Score Level 1 Anchor Paper

This response demonstrates some understanding of the question. The Punnett square for the homozygous female (BB × bb) is correctly completed. The Punnett square for the heterozygous female is incorrect, as it shows a cross between two heterozygous parents (Bb × Bb) instead of a cross between a heterozygous female and a homozygous recessive male (Bb × bb). A general explanation for how the fur color of the offspring would help determine the female’s genotype (If the fur color of the offspring is black … either homozygous or heterozygous; brown, then the scientist will know … heterozygous) is provided. The explanation includes a vague reference to the possible genotypes of the female rabbit (homozygous or heterozygous dominant). The supporting details are minimally effective.

Score Level 1 Anchor Paper

This response demonstrates some understanding of the question. The two possible genotypes for the female rabbit (BB or Bb) are identified. A correctly completed Punnett square for the heterozygous female (bb × Bb) is provided, but the Punnett square for the homozygous female is incorrect, as it shows a cross between a homozygous dominant rabbit and a heterozygous rabbit (BB × Bb) instead of a cross between a homozygous dominant rabbit and homozygous recessive rabbit (BB × bb). The supporting details are minimally effective throughout.

Score Level 2 Anchor Paper

This response demonstrates a basic understanding of the question. The student identifies one possible genotype of the female (Bb-heterozygous black) and provides two correct Punnett squares in the appropriate boxes. The explanation for how the fur color of the offspring would help the scientists determine the female’s genotype is adequate (has to be heterozygous so she can have variation in her offspring; homozygous then they would all be the same). Overall, the supporting details are adequate.

Score Level 2 Anchor Paper

This response demonstrates a basic understanding of the question. Although the possible genotypes of the female are not identified, the student provides correct Punnett squares for the homozygous and heterozygous female in the appropriate boxes. The explanation for how the fur color of the offspring would help determine the genotype of the female rabbit is adequate (the only way that these to rabbits could have brown babies was if the mother was heterozygous hence if they had brown babies we would know the genotypes). The supporting details are adequate.

Score Level 3 Anchor Paper

This response demonstrates a good understanding of the question. The two possible genotypes of the female rabbit are identified (homozygous black ... BB, or heterozygous black … Bb). Two correct Punnett squares, in the appropriate boxes, are provided. The explanation given by the student addresses each possible outcome in terms of how the color of the offspring would help scientists determine the female’s genotype (If the offspring are all black, then the mother is homozygous) and shows a synthesis of information (If half of the offspring are black and half are brown, or is any are brown at all, then … heterozygous). Overall, the supporting details are generally complete.

Score Level 3 Anchor Paper

This response demonstrates a good understanding of the question. The two possible genotypes of the female rabbit (BB or Bb) are identified. The Punnett squares are correct and in the appropriate boxes. The last part of the question demonstrates synthesis as the student provides an explanation for what color fur the offspring would have with each of the possible genotypes (if she were homozygous dominant each of her offspring would have to have dominant black fur; If any of her offspring had brown fur, scientist would no that she has a heterozygous dominant gene because 50 percent … brown fur). The supporting details are generally complete.

Score Level 4 Anchor Paper

This response demonstrates a full and complete understanding of the question. The student identifies the possible genotypes of the female (BB; Bb) and provides two correct Punnett squares. Details are integrated throughout the response, as the results in the Punnett squares support the explanation of how the fur color of the offspring would help determine the female’s genotype (According to the Punnett squares she could have offspring that are all heterozygous … or … ½ the offspring were heterozygous black and half were brown). A full synthesis of information is demonstrated, as the student further explains how to determine the female’s genotype (If she doesn’t have that gene [BB] none of her offspring could have brown fur). The use of accurate scientific terminology (test cross; varience; phenotype) enhances the response.

Score Level 4 Anchor Paper

This response demonstrates a full and complete understanding of the question. The Punnett squares are correct and in the appropriate boxes. The student integrates a pertinent description of inheritance (sexually produced offspring must have one gene from each parent) into a full explanation of how the fur color of the offspring would help determine the females genotype (if any of the offspring … brown, that would mean that they would be bb, and therefore would have gotten a “b” from the female, which would have made her heterozygous or Bb; Since the offspring would automatically receive a “b” from the brown parent, it would be known that since the offspring entirely was black that the female would had to of given the offspring a “B,” and if it happened every time … BB). The possible genotypes of the female are identified in the explanation. The use of accurate scientific terminology (sexually produced offspring; test cross) enhances the response and the supporting details are pertinent and complete.