Genetics Unit Post-assessment (grade 7)

12 Questions

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Genetics Unit Post-assessment (grade 7)

There are so many ways in which the study of biology have allowed us to know our bodies on a whole new level as opposed to those hundreds of years ago. And one of those innovations is through the use of genetics – a practice which allows us to take a look at our genetic make-up and see what our chances are of developing a life-threatening illness. What do you know about the study? Let’s find out.


Questions and Answers
  • 1. 
    A(n)                      is a segment of DNA that carries the instructions for producing a specific trait (Intermediate Core Curriculum 2.2a)
    • A. 

      Chromosome

    • B. 

      Karyotype

    • C. 

      Enzyme

    • D. 

      Gamete

    • E. 

      Gene

  • 2. 
    Kernel corn is a trait determined by two alleles.  The dominant allele (P) produces a purple color, and the recessive allele (p) produces a yellow color.  The diagram below shows an ear of corn produced by crossing two corn plants.  The shaded kernels are purple, and the unshaded ones are yellow.  The yellow corn kernels can best be described as (Intermediate Core Curriculum 2.2b).
    • A. 

      Homozygous dominant

    • B. 

      Hybrid

    • C. 

      Heterozygous

    • D. 

      Homozygous recessive

    • E. 

      Codominant

  • 3. 
    Pea plants come in two sizes – tall plants and dwarf plants.  The dominant allele (T) produces tall pea plants, and the recessive allele (t) produces dwarf pea plants.  The Punnett Square below shows a cross between tall and dwarf pea plants.  What is the probability that the offspring of this cross are homozygous recessive (Intermediate Core Curriculum 2.2c).
    • A. 

      0%

    • B. 

      25%

    • C. 

      50%

    • D. 

      75%

    • E. 

      100%

  • 4. 
    Below is a pedigree for an inherited heart disease.  If the father labeled II 2 is heterozygous, what is the probability that the child labeled III 1 would be a carrier of heart disease (Intermediate Core Curriculum 2.2c)?
    • A. 

      0%

    • B. 

      25%

    • C. 

      50%

    • D. 

      75%

    • E. 

      100%

  • 5. 
    Which of the following is an example of how genes can be modified by the environment (Standard 2.1a):
    • A. 

      Pleiotropy (You may inherit a gene for the complex of symptoms that are collectively called sickle-cell anemia).

    • B. 

      Incomplete Penetrance (You may inherit the gene for diabetes but never get the disease unless you become overweight)

    • C. 

      Epistasis (Your dog inherits a dominant allele that determines whether the fur will have dark pigment and a different allele that determines how dark the pigment will be)

    • D. 

      Polygenic Traits (You inherit many different genes which combined effects determines your skin color).

    • E. 

      Codominance (A cow inherits two alleles that make a positive contribution to the phenotype resulting in a black and white coat).

  • 6. 
    Which statement describes the work of Gregor Mendel  (Standard 2.1a)?
    • A. 

      He developed some basic principles of heredity without having knowledge of chromosomes.

    • B. 

      He developed the microscope for the study of genes in pea plants.

    • C. 

      He explained the principle of dominance on the basis of the gene-chromosome theory.

    • D. 

      He used his knowledge of gene mutations to help explain the appearance of new traits in organisms.

    • E. 

      He studied the beaks of finches which helped him to develop the theory of evolution by natural selection.

  • 7. 
    Some individuals with blood group A may inherit the genes for dimples, while other individuals with blood group A may inherit the genes for no dimples. This can best be explained by the principle of (Standard 2.1b)?
    • A. 

      Dominance

    • B. 

      Multiple alleles

    • C. 

      Independent assortment

    • D. 

      Incomplete dominance

    • E. 

      Segregation

  • 8. 
    Chromosomes normally occur as homologous pairs in (Standard 2.1c): 
    • A. 

      A sperm cell

    • B. 

      An egg cell

    • C. 

      A zygote

    • D. 

      A gamete

    • E. 

      A haploid cell

  • 9. 
    Which of the following statements is true (Standard 2.1c)?
    • A. 

      Chromosome map percentages are not actual chromosome distances, but represent the relative position of genes.

    • B. 

      Gene linkage is an exception to Mendel’s Law of Dominance

    • C. 

      Genetic recombination involves both gene linkage and chromosome mapping.

    • D. 

      Polyploid plants are avoided by plant growers because they are almost always lethal.

    • E. 

      Each somatic cell in the human body has a different number of chromosomes depending on the function of the cell.

  • 10. 
    Breeders have developed a variety of plants with desirable characteristics.  Which two biological concepts below best illustrate this concept (Standard 2.2a)?
    • A. 

      Artificial selection and polyploidy

    • B. 

      Grafting and hybridization

    • C. 

      Regeneration and incubation

    • D. 

      Vegetative propagation and binary fission

    • E. 

      Test cross and gene linkage

  • 11. 
    Rate, on a scale of 1 – 4, 1 being the lowest and 4 being the highest, how much you now know about genetics.
  • 12. 
    Rate, on a scale of 1 – 4, 1 being the lowest and 4 being the highest, how interested are you in genetics now.