Unit 3 Specialization in Animals and Plants

Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms. There must be systems with specific functions in multicellular organisms like us that have a certain organization List each level in the hierarchy of organization in living things and define each level Work in teams of 4 to discuss how you will develop a model to represent this hierarchy of organization

Hierarchy in Multicellular Organisms Hierarchy - an arrangement or classification of things according to: --relative importance --size or --function How is this chart arranged?

What are unicellular organisms? What can unicellular organisms do? Organisms that are made of ONE CELL. Everything that multi-cellular living things do: Grow Eat Reproduce

Unicellular Organisms: Some examples of Unicellular Organisms: Paramecium Euglena Amoeba

What are Multicellular organisms? What must multicellular organisms have in order to survive? What is Cell Specialization? Organisms made of MANY CELLS Cell Specialization When cells throughout an organism develop in different ways to perform ONE job very well.

An example of a specialized cell in animals How are red blood cells specialized? Red blood cells They carry oxygen. Adult RBC’s have no nucleus so there is more room for the oxygen

Newly formed red blood cells have a nucleus Mature red blood cells have lost the nucleus to make room for more oxygen

Organs are part of organ systems Organ systems make an organism Cells make tissues Tissues make organs Organs are part of organ systems Organ systems make an organism Organisms are living things Hierarchy of Animals

Hierarchy of Animals 1. Cell 2. Tissue 3. Organ 4. Organ System 5. Organism

1. Cell 2. Tissue Basic building blocks with specialized functions Example: Stomach cells secrete acid to help digest food 2. Tissue A group of similar cells performing a particular, but limited function Example: Stomach tissue is made of cells that secrete acid to help digest food Epithelial, connective, muscle and nerve

3. Organ 4. Organ System Group of tissues doing similar functions Example: Stomach is an organ that helps digest proteins 4. Organ System Group of organs doing similar things Example: The stomach is part of a system of several organs that digest food

Specialization in plant cells Cells in green plants that carry on photosynthesis have chloroplasts Photosynthesis gives animals: Food like sugar and starch Oxygen to breathe

Plant Tissue – made of many cells Covering Photosynthetic layer Transport layer

The plant organism made of cells, tissues, organs and organ systems too

Homework: p. 193 # 1- 4

HOT Questions Define Cell Specialization. Distinguish between unicellular and multicellular organisms. Sequence the organization of multicellular living things from simple to complex. Categorize a red blood cell and a plant cell with choroplasts according to what they do. Propose an explanation for why Red Blood Cells only live for 120 days. Decide which cell is more important and WHY: a Red Blood Cell or a Plant Cell with chloroplasts.

arm stage base eyepiece 10X Body tube nosepiece 10X 15X 40X Low power objective 10X 15X 40X medium power objective stage high power objective Stage clips Coarse adjustment knob diaphragm Fine adjustment knob Light source base Go to p. 1070 Appendix D Fill in functions

Cheek Cells Cell Membrane Cytoplasm Nucleus

Onion cell Cell Wall Cytoplasm Cell Membrane Nucleus

Green Plant cell - ELODEA Chloroplasts Cytoplasm Cell membrane Cell wall

LS-1-3 Plan and conduct and investigation to provide evidence that feedback mechanisms maintain homeostasis. Do now with partner

Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms. There must be systems with specific functions in multicellular organisms like us that have a certain organization List each level in the hierarchy of organization in living things and define each level Work in teams of 4 to discuss how you will develop a model to represent this hierarchy of organization

Project

HOMEOSTASIS

Preview Read the following pages: 895, 896, 1000 Answer the following questions: What are Feedback Loops? How do they work? What is feedback Inhibition (aka negative feedback)? Explain this information in your own words.

Homeostasis means: The body is in balance Because all the body’s systems are related

Oxygen + food carbon dioxide + water + energy For example - the body’s cells require energy Cell respiration delivers this energy Oxygen + food carbon dioxide + water + energy O2 + glucose CO2 + H2O + 36 ATP Different organ systems work together to get these materials to the cells: Digestion - breaks food into the smallest parts to get into the cells Respiration - gets the oxygen that will go to the cells Circulation - carries these materials to the cells Excretion - gets the waste products out The Nervous system - is aware of all that is happening The Endocrine system - controls much of the activity with hormones

This is the controlled, stable environment of the body Also called HOMEOSTASIS

How is Homeostasis maintained? By feedback loops. A feedback loop is a cycle of 2 DIFFERENT activities that keeps the internal environment balanced. a. Example 1) Eating when you’re hungry vs. 2) not eating because you are full Negative feedback is the stopping of one activity as a result of the first. b. Example 1) low blood sugar signals hunger so you eat 2) Higher blood sugar signals feeling full, so you stop eating

An Example of Feedback Inhibition

Does this happen in the body? One example is a stable body temperature. The hypothalamus regulates body temperature. I. When it gets cold, blood vessels in the skin constrict (become narrower). This reduces heat loss from the skin Skeletal muscles contract involuntarily causing the body to “shiver.” This causes the body temperature to increase. FEEDBACK LOOP

5. When it gets hot, blood vessels near the skin dilate (get wider). II. (the inhibition step) 5. When it gets hot, blood vessels near the skin dilate (get wider). This causes heat to escape from the skin. The body sweats. The body cools by evaporation. HOMEOSTASIS IS MAINTAINED FEEDBACK LOOP

Stem Cell Research Research & Opinion

Once an egg cell is fertilized, it goes through MITOSIS and makes many cells But at this point, they are not specialized yet.

STEM CELLS Once a ball of cells called a morula is formed, there is an “inside” and “outside” layer of cells. These cells are now SPECIALIZED AND CAN ONLY FORM CERTAIN THINGS. The inside layer forms the organs The outside layer forms the skin Outside layer Inside layer Outside layer

STEM CELLS Cells are continuing to divide by mitosis, and the “ball of cells” pushes in on itself, and a 3rd layer is formed. This forms the blood and muscles. Outer layer - nervous system Middle (3rd) layer - circulation Inner layer - organs

The Ethics of Stem Cells P. 253 Should stem cells be harvested from embryos because of what they are able to turn into? Use the library or the Internet to learn more about stem cell research. Write a brief (1-page) report on how this technology will impact the future of medicine both: Positively and negatively Complete Stem Cell Research worksheet Then follow directions

On the other hand