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Chapter 16 Practice Paper: Inheritance and variation — question paper

QuizQuipPractice Series
QQ/GCSE-BIO/CH16

GCSE (9–1) · GCSE Biology (Foundation and Higher)

Chapter 16 Practice Paper

Inheritance and variation

Duration: 40 minutes
Total: 30 marks
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READ THESE INSTRUCTIONS FIRST

  • Answer all questions.
  • Section A contains ten multiple-choice questions. Choose one answer, A, B, C or D, for each.
  • Section B contains structured questions. Write your answers in the spaces provided.
  • You may use a calculator.
  • The number of marks is given in brackets [ ] at the end of each question or part question.
  • The total mark for this paper is 30.

Original practice material written for the MOE GCSE Biology syllabus. It is not an official MOE or school examination paper. Chapter 16: alleles and dominance, genotype and phenotype, Punnett squares and probability, family trees, XX/XY sex determination, polydactyly and cystic fibrosis, embryo screening, Mendel, and variation from genes and environment.

For Examiner’s Use
Section A/ 10
Section B/ 20
Total/ 30

Section A: Multiple-choice questions[10 marks]

Choose one answer for each question. Each question is worth 1 mark.

  1. 1

    A dominant allele is expressed when

    1. Atwo copies are present
    2. Bone copy is present
    3. Cthe environment is cold
    4. Dit is on an X chromosome
    ( )
  2. 2

    The observable characteristics of an organism are its

    1. Agenotype
    2. Bphenotype
    3. Cgenome order
    4. Dpedigree
    ( )
  3. 3

    A Tt × Tt cross gives what proportion of tall offspring (T dominant)?

    1. A0%
    2. B25%
    3. C75%
    4. D100%
    ( )
  4. 4

    Human sex chromosomes in a male are

    1. AXX
    2. BXY
    3. CYY
    4. DOO
    ( )
  5. 5

    The probability of a girl in any pregnancy is

    1. A25%
    2. Bdepends on diet
    3. C75%
    4. D50%
    ( )
  6. 6

    The allele causing polydactyly is

    1. Adominant allele
    2. Brecessive allele
    3. Cvirus
    4. Dmutation in blood cells only
    ( )
  7. 7

    Cystic fibrosis can only be inherited from

    1. Aone affected parent
    2. Bthe father only
    3. Cgrandparents only
    4. Dboth parents carrying the allele
    ( )
  8. 8

    Mendel’s experiments used

    1. Apea plants
    2. Bfruit flies
    3. Cbacteria
    4. Dsunflowers
    ( )
  9. 9

    Body mass is a phenotype shaped by

    1. Agenes only
    2. Benvironment only
    3. Cboth genes and environment
    4. Dchromosome count
    ( )
  10. 10

    Two carriers of cystic fibrosis have four children. The number affected could be

    1. Aexactly 1
    2. Bexactly 2
    3. C0 to 4 — probabilities are not certainties
    4. Dalways 4
    ( )

Section B: Structured questions[20 marks]

Answer all questions in the spaces provided.

  1. 11

    This question is about inheritance terms.

    1. (a)

      Define allele and give the two alleles a person carries for each gene.

      [2]
    2. (b)

      Explain the difference between homozygous and heterozygous.

      [2]
    3. (c)

      State the genotype of someone showing a recessive phenotype.

      [1]
  2. 12

    A flower’s colour is controlled by a gene where red (R) is dominant to white (r). Two heterozygous plants are crossed.

    1. (a)

      Fill in the four cells of the Punnett square grid.

      [2]
    2. (b)

      State the phenotype ratio.

      [1]
    3. (c)

      Calculate the probability of a white flower, and explain why a grower growing exactly four seeds might get no white flowers.

      [3]
  3. 13

    This question is about inherited disorders.

    1. (a)

      Explain why cystic fibrosis can be passed on by parents who do not have the disorder.

      [2]
    2. (b)

      Two carriers have a child. Calculate the probability of an affected child and of a child who is a carrier.

      [2]
    3. (c)

      Explain why the same is not true of polydactyly.

      [1]
  4. 14

    This question is about Mendel and variation.

    1. (a)

      Describe what Mendel’s pea experiments showed.

      [2]
    2. (b)

      Explain why identical twins can differ in height.

      [2]

— End of paper —