Plant Biology Exam Study Guide

Plant Biology Exam Flashcards

What is photosynthesis?

Plants use sunlight, carbon dioxide (CO2), and water (H2O) to make glucose (sugar) and oxygen (O2).

Where does the light reaction take place?

In the thylakoid membranes inside chloroplasts.

How do light reactions work?

Sunlight excites electrons, splits water, makes ATP & NADPH, and releases oxygen.

What do light reactions produce?

ATP, NADPH, and O2.

Where does the Calvin Cycle take place?

In the stroma of the chloroplast (the fluid around thylakoids).

How does the Calvin Cycle work?

Uses ATP & NADPH from light reactions + CO2 to make glucose (sugar).

What do CAM plants do at night?

They open stomata at night to take in CO2 and store it as acid for use during the day.

How do C4 plants handle photosynthesis?

They fix CO2 in one cell, then move it to another for the Calvin Cycle; helps conserve water in hot areas.

What are chloroplasts?

Organelles in plant cells where photosynthesis happens.

What are the three main plant tissue systems?

Dermal (outer protection), Ground (photosynthesis, support, storage), Vascular (transport: xylem & phloem)

Which tissue is responsible for photosynthesis?

Parenchyma cells (found in ground tissue).

What are secondary cell walls?

Extra-thick cell walls that add strength (especially in woody plants); often contain lignin.

What is xylem composed of?

Dead cells that transport water upward (e.g., tracheids, vessel elements).

What is the difference between simple and complex tissue?

Simple = 1 type of cell (e.g., parenchyma); Complex = multiple cell types (e.g., xylem, phloem).

What moves water and what moves sugar in plants?

Xylem moves water; Phloem moves sugar.

What is the relationship between tissues, cells, and organs?

Cells -> Tissues -> Organs

What is primary growth?

Growth in length; occurs at tips of roots and shoots.

What is secondary growth?

Growth in thickness; occurs in woody plants via lateral meristems.

What are cellulose, hemicellulose, and lignin?

Cellulose: main part of plant cell walls; Hemicellulose: connects cellulose fibers; Lignin: hardens walls, adds strength.

What is vascular tissue?

The system that transports water, nutrients, and sugars (includes xylem and phloem).

What are xylem and phloem made of?

Xylem: tracheids, vessel elements (dead); Phloem: sieve tubes, companion cells (alive).

What is leaf arrangement?

How leaves are positioned on a stem (e.g., opposite, alternate, whorled).

What is guttation?

Water droplets forming on leaf tips due to root pressure (usually overnight).

What are modified leaves?

Leaves that have changed to serve other functions (e.g., cactus spines, onion storage leaves).

What are modified stems?

Stems with special functions (e.g., tubers like potatoes, runners like strawberries).

What's the difference between a monocot and dicot stem?

Monocot: scattered vascular bundles; Dicot: ringed vascular bundles.

What does the cork cambium produce?

It makes bark (protective outer covering).

What does the vascular cambium produce?

Xylem (inside) and phloem (outside) for secondary growth.

How is sugar translocated in plants?

Through phloem from source (leaf) to sink (fruit, root) using pressure flow.

What is the tension-cohesion model?

Water is pulled up through xylem due to water sticking to itself (cohesion) and walls (adhesion), driven by evaporation from leaves (transpiration).

What does biennial mean?

A plant that lives for two years grows first year, flowers/dies second year.

What is Ground Tissue made up of?

parenchyma, collenchyma, and sclerenchyma

What is Vascular Tissue made up of?

Xylem and Phloem

What is Dermal Tissue made up of?

Epidermis and Specialized Cells