? A. A single recessive allele and ABO blood group B. Effects of several genes together with differences in…
- Materiał graficzny
Zadanie 22
Consider evidence used to investigate shared ancestry and inherited evolutionary change. I. Comparisons of homologous RNA sequences II. A claim that two independently evolved flight surfaces must share a recent wing-bearing ancestor III. Inherited changes…
Zadanie 23
A threatened woodland dormouse depends on connected patches of native shrubs. Which action is an in situ conservation measure? A. Maintaining a breeding colony entirely in an overseas zoological collection B. Freezing tissue samples in a laboratory collection…
Zadanie 24
This simplified diagram positions terrestrial biomes along two increasing climatic variables. What do X and Y represent? A. X: annual temperature; Y: annual precipitation B. X: annual precipitation; Y: annual temperature C. X: soil nitrogen; Y: day length D.…
- Materiał graficzny
Zadanie 25
A leaf-mimicking insect has a flattened leaf-shaped body and remains motionless among foliage when threatened. Which adaptation categories are illustrated? A. Metabolic and reproductive B. Structural and behavioural C. Physiological and nutritional only D.…
Zadanie 26
A model coastal mammal population is regulated by density-dependent factors. Which explanation best fits its later plateau? A. Crowding increases parasite transmission and limits further population growth B. A volcanic eruption occurs at exactly the same time…
- Materiał graficzny
Zadanie 27
A cover crop releases compounds that suppress germination of nearby plants. What agricultural use could follow from this allelopathic effect? A. Replacing all mineral nutrients with the released compounds B. Developing a treatment that reduces weed…
Zadanie 28
Which labelled carbon transfer can turn primary production into secondary production? A. A B. B C. C D. D
- Materiał graficzny
Zadanie 29
A keystone species disappears from a food web. Which outcome is plausible? A. All interactions necessarily become more stable B. Every remaining species immediately becomes extinct C. The number of trophic levels must increase by one D. Some previously…
Zadanie 30
The diagram represents a feedback involving thawed, waterlogged organic soils. Which combination correctly identifies R and S? A. R: anaerobic decomposition; S: methane B. R: mineral crystallization; S: oxygen C. R: photosynthetic fixation; S: nitrogen D. R:…
- Materiał graficzny