One parent or two: how living things reproduce
Grade 7 Science Worksheet - Building Confidence

Circle the best answer.
A strawberry plant sends out a runner, a stem along the ground that grows a new plant. Ari fills in the Offspring box. What goes in it?
- A mix of genes set P and genes set Q
- Half of genes set P, with half missing
- Genes set P, the same as the one parent
- New genes that are different from set P
Yeast is a living thing made of one cell. A yeast cell grows a bud that breaks away as a new cell. Bo fills in the Offspring box. What goes in it?
Yeast cells (model data). Trait chart, columns: Parent | Way it makes offspring | Offspring. Row 1: one yeast cell, genes set Y | a bud grows and breaks away | new yeast cell, genes ?. Yeast cells (model data). Trait chart, columns: Parent | Way it makes offspring | Offspring. Row 1: one yeast cell, genes set Y | a bud grows and breaks away | new yeast cell, genes ?. Row Parent Way it makes offspring Offspring 1 one yeast cell, genes set Y a bud grows and breaks away new yeast cell, genes ? - Genes set Y, copied from the parent cell
- Different genes from the parent cell
- Part of genes set Y, split with the parent cell
- Genes set Y and set Z from two parent cells
A hydra is an animal. It grows a bud that becomes a new hydra and breaks away. Esme fills in the Offspring box. What goes in it?
Hydra (model data). Trait chart, columns: Parent | Way it makes offspring | Offspring. Row 1: one hydra, genes set H | a bud grows and breaks away | new hydra, genes ?. Hydra (model data). Trait chart, columns: Parent | Way it makes offspring | Offspring. Row 1: one hydra, genes set H | a bud grows and breaks away | new hydra, genes ?. Hydra (model data). Trait chart Parent Way it makes offspring Offspring Row 1: one hydra, genes set H a bud grows and breaks away new hydra, genes ? - Genes set H and set J from two parents
- New genes that differ from the parent
- Genes taken in from the water nearby
- Genes set H, matching the one parent
Kira reads a science word list. Which meaning goes with the words sexual reproduction?
- Egg and sperm cells from two parents join
- A seed lands in soil and begins to grow
- Egg cells from two parents join with no sperm cells
- One parent makes a copy of itself
Luz reads a science word list. Which meaning goes with the word variation?
- The number of offspring a parent makes
- Differences in genes and traits among offspring
- Sameness that protects offspring when the weather changes
- Offspring that are copies of one parent
Milo reads two cases. Which case shows sexual reproduction?
Two cases (model data). Trait chart, columns: Case | Parents | Offspring. Row 1: Case X: a strawberry plant sends out a runner | one parent | new plant, a copy of its genes. Row 2: Case Y: a sperm cell in pollen from one cucumber plant joins an egg cell of another cucumber plant | two parents | new plant, a new mix of genes. Two cases (model data). Trait chart, columns: Case | Parents | Offspring. Row 1: Case X: a strawberry plant sends out a runner | one parent | new plant, a copy of its genes. Row 2: Case Y: a sperm cell in pollen from one cucumber plant joins an egg cell of another cucumber plant | two parents | new plant, a new mix of genes. Two cases (model data). Trait chart Case Parents Offspring Row 1: Case X: a strawberry plant sends out a runner one parent new plant, a copy of its genes Row 2: Case Y: a sperm cell in pollen from one cucumber plant joins an egg cell of another cucumber plant two parents new plant, a new mix of genes - Case Y, because two parents give sperm and egg cells
- Case X, because the runner needs a partner plant nearby
- Case X, because the new plant is a copy of its parent
- Case Y, because the new plant grows from a runner
Pia reads two cases. Which case gives offspring more likely to include some that cope with a change in the weather?
Two cases (model data). Trait chart, columns: Case | Parents | Offspring. Row 1: Case X: a hydra grows a bud that breaks away | one parent | new hydra, a copy of its genes. Row 2: Case Y: pollen from one squash plant reaches a flower of another squash plant, and sperm and egg cells join | two parents | new plant, a new mix of genes. Two cases (model data). Trait chart, columns: Case | Parents | Offspring. Row 1: Case X: a hydra grows a bud that breaks away | one parent | new hydra, a copy of its genes. Row 2: Case Y: pollen from one squash plant reaches a flower of another squash plant, and sperm and egg cells join | two parents | new plant, a new mix of genes. Two cases (model data). Trait chart Case Parents Offspring 1. Case X: a hydra grows a bud that breaks away one parent new hydra, a copy of its genes 2. Case Y: pollen from one squash plant reaches a flower of another squash plant, and sperm and egg cells join two parents new plant, a new mix of genes - Case Y, because it makes offspring much faster
- Case Y, because its offspring have varied genes
- Case X, because copies of one parent suit any weather
- Case X, because a bud is a new and different cell
Ren studies a flower with bright petals and a sweet scent. What job do these parts do for the flower?
- They make the seeds heavier before they fall
- They draw pollinators such as bees to the flower
- They hook onto an animal’s coat so seeds travel
- They keep pollinators away from the pollen and nectar
Tala reads about a cocklebur seed pod with hooks that cling to an animal’s coat. What job do the hooks do for the plant?
- They hold the egg cell inside the flower
- They make nectar for pollinators to drink
- They draw bees that carry pollen from flower to flower
- They carry seeds to a new place on an animal’s coat
Zee listens to a bird sing in spring. What job does bird song do for reproduction?
- It helps attract a partner of the same species
- It carries pollen from flower to flower
- It holds the eggs and keeps the young birds warm
- It tells the plants in the garden when to bloom

