Specialized Cells

1. Specialized Cells

2. Specialized Cells • There are a wide variety of cell types that make up plants and animals • We started as a single fertilized egg; now made up of dozens of different types of cells • Remember: all cells come from pre-existing cells • Organisms are just like a city - needs different specialty jobs done: energy, transportation, waste disposal, etc.

3. Specialized Cells • Every cell cannot digest food, fight disease, carry nutrients, and coordinate movement • Specialized cells - Do a single job instead of everything an organism needs • Have physical and chemical differences • Allow them to perform one job very well

4. Starting out... • Stem cells - undifferentiated cell that can divide to form specialized cells • Cellular differentiation - process by which a cell becomes specialized • Embryonic stem cells: can differentiate into any type of cell • Adult stem cell: exist within specialized tissues

5. Specialized human cells Nerve cell Goblet cell Red blood cells Skin cells Bone cells Sperm cells

6. Specialized plant cells Guard cell Photosynthetic cells Phloem cells Meristem cells

7. Levels of Organization in Animals

8. Single Cellular vs. Multicellular Organisms • Single celled organisms function independently • Ex. bacteria, algae • Multi-cellular organisms are made up of specialized cells • Ex. stinging cells in jelly fish, light-emitting cells in fireflies • Specialized cells cannot survive on own • Complexity of animal bodies varies • Ex. Sponge vs. slug vs. cardinal 8

9. Levels of Organization: The Animal Body • Bodies of animals look different, yet all are made up of cells organized to perform life’s functions • Levels of organization form a hierarchy - most complex to least complex • Familiar terms? • Tissue • Organs • Organ system • Organism • These terms refer to the hierarchy of structure within the animal body

10. Levels of Organization • Cell: basic unit of life • Tissue: collection of similar cells that perform a particular function • Organ: a structure composed of different tissues working together to perform a complex body function • Organ system: a system of one or more organs and structure working together to perform a vital body function 10

11. Classifying Tissues • Epithelial: thin sheet of tightly packed cells the covers body surfaces, lines internal organs and body cavities (Ex. skin) • Connective: specialized tissue, provides support and protection for various parts of the body (Ex. bone, tendons) • Muscle: group of tissues containing proteins that can contract and enable the body to move (Ex. muscles that make bones move, cardiac muscle) • Nerve: specialized tissue that conducts electrical signals from one part of the body to another (Ex. brain) 11

12. Organs and Organ Systems • Highly specialized organs and other structures work to perform overall function of organ system • Most organs work in 1 system, some play a role in many • Systems allow organism to accomplish basic functions: • Obtain oxygen (respiratory and circulatory system system) • Obtain nutrients & eliminate waste (digestive system and circulatory system) • Sense and respond to environment (nervous system & musculoskeletal system) • Reproduce (reproductive system) 12

13. Where are we going?? • Going to look at the following systems: • Digestive • Circulatory • Respiratory • Musculoskeletal • Nervous • HOW DO ALL THESE SYSTEMS WORK TOGETHER??

14. Ticket out of Class • What process in the human body are you interested in learning about? 14