Blended and both-showing traits
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Read this first
A snapdragon cross (model data)
offspring counted flower color 60 all pink Ari reads a snapdragon cross card. Every offspring has pink flowers. Which parents could these be?
- One red parent and one pink parent (RR × RW)
- One red parent and one white parent (RR × WW)
- Two pink parents (RW × RW)
- One pink parent and one white parent (RW × WW)
Bo reads a snapdragon cross card. The offspring are about half pink and half white. Which parents could these be?
- A pink parent and a white parent (RW × WW)
- Two pink parents (RW × RW)
- One red parent and one white parent (RR × WW)
- One red parent and one pink parent (RR × RW)
A cattle cross (model data)
coat calves counted red 24 roan 51 white 25 Esme reads a model cattle cross card. The calves are red, roan and white. Which parents could these be?
- Two roan parents (RW × RW)
- One red parent and one white parent (RR × WW)
- One roan parent and one white parent (RW × WW)
- One roan parent and one red parent (RW × RR)
Jun picks one seedling at random from the pink × pink offspring. Its flowers are not white. What is the chance they are pink?
- 1 in 2, since 2 of the 4 boxes are pink
- 1 in 3, since 1 of the 3 boxes that are not white is pink
- 3 in 4, since 3 of the 4 boxes are not white
- 2 in 3, since 2 of the 3 non-white boxes are pink
Kira grows two seedlings from the cross of two pink snapdragons. What is the chance that both have white flowers?
Use the picture in question 4.
- 1 in 4, the chance for one seedling
- 1 in 16, since 1/4 × 1/4
- 0, since the white allele is blended away in pink plants
- 1 in 2, since 1/4 + 1/4
Luz follows a model cross of a roan parent and a red parent. What is the chance that three calves in a row are roan?
- 1 in 8, since 1/2 × 1/2 × 1/2
- 1 in 6, since 1/2 ÷ 3
- 1 in 4, since 1/2 × 1/2
- 1 in 2, the chance for one calf
Notebook
Notes on a pink × pink cross (classmate's notebook), 4 lines. Columns: line, entry. Line 1: The expected ratio is 1 red : 2 pink : 1 white. Line 2: Of 80 seedlings, the expected counts are 20 red, 40 pink and 20 white. Line 3: The class counted 23 red, 38 pink and 19 white. Line 4: The counts are not 20, 40 and 20, so the cross does not follow the ratio.
Pia reads a classmate's notebook about a pink × pink cross. Which line has the mistake?
- Line 4: counts land near the expected counts, not on them
- Line 1: the expected ratio should be 3 : 1
- Line 3: the class should have counted exactly 20, 40 and 20
- Line 2: 80 seedlings should give counts that add to 100
Ren says pink snapdragons breed true, so two pink parents give only pink offspring. Do you agree?
- Yes, because red and white blend into one pink allele
- No, because two pink parents give 3 pink to 1 white
- Yes, because pink parents have no other alleles to pass on
- No, because pink parents also give red and white offspring
Class counts for a pink × pink cross (model data)
flower color counted expected red 24 25 pink 52 50 white 24 25 Tala says the cross failed because the counts are not exactly the expected counts. Do you agree?
- No, because real counts land near the ratio, not on it
- Yes, because the cross should give 75 colored and 25 white
- No, because 52 pink shows pink is dominant over red and white
- Yes, because counts must match the ratio exactly
Table
Two patterns (model), 2 rows. Columns: pattern, what the heterozygote shows. Row 1: incomplete dominance, one in-between look, such as pink snapdragons. Row 2: codominance, both parent looks side by side, such as roan red and white hairs.
Zee says roan is just incomplete dominance, since the roan calf looks in between red and white. Do you agree?
- No, because roan parents give roan calves, not red or white
- No, because roan is complete dominance, with red hiding white
- No, because roan shows both looks, not one in-between look
- Yes, because both patterns give one mixed color