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 differ in their genes
   • 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 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.

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

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

   • Its strong scent helps the seeds cling to the coat of a passing animal
   • Wind carries its pollen, so it needs no scent
   • Moths and bats that visit at night can find pale, scented flowers
   • Bees visit it at night, since pale petals glow
5. 4.

   Kira reads that some plants make seeds without fertilization (egg and sperm cells joining). The seedlings match the parent plant’s genes. Which line explains this?

   • A second parent gave genes that happen to match the first
   • No egg and sperm cells joined, so the seedlings have only the parent’s genes
   • Egg and sperm cells joined, but the genes stayed the same in each seed
   • The seedlings changed their genes to look like the parent
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?

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

   Milo says the chart and the table prove that plants grown from pieces of one parent do well in any weather. Which response finds the flaw?

   • Pieces of one parent change their genes each year, so the data cannot be trusted
   • Pieces of one parent need a partner plant, so the bed cannot be trusted
   • Copies of one parent cope with any weather, so the claim is correct
   • All three years were mild, so the data cannot show a harsh year
8. 7.

   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 move a seed after it forms, so they do not show how it was made
   • 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
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, because seeds are exact copies of one parent
    • Plant pieces of one parent, because copies suit any weather
    • Plant seeds from two parents, because varied plants may include some that suit each year
    • Plant pieces of one parent, because the copies will change to suit each year
11. 10.

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

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