Review 1 - 7th

Levels of Organization

Today we are going to look at the different levels of organization and how they build upon one another.

Life is organized into different levels based upon size (from small to large).

Organisms and Cells

• Some organisms are unicellular. This means they are made of only one cell. Ex: bacteria, yeast

• Some organisms are multicellular. This means they are made of many cells. Ex: humans, trees

Multiple Choice

Which of the following is the correct order of organization in living things from most basic (simple) to most complex?

• organism, cell, tissue, organ, organ system

• organ system, organ, tissue, cell, organism

• cell, tissue, organ, organ system, organism

• cell, organ, tissue, organism, organ system

Cell

• The smallest unit of life (building blocks of life)

• Cells are specialized by size and shape for the job they do.

• Example: nerve cell, also called a neuron

Multiple Choice

The basic unit of structure and function of living organisms

• organ

• organ system

• cell

• tissue

• organism

Tissue

• The same type of cells grouped together that are working together to do a specific job.

• Ex: nerve tissue, muscle tissue

Multiple Choice

A group of similar cells that work together to form the same function is called .......

• organ

• cell

• organ system

• organism

• tissue

Multiple Choice

What is the difference between a cell and a tissue?

• cell is basic unit of life; tissue is group of cells that work as one

• cell is group of tissues; tissue is basic unit of life

• cell is basic unit of life; tissue is groups of different cells

• cell is group of organs; tissue is group of different cells

Organ

• A bunch of tissues working together to do a job.

• Ex: brain, heart

Multiple Choice

A structure that is composed of different kinds of tissues

• organ

• cell

• organ system

• organism

• tissue

Organ System

• A bunch of organs working together

• Ex: nervous system, circulatory system, digestive system, etc.

Multiple Choice

A group of organs that work together to perform a major function....

• organ

• cell

• organ system

• organism

• tissue

Organism

• All cells, tissues, organs, and organ systems working together makes an organism.

• Ex: human, animal

Multiple Choice

Any living thing made up of one or more cells....

• organ

• cell

• organ system

• organism

• tissue

Levels of Organization

When we look at the levels of organization, we must remember the order in which they are listed. Cells are the basic units of life, and when cells come together they form tissues, and so on.

Multiple Select

Please choose from the options below, which are levels of organization.

• cells

• organ

• face

• skin

• tissue

Body Systems: The Muscular System

7th Grade Science

Guide for Reading:

--What three types of muscles are found in the body?

--Why do skeletal muscles work in pairs?

Muscles:

There are about 600 muscles in your body. The muscles that are not under your conscious control are called involuntary muscles. Involuntary muscles are responsible for activities such as breathing and digesting food.

Muscles:

The muscles that are under your control are called voluntary muscles. Smiling and turning the pages in a book are actions of voluntary muscles.

Types of Muscle:

Your body has three types of muscle tissue—skeletal muscle, smooth muscle, and cardiac muscle.

Skeletal Muscles:

Skeletal muscles are attached to the bones of your skeleton. Because you have conscious control of skeletal muscles, they are classified as voluntary muscles.

Skeletal Muscles:

These muscles provide the force that moves your bones. Skeletal muscles react quickly and tire quickly. At the end of a skeletal muscle is a tendon. A tendon is a strong connective tissue that attaches muscle to bone.

Multiple Select

Click the choices that describe the characteristic the muscle type: Skeletal Muscle

• Voluntary

• Involuntary

• Reacts Quickly

• Tires Quickly

Smooth Muscles:

Smooth muscles are called involuntary muscles because they work automatically. They are inside many internal organs of the body, and control many types of movements inside your body, such as those involved in the process of digestion. Smooth muscles react more slowly and tire more slowly than skeletal muscles.

Multiple Select

Click the choices that describe the characteristic the muscle type: Smooth Muscle

• Voluntary

• Involuntary

• Reacts Quickly

• Tires Quickly

Cardiac Muscles:

Cardiac muscles are involuntary muscles found only in the heart. Cardiac muscles do not get tired.

