Quiz: Functional Organization of Flowering Plants — 24 questions

1. Regarding the constraints of a fixed plant lifestyle, which statements are correct?

A. Stomata are microscopic pores mainly located on leaves that permit gas exchange.

B. Roots absorb water and mineral ions from the soil rather than exchanging atmospheric gases.

C. Fixed plants obtain light, water, carbon dioxide, minerals, and reproduction without relocating.

D. Mobile organisms remain at one location while obtaining environmental resources.

E. Stomata are microscopic pores mainly located on stems that absorb mineral ions.

Answer: (A), (B), (C)

Explanation

Stomata are pores that mediate gas exchange between leaves and air, while roots absorb water and mineral ions. A fixed plant must obtain light, water, carbon dioxide, minerals, and reproductive opportunities without relocating.

2. Which adaptations help plants cope with environmental stresses and herbivory?

A. Plants may reduce winter activity and stop sap circulation during cold conditions.

B. Thorns provide a physical defense against herbivores.

C. Stomatal control can help limit extreme temperature stress in plants.

D. Plants cope with mountain altitude by increasing herbivore attraction through leaf chemistry.

E. Severe heat can trigger leaf loss as a plant response to temperature stress.

Answer: (A), (B), (C), (E)

Explanation

Plants reduce temperature stress through several physiological and structural responses, including stomatal control, leaf loss, reduced winter activity, and altered sap circulation. Thorns are physical defenses against herbivores, not temperature adaptations.

3. Concerning photosynthesis, tick the correct statements:

A. Photosynthesis produces organic matter using light energy, carbon dioxide, and water.

B. Photosynthesis uses mineral ions as its principal carbon source.

C. Photosynthesis consumes oxygen and releases carbon dioxide during organic-matter production.

D. Cellular respiration produces glucose and oxygen from light energy and water.

E. Plants, some algae, and some bacteria can perform photosynthesis.

Answer: (A), (E)

Explanation

Photosynthesis uses light energy, carbon dioxide, and water to produce organic matter. The process occurs in plants, some algae, and some bacteria; cellular respiration has the opposite gas-consumption pattern.

4. The basic equation for photosynthesis includes which accurate statements?

A. Light energy is released as the principal product of photosynthesis.

B. Six water molecules participate as reactants alongside light energy.

C. Six carbon dioxide molecules participate as reactants in the equation.

D. The reaction produces one glucose molecule and six oxygen molecules.

E. The reaction produces six carbon dioxide molecules and one water molecule.

Answer: (B), (C), (D)

Explanation

The photosynthesis equation has six molecules each of carbon dioxide and water as reactants, with light energy, and produces one glucose molecule plus six oxygen molecules. Respiration is associated with carbon dioxide and water production rather than this equation.

5. Which statements correctly distinguish angiosperms from gymnosperms?

A. Gymnosperm ovules are enclosed in flowers and later exposed after fertilization.

B. Angiosperm ovules are fertilized directly by pollen without floral enclosure.

C. Gymnosperm ovules are exposed rather than enclosed within a fruit.

D. Angiosperm ovules are enclosed within a flower before fertilization.

E. After fertilization, angiosperm ovules become enclosed in a fruit.

Answer: (C), (D), (E)

Explanation

Angiosperm ovules are enclosed in flowers and become enclosed in fruits after fertilization. Gymnosperm ovules remain exposed and are fertilized directly by pollen, distinguishing the two groups.

6. Which statement accurately describes the piliferous zone of a root?

A. It contains fungal filaments that always remain outside root cells.

B. It is located near the root tip and contains numerous root hairs.

C. It is the region farthest from the root tip and lacks absorbing structures.

D. It consists mainly of stomata that exchange gases with the atmosphere.

E. It is formed by leaves surrounding the upper stem.

Answer: (B)

Explanation

The piliferous zone lies near the root tip and contains numerous root hairs. This location distinguishes it from other root regions and explains its role in absorption.

7. Concerning mycorrhizal associations and root absorption, which statements are correct?

A. Endomycorrhizal filaments remain outside root cells during the association.

B. The plant supplies organic matter to its fungal partner.

C. Mycorrhizal symbiosis benefits both the fungus and the plant root.

D. Ectomycorrhizal filaments penetrate through the interior of root cells.

E. The fungus improves the plant's absorption of water and mineral ions.

Answer: (B), (C), (E)

Explanation

Mycorrhizal symbiosis benefits both partners: the fungus improves water and mineral-ion absorption, while the plant supplies organic matter. Endomycorrhizal filaments enter root cells, whereas ectomycorrhizal filaments remain outside them.

