Plants and Animals

Plants and Animals

Middle School

​

Learning Objectives

• Identify the cell as the basic unit of life and compare unicellular and multicellular organisms.

• Describe the function of the nucleus, cell membrane, cell wall, chloroplasts, and mitochondria.

• Explain how cells form tissues, tissues form organs, and organs form organ systems.

• Differentiate and classify organisms based on their cellular structures, energy needs, and other features.

Key Vocabulary

​

Cell

The cell is the basic structural and functional unit of all known living organisms.

​

Unicellular

A unicellular organism is composed of only one single cell, like bacteria or amoeba.

​

Multicellular

Multicellular organisms are made of many different types of cells, like plants and animals.

​

Cell Membrane

The cell membrane controls what substances can enter or leave the cell, acting like a gatekeeper.

​

Cell Wall

The cell wall is a rigid outer layer that provides structural support and protection to plant cells.

​

Chloroplast

Chloroplasts are the organelles in plant cells where photosynthesis happens, converting light into energy.

Key Vocabulary

​

Mitochondria

Mitochondria are the powerhouses of the cell, responsible for creating the energy it needs.

​

Organelle

An organelle is a specialized part within a cell that performs a specific function.

​

Tissue

A tissue is a group of similar cells that work together to perform a specific job.

​

Organ

An organ is a collection of different tissues that work together to perform a function.

​

Organ System

An organ system is a group of organs that cooperate to perform major functions.

​

Symmetry

Symmetry describes a balanced arrangement of body parts on opposite sides of a central line.

​

​

The Cell: Basic Unit of Life

• All living things are made up of tiny building blocks called cells.

• Anything that is not made of cells is considered non-living.

• Organisms can be unicellular (one cell) or multicellular (many cells).

• Most cells are too small to see without using a microscope.

​

Multiple Choice

What are the basic building blocks that make up all living things?

• Cells

• Water

• Organs

• Sunlight

Multiple Choice

How is a unicellular organism different from a multicellular organism?

• By the number of cells they have

• By the size of their cells

• By where they live

• By the color of their cells

Multiple Choice

A scientist uses a microscope to view a drop of pond water and observes a tiny object moving on its own. Based on this evidence, what is the most likely conclusion?

• The object is likely a living, unicellular organism.

• The object must be non-living because it is so small.

• The object must be a part of a large, multicellular animal.

• The object is not a cell because it was found in water.

​

​

Specialized Cell Structures

• Cells have special structures called organelles; the nucleus directs all cell activities.

• The cell membrane controls what enters and leaves, forming a boundary for cells.

• Mitochondria provide energy, and plant cells have a cell wall for support.

• Plant cells contain chloroplasts to make their own food through photosynthesis.

​

Multiple Choice

What is the primary role of the nucleus within a cell?

• To direct all cell activities.

• To provide the cell with energy.

• To control what enters and leaves the cell.

• To make food for the cell.

Multiple Choice

How do the functions of the cell membrane and the cell wall differ in a plant cell?

• The cell membrane provides energy, while the cell wall makes food.

• The cell membrane controls what moves in and out, while the cell wall provides support.

• The cell membrane directs cell activities, while the cell wall stores food.

• The cell membrane provides a boundary, while the cell wall provides energy.

Multiple Choice

A scientist observes that a plant cell is not producing its own food. Which organelle is most likely not working correctly and why?

• The mitochondria, because they are failing to provide energy.

• The nucleus, because it is not directing cell activities correctly.

• The cell membrane, because it is letting too many things leave the cell.

• The chloroplasts, because they are responsible for making food.

​

​

From Cells to Organ Systems

• In multicellular organisms, specialized cells group together to form different kinds of tissues.

• Tissues then work together in groups to form organs, like the heart.

• Organs team up to create organ systems that carry out complex functions.

• The circulatory and respiratory systems work together to transport needed oxygen.

​

Multiple Choice

Which of the following correctly shows the levels of organization in a multicellular organism, from simplest to most complex?

• Cells, Tissues, Organs, Organ Systems

• Tissues, Organs, Cells, Organ Systems

• Organ Systems, Organs, Tissues, Cells

• Cells, Organs, Tissues, Organ Systems

Multiple Choice

What is the relationship between tissues and organs in a multicellular organism?

• Different tissues work together to form an organ.

• Different organs work together to form a tissue.

• Tissues are made up of many different organ systems.

• An organ is made up of only one type of specialized cell.

Multiple Choice

The circulatory system's job is to transport materials through the body. If the respiratory system fails to bring in oxygen, what is the most likely effect on the body?

• The circulatory system would not be able to deliver oxygen to the rest of the body.

