Section 1-3 Studying Life Chapter 1 Section 1-3 Studying Life

I. Characteristics of Living Things A. All Living things share the following characteristics. 1. Contain Cells 2. Reproduce – Sexual, 2 parents, Sperm and egg, Asexual, 1 parent, fission, mitosis, budding and regeneration. 3. Contain DNA – Universal genetic code 4. Grow and Develop 5. Respond to the environment 6. Take in Energy

7. Homeostasis 8. Change over time 9. Ability to move ( not necessarily, moving from place to place.) 10. A particular life span All of these characteristics play an important role in the survival of living organisms, whether plant, animal or single celled organisms.

Homeostasis – Process by which an organism maintain a relatively stable internal environment. Metabolism – Set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes. Stimuli – a signal to which an animal responds

II. Levels of Organization A. Biosphere – Earth that contains all ecosystems. B. Ecosystem – community and it’s nonliving surroundings. C. Community – populations that live together in a defined area. D. Population – group of organisms of one type that live in the same area.

E. Organism – an individual living thing. F. Group of cells – tissues, organs and organ systems. G. Cells – smallest functional unit of life. H. Molecules – group of atoms: smallest unit of most chemical compounds.

Biosphere

Ecosystem

Community

Populations

Organism

Groups of Cells

Cells

Molecules

Other important characteristics of living organisms Metabolism – The ability for an organism to build up and break down material it takes in, as it carries out its life processes. Stimuli – Anything that causes a reaction or response by an organism. Could be a live saving response of reaction by the organism. Homeostasis – The process by which animals maintain a relatively stable internal environment: Blood pressure , body temperature, hydration, sugar levels.

Chapter 1 Section 1:4 Tools

Chapter 1 Section 1:4 Tools in Science Microscopes Electron Microscopes Centrifuge

III. Tools used in science A. Compound Light Microscope – device that uses light and lens that magnify images or structures that are too small to see with the unaided eye. It can also observe living organisms.

B. Electron Microscope – Uses beams of electrons to produce magnified images. The specimens viewed must be preserved (DEAD) and dehydrated. Living things cannot be observed through this type of tool.

1. 2 Main Types a. Transmission Electron Microscope (TEM) – shines beams of electrons through a thin specimen, that can reveal details inside the cell. b. Scanning Electron Microscope (SEM)– scans a narrow beam of electrons back and forth a cross the surface of a specimen, producing three-dimensional images of the surfaces of objects.

Foot of a fly

Wolf Spider

Ant

Pollen Grains

IV. Laboratory Techniques A. Cell Cultures – a single cell is placed in a dish of nutrients, where the cell is expected to reproduce to later be studied. B. Cell Fractionation – this process is used to research just one part of the cell. 1. To obtain the separation of parts, the cell is placed in a test tube, then inserted into a tool called a centrifuge that spins the tube separating the parts inside the tube.