CELLS Cells- the Building Blocks of Living Things Cells are the building blocks of life. All living things are made of cells. A unicellular organism is made up of only one cell while multicellular organisms are made up of many cells. Animal and plant cells have similar and different parts. Both cells include a nucleus and a cell membrane. Each of the cell parts have different jobs and functions to do in order to keep the cell healthy and working properly. Lesson Checkpoint: Why are cells referred to as the building blocks of life? The nucleus is the control center of the cell. The nucleus holds all the instructions for cell’s activities. It is the nucleus’ job to make sure all the cell parts do their jobs in order to keep the cell working properly. Another important part of a cell is the cell membrane. The cell membrane separates the cell from everything outside the cell. It guards everything that comes in and out of the cell, which protects the cell. Lesson Checkpoint: What is the job of the nucleus of the cell? © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Every cell is filled with a gel-like liquid called cytoplasm. The main job of the cytoplasm in a cell is to hold all cell parts in one place. Each cell in an organism has its own job to do in order to keep the cell working properly. Cells make up all the different parts of the human body. A group of one kind of cell is a tissue, which means a tissue contains MORE than one cell. A group of tissues that work together is an organ. Lungs are an example of organs in the human body. Groups of organs that work together form systems in the human body, such as the human respiratory system, for example. Lesson Checkpoint: What do we call a group of tissues working together in a human body? Differences Between Plant and Animal Cells Plants and animals have similar and DIFFERENT parts. Chloroplast is a part of a plant cell but not an animal cell. Chloroplast catches the sun’s energy for the plant because plants need the sun’s energy to make their own food. Animal cells do not have chloroplasts because they do not make their own food. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Plant cells also have a cell wall, which an animal cell does not have. The main job of a plant’s cell wall is to support and protect the cell. It is located outside the plant cell’s cell membrane. Lesson Checkpoint: What is one structure a plant cell has that an animal cell does NOT have? A microorganism is an organism that is too small to see with our eyes alone. Scientists are only able to view a microorganism through a microscope. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.