midterm Flashcards
What are the goals of science?
to investigate and understand the natural world
to explain events in the natural world
to make useful predictions
information gathered during an experiment
data
a prediction about what will happen in an experiment
hypothesis
How many variables should be tested in a controlled experiment?
1
What are the characteristics of a scientist, and what do they mean?
curious - want to know
creative - think of new ideas
open-minded - willing to accept possibilities
skeptical - don’t blindly trust (want proof)
Who reviews for peer-reviewed journals?
anonymous and independent experts
What would we call a well tested idea that makes predictions in numerous circumstances with one particular exception?
a theory that needs revision
a personal preference or point of view
bias
the process by which organisms keep everything inside their body within certain limits
homeostasis
the basic unit of length in the metric system
meter
the three particles in an atom
proton, neutron, electron
How do you find the mass of an atom?
protons plus neutrons
In C-14, what does the 14 stand for?
protons plus neutrons (mass)
What is an isotope?
an atom of the same element with an unusual number of neutrons
What do we call a substance formed by the chemical joining of two or more elements in definite amounts?
compound
What makes a covalent bond?
sharing electrons
What electrons are available to form bonds?
valence electrons
Since electrons spend more time around oxygen, the oxygen is what?
slightly negative
When salt is dissolved in water, the salt and water are called what?
salt - solute
water - solvent
pH of 6 indicates what type of solution?
acid
solutions with more OH than H are called what?
base (alkaline)
Carbon is element number 6 with 2 electrons in the first ring and 4 electrons in the second ring. How many bonds can carbon form?
4
What happens to atoms in a chemical reaction?
rearranged
Identify the reactants and products in the following equation:
CO2 + H2O yields H2CO3
reactants - CO2 and H2O
product - H2CO3
What is the term for substances that speed up chemical reactions?
catalysts
Cells with a nucleus and membrane - bound organelles are called what?
eukaryotes
Organisms that must eat other organisms for energy are called what?
heterotroph
How would a student be able to look at cells under a microscope and tell that they are not animal cells?
have cell walls
In fish, what do pharyngeal pouches become?
gills
What is the function of the notochord in a chordate embryo?
structure and support
What is the advantage of sexual reproduction?
increases genetic diversity
What type of skeleton do vertebrates have?
endoskeleton
What is the advantage of asexual reproduction?
rapid reproduction - lots of babies
Animals with a space around their digestive tract but no mesoderm around the tract are called what?
pseudocoelomates
What is bilateral symmetry?
when animals can be cut in only one plant and have mirror image right and left sides
What type of symmetry has body parts extending out from a center?
radial symmetry
What is a coelom?
a body cavity completely lined with mesoderm
the embryo stage which is a hollow ball of cells
blastula
Name the three germ layers, and describe where each is found?
endoderm - inner layer
mesoderm - middle layer
ectoderm - outer layers
What is the difference between protostomes and deuterostomes?
protostomes - mouth first (from blastopore)
deuterostomes - mouth second (anus from blastopore)
a fertilized egg
zygote
Name what tissues develop from each of the three germ layers?
endoderm - lining of digestive and respiratory tracts (lungs)
ectoderm - skin and nerves
mesoderm - muscle, bone, and blood
How many planes of symmetry are found in radially symmetrical organisms?
many - infinite
What happened during the Cambrian Explosion?
most animal phyla developed
What are the most simple animals with body symmetry?
Cnidarians - radially symmetrical
a flexible, supporting rod found only in chordates
notochord
a thumb moving against the fingers - what is it for
opposable thumb - grasping
