Plant Biology

What is a role of xylem?

• It absorbs minerals from the soil by active transport

• It translocates amino acids from source to sink.

• It carries glucose to the leaves.

• It contributes to the plant support with lignified walls.

Which process and cause are reponsible for water uptake by the roots?

• Simple diffusion: solute concentration in the root lower than in the soil

• Osmosis: solute concentration in the root greater than in the soil

• Osmosis: solute concentration in the root lower than in the soil

• Cohesion: solute concentration in the root greater than in the soil

Which graph represents the effect of humidity on the transpiration rate in plants?

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Under which conditions would the rate of transpiration be greatest?

• Humid and cool with wind

• Dry and hot with wind

• Dry and hot with no wind

• Humid and cool with no wind

Which letter indicates phloem?

• A

• B

• C

• C

A man attaches a bird box to the trunk of a dicotyledonous tree. A few years later he returns to the tree and finds that his bird box is still attached and the tree is much taller.

How high will his bird box be from the ground?

• Unchanged as growth from the apical meristem would be above the box.

• Unchanged as growth from the lateral meristem would be above the box.

• Higher as growth from the apical meristem would be below the box.

• Higher as growth from the lateral meristem would be below the box.

The picture shows lentils sprouts growing towards a light source from the left. How has this response been brought about?

• A higher concentration of auxins on the light side caused faster photosynthesis.

• A higher concentration of auxins on the shaded side caused faster meiosis.

• A higher concentration of auxins on the shaded side caused faster cell elongation.

• A higher concentration of chloroplasts on the light side allowed for more photosynthesis.

What is/are the effect(s) of auxin in plants?

I.   Increasing the rate of cell elongation in stems
II.  Changing the pattern of gene expression in shoot cells
III. Detecting the direction of light

• I only

• I and II only

• II and III only

• I, II and III

Chrysanthemums are short-day plants. Growers can induce them to flower out of season by exposing them to...

• short bursts of light for 24 hours

• 15 hours of continuous light

• 12 hours of light and 12 hours of darkness

• 15 hours of continuous darkness

Micropropagation is used to produce large numbers of plants in a short period of time.

What is a feature of micropropagation?

• Any tissue from a plant can be used for micropropagation

• The plants grown have different variations allowing for adaptations to the environment

• Micropropagation requires plant pollen and agar gel only

• The process is sterile and resulting plants are disease-free