Topic 9_Plant Biology

Which process is most responsible for movement of water from roots to leaves of a plant on a hot sunny day?

• Active translocation of mineral ions in roots

• Active transport of organic compounds into sieve tubes

• Raised hydrostatic pressure gradients

• Evaporation of water from mesophyll cell walls

In the micrograph of a plant stem, which letter indicates the xylem?

• A

• B

• C

• D

A pollen tube grows down the style to an egg inside the ovary of a flower. What is the next process that occurs?

• Dispersal

• Fertilization

• Germination

• Pollination

The image shows a cross-section of a flower. Where does production of haploid gametes occur?

• I and II only

• III and IV only

• I and III only

• II and IV only

The image shows part of a section through the stem of a non-woody plant. Which feature distinguishes the transport of materials in the tissue labelled I from that in the tissue labelled II?

• In II, active transport is used.

• In II, products of photosynthesis are transported.

• In I, movement of materials is the result of transpiration.

• In I, there is a higher solute concentration.

Which statement describes the control of reproduction in flowering plants?

• Flowering in short-day plants results from changes in gene expression in the shoot apex.

• Flowering in long-day plants is controlled by the production of auxins in the shoot apex.

• All flowering plants depend on the duration of periods of light and darkness to regulate the timing of reproduction.

• Flowering in short-day plants occurs when day length is longer than 12 hours.

The image is a cross section through an Ammophila leaf, which grows on coastal sand dunes. What feature suggests that Ammophila is a xerophyte?

• The leaf surface area is increased.

• The rolled leaf reduces the upper epidermis area.

• The rolled leaf protects the lower epidermis from the wind.

• The lower epidermis can transpire more easily.

What could be used in a technique for measuring flow rates in phloem?

I. Potometers

II. Aphid stylets

III. ¹⁴CO₂

• I and II only

• I and III only

• II only

• II and III only

How do most angiospermophyta improve sexual reproductive success?

• By flowering during long days

• By flowering during short days

• By using mutualistic pollinators

• By using micropropagation

Cobalt chloride paper is blue when dry but turns pink with water. Blue cobalt chloride paper was fastened to the upper and lower surfaces of a plant leaf. After 20 minutes, many small pink dots were observed on the paper on the lower surface, and a few pink dots were seen on the upper surface. What conclusions can be drawn?

I. There are more stomata on the lower surface than on the upper surface.

II. Stomata on the upper surface are blocked by the waxy cuticle.

III. More transpiration occurs through the lower surface than through the upper surface.

• I and II only

• I and III only

• II and III only

• I, II and III