HL C3.1 Integration of body systems (LO 17 - 23)

Which of the following best describes a qualitative observation in a tropism experiment?

• Measuring the angle of seedling curvature

• Recording the exact length of a seedling shoot

• Noting that seedlings bent toward the light source

• Calculating the mean curvature angle of multiple seedlings

Which factor would increase the precision of measurements in a tropism experiment?

• Measuring angle of curvature using a protractor

• Describing how much the seedling has bent using words

• Using one seedling for the experiment

• Observing seedlings only once during the experiment

Why is it important to distinguish between accuracy and precision in plant tropism experiments?

• To determine the color of the seedlings

• To ensure that all seedlings grow at the same rate

• To evaluate whether the measurements reflect true values and are consistent

• To calculate the number of auxin molecules

Positive phototropism in shoots occurs because:

• Light destroys auxin in the shaded side

• Auxin accumulates on the shaded side, causing cells to elongate

• Water pressure increases on the lighted side

• Chloroplasts migrate away from light

What is the primary purpose of positive phototropism in shoots?

• To maximize exposure to gravity

• To prevent dehydration

• To increase photosynthetic efficiency

• To reduce auxin production

Which condition would most likely prevent positive phototropism?

• Uniform light from above

• Light from one side

• Red light exposure

• Continuous darkness

Which of the following is NOT considered a phytohormone?

• Auxin

• Cytokinin

• Insulin

• Ethylene

What do phytohormones control in plants?

• Digestion and circulation

• Growth, development, and response to stimuli

• Respiration and photosynthesis

• Heart rate and temperature

Which statement best reflects the role of phytohormones?

• They are produced in animal cells only

• They are used only in response to injury

• They regulate multiple aspects of plant physiology through signaling

• They are stored in large quantities in plant vacuoles

What is the role of auxin efflux carriers in plant cells?

• To synthesize auxin in the cytoplasm

• To destroy auxin in the nucleus

• To actively transport auxin out of cells in one direction

• To convert auxin into glucose