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ZIMSEC O Level · 4025/1 · J2024

Biology Paper 1 June 2024

Questions
40
Time allowed
60 min
Syllabus code
4025/1

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Questions
40
Pass mark
24
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Answer every question in the printed order, get marked at the end, then see the answers.

The questions

Question 1

Branches of Biology
Which branch of Biology uses biological processes, organisms or systems to make products that improve lives of people?
  1. Aanatomy
  2. Bbiotechnology
  3. Ccytology
  4. Dphysiology

Question 2

Laboratory safety
If the flame jumps out too high, when lighting a Bunsen burner,
  1. Ashout to alert the others.
  2. Bturn off the gas tap.
  3. Cclose the air holes.
  4. Dblow out the flame.

Question 3

Biological molecules
Polysaccharides are a class of
  1. Alipids.
  2. Bproteins.
  3. Ccarbohydrates.
  4. Dnucleic acids.

Question 4

Nutrition

The diagram shows stages in an experiment to test for a food nutrient.

The test is for

  1. Aglucose.
  2. Bprotein.
  3. Cstarch.
  4. Dfat.

Question 5

Cell structure
A cell is the
  1. Asmallest part of an organism.
  2. Bbasic functional unit of life.
  3. Csite of biochemical reactions.
  4. Dactive part of an organism.

Question 6

Cell structure
What is true about the nucleus of a plant cell?
  1. AIt contains DNA.
  2. BIt is a site of respiration.
  3. CIt contains cell sap.
  4. DIt is a site of photosynthesis.

Question 7

Cells and tissues

The diagram shows a specialized cell.

The cell is specialised for

  1. Aproducing antibodies.
  2. Bingesting pathogens.
  3. Ctransporting oxygen.
  4. Dtransmitting impulses.

Question 8

Enzymes
A detergent which contains enzymes will work best in water at
  1. Aany temperature.
  2. Bcold temperature.
  3. Chot temperature.
  4. Dwarm temperature.

Question 9

Enzymes

The graph shows the effect of substrate concentration on the rate of an enzyme-controlled reaction.

At point X, the active sites are

  1. Aunoccupied.
  2. Bsaturated.
  3. Cdestroyed.
  4. Ddenatured.

Question 10

Enzymes
Which property of enzymes makes them specific?
  1. Asensitive to pH
  2. Bposses active sites
  3. Caffected by temperature
  4. Dthey are protein in nature

Question 11

Plant nutrition
An example of a micronutrient in plant nutrition is
  1. Anitrogen.
  2. Bphosphorus.
  3. Cmagnesium.
  4. Dpotassium.

Question 12

Plant responses
Which hormone is essential for cell multiplication in plants?
  1. Aethylene
  2. Bgibberellin
  3. Cauxin
  4. Dcytokinin

Question 13

Plant responses

Some plants, grown in a greenhouse, are supplied with all nutrients required for growth. The temperature is maintained at optimum and the supply of water is adequate. The plants have short roots and stems.

To promote shoot and root elongation in the plants, they can be sprayed with

  1. Aethylene.
  2. Bgibberellins.
  3. Cauxins.
  4. Dcytokinins.

Question 14

Reproduction in plants

The diagram shows a flower.

It is wind pollinated because it has

  1. Aspiky pollen.
  2. Blarge petals.
  3. Csticky stigma.
  4. Dexposed anthers.

Question 15

Growth
When investigating conditions necessary for germination, pyrogalic acid is used to exclude
  1. Amoisture.
  2. Bwarmth.
  3. Coxygen.
  4. Dcarbon dioxide.

Question 16

Nutrition

The table shows the end products of digestion of starch, proteins and lipids.

Which row, A, B, C or D, is correct?

  1. AA
  2. BB
  3. CC
  4. DD

Question 17

Respiration

The table shows the carbon dioxide percentage composition of inhaled and exhaled air.

Which row, A, B, C or D, shows the correct percentage in inhaled air and exhaled air?

  1. AA
  2. BB
  3. CC
  4. DD

Question 18

Respiration
Breathing rate increases during physical activity to
  1. Aremove lactic acid from blood.
  2. Bsupply more oxygen to the blood.
  3. Csupply more glucose to active tissues.
  4. Dremove carbon dioxide from the tissues.

Question 19

Health and disease
Which specialised cells are affected by HIV?
  1. Athrombocytes
  2. Berythrocytes
  3. Clymphocytes
  4. Dphagocytes

Question 20

Health and disease
Which animal parasite damages the liver?
  1. Abacteria
  2. Bfluke
  3. Ctick
  4. Dvirus

Question 21

Reproduction in animals
Which method of contraception is used by males only?
  1. Aloop
  2. Bvasectomy
  3. Cdiaphragm
  4. Dtubal ligation

Question 22

Excretion

The diagram shows the cross section of a kidney.

