One parent or two: how living things reproduce
Grade 7 Science Worksheet
Circle the best answer.
Ari plants a piece of potato tuber, an underground stem, with a sprouting eye. The new potato plant grows. How do its genes compare with the plant the tuber came from?
- They are a new mix, since the sprout joined cells from two plants
- They differ, since the new plant grew in new soil
- They match, since one plant made the new plant
- They are halved, since the tuber is a piece of a plant
Bo watches a bee carry pollen from one sunflower plant to a different sunflower plant. Sperm and egg cells join, and seeds form. How do the seedlings’ genes compare with the two plants?
- Each seedling is a copy of the plant that gave the pollen
- The seedlings match each other, with the same genes
- Each seedling has a new mix of genes from both plants
- Each seedling has half as many genes as its parents
Esme reads a chart for two parent birds. Their sperm cell and egg cell join. What goes in the Offspring box?
- Genes set B alone, matching the first parent
- Genes set C alone, matching the second parent
- New genes unlike either parent
- A mix of genes set B and genes set C
Jun reads that a ginger plant grows a new shoot from its underground stem, a rhizome. The shoot becomes a new plant. Is this asexual or sexual reproduction, and why?
- Asexual, because one parent makes the new plant
- Asexual, because the offspring differ from the parent
- Sexual, because a new plant is a new living thing
- Sexual, because the shoot needs a partner plant
Kira reads that a hummingbird carries pollen from a red flower to a flower on a different plant. Seeds form. Is this asexual or sexual reproduction, and why?
- Sexual, because each seed copies the pollen plant
- Sexual, because sperm in the pollen joins an egg cell of another plant
- Asexual, because plants make seeds from one flower
- Asexual, because a bird just moves the pollen
Luz grows a tray of seedlings from seeds made when pollen from one plant reached the flower of another plant. The seedlings differ from each other. How were they most likely made?
- Asexual reproduction, because one parent changes its genes each time
- Sexual reproduction, because each seedling copies one parent
- Asexual reproduction, because offspring copy their parent
- Sexual reproduction, because two parents mixed their genes
Noah reads about three seeds. Which seed is most likely to be carried on an animal’s coat?
- Seed J, because its hooks cling to a coat
- Seed K, because its wing-like parts grip a coat
- No seed, because seeds stay where they form
- Seed L, because light seeds hitch a ride on fur
Pia reads about two bird behaviors in spring. Which pair of jobs matches them?
- Song carries seeds away; the nest carries pollen
- Song draws a partner; the nest carries seeds away
- Song holds eggs and young; the nest draws a partner
- Song draws a partner; the nest holds eggs and young
Ren’s garden stays the same year after year. Which is an advantage of asexual reproduction there?
- Offspring get a new mix of genes from two parents
- Offspring match a parent that already does well there
- Offspring change their genes to suit the garden
- The new plants reach maturity more slowly than seedlings
Zee compares the two ways of reproducing. Which is a cost of sexual reproduction?
- Offspring are exact copies of one parent’s genes
- Offspring cope less well when conditions change a lot
- Offspring share the same weakness when the weather changes
- A parent must find a partner, which takes time and energy
