Lesson 2: Plant Structure and Function

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Questions and Answers

What is the primary function of root hairs in plants?

To protect the root tip from soil organisms

To increase the surface area for water and nutrient uptake (correct)

To produce root cap cells

To facilitate photosynthesis in roots

Which type of vascular tissue is responsible for transporting water in plants?

Sclerenchyma

Xylem (correct)

Phloem

Parenchyma

What are the main types of cells that compose phloem tissue?

Vessel elements and tracheids

Parenchyma and collenchyma

Root cap and epidermal cells

Sieve tube members and companion cells (correct)

What type of ground tissue primarily provides support and flexibility to plant structures?

Sclerenchyma Signup and view all the answers

Which tissue type is not classified as meristematic, dermal, or vascular?

Ground tissue Signup and view all the answers

How do vessel elements in xylem facilitate the movement of water?

They are tubular and lack end walls Signup and view all the answers

What is the role of the root cap in plants?

To protect the root tip as it grows through the soil Signup and view all the answers

Which of the following cells in phloem lack nuclei when mature?

Sieve tube members Signup and view all the answers

What is the primary function of the palisade mesophyll in leaves?

Photosynthesis Signup and view all the answers

Which part of a leaf connects the blade to the stem?

Petiole Signup and view all the answers

What is a defining characteristic of nastic responses in plants?

They are not growth responses Signup and view all the answers

What function does transpiration serve in plants?

Water movement Signup and view all the answers

In terms of tropism, what is a positive tropism?

Growth toward a stimulus Signup and view all the answers

Which characteristic of spongy mesophyll supports its function in leaves?

Irregular cell shape and air spaces Signup and view all the answers

What does the vascular tissue in the petiole connect?

Stem to leaves Signup and view all the answers

Which of the following is NOT a characteristic of nastic movements?

Growth-dependent Signup and view all the answers

What is a primary role of the cuticle in plant tissues?

To reduce water loss and prevent bacteria entry. Signup and view all the answers

What could be the consequence of removing the apical meristem from a plant?

The plant would grow horizontally instead of vertically. Signup and view all the answers

How do trichomes benefit plants?

By providing physical protection against herbivores. Signup and view all the answers

Which type of tissue is responsible for the transport of water and nutrients in plants?

Vascular tissue. Signup and view all the answers

In what way might the cuticle of a desert plant differ from that of a rainforest plant?

Desert plants have a thicker cuticle to conserve water. Signup and view all the answers

What is the role of guard cells in stomata functioning?

They control the opening and closing of stomata. Signup and view all the answers

What type of tissue forms the outer protective layer of a plant?

Dermal tissue. Signup and view all the answers

Which plant structure primarily facilitates nastic responses?

Leaves. Signup and view all the answers

Study Notes

Lesson 2: Plant Structure and Function

This lesson is part of Module 19: Introduction to Plants (pages 513 to 522).
All multicellular organisms, including plants, have cells and tissues that work together to maintain homeostasis.
Plant cells and animal cells have differences and similarities.
Plant cells and tissues help plants maintain structure and homeostasis.
The focus question is: What are the structures and functions of plant cells and tissues?
Plant cells are characterized by cell walls, large central vacuoles, and chloroplasts.
A vacuole is a structure inside a cell that contains cell sap (fluid), surrounded by a membrane called the tonoplast. The large central vacuole in a plant cell is a key example.
Plants have many types of cells adapted to specific functions.
Parenchyma cells are involved in storage, photosynthesis, gas exchange, protection, and tissue repair and replacement (e.g., potato cells).
Collenchyma cells provide support and transport materials.
Sclerenchyma cells support surrounding tissues, provide flexibility, and are involved in repair.
A tissue is a group of cells that work together to perform a function. Plants have four main types of tissues: Meristematic, Dermal, Vascular, and Ground.
The apical meristem produces cells that increase the length of a stem.
As plants grow taller, increasing stem diameter provides additional support.
The age of a tree can be estimated by counting the annual growth rings.
Root hairs increase the root's surface area, enabling roots to absorb more water and materials.
The cuticle is made of fatty substance that reduces water loss and prevents bacteria from entering the plant.
Stomata are small openings on the epidermis through which gases pass; guard cells regulate the opening and closing of stomata.
Trichomes are hair-like projections that protect the plant from insects and animal predators. The tiny glands on the tips of trichomes may contain toxic substances.
Vascular tissue (Xylem and Phloem) transports water, food, and dissolved materials throughout the plant.
- Xylem is the water-carrying tissue in vascular plants, made of vessel elements and tracheids. Vessel elements are tubular cells stacked end-to-end; tracheids have pitted ends and are less efficient at transporting water.
- Phloem is the main food-carrying tissue in vascular plants, composed of sieve tube members and companion cells. Sieve tube members lack nuclei and ribosomes when mature, but are supported by companion cells.
Ground tissue consists of parenchyma, collenchyma, and sclerenchyma cells, and is responsible for photosynthesis, storage, and support.
Roots:
- The root cap protects root tissues as the root grows.
- The cortex is composed of ground tissue that transports and stores substances
- The endodermis is the inner boundary of the cortex and forces water and substances to pass through the endodermal cells, rather than around them.
- The pericycle produces lateral roots.
Types of roots include: taproot (e.g., carrots), fibrous (e.g., grass), modified (e.g., storage roots like beets, and other specialized forms like pneumatophores or prop roots).
Stems:
- The main function of stems is to support leaves and reproductive structures.
- Herbaceous stems are soft, flexible, and capable of photosynthesis.
- Woody stems are rigid and fibrous.
Leaves:
- The main function of leaves is photosynthesis.
- Leaves have a blade and a petiole (stalk).
- The blade has an upper and lower epidermis, mesophyll (palisade and spongy), and vascular bundles. The spaces in the spongy mesophyll allow gases to move between them to facilitate photosynthesis.
- Water evaporates from leaves through stomata in a process called transpiration, which can help pull water up from roots.
Types of leaf arrangement include opposite (leaves across from each other), alternate (leaves staggered along stem), and whorled (leaves arranged in a ring).
Plant responses:
- Nastic responses are plant responses to stimuli that aren't dependent on the direction of the stimulus and are reversible.
- Tropisms are plant growth responses to external stimuli (positive if growth is toward; negative if growth is away from the stimulus). This includes phototropism (light), gravitropism (gravity), and thigmotropism (mechanical touch/support).

Quiz (examples of questions and answers about plant anatomy)

Question 1: Which plant structure is NOT part of a root?
- Answer: Stomata (stomata are on leaves)
Question 2: Which controls the movement of water vapor through stomata?
- Answer: Guard cells
Question 3: Which vascular tissue transports water and dissolved minerals from roots to leaves?
- Answer: Xylem
Question 4: Which fill(s) the space between spongy mesophyll cells?
- Answer: Gases
Question 5: Which describes a positive phototropism?
- Answer: The plant grows toward the light.

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Description

Explore the intricate structures and functions of plant cells and tissues in this quiz based on Module 19: Introduction to Plants. Delve into the differences and similarities between plant and animal cells, and discover how various plant cells contribute to homeostasis and support. Test your knowledge on key concepts like vacuoles, parenchyma, and collenchyma cells.