Which part, W, X, Y or Z has the least concentration of urea?

  1. AW
  2. BX
  3. CY
  4. DZ

Question 23

Homeostasis
Which response will increase body temperature?
  1. Avasodilation
  2. Bvasoconstriction
  3. Cshivering
  4. Dsweating

Question 24

Coordination

The diagram shows an eyesight defect which needs to be corrected.

The defect can be corrected by use of

  1. Aconcave lens.
  2. Bconvex lens.
  3. Cbifocal lens.
  4. Dmultifocal lens.

Question 25

Support and movement
Which one is a ball and socket joint?
  1. Aankle
  2. Belbow
  3. Cknee
  4. Dshoulder

Question 26

Classification
In a bread mould, which statement describes rhizoids?
  1. Ahyphae that grow vertically upwards
  2. Bstructures that germinate into new hyphae
  3. Chyphae that grow horizontally on the substrate
  4. Dhyphae that penetrate into the substrate

Question 27

Health and disease
The growth of bacteria is not affected by
  1. Atemperature.
  2. Blight.
  3. Csubstrate.
  4. DpH.

Question 28

Genetics
An allele is
  1. Aa unit of inheritance.
  2. Bexpressed only when heterozygous.
  3. Cthe alternative form of a gene.
  4. Dthe observable appearance of an organism.

Question 29

Genetics

The gene for eye colour has two alleles, an allele for blue eyes (b) and an allele brown eyes (B). The allele for blue eyes is recessive to that for brown eyes. A blue eyed mother has children, half are blue eyed and half are brown eyed.

What is the genotype and phenotype of the biological father?

  1. ABB and brown
  2. BBb and brown
  3. CBb and blue
  4. Dbb and blue

Question 30

Genetics

A normal carrier male had a child with a female with albinism.

What is the probability of them having a normal child?

  1. A0
  2. B0.25
  3. C0.50
  4. D0.75

Question 31

Variation
Which characteristic shows discontinuous variation?
  1. Acomplexion
  2. Bmass
  3. Cleaf length
  4. Dear shape

Question 32

Genetics

The discovery of antibiotics has made it possible to cure infections caused by bacteria. Some bacteria are now resistant to antibiotics.

This is as a result of

  1. Aartificial selection.
  2. Bnatural selection.
  3. Crecombinant DNA technology.
  4. Dinbreeding by the bacteria.

Question 33

Classification

The diagram shows different microorganisms.

Which organism A, B, C or D belongs to the same family as the 2019 Novel Corona Virus?

  1. AA
  2. BB
  3. CC
  4. DD

Question 34

Ecology

The steps numbered 1 to 5 show the sequence of events for a process, X.

1. nitrates and phosphates from raw sewage and fertilisers washed into water bodies
2. algae absorb nutrients and grow
3. algae form a blanket on water surface blocking out the sun
4. algae die
5. bacteria decompose dead algae using oxygen for respiration

Process X is

  1. Aphotosynthesis.
  2. Beutrophication.
  3. Cdecomposition.
  4. Dfossilisation.

Question 35

Soil
Leaching of soil is the loss of
  1. Awater.
  2. Bmicroorganisms.
  3. Cnutrients.
  4. Dhumus.

Question 36

Soil

20 cm3 of soil x was put in beaker 1 and 20 cm3 of soil y was put in beaker 2. 20 cm3 of water was added to each beaker and the resultant volumes are as shown in the diagrams.

The difference in the final volume is caused by larger

  1. Asoil particles in soil x.
  2. Bair spaces in soil x.
  3. Csoil particles in soil y.
  4. Dair spaces in soil y.

Question 37

Carbon cycle

The diagram shows the carbon cycle.

Arrow X represents

  1. Aphotosynthesis.
  2. Bcombustion.
  3. Cfossilation.
  4. Drespiration.

Question 38

Health and disease
Which disease is caused by Protozoa?
  1. Acholera
  2. BHIV
  3. CTB
  4. Dmalaria

Question 39

Health and disease
Which drugs are suitable for an H.I.V patient?
  1. Aantibiotics
  2. Banti retrovirals
  3. Canalgesics
  4. Dprophylactics

Question 40

Health and disease
Sexually transmitted infections are best prevented by
  1. Aabstaining from sexual intercourse.
  2. Bproper use of condoms.
  3. Cbeing faithful to one uninfected partner.
  4. Dregular testing and screening.

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