Intro to Biology Flashcards
Characteristics of life, scientific processes, and basic chemistry
What is biology?
The study of life
Levels of biology (in order)
1) molecules
2) cells
3) groups of cells
4) organism
5) population
6) community
7) ecosystem
8) biosphere
Characteristics of living things
(C) made of cells / have organized structure (multicellular / unicellular)
(H) homeostasis
(E) obtain and use materials and energy
(R) reproduce (sexually and asexually)
(G) grow and develop
(R) respond to environment / stimuli
(E) able to evolve (change over time in a population)
(G) have genetic material (DNA or RNA)
Sexual reproduction (ex)
- Reproduction where two cells (sperm + egg) unite to produce the first cell of a new organism, creating unique offspring
- Plants, animals, some fungi
Asexual reproduction (ex)
- A single organism can reproduce without the aid of another by binary fission or budding, producing genetic clones of their parent
- Bacteria, plants
Metabolism
- The sum of all anabolic and catabolic reactions in the body
- Sum of the physical and chemical processes in an organism, by which its material substance is produced, maintained, and destroyed, and by which energy is made available
Catabolism (ex)
- Breaking down complex molecules
- Cellular respiration
Anabolism (ex)
- Build complex molecules
- Building muscle tissue, photosynthesis
Homeostasis (ex)
- The regulation of an organism’s international environment to maintain conditions suitable for life
- Water level, temp, hormone levels, blood pressure, blood sugar levels
Growing
Increase in the amount of living material
Cellular respiration
- The catabolic process by which most organisms extract energy from the food they eat
- Nutrients like sugar are broken down, energy is released and wastes like CO2 are produced
External stimuli (Ex)
- Environmental: air, water, temperature, other organism
- Cause a response from living things
Scientific process steps*
1) Observation and define + identify the problem / question
2) Form hypothesis
3) Design a controlled experiment to test hyp.
4) Collect data + analayze
5) Use data to draw conclusion(s)
6) Repeat experiment to verify results
7) Publish / share results
What is the independent (manipulated) variable? Why can there only be one?
- What the experimenter is purposefully changing in an experiment
- With more than one, you wouldn’t know which variable is affecting the outcome
Why are other factors held constant in an experiment?
-So that the experimenter may be assured that the changes are due only to the changes in the independent variable
Dependent (responding) variable
-What is being measured in an experiment, the result that changes due to the independent variable
Purpose of control group?
- Provides baseline data in which the independent variable being tested cannot influence the results
- Used in comparison to the experimental group
- Helps to rule out the effect of factors other than the independent variable in the experiment
What is a theory? How is it developed?
- An overarching idea or explanation about natural phenomena, which has extensive evidence supporting it, has no evidence to the contrary, and is widely accepted
- Continue to generate new hypotheses
- If enough evidence accumulates to support a hypothesis, then it can be called a theory
What are the subatomic particles? (charge, mass, location)
- Proton (positive / 1 dalton / nucleus)
- Electron (negative / close to 0 / orbit nucleus)
- Neutron (neutral / 1 dalton / nucleus)
Ion
-An atom or molecule with an electrical charge resulting from a gain or loss of one or more electrons
Isotope
-Atoms of an element with varying numbers of neutrons
Valence electrons, how do you determine the # of them in a given atom?
-Number of covalent bonds an atom can form = number of additional electrons needed to fill its outer shell
Ionic bond*
-Two ions with opposite charges attract each other — when the attraction holds them together, it is called an ionic bond — resulting compound is electrically neutral
Covalent bond*
-Two atoms share one or more pairs of outer shell electrons
Similarities and differences between ionic and covalent bonds
-
Covalent bonding in H / O / N / C
Using bonding rules for these atoms
-
How to predict the chemical structure of a molecule given its chemical formula
-
Molecule (ex)
- Two or more atoms held together by covalent bonds
- Water (H20, hydrogen + oxygen)
Compound (ex)
- Two or more different elements, bonded (ionically or covalently) in a fixed ratio.
- Salt
How can you use the # of valence electrons to predict if an atom will bond/react with another atom?
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Unicellular organism
- Grow by increasing in size
- Develop by the formation of new structures internally + on the surface
Multicellular organism
- Grow by increasing in cell size and cell number
- Develop by formation of new structures inside cells, on cell surfaces, and by the formation of new arrangements of cells into tissues + organs
Heterotroph
-
Autotroph
-
Why is it necessary for scientists to record and publish their experiments and results?
- So other scientists can recreate their experiment and verify the results, to make sure the results are repeatable
- So they can get credit for their work / discoveries
- To inform others about discoveries, to give others a groundwork to build off of
- So it won’t be forgotten (written record)
