fall midterm Flashcards
what are the 7 characteristics we use to define life?
order, process energy & metabolize, growth & development, reproduction, respond to environment, homeostasis/ regulation, and adaptation/ acclimation
how do we maintain order?
everything that is alive is organized on the cellular principal that is organisms are composed of one or more cells
what is the FIRST law of thermodynamics?
law of energy conservation states energy cannot be created or destroyed
what is the SECOND law of thermodynamics?
the entropy law states all things tend towards maximum entropy or randomness/disorganization
growth & development
growth increases mass, cell size or how many cells there are.
development involves differentiation
reproduction
living things must reproduce to sustain spices. reproduction can include repro of new cells or of a new life
responsiveness
the ability to respond is fundimental to homeostasis. this can be an active response or passive response
what is homeostasis/ regulation
homeostasis is the ability for the body to maintain stability while going through changing conditions
what is adaptations and acclimation?
adaptations, long term change in genes to maintain survival
acclimations, short term responses to the environment like humans wearing coats in the winter to stay warm
what are ectotherms?
rely on the temperature of their surroundings for body heat
what is the biological organization?
atoms -> molecules -> organelles -> cell -> tissue -> organ -> organ sys -> organism -> population (group of species)-> community ( all species in the place) -> ecosystem (living & non) -> biosphere(earth)
what is the chemical level of organization?
atom -> molecule -> macromolecule
what is the first level of organization that life emerges?
cells
what is the flow of energy? what is this cycle called?
nature does not waste energy, so it uses the cycle of matter. inflow of light energy comes from the sun -> used producers (plants) -> to make chemical energy in food -> eaten by consumers (animals) -> creates outflow of heat
each step uses heat and energy, the energy goes into less useful forms each time it transitions
what evidence shows that all life is unified?
the universal usage of DNA to store genetic info. all life is made up of cells that contain this DNA and provides the cell with instructions on how to make proteins we need to survive and reproduce.
what creates diversity?
diversity of life arises from the differences in DNA sequences allowing us to all have different genes
what are the 3 domains of life?
-bacteria, diverse and wide spread
-archaea, similar to bacteria, found in hot and high pressure places
-eukarya, includes us and plants, has smaller kingdoms like protists (unicellular like algae and ameoba), plantae (producers), fungi (decomposers), and animalia ( consumers)
How does the theory of evolution describe both the unity and diversity of life? what are the two observations from Darwin?
-heritable variations, variety of traits you inherit from parents
-overproduction of offspring, populations produce more offspring than the environment can support, because of this the offspring that are able to adapt the most are going to survive
because of these observations we can see that throughout evolution all species change to be able to survive
what is natural selection?
natural selection is how life changes over time. species adapt to their environments to maintain life and overtime the offspring who cannot adapt will disappear and leave only the strongest to reproduce
what is a hypothesis?
a hypothesis is a testable explanation for observations based on data, ex: if flashlight batteries are dead then changing the batteries will make it work
what is a controlled experiment?
a controlled experiment is testing one variable at a time. this means changing only one factor to see the effects while others are kept constant.
what is the order of the scientific method?
-observation
-question
-hypothesis
-prediction
-test
how was mimicry helpful to non-poisonous King snakes in an environment where there were population overlaps with
coral snakes?
by mimicking the look of the poisonous snakes it allowed the non poisonous snakes to survive. Predators who live in areas with coral snakes have “learned” to avoid them and
so will also avoid a similarly coloured snake
what is the control group? what is the test group?
-the control group in the experiment that does not receive treatment
-the test group in the experiment receives the treatment
what is an atom?
smallest unit of matter
what is a molecule?
the covalent bonding of two or more atoms together (H2)
what is an element?
a substance that cannot be broken down into other substances by ordinary
chemical means
what is a compound?
the combination of two or more DIFFERENT elements (H2O)
what elements make up 96% of life?
H (hydrogen), C (carbon), N (nitrogen), and O (oxygen). in smaller amounts there is also S (sulfur) and P (phosphorus)
what are the 3 subatomic particles? charges, sizes? which one is responsible for defining the element? which one is responsible for reactivity?