Multiple Select

Click the choices that describe the characteristic the muscle type: Cardiac Muscle

• Voluntary

• Involuntary

• Reacts Quickly

• Tires Quickly

Movement:

Muscles work by contracting, or becoming shorter and thicker. Because muscle cells can only contract, not extend, skeletal muscles must work in pairs.

Movement:

While one muscle contracts, the other muscle in the pair returns to its original length. For example, in order to move the lower arm, the biceps muscle on the front of the upper arm contracts to bend the elbow. This lifts the forearm and hand.

Movement:

As the biceps contracts, the triceps on the back of the upper arm returns to its original length. To straighten the elbow, the triceps muscle contracts while the biceps returns to its original length.

Multiple Choice

Why do skeletal muscles have to work in pairs?

• You have conscious control of skeletal muscles.

• They work automatically.

• Muscle cells can only contract, not extend.

Healthy Muscles:

Exercise is important for maintaining both muscular strength and flexibility. Exercise makes individual muscle cells grow wider, thicker, and stronger.

Healthy Muscles:

Some of the same precautions that help prevent bone and joint injuries, such as warming up and using proper safety equipment, can also help prevent muscle injuries.

Multiple Choice

How can you help prevent muscle injuries?

• Work out for several hours at a time.

• Warming up and using proper safety equipment

• Work out alone.

Multiple Choice

What type of muscle is smooth muscle?

• voluntary

• involuntary

Multiple Choice

What type of muscle is skeletal muscle?

• voluntary

• involuntary

Multiple Choice

What type of muscle is cardiac muscle?

• voluntary

• involuntary

Great job!

Human Body Systems

EOG Review

Multiple Choice

Which system of the human body provides protection to most of the major organs?

• A. skeletal system

• B. circulatory system

• C. respiratory system

• D. muscular system

Multiple Choice

Which of the following body systems is responsible for producing heat?

• A. skeletal system

• B. nervous system

• C. muscular system

Multiple Choice

Which BEST describes the function of the skeletal system?

• A. It transports oxygen to cells and tissues.

• B. It gives shape and support to the human body.

• C. It takes in and breaks down all necessary nutrients for the body.

Multiple Choice

Which BEST explains how the muscular system relies on the respiratory system?

• A. The respiratory system cools the muscular system.

• B. The respiratory system acts as the support system for the muscular system.

• C. The respiratory system brings oxygen into the body for the muscular system to use.

Multiple Choice

Which are parts of the digestive system?

• A. mouth, lungs

• B. mouth, teeth

• C. mouth, brain

Multiple Choice

In which system of the human body does the heart belong?

• A. skeletal system

• B. respiratory system

• C. cardiovascular system

Multiple Choice

Which best describes a function of the circulatory system?

• A. transport blood

• B. provide oxygen

• C. help the body move

Multiple Choice

Which body system’s main purpose is to help the body move?

• A. digestive system

• B. muscular system

• C. respiratory system

Multiple Choice

Which body system sends messages to the brain?

• A. nervous

• B. muscular

• C. circulatory

Multiple Choice

Why does damage to the skeletal system have an effect on the other systems?

• A. Nutrients for other systems would not be passed on by the skeletal system.

• B. The skeletal system would not be able to pass on messages from the brain.

• C. Nutrients needed to repair the skeletal system would be taken from other systems.

Multiple Choice

Which body system includes the lungs?

• A. respiratory system

• B. digestive system

• C. skeletal system

Multiple Choice

Which system is controlled by involuntary muscle movement in the diaphragm?

• A. digestive

• B. respiratory

• C. cardiovascular

Multiple Choice

Which system moves waste from the digestive system?

• A. nervous system

• B. muscular system

• C. circulatory system

Multiple Choice

Which best describes the circulatory system?

• A. a system made up of the brain and nerves that delivers nutrients and removes waste from the body

• B. a system made up of lymph and blood that delivers nutrients and removes waste from the body

• C. a system made up of the brain and nerves that delivers messages throughout the body

• D. a system made up of the heart and blood that delivers messages throughout the body