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IBBiology: SLDPExam Questions3. Genetics3.3 Inheritance

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First teaching 2014

Last exams 2024

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Inheritance (DP IB Biology: SL)

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3.3 Inheritance

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3.3 Inheritance

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11 mark

Which of the following statements best describes how Mendel eliminated any uncertainty from his experiments?

  • He performed a large number of crosses over many years.

  • He studied the trait of height, which could be measured easily.

  • He studied a wide variety of traits, such as flower colour, shape of pea, height of stem.

  • He carefully transferred pollen from one pea plant to the reproductive parts of another.

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21 mark

Which option correctly completes the sentence below?

The segregation of alleles occurs during  _________ in eukaryotic organisms

  • Mitosis

  • Binary fission

  • Meiosis

  • DNA replication before cell division

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31 mark

Which of the following statements correctly describes co-dominance?

  • The alleles are both expressed to an equal extent in the phenotype.

  • Two alleles are 'blended together'.

  • One allele is dominant over the other. 

  • Neither allele is expressed in the phenotype. 

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4
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Which of the following statements is a feature of X-linked genetic diseases in humans?

  • Females can’t inherit the defective gene as they don’t possess a Y chromosome.

  • Females can either be normal, a carrier or have the disease.

  • Males can be a carrier for the defective allele.

  • Females can only be heterozygous for the defective gene.

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51 mark

Which of the following statements correctly describes the consequences of the Chernobyl nuclear accident in 1986?

I. Concentrations of radioactive iodine in the environment increased.

II. There was a large increase in the reported cases of thyroid cancer.

III. Horses and cattle near the nuclear power plant died due to damage to their thyroid glands.

IV. The effects of the disaster were localised to the immediate area.

  • I and II only.

  • I, II and III.

  • III and IV only

  • I, II, III and IV.

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11 mark

Through extensive experiments with pea plants, Gregor Mendel was able to show: 

  1. The principles of inheritance.
  2. That purebred individuals could be cross-bred to produce a generation of offspring with identical phenotypes.
  3. That mutations within alleles could result in unexpected ratios of offspring.

  • I only

  • II only

  • II and III

  • I and II

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21 mark

How did Gregor Mendel ensure the reliability of his data?

  • Repeating his investigation many times.

  • Collecting large amounts of qualitative data.

  • Making observations of a pea plant over many years.

  • Completing a statistical test on his results.

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31 mark

Which statement best describes the cells produced as a result of meiosis?

  • Haploid and genetically identical.

  • Diploid and genetically identical.

  • Haploid and genetically different.

  • Diploid and genetically different.

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41 mark

A species of plant can have either blue or white flowers. The colour of the flower is controlled by a single gene where the dominant allele codes for blue flowers. 

Two heterozygous plants are crossed; which of the observed outcomes matches up most accurately to the expected ratio of blue to white flowers. 

  Blue White
A 93 46
B 77 203
C 107 33
D 127 42

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    51 mark

    Two parents have an equal chance of having a child with blood groups A, B, AB, or O.

    What are the genotypes of the parents?

    • AB, AO

    • AO, BO

    • AB, OO

    • AB, AB

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    61 mark

    A woman is a carrier of haemophilia; her husband does not have haemophilia. 

    What are the possible genotypes of their children?

      Sons Daughters
    A All sufferers All carriers
    B Half healthy All carriers
    C Half healthy All healthy
    D Half healthy Half carriers

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      71 mark

      The pedigree diagram shows the inheritance of cystic fibrosis across 3 generations.

      biology-3-3-q7-ib-hl-

      Identify the genotype of the individuals labelled 1, 2 and 3 in the pedigree diagram.

       

      		 1 2 3
      A Heterozygous Homozygous dominant Heterozygous
      B Homozygous recessive Homozygous dominant Heterozygous
      C Homozygous recessive Heterozygous Heterozygous
      D Heterozygous Homozygous recessive Homozygous dominant

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        81 mark

        A couple are trying to decide whether their children may be at risk of inheriting Huntington's disease. One parent is heterozygous for Huntingtons and the other is a healthy individual. 

        Calculate the % chance that their offspring are likely to suffer from the disease.

        • 50%

        • 25%

        • 100%

        • 75%

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        91 mark

        The pedigree diagram below shows the inheritance of haemophilia across three generations.

        biology-q9-3-3-ib-hl

        Identify the genotype of person Y.

        • XhXh

        • XHXH

        • XHXh

        • XHY

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        101 mark

        Which of the following are mutagenic agents?

        • X-rays, benzo(a)pyrene, radio waves

        • X-rays, microwaves, radio waves

        • X-rays, benzo(a)pyrene, gamma rays

        • X-rays, benzo(a)pyrene, microwaves

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        11 mark

        Which rows correctly describe monohybrid crosses that follow Mendel's principles of inheritance?

          Cross Predicted outcome
        I A pure-breeding parent with dominant alleles is crossed with a pure-breeding parent with recessive alleles. All of the offspring will have the same characteristic as the dominant parent
        II A plant which is heterozygous dominant for a trait is crossed with a plant that is homozygous recessive.    Equal 1:1 ratio of offspring with either phenotype exhibited by the parent.
        III Pure breeding parents that have co-dominant alleles are crossed.

        Equal proportions of offspring with a characteristic of either of the parents.
        IV Two parents that are heterozygous dominant are crossed Three times as many offspring have the dominant phenotype (3:1 ratio).

        • I and II only.

        • I, II and IV.

        • I and IV only.

        • II, III and IV.

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        21 mark

        The pedigree chart below shows the inheritance of Tay-Sachs disease which is an autosomal recessive trait, characterised by neurological problems caused by the death of nerve cells. 

        In the pedigree chart, a filled in circle or square means the individual is affected and shows the genetic condition.

        What is the probability that individuals 3 and 4 will have another child with Tay-Sachs disease?

        UpV6A5dP_h-2

        • 25%

        • 50%

        • 75%

        • 100%

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        31 mark

        Which statements best explain why the ABO blood system in humans is an example of co-dominance?

        1. Allele IA and the allele IB are both expressed in the heterozygote/AB type blood.
        2. Neither allele IA or the allele IB can mask the expression of the other allele.
        3. There are three alleles of the gene that controls the blood group.
        4. There are more than two blood groups.

        • All of them.

        • I. II. and III.

        • I. and II.  

        • II. and III.

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        41 mark

        Two parents with normal factor VIII have a child with haemophilia.

        Which is the correct statement?

        • The mother is normal but the father carries the defective gene.

        • Both parents are carriers for the defective gene.

        • Only the mother is a carrier for the defective gene.

        • The child must have been female.

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        51 mark

        Which statements best explain why a significant increase in the incidence of cancer was reported following the nuclear bombing of Hiroshima and Nagasaki, and the nuclear accident of Chernobyl?

        I. Ionising radiation can induce breaks in the DNA structure.

        II. Control of the cell cycle can be affected by mutagens.  

        III. Mutations were passed down to offspring leading to increased cancer rates. 

        IV. Mutations arise when the body repairs a break in the DNA structure. 

        • I, II and III.

        • I, II, and IV.

        • I, III and IV.

        • I, II, III and IV.

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