III. What is biology?

Transcription

1 III. What is biology? A. Bio = Life -logy = the study of B. Therefore biology is the study of life (living organisms)

2 IV. Why is biology so important? A. Solve real-world problems: 1. Preserving our Environment: i. Every second an acre of rain forest is being destroyed ii. Half of the worlds species are found in the tropical rain forest 2. Improving Food Supply: i. Genetic engineering of crop plants ii. Transfer genes that then become more resistant to herbicides, drought, toxic to insects but not humans, ripen faster and grow bigger. 3. Understanding the Human Genome: i. Genome = the complete genetic material an individual. ii. Human genome contains 3 billion individual units. Cloning

3 B. Fighting Disease: 1. AIDS = Acquired Immune deficiency Syndrome: i. Caused by HIV = human immune deficiency virus ii. Medicine can slow down the progression but can t stop the spread iii. New vaccine can target two parts of the virus viruses change as they move from body to body. 2. Cancer = growth defect in cells = uncontrolled cell division: i. A protein causes cancer..a new anti cancer gums up these proteins 3. Cystic Fibrosis = inherited defect which is fatal. Characterized by a thick mucus which clogs up passages in body s organs i. Gene Therapy replaces defective gene with a normal version.

4 V. Branches of biology A. There are many branches of biology 1. Some include: zoologist botanist microbiologist paleontologist ecologist B. Questions in biology can occur at many levels 1. Molecular level: study DNA or how drugs affect certain molecules 2. Cellular level: how do normal cells become cancerous? 3. Multi-Cellular level: what tells an animal when to eat, sleep or mate? 4. Population level: how do groups of species interact 5. Global level: how does burning coal and oil affect the earth s climate?

5 VI. Tools of a Biologist A. Compound Light Microscope 1. Uses light and two lenses to magnify objects 2. Can observe many organisms that are ALIVE B. Electron Microscope 1. Uses electromagnets to bend waves of electrons to magnify objects 2. Can not observe live organisms

6 Light verse Electron Microscope Limit of Resolution: we can magnify up to a point with clarity. Beyond a point called limit of Resolution, objects get blurry and detail is lost. Light Microscope can observe live organisms limit of resolution is not as good Electron Microscope can t observe live organisms limit of resolution is 1000 times better

7 Microscope Compound Light

8 VII. Laboratory Techniques A. Staining: 1. used to color cells or cell parts 2. Stains stick to certain compounds Ex: Feulgen stain is used to color DNA a pinkish color. B. Centrifugation: 1. The way you can obtain certain parts of cells 2. Must fractionate 3. Place blended material into tube of liquid 4. Place into centrifuge 5. While centrifuge spins, it separates liquid into layers heaviest on bottom/lightest on top. C. Micro-manipulation: 1. Used to dissect, insert, and remove things that are microscopic. D. Cell Cultures: 1. making many identical cells from one cell by putting them into a dish of nutrients.

9 VIII. CHARACTERISTICS OF LIVING THINGS A. Are made up of Cells B. Reproduce C. Grow & Develop D. Obtain & Use Energy E. Respond to their Environment

10 A. ARE MADE UP OF CELLS 3.Uni-cellular: i. Single Cell ii. Ex: bacteria, paramecium, euglena 1. All living things are made up of one or more cells 2. Cell: smallest unit of life 4.Multi-Cellular: i. Many cells ii. Ex: humans, dogs, fish

11 B. REPRODUCE 1. Asexual reproduction: i. a = without so asexual = without sex ii. A single organism can reproduce without the aid of another organism. Example: single-celled organisms 2. Sexual reproduction: i. requires that two cells from different individuals unite to produce the first cell of a new organism.

12 C. GROW AND DEVELOP 1. Acorns and humans start out as a single cell and become large tree s or adults. That one cell divides into many cells and differentiate into many types of cells that make up our body. We continue to change as we take in substances and use that to make more tissue.

13 D. OBTAIN AND USE ENERGY 1. Anabolism: i. any process in a living thing that involves putting together, or synthesizing, complex substances from simpler substances. Ex: Photosynthesis 2. Catabolism: i. the breakdown of complex substances into simpler substances. Ex: Respiration 3. Metabolism: i. sum of all chemical reactions in the body.a balance of anabolism and catabolism.

14 E. RESPOND TO THEIR ENVIRONMENT 1. a response that improves the survival of the organism. 2. can be quick (behavior) or slow (metabolic processes or growth). Ex: a plant s roots grow toward gravity into the soil and the leaves toward the sun. 3. Irritability: ability to respond to a stimuli. 4. Homeostasis: process by which organisms respond to stimuli in ways that keep conditions in their body suitable for life