8. Which statements accurately describe the exchange surface provided by rye roots?

A. Rye root hairs provide a soil-contact surface of $215.5\ \text{m}^2$.

B. The measured surface reflects the extensive contact created by root hairs.

C. Rye leaves provide the measured soil-contact surface of $215.5\ \text{m}^2$.

D. Rye root hairs provide a soil-contact surface of $125.5\ \text{m}^2$.

E. The measured surface is produced by stomata exchanging gases with air.

Answer: (A), (B)

Explanation

Rye root hairs provide a soil-contact surface of 215.5 square metres. This large surface results from the extensive network of fine roots and root hairs, not from stomata or leaves.

9. Regarding leaf exchange surfaces, which statements are correct?

A. A broad leaf surface supports gas exchange with the surrounding air.

B. A leaf's light-exposed surface mainly prevents carbon dioxide entry.

C. Reducing leaf surface increases the amount of light available for photosynthesis.

D. A large leaf surface improves light capture for photosynthesis.

E. A large leaf surface can help limit excessive evapotranspiration.

Answer: (A), (D), (E)

Explanation

A broad light-exposed leaf surface supports both light capture for photosynthesis and gas exchange. It can also reduce excessive evapotranspiration relative to the functions it supports; the statements about reduced surfaces and incorrect stomatal structures do not match the described adaptations.

10. Concerning stomatal opening and closure, select the correct statements:

A. An open ostiole permits gas exchange between the leaf and air.

B. Guard cells regulate the pore by changing the volume of xylem vessels.

C. A closed ostiole prevents gas exchange through that stomatal opening.

D. The stomatal pore controlled by guard cells is called the ostiole.

E. Guard-cell volume changes can open the stomatal pore.

Answer: (A), (C), (D), (E)

Explanation

Guard cells alter their volume to control the stomatal pore, or ostiole. An open ostiole permits gas exchange, whereas closure restricts gas exchange; the pore is not called a lenticel and guard cells do not transport sap.

11. Which statements correctly compare gas exchanges during photosynthesis and cellular respiration?

A. Cellular respiration involves oxygen and water entering the leaf.

B. Cellular respiration involves carbon dioxide leaving the leaf.

C. Photosynthesis involves water vapor leaving the leaf.

D. Photosynthesis involves oxygen leaving the leaf.

E. Photosynthesis involves carbon dioxide entering the leaf.

Answer: (A), (B), (C), (D), (E)

Explanation

During photosynthesis, carbon dioxide enters the leaf while oxygen and water vapor leave. Cellular respiration has the opposite exchange pattern described here: carbon dioxide leaves, while oxygen and water enter.

12. Regarding raw sap transport through plants, which statements are correct?

A. Raw sap includes mineral ions absorbed from the soil.

B. Raw sap is transported through phloem sieve tubes.

C. Raw sap contains more than 99 percent water.

D. Raw sap contains organic molecules produced by photosynthetic cells.

E. Raw sap moves upward through the plant.

Answer: (A), (C), (E)

Explanation

Raw sap is composed of more than 99 percent water together with mineral ions absorbed from soil, and it moves upward. Organic molecules produced by photosynthetic cells characterize elaborated sap, while phloem transports elaborated rather than raw sap.

13. Among the following statements about elaborated sap, which are accurate?

A. Elaborated sap contains water and mineral ions.

B. Elaborated sap consists mainly of water moving upward from roots.

C. Elaborated sap is transported through xylem vessels.

D. Elaborated sap contains organic molecules produced by photosynthetic cells.

E. Elaborated sap is transported throughout the plant.

Answer: (A), (D), (E)

Explanation

Elaborated sap contains water, ions, and organic molecules made by photosynthetic cells, and it is transported throughout the plant. Raw sap is mainly water and mineral ions and moves upward from the roots, so the reversed descriptions are incorrect.

14. Concerning the conducting tissues involved in sap transport, which statements are correct?

A. Phloem sieve tubes transport raw sap upward from roots.

B. The two conducting tissues transport the same type of sap.

C. Xylem vessels transport raw sap.

D. Xylem vessels transport elaborated sap from photosynthetic cells.

E. Phloem sieve tubes transport elaborated sap.

Answer: (C), (E)

Explanation

Xylem vessels conduct raw sap, whereas phloem sieve tubes conduct elaborated sap. The proposed reversal of these conducting tissues is therefore incorrect.

15. A leaf receives radioactive carbon dioxide and is examined 24 hours later; which statements are correct?

A. The radioactive carbon is found in elaborated sap.

B. Radioactive carbon can later be detected throughout the plant.

C. Photosynthesis converts radioactive carbon into organic molecules.

D. The radioactive carbon is converted into mineral ions absorbed from soil.

E. Phloem transports the elaborated sap containing radioactive carbon.

Answer: (A), (B), (C), (E)

Explanation

Radioactive carbon dioxide supplied to a leaf is incorporated by photosynthesis into organic molecules. After 24 hours, the radioactive carbon can be detected throughout the plant in elaborated sap carried by phloem; it is not converted into mineral ions or transported by xylem.

