Question 1

Which of the following best explains why plants require nitrogen-fixing bacteria in the soil?

Accepted Answer

Atmospheric nitrogen ($$N_2) is $$abundant but chemically inert, and plants cannot convert it to usable forms without bacterial assistance.

Question 2

Which of the following is a primary function of the Casparian strip in plant roots?

Accepted Answer

It prevents the passive flow of substances into the vascular cylinder, forcing water and minerals to pass through the plasma membranes of endodermal cells.

Question 3

A plant is growing in soil with a high proportion of sand. Which challenge is most likely to affect its nutrition?

Accepted Answer

Rapid leaching of nutrients because large particles allow water to drain quickly.

Question 4

Which of the following best describes the process of cation exchange in soils?

Accepted Answer

Roots release $$H^+$$ ions, which displace nutrient cations (like $$K^+$$, $$Ca^{2+}$$, $$Mg^{2+}) $$from soil particles, making them available for absorption.

Question 5

Which of the following correctly matches a plant hormone with its primary effect?

Accepted Answer

Gibberellin – stimulates stem elongation and seed germination

Question 6

A seed is exposed to far-red light after being exposed to red light. According to the phytochrome system, what is the most likely outcome?

Accepted Answer

The seed will remain dormant because far-red light converts phytochrome to its inactive form.

Question 7

Which of the following best explains why mycorrhizal fungi are beneficial to plants?

Accepted Answer

They increase the surface area for water and mineral absorption by forming associations with roots.

Question 8

Which of the following is a correct sequence for the movement of water from soil to the atmosphere through a plant?

Accepted Answer

Soil solution → root hair → cortex → endodermis (Casparian strip) → xylem → leaf mesophyll → stoma → atmosphere

Question 9

Which of the following best describes the role of guard cells in plant leaves?

Accepted Answer

They regulate the opening and closing of stomata, thus controlling transpiration and gas exchange.

Question 10

Which of the following is a distinguishing feature of secondary growth in plants?

Accepted Answer

It results from cell division in the lateral meristems (vascular and cork cambium), leading to increased girth.

Question 11

Which of the following best explains why leaching of anions (such as $$NO_3$$^-$$) is a problem for plants?

Accepted Answer

Anions are not retained by soil particles and are easily washed away by water, reducing nutrient availability.

Question 12

Which of the following is true regarding the arrangement of vascular bundles in monocot and eudicot stems?

Accepted Answer

Monocot stems have scattered vascular bundles; eudicot stems have vascular bundles arranged in a ring.

Question 13

A plant is exposed to blue light on one side. Which response is most likely, and which hormone is primarily involved?

Accepted Answer

The plant bends toward the light; auxin redistributes to the shaded side, promoting cell elongation.

Question 14

Which of the following best describes double fertilization in angiosperms?

Accepted Answer

One sperm fertilizes the egg, and another sperm fertilizes the two central nuclei, forming the endosperm.

Question 15

Which adaptation would most likely help a seed overcome the challenge of fire in its environment?

Accepted Answer

A thick, heat-resistant seed coat that requires exposure to high temperatures to break dormancy.

Question 16

Which of the following is NOT a macronutrient required by plants?

Accepted Answer

Iron ($$Fe)$$

Question 17

Which of the following best describes the role of heat-shock proteins in plants?

Accepted Answer

They help protect cellular proteins from denaturation during extreme heat.

Question 18

Which of the following is an example of a plant's mechanical defense against herbivores?

Accepted Answer

Development of thorns or spines.

Question 19

Which of the following best describes the difference between a complete and an incomplete flower?

Accepted Answer

A complete flower has all four floral organs (sepals, petals, stamens, carpels); an incomplete flower is missing one or more of these organs.

Question 20

Which of the following best explains why toggling between red and far-red light is adaptive for seeds in shaded environments?

Accepted Answer

Far-red light is more abundant in shade, which keeps phytochrome in its inactive form and prevents germination until conditions are favorable.

Plant Structure, Nutrition, Growth, Hormones, and Reproduction: Study Guide for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard