Question 1

Which of the following best describes the fluid mosaic model of biological membranes?

Accepted Answer

A dynamic structure with proteins and lipids moving laterally within the bilayer.

Question 2

A red blood cell is placed in a solution with a lower solute concentration than its cytoplasm. Which process will primarily occur, and what is the expected outcome?

Accepted Answer

Passive diffusion will move water into the cell, causing it to swell and possibly lyse.

Question 3

Which equation correctly represents the calculation of water potential ($$\Psi) in $$plant cells?

Accepted Answer

$$\Psi = \Psi_s + \Psi_p$$

Question 4

Which of the following best explains why ATP is considered the primary energy currency in cells?

Accepted Answer

ATP contains high-energy phosphate bonds that, when hydrolyzed, release energy for cellular work.

Question 5

A plant cell is exposed to blue light, causing its stomata to open. Which mechanism is primarily responsible for this response?

Accepted Answer

Active transport of potassium ions into guard cells, decreasing water potential and causing water influx.

Question 6

Which of the following is a key difference between phosphorylation cascades and second-messenger-mediated signal transduction?

Accepted Answer

Phosphorylation cascades involve sequential activation of kinases, while second messengers amplify signals through small molecules like cAMP.

Question 7

Which plant tissue is primarily responsible for transporting water and minerals from roots to shoots, and what is the main cell type involved?

Accepted Answer

Xylem; tracheids and vessel elements

Question 8

Which of the following best describes the process of symbiotic nitrogen fixation in legumes?

Accepted Answer

Bacteria in root nodules convert atmospheric $$N_2$$ into ammonia ($$NH_3) $$for plant use, initiated by reciprocal signaling between plant and bacteria.

Question 9

Which of the following statements about cell theory is correct?

Accepted Answer

All living organisms are composed of one or more cells, and all cells arise from pre-existing cells.

Question 10

A scientist observes that a plant continues to grow taller and produce new leaves throughout its life. This is an example of which type of growth, and what is the underlying mechanism?

Accepted Answer

Indeterminate growth; activity of apical meristems

Question 11

Which of the following best explains how electrochemical gradients are used in co-transport across membranes?

Accepted Answer

The energy stored in the gradient of one ion (such as $$H^+) is $$used to drive the active transport of another molecule against its concentration gradient.

Question 12

Which of the following is NOT a function of the Golgi apparatus?

Accepted Answer

Synthesis of ATP for cellular energy

Question 13

Which of the following best describes the role of phytochrome in plant responses to light?

Accepted Answer

Phytochrome detects red and far-red light, allowing plants to regulate processes like seed germination and flowering.

Question 14

Which of the following is a correct sequence of events in a general signal transduction pathway?

Accepted Answer

Reception → Transduction → Response

Question 15

Which of the following best explains the difference between determination and differentiation during development?

Accepted Answer

Determination commits a cell to a specific fate, while differentiation is the process by which the cell expresses specialized functions.

Question 16

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

Accepted Answer

Increasing surface area for absorption of water and minerals

Question 17

A mutation causes a plant to lack functional sieve tube elements. Which process would be most directly affected?

Accepted Answer

Long-distance transport of sugars via phloem

Question 18

Which of the following is a feature of PAMP-triggered immunity (PTI) in plants?

Accepted Answer

Recognition of conserved microbial molecules, leading to a broad-spectrum defense response

Question 19

Which of the following best describes the pressure-flow hypothesis for long-distance movement of sugars in plants?

Accepted Answer

Sugars are actively loaded into phloem, creating a pressure gradient that drives bulk flow from source to sink.

BI222 Midterm Study Guide: Membranes, Cells, Energy, Signaling, Plant Form & Function, Nutrition, Transport, and Plant Responses

Study Guide - Practice Questions

Study Guide - Flashcards