Home / 2018 May Biology paper 1 TZ1 SL Concept Questions

2018 May Biology paper 1 TZ1 SL Concept Questions

  1. What feature of both striated muscle and aseptate fungal hyphae is different from typical cell structure?

    1. They have multiple nuclei within a structural unit.

    2. They have a cell wall that is not made of cellulose.

    3. They have plasmids.

    4. They have an absence of cholesterol in the plasma membrane.

▶️Answer/Explanation

Ans: A

 

Common pesticides used by gardeners contain neonicotinoids.

What is the effect of a neonicotinoid pesticide on the transmission of a nerve impulse between neurons in an insect?

    1. It prevents the release of acetylcholine from the presynaptic membrane.

    2. It widens the synaptic cleft so diffusion of acetylcholine across the gap is slower.

    3. It irreversibly binds with acetylcholine receptors on the postsynaptic membrane.

    4. It interferes with the enzymatic breakdown of acetylcholine by acetylcholinesterase.

▶️Answer/Explanation

Ans: C

 

3. How does potassium move across the membrane of a neuron during repolarization?

    1. Simple diffusion

    2. Facilitated diffusion

    3. Endocytosis

    4. Active transport

Ans: B

4. Which organelle provides evidence that eukaryotic cells originated when large prokaryotes

engulfed small free-living prokaryotes?

    1. Chloroplast

    2. Nucleoid

    3. 80S ribosome

    4. Vacuole

      Ans: A

 

5. The concentrations of cyclins rise and fall in cells at certain times.

             

[Source: https://en.wikipedia.org/wiki/Cyclin#/media/File:Cyclin_Expression.svg]

What times are these?

    1. Day and night

    2. Seasons of the year

    3. Stages of mitosis and interphase

    4. Developmental stages in the life cycle

      Ans: C

 

6. What feature of carbon makes it most suitable as a basis for life?

    1. Its abundance in nature

    2. Its bonding properties

    3. Its reactivity to light

    4. Its presence in the early atmosphere of the Earth

Ans: B

7. Researchers have developed a skin patch which can detect and measure very small concentrations

of ions, sugars, amino acids, proteins and hormones which remain when sweat evaporates.

What allows the presence of these substances in sweat?

    1. Cohesion

    2. Hydrophobic interactions

    3. Solvent properties

    4. Thermal properties

      Ans: C

8. Which type(s) of fatty acid in the diet is/are positively correlated with an increased risk of coronary heart disease?

 

I.

Saturated

II.

Trans unsaturated

 

III.

Cis unsaturated

A. I only
B. I and II only
C. II only
D. II and III only

Ans: B

9. Which protein has the highest tensile strength (ability to resist breaking when stretched)?

    1. Cellulose

    2. Actin

    3. Spider silk

    4. Albumin

      Ans: C

10. What is the advantage of using lactase in an immobilized state in the food manufacturing industry?

    1. It functions within cells.

    2. It dissolves in multiple solvents.

    3. It converts cellulose into glucose.

    4. It is less likely to become denatured.

Ans: D

11. Nucleic acids are polymers of nucleotides. What parts of nucleotides are joined together in both

DNA and RNA to make these polymers?

    1. Large nitrogenous bases with small nitrogenous bases

    2. Nitrogenous bases with hexose sugars

    3. Nitrogenous bases with phosphates

    4. Pentose sugars with phosphates

      Ans: D

12. What do DNA replication, transcription and translation have in common?

    1. Take place in cell nucleus

    2. Require free nucleotides

    3. Catalysed by polymerase

    4. Complementary base pairing

Ans: D

13. Where could genes be located in a prokaryotic cell?

Nucleoid

Plasmids

Ribosomes

          A

✔

✔

B ✔

✔

 

C ✔

 

✔

D ✔

✔

✔

Ans: B

14. What is the same in all parts of homologous chromosomes?

    1. Base pair sequence

    2. Alleles

    3. Sequence of genes

    4. Deletions

Ans: C

 

15. What helps make the genome of each human unique?

Orientation of pairs

Crossing over during

Fusion of gametes

of homologous

meiosis

from two different

chromosomes during

 

parents

meiosis

 

 

A ✔

 

✔

                        B

✔

✔

C ✔

✔

 

D ✔

✔

✔

Ans: D

16. Which genotype would be seen in a person suffering from Huntington’s disease?

    1. Hh

    2. hh

    3. XHY

    4. XhY

      Ans: A

17. Animals in the highest trophic level of a food chain will often be the largest in body

size but will be few in numbers. What accounts for the small numbers?

