Worksheet+2

Cells 1. What are cells? 2. Why are cells considered living? 3. Cells have special jobs. This is called cell specialization. Describe the structure (how it is made) and function (what it does) of five different types of cells in human bodies.

4. Cells join together to make tissues. Describe the structure and function of one human tissue. 5. Tissues join together to make organs. Describe the structure and function of one human organ.

6. Organs join together to form body systems. Name all the human body systems (you should have at least seven). 7. Cells are made of many different smaller parts called cell organelles. Copy and complete the table.
 * Organelle || Function ||
 * Cell wall ||  ||
 * Cell membrane ||  ||
 * Cytoplasm ||  ||
 * Chloroplasts ||  ||
 * Mitochondria ||  ||
 * Nucleus ||  ||
 * Vacuoles ||  ||

8. Plant and animal cells have three obvious differences. What are those differences and why do they occur? **//Here are my answers to the questions above//** 1. Cells are what make up all living things. They come in all shapes and sizes, but contain some parts that are the same. Cells that do special things have special parts to them, for example, the cells in your brain are organised so that you can learn. They are the microscopic building blocks of life. 2. Cells are considered to be living because either individually of in a group together they can reproduce themselves. 3. **Sex cell:** Male sex cells are called sperm and female sex calls are called eggs of ova. Sex cells combine during reproduction to form a new organism. **Muscle cell:** A mucle cell can shorten to make movement. **Motor nerve cell:** A motor nerve cell control movement. It sends messages from the brain to the muscle. **White blood cell:** White blood cells help fight disease. Soem move around to 'swallow up' bacteria. **Brain cell:** A brain cell sends electrical messages to other cells through its many connections. 4. One type of human tissue is the skin. The cells that make up the skin are protective. They are flat and square like paving stones.The tissue which makes up the skin is called epithelial tissue and it covers and protects the rest of the body. 5. The lungs are an organ in the human body. The tissues of the lungs work together to perform a specific function (breathing). The lungs contain muscle tissue as well as tissues to make the outside lining. The lungs also contain blood vessels and nerves in their lining. 6. Systems make up a group of organs all working together to perform a particular function. The human body possess the following systems:  A. Circulatory System (heart, blood, vessels) B. Respiratory System (nose, trachea, lungs) C. Immune System (many types of protein, cells, organs, tissues) D. Skeletal System (bones) E. Excretory System (lungs, large intestine, kidneys) F. Urinary System (bladder, kidneys) G. Muscular System (muscles) H. Endocrine System (glands) I. Digestive System (mouth, esophogus, stomach, intestines) J. Nervous System (brain, spinal cord, nerves) K. Reproductive System (male and female reproductive organs)   7.
 * Organelle || Function ||
 * Cell wall || Framework for support in plant cells ||
 * Cell membrane || selective permeability ||
 * Cytoplasm || To maintain the shape, the consistency of the cell and to provide suspension to the organelles. ||
 * Chloroplasts || Captures sunlight for photosynthsis ||
 * Mitochondria || Powerhouse of the cell, site of cellular repiration, produces ATP ||
 * Nucleus || Directs cell activity ||
 * Vacuoles || Contain H2O, digestive ensymes wastes, food ||