Coordination, Defense & Reproduction — Chapter quiz · Life Science & Scientific Inquiry, Grade 7

Five focused units, a three-session investigation, chapter review, and chapter quiz.

Problem 1

Why is “the brain never learns about a reflex” too strong?
Answer and explanation

A reflex can begin without conscious decision, while related information can still reach the brain.

Problem 2

Why could different task instructions change a response-time comparison?
Answer and explanation

They can change what must be detected, interpreted, or done. Comparable instructions and timing methods are needed before comparing outcomes.

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 3

Why should a hormone model show responsive target cells?
Answer and explanation

Cells differ in their ability to respond to a particular signal; transport everywhere does not mean the same response everywhere.

Problem 4

A student says “negative feedback is bad feedback.” Correct the terminology.
Answer and explanation

Negative describes opposition to a deviation. It does not label the process morally or medically harmful.

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 5

Why is a matching-shape model limited?
Answer and explanation

It illustrates recognition but omits molecular complexity, multiple defense pathways, and real organism variation.

Problem 6

Why should a decomposition bacterium not automatically be labeled a harmful pathogen?
Answer and explanation

Its role depends on organism and context. Decomposition can recycle matter; being microscopic or bacterial does not by itself establish disease-causing activity.

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

Why is egg count not the same as successful adult offspring?
Answer and explanation

Some eggs may not be fertilized or survive development, and later survival and reproduction depend on conditions.

Problem 8

Two sexual offspring share parents but differ in traits. Does that by itself contradict inheritance?
Answer and explanation

No. They can receive different combinations of inherited material and experience different environments. Sexual inheritance is not an exact visual blend.

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 9

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 10

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.

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