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
Evolution
Theme 4
A concept that organisms from today descended and developed from ancestral species from many years ago
Natural selection
Theme 4
How organisms adapted to their environment over time and those who didn’t adapt were killed off because they weren’t best suited for the environment ensuring that only the best/most adapted species survived
Evolution v natural selection
Theme 4
Evolution happened because of natural selection
Theory of biogenesis
Theme 4
Complex living things can only come from other living things by reproduction
Artificial selection
Theme 4
Humans changed the environment and made a specific trait more desireable and those who didn’t adapt died off
- impact humans had on the environment that forces the organisms to adapt
Characteristics of living things
- order
- Regulation
- Growth and development
- Energy processing
- Response to the environment
- Reproduction
- Evolutionary adaptation
Characteristics of living things: order
Living things have complex organization (structure of a sunflower)
Characteristics of living things: Regulation
The environment around an organism may change, but mechanisms maintain an organisms internal environment within limits that sustain life (increase of temperature with sickness)
Characteristics of living things: Growth and development
Inherited information in genes control the pattern of growth and development of organisms (growing from an infant)
Characteristics of living things: energy process
Organisms take in energy and transform it to perform all of life’s activities (calories, bears eat fish to be able to fo life’s activities)
Characteristics of living thingsCharacteristics of living things: Response to the environment
Organisms reposnd to environmental stimuli (venus flytrap closing)
Characteristics of living things: reproduction
Organisms reproduce their own kind (kittens)
Characteristics of living things: Evolutionary adaptation
Adaptions that evolve over many generations as individuals with Trait best suited to their environment pass them to off spring (camouflages, cheetah print)
Molecule
A cluster of atoms held together by chemical bonds
Organelle
A membrane-bound structure that performs a specific function in a cell
Cell
Is separated from the environment by a boundary called a membrane. A basic unit of living matter. The fundamental structural unit of life
Tissue
Made up of a group of similar cells, performs a specific function within an organ
Organ
Works together to perform specific functions within an organ system. A structure consisting of several tissues adapted as a group to perform specific functions
Organ system
Like the digestive system. Made up of several organs that work together in doing specific functions
Organism
An individual living thing
Population
Consists of all the individuals of a species living in a specified area
Community
The entire array of organisms inhabiting a particular ecosystem
Ecosystem
Made up of all the organisms living in a particular area, as well as the nonliving, physical components of the evironment with which the organisms interact such as air, soil, water, and sun light
Biosphere
Consists of all the environments on Earth that support life-most region of land, bodies of water and the lower atmosphere
Quantitative v qualitative data
Quantitative data- Data consisting of numbers like speed
Qualitative data is data that can’t be expressed in numbers, like niceness.
Quantitative- number
Qualitative- quality
Eye piece
Where one looks into the microscope. Magnification of 10X
Body tube
Connects objective lenses to eyepiece
Arm
Connects body tube to base. Where one would carry the microscope by
Revolving nosepiece
Holds and rotates objective lenses
High power objective lense
Highest power magnification lense with smallest field of view. Magnification of 40 X
Low power objective
Medium power magnification of 10 X. Medium field of view
Scanning objective
Enables one to see more of the slide. Lowest power magnification of 4x
Coarse adjustment
Move stage/slide closer or farther away from the lense to focus on it. Only use with scanning and low objectves
FIne adjustment
Used to fine tune focus on the slide or specific area of the slide
Mechanical stage
Moves the slide around the stage
Stage
Flat plate where slides are placed for observation
Diaphram
Changes the amount of light passing through the stage opening
Light
Source of light
Base
Bottom support of the microscope. Where one might hold the microscope
Stage opening
Hole in the stage where light passes through
When to use a compound light microscope
Uses a beam of light and lenses to enlarge and image of a living or dead specimen. USe when you want to look at something that is living or dead. Look at specimens under high magnification
When to use a stereoscope
When looking at something with low magnification using light reflected from the surface of the specimen. Has two eyepieces. When looking at something that is not very transparent or something that is large.
When to use an electron microscope
To see a dead specimen. 3-D image. Very high magnification with good resolve. See smaller objects in higher detail
Field of view
Diameter of the circle one sees when looking through a microscope
Working distance
How far away the specimen is from the lense. Higher power objective = smaller working distance
Magnification
The degree that something is magnified (the image of something is enlarged so that it looks larger than it actually is)
Resolution
How sharp and image is
Power of magnification
the extent to which the object being viewed is magnified/ appears enlarged
- total magnification
Calculate total magnification
Low power- 10X Scanning- 4X High- 40 X Eyepiece- 10X Magnification of objective x power of eyepiece (10X) = total magnification
Compound light microscope
- Magnify specimen
- produce an image
- Uses a beam of light and lenses to enlarge the image of the living or dead specimen
Stereoscopes
- Magnify specimen and produces enlarged image
- Use light reflecting off of the living or dead specimen to magnify it
- two eyepieces
Electron microscopes
-Magnify specimen and produces enlarged image
-uses a beam of electrons to make a micrograph. Specimen must be dead
Transmission electron microscope (TEM) uses electrons to go through the object and make a flat image unlike the Scanning electron (SEM) where elctrons flow over and bounce off the surface object to make a 3-D image.
TEMS go up to 200,000 X and SEMs to 100,000X. WIth a TEM, the specimen is frozen in plastic and sliced with a microtome
Evolution V natural selection
Evolution is something that happens to a population. Natural selections -> animals adapting to the environment
-evolution happened because of natural selection
