Which structural adaptation of chloroplasts is specifically designed to maximize their function in photosynthesis?

Question

BlackTom AI · Accepted Answer

Question restatement: Which structural adaptation of chloroplasts is specifically designed to maximize their function in photosynthesis?
Option 1: The stroma and thylakoid space are maintained at identical pH levels to ensure chemical equilibrium. While pH differences across compartments are important for photosynthesis (the lumen becomes acidic during electron transport, while the stroma is more neutral to alkaline), the statement about identical pH across stroma and thylakoid space is incorrect. It overlooks the purposeful pH gradient that drives ATP synthesis and the separation of light-dependent versus light-independent processes.
Option 2: The thylakoid membranes are organized into stacked grana connected by unstacked stroma lamellae, creating specialized compartments for light-dependent and light-independent reactions. This description accurately captures a core chloroplast adaptation: grana increase surface area for photosystems I and II and the electron transport chain, while the stroma lamellae connect grana and facilitate metabolite exchange, effectively separating and optimizing the light-dependent reactions from the Calvin cycle in the stroma.
Option 3: Chloroplasts have a single, uniform membrane to allow unrestricted movement of all molecules. This is incorrect: chloroplasts have a double membrane system (outer and inner envelope) plus internal membranes (thylakoid), and the idea of a single uniform membrane contradicts the classic organelle structure that supports selective transport and compartmentalization essential for photosynthesis.
Option 4: Chloroplasts contain no DNA to prevent competition with nuclear control of photosynthesis. This is false: chloroplasts contain their own circular DNA and ribosomes, which encode a subset of photosynthetic proteins and enable local synthesis of some components, not to mention the broader genetic autonomy that supports organelle function.
Summary: Among the options, only Option 2 aligns with the well-established structural adaptation that maximizes photosynthetic efficiency by organizing thylakoids into grana and connecting lamellae, thereby optimizing light reactions and substrate exchange within the chloroplast.

Bio 93 Section CDE 2025 Midterm 1- Section E

Which structural adaptation of chloroplasts is specifically designed to maximize their function in photosynthesis?

View Explanation

Log in for full answers

Similar Questions

What structure within the chloroplast resembles a flattened disk? A) photosystem I B) photosystem II C) stroma lamellae D) thylakoid E) cytochrome bf complex

In a consumer society, many adults channel creativity into buying things

Economic stress and unpredictable times have resulted in a booming industry for self-help products

People born without creativity never can develop it

A product has a selling price of $20, a contribution margin ratio of 40% and fixed cost of $120,000. To make a profit of $30,000. The number of units that must be sold is: Type the number without $ and a comma. Eg: 20000

Which of the following statement regarding cost is correct:

Under the assumptions used in cost-volume-profit analysis, as the activity increases:

More Practical Tools for Students Powered by AI Study Helper

Homework AI Solver

Stylized AI Paper Writer

Plagiarism Checker Assistant

Citation AI Academic Writing Tool

In-Class Translation Assistant

AI Note Generator

AI Quiz Answers

Past Exam Questions from University Test Bank

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler