Chapter One - Studying Life Flashcards
what is biology?
the scientific study of organisms, living and fossil
first characteristic of life:
made of a common set of chemical compounds
second characteristic of life
made up of cells
third characteristic of life
use molecules from the environment to make new biological molecules
fourth characteristic of life
extract energy from the environment and use it to do work
fifth characteristic of life
contain genetic information that enables them to develop, function, and reproduce
sixth characteristic of life
use a universal genetic code to build proteins
seventh characteristic of life
regulate their internal environments (homeostasis)
eight characteristic of life
exist in populations over time
what are the different levels of biological organization?
atoms, small molecules, large molecules, cells, organism, population, community, ecosystem, biosphere
what is the lowest level of organization that can perform all activities required for life?
a cell
what is inductive reasoning?
inductive reasoning uses observations or facts to develop a tentative hypothesis or answer. it goes from something specific to something general
what is deductive reasoning?
deductive reasoning is used to predict what facts would also have to be true if they are compatible with the hypothesis. it goes from something general to something specific
define hypothesis
a hypothesis is a tentative answer to a question from which testable predictions can be generated
characteristics of a hypothesis
a hypothesis must be testable, and must have the potential of being rejected by direct observations and experiments
Darwin’s first big idea in biology
descent with modification: all species share a common ancestor and have diverged from one another gradually over time
Darwin’s second big idea in biology
natural selection: the differential condition of offspring to the next generation by various genetic types belonging to the same population - this is the mechanism of evolution as the environment determines which organisms survive
ex: limbs of a frog evolving for varied environment
what is the scientific method?
- make observations
- ask a question
- form a hypothesis
- make a prediction
- design and conduct an experiment
- use statistical tests to evaluate significance of results
what is qualitative data?
qualitative data is descriptive and refers to things that can be observed but not measured such as colors or emotions
what is quantitative data?
quantitative data is anything that can be counted or measured
what is a control?
a control is that which receives no treatment in an experiment and acts as a basis for test results
what is an independent variable?
an independent variable is that which receives treatment and is always going to be what is manipulated from one experimental group to the next
(x-axis)
what is a dependent variable?
a dependent variable is that which is a measurable outcome. it is what you are directly measuring as a response to what you initially set up
(y-axis)
what were the major events in the history of life on earth?
- Earth formed over around 4 billion years ago
- Temperatures cooled
- Surface water formed
- Nucleic acids formed
- Life appeared less than 4 billion years ago
- Around a billion years later, photosynthesis begins occurring
- Then, eukaryotic cells appear
- Shortly after, multicellular organisms began occurring
The three domains of life
Archaea, Bacteria, Eukarya
prokaryotes
prokaryotes are unicellular, have a single outer membrane, and do not have a nucleus
eukaryotes
eukaryotes have an outer and inner membrane, have a nucleus, possess membrane bound organelles, and are multicellular
DNA’s role in evolution
Changes in DNA can cause mutations which are adaptations that help organisms evolve
what is evolution?
evolution is the change in genetic composition of populations over time
