Chapter 1: Basic Unit of Life Lesson 1: Living things are made of cells

Lesson 1: Living things are made of cells Objectives: Describe a cell and explain some functions. Explain what tissues are. Explain what organs are.

Living things are made of cells All living things are made of cells – the basic unit of life. The smallest thing you can call “alive”. Cells are found in all parts of animals and plants. Bones, blood, muscle, skin and nerves. Stems, leaves, roots, and flowers.

Jobs of cells Cells have many functions or jobs: Skin cells – cover and protect . Bone Cells – support and protect. Muscle cells – allow for movement .

Bacteria Simplest single cell organism that carry out all of basic life activities.

Observing cells Cells come in different shapes and sizes. They are so small that they are invisible unless you use a microscope an instrument used to magnify small things to make them appear larger.

Light Microscope Use a beam of light to magnify objects – light travels through the object. Tiny structures become visible . Organelles - tiny structures inside a cell perform a specific function or job . Objects can only be magnified so much before the image becomes blurry . Can’t see a lot of fine details in really tiny parts of the cell.

Electron Microscope An instrument that uses a beam of tiny particles called electrons to magnify things. Magnifies objects a lot more and better than a light microscope. Organelles can be seen very clearly.

Tissues Tissues – Groups of cells that are similar and act together to do a certain job are called tissues. Muscle cells join together to make muscle tissue . Leaf cells join together to make leaf tissue .

Organs Organs - Different kinds of tissue join together to form an organ. Main working part of plants and animals Do special jobs: Heart: pumps blood through body Lungs : allow you to breathe Roots: take water and minerals from the soil Leaves : make food for the plant.

Biological Levels of Organization

Homework: On a separate sheet of paper: Answer the review questions at the end of lesson 1 in the packet/textbook. Write and underline the question. Answer the question using your notes and the lesson. Be sure to number the questions and to leave space between each question so that your answers are easy to read. There will be a quiz next class over this lesson.