Comparing Living Things Science Unit A – Chapter 1 Comparing Living Things
Lesson 1: Is It Living or Nonliving?
Life Processes All living things carry out activities called life processes. Get energy Use energy Get rid of wastes Reproduce Grow Respond to changes
Life Processes Gets energy Uses energy Gets rid of wastes Reproduces Grows Responds to changes
Virus & Bacteria It isn’t as easy to tell if some things are living or non-living. Virus Many scientists think they aren’t living things. Viruses can only reproduce when they are inside living cells. Viruses don’t grow, release, or use energy like other living things.
Virus & Bacteria Bacteria Bacteria carry out all the life processes. Bacteria are slightly bigger than viruses, but both are microscopic. Viruses are usually harmful. They make us sick. Bacteria are usually harmless. Some are even helpful. A few can make you sick though.
Cells Cells are the smallest units of life. All living things are made up of cells. Most cells are so tiny they must be viewed with a microscope. Some living things are made up of only one cell. Bacteria -- Ameba Others are made up of millions of different kinds of cells. Trees -- People
Animal & Plant Cells Different in some ways and similar in others Animal cells have a cell membrane (skin), a nucleus (brain), and cytoplasm (blood). Plant cells have a cell membrane (skin), a nucleus (brain), and cytoplasm (blood). They also have chloroplasts and a cell wall. Chloroplasts: They give plants their green color and help them make food. Cell Wall: It helps the plant hold its shape.
Special Kinds of Cells Nerve cells Carry messages throughout your body Shaped like branches Red blood cells Carry oxygen to all your cells Flat center with bulging edges Skin cells Square shapes that fit together Protect other cells from damage
Tissues, Organs, & Systems Groups of similar cells working together Organs Different kinds of tissues working together Systems Several organs working together Our bodies are made up of many different organ systems.
Questions What are the six processes of life? What are cells? What are tissues, organs, and systems? Compare & contrast living & nonliving things.