-protons (+), found in nucleus, defines what the element is because no two elements have the same number of protons
-neutrons (=), found in nucleus
-electrons (-), found around the nucleus in orbitals or shells, smallest, determines reactivity of element by how full the valence shell is
what is atomic number?
the number of protons in the nucleus
what is atomic mass/weight?
the sum of protons and neutrons
what is an isotope?
an element that has more of less neutrons than it normally would but still has all of the same properties and reactivity
of the atom
what is a radioactive isotope?
an element is unstable (nucleus breaking down) and degrades gradually over time as it
emits radiation, we can quantify this and use it in medicine
how many electrons fit into the first shell? second? outer most?
2, 8, 8
how many electrons can fit on 1s orbital and 2s orbitals? how many in three 2p orbital?
each orbital can hold 2 electrons. a three 2p orbital can hold a total of 6 electrons because there is three orbitals together (makes flower shape)
how are electron shells and orbital related?
each electron shell consists of orbitals. the first shell has one, second has 4, and so on.
what do you call electrons in the outer shell?
valence electrons
What is a stable number of electrons in a valence shell?
8
what are the three types of chemical bonds?
-covalent, formed by the sharing of valence electrons between two atoms (nonpolar- share equally, polar- share non equally)
-ionic, formed when one atom gives
up an electron from an outer shell and the other atom adds the free electron to its
outer most shell, thereby holding the atoms together
-hydrogen, an attraction between two atoms that already participate in other chemical bonds that always include H
what is a double bond?
the sharing of two electrons between two atoms
What is electronegativity?
The ability to attract electrons from other atoms in a molecule
Do electrons closer to or further from the nucleus have a higher energy level?
further
what are polar bonds? why are they important to water?
there is an unequal sharing of the
electrons, the electrons spend more time orbiting one nucleus than the other.
in water, electrons are closer to O atom than H giving O slightly (-) charge and H slightly (+) charge making water polar. because water is polar, each water molecule attracts other water molecules because of the opposite charges between them, forming hydrogen bonds.
What are some of the unique properties of water because of this hydrogen bonding?
-high freezing (0) and boiling point (100)
-tensile strength due to cohesion (water moles sticking together) allows for resistance of molecules to being pulled apart (why bugs can walk on water)
-adhesion (water moles stick to other moles) allows for meniscus which is when water adheres to the sides of a container making a curved surface
-density, water is the only substance that is denser in liquid form than in solid form
what is a solution?
a liquid that consists of two or more substances
what is a solvent?
the dissolving agent
what is a solute
the agent being dissolved
what is the pH of water?
7
what is the concentration of H an OH in pure water?
1.0 x 10-7 moles (-7 is an exponent)
how much change is there between each number on the pH scale?
10 fold
what is acidic? what is basic?
-acidic, more H 0-6
-basic, less H 8-14
What is a buffer? what is the bicarbonate buffer system?
- a buffer is a solution that can convert or neutralize strong acids or bases into weak ones, resist drastic changes in pH
-bicarbonate buffer is a reversible equation, cardon dioxide (CO2) + water (H2O)= carbonic acid (H2CO3+), carbonic acid can donate an H if something is too acidic leaving us with a weak base called bicarbonate ion (HCO3-), because it is reversible, if solution is too basic, the bicarbonate ion will bind w the H (already has been donated by acidic part) to once again become acidic
what causes acid rain? what are the affects of acid rain?
-caused by man made sources like burning fossil fuels or natural sources like volcanoes. normal rain pH is 5.6 but acid rain is 4.2-4.4.
-it affects; -soil increased acidity dissolves nutrients that trees need to be healthy and makes it hard for them to intake water
-damages leaves, leach nutrience from soil and reduce soil fertility, and damages root systems
what causes ocean acidification? what/whos affected?
-caused by CO2 in the atmosphere coming to equilibrium with the CO2 that dissolves at the surface of water. this results in a decrease of pH in the oceans making them more acidic.
-coral reefs and marine animals with shells are affected. reducing pH and availability of calcium carbonates for making
shells results in impacts on the food web and decrease of biodiversity. decrease in calcification resulting from more
carbon dioxide in the water. if corals cannot make their skeleton quickly they dissipate.