16. Regarding phototropism in plants, which statements are correct?

A. Phototropism involves bending of a plant stem.

B. Phototropism describes movement of seeds away from the parent plant.

C. Phototropism is bending of roots toward gravity.

D. Phototropism is a growth response to light.

E. Phototropism is directed toward lateral light.

Answer: (A), (D), (E)

Explanation

Phototropism is the bending of a plant stem toward lateral light. It describes a growth response, not the movement of seeds away from a parent plant or bending toward gravity.

17. Which statements accurately describe a root meristem?

A. A root meristem lies at the root tip.

B. It contains small, cubical, undifferentiated cells.

C. It contributes to elongation of the root.

D. Its cells divide by mitosis.

E. It consists mainly of differentiated cells specialized for sap transport.

Answer: (A), (B), (C), (D)

Explanation

The root meristem is located at the root tip and consists of small, cubical, undifferentiated cells. These cells divide by mitosis and contribute to root elongation; the meristem is not a differentiated vascular tissue or a shoot structure.

18. Concerning the sequence of plant growth, select the correct statements:

A. Plant growth begins with seed dispersal rather than meristematic division.

B. Cell division occurs in plant meristems.

C. Cell elongation contributes to plant growth.

D. Cell differentiation can occur later in development.

E. Differentiation produces cells with specialized functions.

Answer: (B), (C), (D), (E)

Explanation

Plant growth involves a sequence of meristematic cell division, cell elongation, and later differentiation into specialized cells. The alternatives reverse this order or replace differentiation with seed dispersal, neither of which describes the stated growth process.

19. Which statements correctly describe apical dominance and related plant growth?

A. Apical dominance promotes lengthwise growth of the plant.

B. Apical dominance directly transforms root meristem cells into vascular tissues.

C. Secondary stems can form after weakening apical dominance.

D. Removing the apical bud can allow axillary buds to develop.

E. Apical dominance keeps axillary buds dormant.

Answer: (A), (C), (D), (E)

Explanation

Apical dominance maintains axillary buds in a dormant state and promotes lengthwise growth. Removing or weakening the apical bud releases axillary buds, allowing secondary stems and promoting growth in width; the coleoptile and vascular-tissue statements concern different concepts.

20. Regarding the experimental basis and mechanism of phototropism, which propositions are correct?

A. The shoot apex controls phototropic curvature in the coleoptile.

B. Phototropism results from uniform elongation on both sides of the coleoptile.

C. Phototropic bending occurs because hormones prevent elongation in the shoot apex.

D. Water-soluble hormones from the shoot apex influence coleoptile cell elongation.

E. The root meristem directs the coleoptile's curvature toward light.

Answer: (A), (D)

Explanation

Phototropism is caused by water-soluble hormones from the shoot apex that alter cell elongation and bend the coleoptile toward light. The root meristem is associated with root cell production, not control of phototropic curvature.

21. To determine which part of a coleoptile detects light, which experimental features are appropriate?

A. Plants with different coleoptile regions covered should be compared.

B. A negative control shows the result when the tested condition is absent.

C. Covering every plant provides a sufficient control design by itself.

D. A positive control demonstrates that the expected response can occur.

E. The experiment can identify light detection without comparing differently treated plants.

Answer: (A), (B), (D)

Explanation

Comparing plants with different regions covered allows researchers to determine whether the coleoptile tip or the whole coleoptile detects light. Positive and negative controls establish, respectively, that the expected response can occur and what happens when the tested condition is absent.

22. Which responses contribute to plant resistance during drought?

A. Increasing exposed leaf surface improves drought resistance.

B. Protecting stomata can help reduce evapotranspiration.

C. Water storage helps plants withstand periods of drought.

D. Stomatal opening and closing can regulate water loss.

E. Reducing leaf surface limits evapotranspiration.

Answer: (B), (C), (D), (E)

Explanation

Drought resistance involves conserving water and reducing evapotranspiration. Plants can achieve this by storing water, regulating stomata, reducing leaf surface, and protecting stomata.

23. The shoot meristem is characterized by which features?

A. Bud scales protect the shoot meristem.

B. It is located at the top of a bud.

C. Its development produces a new stem.

D. It produces a new root when the bud develops.

E. It is located within the root elongation zone.

Answer: (A), (B), (C)

Explanation

The shoot meristem lies at the top of a bud and is protected by bud scales. As the bud develops, this meristem produces a new stem.

24. In a root meristem, what is the typical fate of the two daughter cells?

A. The displaced daughter cell elongates before later differentiating.

B. Both daughter cells remain permanently within the meristem.

C. One daughter cell remains within the root meristem.

D. The displaced daughter cell differentiates before reaching the elongation zone.

E. The other daughter cell is progressively displaced toward the elongation zone.

Answer: (A), (C), (E)

Explanation

In the root meristem, one daughter cell remains in the meristem while the other moves toward the elongation zone. That displaced cell elongates and later differentiates.