    1. Food eaten by animals at the highest trophic level has a lower energy content per gram

    2. Energy losses through the food chain

    3. Conversion of heat energy into chemical energy

    4. Biomass of producers is small

      Ans: B

18. Which conditions favour peat formation?

A Dry

Aerobic

Acidic

B Wet

Anaerobic

Acidic

C Dry

Anaerobic

Basic

D Wet

Aerobic

Acidic

Ans: B

19. In addition to carbon dioxide, which of these greenhouse gases is the most significant?

    1. Methane

    2. Ozone

    3. Nitrogen oxides

    4. Water vapour

      Ans: D

20. Balkan green lizards, Lacerta trilineata, living in mainland Greece eat mostly insects but also small amounts of plants. The same species living on Greek islands (where insects are scarce) show a greater percentage of those physical traits useful for eating plants than the mainland lizards.

                                         

What is the biological explanation for these observations?

    1. Variation in each lizard population allowed adaptation to occur.

    2. Lizards migrated to areas where they were better adapted.

    3. Lizards on the islands diverged due to lack of interbreeding with the mainland population.

    4. Homologous structures have prevented separate species from evolving.

      Ans: C

21. What explains the presence in living humans of DNA sections which are identical to DNA found in

Neanderthals who lived 40 000 years ago?

    1. Genetic mutation

    2. Inheritance

    3. Adaptation

    4. Speciation

Ans: B

22. Which phylum shows radial symmetry?

    1. Annelida

    2. Cnidaria

    3. Platyhelmintha

    4. Porifera

      Ans: B

23. The cladogram was constructed using DNA base sequences from six species. Which node

indicates the greatest difference in base sequences?

                   

Ans: A

24. The photomicrograph drawing shows a longitudinal section of the small intestine.

               

[Source: Henry Gray (1918) Anatomy of the Human Body]

What is the function of the tissue layers labelled X and Y?

    1. Secretion of digestive enzymes

    2. Absorption of digested food

    3. Transport of absorbed foods

    4. Movement of food in the intestine

Ans: D

25. Which vessel carries deoxygenated blood away from the heart?

    1. Aorta

    2. Pulmonary artery

    3. Vena cava

    4. Pulmonary vein

      Ans: B

26. A combination of antibiotics and bioengineered antibodies to bacterial antigens is now being used in hospitals to treat bacterial infections. What makes this method more effective than just using antibiotics alone?

    1. Increases selective pressure on bacteria to evolve antibiotic resistance

    2. Bacteria become noticeable to phagocytes

    3. Antibodies can be cloned by the immune system

    4. Blocks metabolic pathways in bacteria

Ans: B

27. After 8 hours of sleep and before eating, which hormone will be secreted and what cells secrete it?

Hormone

Cells in the pancreas

A Insulin

∝ cells

B Glucagon

∝ cells

C Insulin

β cells

D Glucagon

β cells

Ans: B

28. How are the insides of alveoli prevented from sticking together?A

Method of prevention

Produced by

A Surfactant

Type I pneumocytes

B Surfactant

Type II pneumocytes

C Pressure

Mixture of O2 and CO2 within alveoli

D Pressure

CO2 concentration gradient inside capillaries

Ans: B

29. Neural pathways in living brains can now be mapped by tracking the movement of

water molecules inside axons. What keeps water molecules inside axons?

    1. Plasma membrane

    2. Hydrogen bonding

    3. Pump proteins

    4. Synapse

      Ans: A

30. What hormone controls the metabolic rate of body cells?

    1. Insulin

    2. Leptin

    3. Melatonin

    4. Thyroxin

Ans: D

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