One parent or two: how living things reproduce

Grade 7 Science Worksheet - Challenge Me

Circle the best answer.

2. 1.

   Ari’s class reads the chart and the table. Which claim and reason fit what the data show?

   • Bed S had more plants growing well in Year 2, because its plants copy one parent
   • Bed R had fewer plants growing well in Year 2, because pieces of one plant need a partner plant
   • Bed S had more plants growing well in Year 2, because its plants differ in their genes
   • Bed R had more plants growing well in Year 2, because copies handle any change
3. 2.

   Bo reads the same chart and table. Which line explains why Bed R went from 8 plants growing well to 0?

   Use the picture in question 1.

   • Each Bed R plant changed its own genes once the weather turned dry
   • Bed S had more plants growing well in Year 1, so it did better in Year 2
   • Bed R plants share the same genes, so the dry weather affected them alike
   • Bed R plants had one parent, so they could not grow well without a partner plant
4. 3.

   In Year 3 the weather turns very cold. Esme uses the chart and the table to predict. Which prediction fits best?

   Use the picture in question 1.

   • Bed S plants will react alike, since seeds copy their parents
   • Some Bed S plants may cope, but the Bed R plants will react in the same way
   • Bed R plants will cope, since copies of one parent handle change well
   • Bed R plants will cope better, since pieces of one plant adjust their genes
5. 4.

   Jun reads about Flower Q. It is pale, not brightly colored, yet it draws pollinators. Which line explains this?

   • Moths and bats that visit at night can find pale, scented flowers
   • Its strong scent helps the seeds cling to the coat of a passing animal
   • Bees visit it at night, since pale petals glow
   • Wind carries its pollen, so it needs no scent
6. 5.

   Luz reads that an iris spreads by underground stems called rhizomes and also makes flowers that form seeds. Which statement fits both ways of reproducing?

   • Both give copies, since each starts from one plant
   • Rhizomes give a new mix of genes; seeds give copies of the plant
   • Rhizomes need a partner plant; seeds come from one plant
   • Rhizomes give copies of the plant; seeds give a new mix of genes
7. 6.

   Noah says that hooks on a cocklebur seed pod prove its seeds came from one parent and no partner. Which response finds the flaw?

   • Hooks draw pollinators, so the seed must have come from two parents
   • Hooks change the seed’s genes to match the animal’s coat
   • Seeds are copies of one parent, so the claim is correct
   • Hooks move a seed after it forms, so they do not show how it was made
8. 7.

   Pia says sexual reproduction gives better results than asexual reproduction in every year. Which response uses the chart and the table to find the flaw?

   • In Year 1 both beds had 8 plants growing well, so Bed S was not better then
   • Bed R is a flawed test, since pieces of one plant need a partner
   • Bed S is a flawed test, since its seeds are copies of one parent
   • In Year 2 Bed S had 3 plants growing well, so the claim fits the whole table
9. 8.

   Ren wants new daffodils with the same genes as a favorite daffodil plant. Which plan and reason fit best?

   • Plant seeds from it, because seeds are copies of one parent
   • Plant bulbs from it, because bulbs make copies of one parent
   • Plant seeds from two plants, because the mix will match the favorite
   • Plant bulbs from it, because a bulb needs a partner plant’s genes
10. 9.

    Tala plans a plant bed in a field where the weather changes from year to year. Which plan and reason fit best?

    • Plant seeds from two parents, because varied plants may include some that suit each year
    • Plant pieces of one parent, because copies suit any weather
    • Plant pieces of one parent, because the copies will change to suit each year
    • Plant seeds, because seeds are exact copies of one parent
11. 10.

    Zee compares bright, scented flowers with bird song in spring. Which statement and reason fit best?

    • The flowers alone help reproduction, because song and nests are for shelter
    • Both help sexual reproduction, because the flowers draw a partner and the song draws pollinators
    • Both help sexual reproduction, because one draws pollinators and the other a partner
    • Both help asexual reproduction, because each lets one parent copy itself