Chapter 1 Flashcards
Biology
The scientific study of life
Homeostasis
The steady state of body functioning. Equalization achieved by outside forces that change an organisms internal environment and the internal control mechanisms that oppose such changes
Ecology
Scientific study of how organisms interact with their environment
Heterotrophs
Organism that can’t make it’s own food and has to get food by eating other organisms or their products; a consumer or decomposer
Metabolism
The totality of an organisms chemical rections
SI Units
International system of units. the metric system
Differentiation
Specialization in the structure and function of cells that happens during the development of an organism. results from selective activation and deactivation of the cell genes.
- breaking things down by ability
Genes
Unit of hereditary information made out of a special DNA sequence (or RNA in some viruses).
Chromosomes
Thread-like gene-carrying structure for eukaryotic and prokaryotic cells
- in the nucleus of a eukaryotic cell most visible during mitosis and meiosis..
- Consists of chromatin (DNA and protein)
DNA
- Deoxyribonucleic acid.
- A double-stranded nucleic acid molecule
- Able to replicate itself.
- Is an organisms genetic material.
Hypothesis
Unproved explanation a scientist gives for a specific phenomenon that has been observed
Prediction
A forecast of what one thinks is going to happen
Experiment
Scientific procedure done to discover something or test a hypothesis
Scientific sampling
Randomly picking respondents with an un-biased procedure
Important aspects of a hypothesis
- If… then logic
- be testable (has to be a way to test the validity of the hypothesis
- be falsifiable (there must be some observation or experiment that could show that it is not true)
Dependent variable
What is being tested in an experiment and what the question that started the experiment is based around. Changes in response to the independent variable being changed. EX- weight of rats
Independent variable
What is being changed in the experiment to test the dependent variable. EX- amount of food fed to rats
How many variables are tested at one time in a controlled experiment
1 variable is tested at a time. Too many variables in an experiment or the test subjects being tampered with may make experimental data invalid.
Control group
A group of subjects that are not tested. They provide a baseline to measure how much the experimental group changed.
Controls (constants)
Variables in the experiment that are not changed at all throughout the experiment. Makes sure that only one variable in the experiment is being brought into play
The role of observations in scientific experiments
- Lead to scientific experiments
- Evaluate what is being tested in the experiment and lead to a conclusion about the hypothesis
- first thing you want to do, getting information, making explanations and lead to hypothesis
Law Vs. Theory
A theory explains a great diversity of observations and is supported by a lot of evidence that continues to grow but isn’t proved beyond a shadow of a doubt. EX- Big Bang theory.
A scientific law is a statement that is based on repeated experimental observations. Is proved beyond a shadow of a doubt, it will happen over and over again no matter how many times you test it (ie. Newton’s law of motion)
What are the 4 major themes of biology
Theme #1- Life is organized and organisms interact
Theme #2- Structure is related to function
Theme #3- LIfe is Unified
Theme #4- LIving things change over time
Levels of organization (smallest to largest)
Theme 1
Molecule, organelle, cell, tissues, organ, organ system, organism, population, community, ecosystem, biosphere
Emergent properties
Theme 1
A new property emerges, but only at a certain level of organization. Example- cell -> first emergent level, life. Ecosystem-> first inclusion of abiotic and biotic things
Producers
Theme 1
Photosynthetic organisms and plants that provide food for the consumers
Consumers
Theme 1
Organisms that eat plants and other animals
Movement of energy in an ecosystem
Theme 1
Sun and soil to plants (photosynthesizers) to consumers to decomposers and back to the soil
NOT A CYCLE
How are organisms linked through nutrients
- Theme 1
Energy passes from one organism to another and the energy transfer links them together until the energy continues down the chain until the energy has made it back to the soil and the air
What does structure is related to function mean
Theme 2
How something is structured fits to what the thing is supposed to do and looking at what the thing does can tell one how it is structured and vice versa. WHat the cell is supposed to do the cell determines how the cell is structured
Systems biology
Theme 2
Constructing models for the behavior of entire biological systems from cell to the biosphere. Studies interactions within biological systems
Prokaryotic cells
Theme 2
- Small
- Simpler
- unicellular
- organelle-less
- nucleus-less
- make up non-living things
- DNA just floats around
Eukaryotic cells
Theme 2
- complex
- large
- multicellular
- organelles
- nucleus with DNA inside
- make up living things
- many different cells that make up something that does many functions
Sexual reproduction
Theme 3
- Genetic information from the parents is combined creates child cell
- Requires 2 organisms
- Child cell has slightly different DNA than parents (because the parent DNA’s combined)
Asexual reproduction
Theme 3
- a cell splits in half and creates a child cell
- only one organism needed
- child cell has exact DNA as the parent
- usually prokaryotic cells and unicellular eukaryotes