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Genetic crosses and Punnett squares

9th grade (Year 10 in England) · 16 questions · Common Core: NGSS.HS-LS3-2, NGSS.HS-LS3-3 · England: KS4 Combined Science: Evolution, inheritance and variation

Name

Date

Score/ 16

  1. Question 1

    Two Bb parents have 400 offspring. Brown fur is dominant. About how many offspring would you expect to have white fur?

    Answer

  2. Question 2

    Brown fur (B) is dominant over white fur (b). Two parents with genotypes BB and bb are crossed. What percentage of the offspring are expected to have brown fur?

    Answer%

  3. Question 3

    A recessive characteristic only shows when…

    • A. there are two recessive alleles
    • B. there is a dominant allele
    • C. the organism is old
    • D. there is one recessive allele

  4. Question 4

    Two Tt parents have 100 offspring. Tall stems is dominant. About how many offspring would you expect to have short stems?

    Answer

  5. Question 5

    Brown fur (B) is dominant over white fur (b). Two parents with genotypes BB and bb are crossed. What percentage of the offspring are expected to have brown fur?

    Answer%

  6. Question 6

    What does "heterozygous" mean?

    • A. having two different alleles of a gene, such as Bb
    • B. having two identical alleles, such as BB
    • C. having four alleles
    • D. having no alleles

  7. Question 7

    Two Pp parents have 200 offspring. Purple flowers is dominant. About how many offspring would you expect to have white flowers?

    Answer

  8. Question 8

    Purple flowers (P) is dominant over white flowers (p). Two parents with genotypes Pp and pp are crossed. What percentage of the offspring are expected to have white flowers?

    Answer%

  9. Question 9

    A recessive characteristic only shows when…

    • A. there is one recessive allele
    • B. there is a dominant allele
    • C. the organism is old
    • D. there are two recessive alleles

  10. Question 10

    Two Tt parents have 200 offspring. Tall stems is dominant. About how many offspring would you expect to have short stems?

    Answer

  11. Question 11

    Tall stems (T) is dominant over short stems (t). Two parents with genotypes TT and tt are crossed. What percentage of the offspring are expected to have short stems?

    Answer%

  12. Question 12

    What does "heterozygous" mean?

    • A. having four alleles
    • B. having no alleles
    • C. having two identical alleles, such as BB
    • D. having two different alleles of a gene, such as Bb

  13. Question 13

    Two Tt parents have 400 offspring. Tall stems is dominant. About how many offspring would you expect to have short stems?

    Answer

  14. Question 14

    Brown fur (B) is dominant over white fur (b). Two parents with genotypes Bb and bb are crossed. What percentage of the offspring are expected to have brown fur?

    Answer%

  15. Question 15

    What is a phenotype?

    • A. a type of cell division
    • B. a chromosome
    • C. the alleles an organism has, such as Bb
    • D. the characteristic that is shown, such as eye colour

  16. Question 16

    Two Pp parents have 120 offspring. Purple flowers is dominant. About how many offspring would you expect to have white flowers?

    Answer

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  1. 100
  2. 100 %
  3. there are two recessive alleles
  4. 25
  5. 100 %
  6. having two different alleles of a gene, such as Bb
  7. 50
  8. 50 %
  9. there are two recessive alleles
  10. 50
  11. 0 %
  12. having two different alleles of a gene, such as Bb
  13. 100
  14. 50 %
  15. the characteristic that is shown, such as eye colour
  16. 30