• The body's tissues would start to create their own oxygen.

• The circulatory system would take over the job of the respiratory system.

• The respiratory system would begin to transport blood.

​

​

What Makes Plants and Animals Different?

Plants

• ​Plants are producers that make their own food using photosynthesis in chloroplasts.

• ​​They are typically anchored to the ground and cannot move from place to place.

• ​Their cells have a rigid outer layer called a cell wall for structural support.

Animals

• ​Animals are consumers that get energy by eating other plants or animals.

• ​​Most animals are mobile and can move around to find their food.

• ​Their cells do not have a cell wall, which allows for more flexibility.

Multiple Choice

What is the main difference in how plants and animals get the energy they need to live?

• Plants make their own food, while animals get energy by eating other organisms.

• Plants get energy from moving around, while animals stay in one place.

• Plants have flexible cells, while animals have rigid cells for support.

• Plants are consumers that eat other organisms, while animals are producers.

Multiple Choice

What is the relationship between a plant's cell wall and its ability to move?

• The cell wall provides rigid support, which is why plants are anchored in place.

• The cell wall allows a plant to move around to find sunlight.

• The cell wall helps a plant consume other organisms for energy.

• The cell wall stores the food that the plant makes.

Multiple Choice

If an animal's cells were suddenly to develop a rigid cell wall like a plant's, what would be the most likely outcome?

• The animal would have less flexibility and difficulty moving.

• The animal would be able to produce its own food using photosynthesis.

• The animal's cells would become producers instead of consumers.

• The animal would no longer need to eat plants or other animals.

Specialized Structures of Land Plants

​

Roots

• ​Anchor the plant firmly into the ground.

• ​​Absorb water and essential nutrients from the soil.

• ​Transport these materials up towards the stem.

​

Stem

• ​Provides structural support for the entire plant.

• ​​Connects the roots to the leaves, acting as a bridge.

• ​Transports water and nutrients throughout the plant.

​

Leaves

• ​Capture sunlight to make food for the plant.

• ​​Contain small pores called stomata for gas exchange.

• ​Allow carbon dioxide to enter and oxygen to exit.

Multiple Choice

What is the main purpose of a plant having specialized structures like roots, stems, and leaves?

• To perform different essential tasks needed for the plant to live.

• To make the plant grow taller than other plants.

• To protect the plant from being eaten by animals.

• To help the plant reproduce by creating seeds.

Multiple Choice

How do a plant's structures work together to move water from the ground to the leaves?

• The roots absorb water from the soil, and the stem transports it to the leaves.

• The leaves create water from sunlight, and the stem carries it down to the roots.

• The stem absorbs water from the air, and the roots store it underground.

• The leaves capture water from rain, and the roots release it into the soil.

Multiple Choice

If a plant's stem was blocked, preventing anything from moving through it, what would be the most likely consequence?

• The plant's leaves would wilt because they could not receive water from the roots.

• The plant's roots would stop anchoring the plant firmly in the ground.

• The plant's leaves would be unable to exchange carbon dioxide and oxygen.

• The plant's roots would absorb too much water and cause the plant to flood.

​

​

Vascular vs. Nonvascular Plants

Vascular Plants

• These plants have tube-like structures called vascular tissue for transporting materials.

• Xylem tissue carries water from roots, while phloem tissue moves food from leaves.

• This efficient transport system allows vascular plants to grow very tall.

Nonvascular Plants

• These plants are low-growing and completely lack any vascular tissue.

• They absorb water and minerals directly from the moist environment around them.

• Because they lack the support of vascular tissue, they cannot grow tall.

Multiple Choice

What is the main structural difference between vascular and nonvascular plants?

• The presence of special tube-like tissues for transporting materials.

• The type of soil they prefer to grow in.

• The color and shape of their leaves.

• The amount of sunlight they need to survive.

Multiple Choice

How does a vascular plant transport the materials it needs to live?

• Xylem transports water from the roots, while phloem moves food from the leaves.

• They both absorb water and food directly from the moist environment around them.

• Phloem transports water from the roots, while xylem moves food from the leaves.

• The leaves absorb water and the roots create food from minerals.

Multiple Choice

A giant sequoia tree can grow hundreds of feet tall, while low-growing moss covers the ground nearby. Which statement best explains this difference?

• The tree has a vascular system for support and transport, while the moss does not.

• The moss grows in the shade, while the tree grows in the sun.

• The tree has larger leaves to absorb more sunlight than the moss.

• The moss absorbs water from the environment, while the tree gets water from its roots.

Classifying Animals by Body Plan

​

Asymmetrical

• ​These animals have no symmetry or balance in their body shape.

