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 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 S had more plants growing well in Year 2, because its plants copy one parent
   • 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 share the same genes, so the dry weather affected them alike
   • Each Bed R plant changed its own genes once the weather turned dry
   • Bed R plants had one parent, so they could not grow well without a partner plant
   • Bed S had more plants growing well in Year 1, so it did better in Year 2
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
   • Bed R plants will cope better, since pieces of one plant adjust their genes
   • Bed R plants will cope, since copies of one parent handle change well
   • Some Bed S plants may cope, but the Bed R plants will react in the same way
5. 4.

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

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

   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?

   • No egg and sperm cells joined, so the seedlings have only the parent’s genes
   • A second parent gave genes that happen to match the first
   • Egg and sperm cells joined, but the genes stayed the same in each seed
   • The seedlings changed their genes to look like the parent
7. 6.

   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 give a new mix of genes; seeds give copies of the plant
   • Rhizomes need a partner plant; seeds come from one plant
8. 7.

   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
   • All three years were mild, so the data cannot show a harsh year
   • Copies of one parent cope with any weather, so the claim is correct
9. 8.

   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 change the seed’s genes to match the animal’s coat
   • Hooks draw pollinators, so the seed must have come from two parents
   • Seeds are copies of one parent, so the claim is correct
10. 9.

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