Flowers, Seeds & Plant Life Cycles — Practice · Grade 7 Science

Chapter: Coordination, Defense & Reproduction

What this practice covers

By the end of Flowers, Seeds & Plant Life Cycles you should be able to:

8 questions, written answer, multiple choice and numeric, each with a worked explanation.

Vocabulary used: pollination, ovule, embryo, germination, dispersal.

Problem 1

Does observing a pollinator visit prove viable seeds formed?
Answer and explanation

No. The visit is one stage; transfer, compatibility, fertilization, and development need further evidence.

Problem 2

Why can early germination occur before a seedling has green leaves?
Answer and explanation

The seed can use stored resources and cellular respiration to support initial growth.

Problem 3

Does moving a seed automatically create a mutation?
Answer and explanation

No. Location changes environmental conditions; mutation is a change in genetic material and is a different process.

Problem 4

Why should the denominator include all tested seeds?
Answer and explanation

It defines success relative to the original sample; excluding failures would inflate the reported germination percentage.

Problem 5

Illustrative seven-day data: Treatment A has 18 germinated seeds of 20; B has 12 of 20. Species and other conditions are stated matched; the treatment is water amount. Calculate both percentages, describe the measured difference, and qualify the claim about lifelong plant success.
Answer and explanation

A has 90% germination and B 60%, a 30-percentage-point difference in this illustrative comparison. It supports a treatment-related germination question under the matched conditions, but does not establish adult survival, universal species response, or every causal detail. Replicate independent groups and record later growth separately.

A: 18/20×100=90%.

B: 12/20×100=60%.

Difference is 30 percentage points.

Limit the claim to the stipulated germination interval.

Response criteria

  • Explain the relevant biological process accurately.
  • Use the supplied evidence and show calculation steps with units where needed.
  • Connect a labeled model or mechanism with the claim.
  • State an assumption, evidence limitation, or useful next observation.

Problem 6

Why is the same germination treatment not automatically best for every plant species?
Answer and explanation

Species can have different requirements and tolerances. Evidence from one species and interval needs qualification before generalizing.

Response criteria

  • Explain the relevant biological process accurately.
  • Use the supplied evidence and show calculation steps with units where needed.
  • Connect a labeled model or mechanism with the claim.
  • State an assumption, evidence limitation, or useful next observation.

Problem 7

Which is pollination?
  1. Pollen transfer
  2. Every seed’s first leaf
  3. DNA duplication
  4. All adult survival
Answer and explanation

Pollen transfer

Pollination is pollen transfer; fertilization and development are subsequent distinct processes.

Problem 8

Eight of ten seeds germinate. Find germination percentage.
Answer and explanation

80 %

8/10×100=80%.

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