• ​​You cannot draw a line to divide them into equal halves.

• ​A sea sponge is a great example of an asymmetrical animal.

​

Radial Symmetry

• ​Body parts are arranged around a central point, like bicycle wheels.

• ​​They can be divided into equal halves by using multiple lines.

• ​A jellyfish has this type of symmetry in its body plan.

​

Bilateral Symmetry

• ​These animals can be divided into two matching mirror-image halves.

• ​​There is only one single line that can divide them perfectly.

• ​Beetles and humans have bilateral symmetry in their body plans.

Multiple Choice

What is the primary characteristic used to classify animals by their 'body plan'?

• The way an animal's body parts are arranged.

• The color of an animal's skin or fur.

• The type of food an animal eats.

• The environment where an animal lives.

Multiple Choice

What is the key difference between an animal with radial symmetry and one with bilateral symmetry?

• Radial symmetry allows for division along multiple lines, while bilateral only allows for one.

• Radial symmetry means there is no balance, while bilateral symmetry means there is.

• Animals with radial symmetry are always larger than those with bilateral symmetry.

• Radial symmetry is for animals like beetles, while bilateral is for animals like jellyfish.

Multiple Choice

A scientist discovers a new sea creature whose body is irregular and cannot be divided into equal halves along any line. Based on this evidence, what conclusion can be drawn about its body plan?

• Asymmetrical, because it has no balance in its body shape.

• Radial, because its body parts are arranged like wheel spokes.

• Bilateral, because it has two matching halves.

• Symmetrical, because it can be divided down the middle.

​

​

Invertebrates and Vertebrates

Invertebrates

• The vast majority of animals are invertebrates, which are animals that completely lack an internal backbone.

• Many have a hard outer covering called an exoskeleton that provides support and protection to them.

• This group is incredibly diverse and includes insects, spiders, worms, and jellyfish among many other animals.

Vertebrates

• Vertebrates are a group of animals that are mainly defined by having a backbone or spine.

• Ectotherms are animals whose body temperature changes based on the temperature of their surrounding environment.

• Endotherms are animals that can control their internal heat to maintain a constant body temperature.

Multiple Choice

What is the primary characteristic that distinguishes vertebrates from invertebrates?

• The presence or absence of a backbone

• Whether they live on land or in water

• The type of food they eat

• If they have an exoskeleton or not

Multiple Choice

How does an exoskeleton benefit an invertebrate?

• It provides the animal with support and protection.

• It helps the animal control its internal body temperature.

• It allows the animal to move more quickly.

• It helps the animal find food.

Multiple Choice

An animal with a spine is found to be very active in a cold, snowy forest. Based on this information, what can be concluded about how it regulates its body temperature?

• It is an endotherm because it can generate its own internal heat.

• It is an ectotherm because it must be getting heat from its surroundings.

• It has an exoskeleton that keeps it warm.

• It is a vertebrate, so its temperature does not change.

Animal Adaptations for Survival

• Adaptations are inherited traits that help an animal survive in its environment.

• Animals have special parts for movement, like wings to fly or fins to swim.

• Some animals have special kidneys to save water in dry or salty environments.

Multiple Choice

What is the primary role of an inherited adaptation?

• To help an animal survive in its environment

• To allow an animal to change its environment

• To make an animal larger and stronger

• To help an animal find a partner to mate with

Multiple Choice

What is the relationship between structures like wings or fins and an animal's survival?

• They are specialized structures for movement

• They are used for storing water

• They help animals hide from predators

• They are designed to keep the animal warm

Multiple Choice

Which of these animals is best prepared to survive in a newly formed hot, dry, and salty desert environment?

• An animal with wings to fly away

• An animal with fins to swim to a new place

• An animal with special kidneys to conserve water

• An animal with thick fur to stay warm

​

Common Misconceptions

Misconception	Correction
Living things are only things you can see move.	All living things are made of cells, even if they don’t move.
Organs work by themselves.	Organs are part of interacting organ systems that work together.
All animals have a backbone.	Most animal species are invertebrates, which do not have a backbone.
All plants are tall like trees.	Plants can be tall (vascular) or low-growing (nonvascular).

​

Summary

• All living things are made of one (unicellular) or many (multicellular) cells.

• Cells have specialized organelles that perform specific functions.

• In multicellular organisms, cells form tissues, organs, and organ systems.

• Plants are autotrophs with a cell wall; animals are heterotrophs and typically mobile.

• Vascular plants have transport tissues, while nonvascular plants do not.

• Animals are classified by symmetry and having a backbone (vertebrate) or not.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

• 1

• 2

• 3

• 4