Midterm: Topics 1 - 6 Flashcards
A suggested explanation for a problem that can be tested such as a microorganism was causing significant fish kills in a lake would be called a
Hypothesis
What is the smallest, basic unit of life?
Cell
Homeostasis provides what kind of environment?
Constant
Organizing known species of organisms according to their evolutionary relatedness is known as
Taxonomy
What is a form of logical thinking that uses related observations to come to a general conclusion?
Inductive reasoning
A collection of tissues involved in a common function are known as
Organs
The study of the structure and function of single-celled organisms is known as
Microbiology
The type of science that is done in order to understand living things without regard to an ability to directly use that knowledge is known as
Basic science
Which is a group of the same species living in a geographical area?
Population
The idea that organisms are able to “fit” their environment due to their characteristics is known as
Adaptation
Which is the smallest portion of a substance that retains the properties of an element?
Atom
The negative subatomic particles that orbit the nucleus are
Electrons
Water is an example of a(n)
a. atom
b. ion
c. compound
d. mixture
e. element
Compound
How do hydrophobic molecules react with water?
Repelled by
Starch is
a. a polypeptide
b. a polysaccharide
c. a lipid
d. a nucleic acid
b. a polysaccharide
Carbon usually forms how many bonds with other atoms?
4
Which are NOT macromolecules (also known as polymers)?
a. proteins
b. cellulose
c. amino acids
d. nucleic acids
c. amino acids
Which of the following includes all the others?
a. sucrose
b. glucose
c. cellulose
d. starch
e. carbohydrate
e. carbohydrate
What kind of bond exists between two amino acids in a protein?
peptide
A chemical buffer
a. makes things shiny
b. equalizes ions
c. provides hydrogen ions or removes them to maintain pH
d. puts up a sphere of hydration between ions
c. provides hydrogen ions or removes them to maintain pH
The idea that mitochondria and chloroplasts likely came from a larger prokaryotic cell engulfing and enslaving a smaller prokaryotic cell is known as the _____ theory.
Endosymbiotic
Which of the following has a cell wall made up of peptidoglycan?
a. bacteria
b. plants
c. animals
d. archaea
e. all of these
bacteria
________ is responsible for making lipids (and membrane vesicles).
Smooth ER
________ are specialized storage structures in plants (can hold water for rigidity).
Central vacuole
_________ is (are) primarily responsible for moving things from one part of the cell to another.
Vesicles
_______ is the “powerhouse” of the cell, known for making ATP.
Mitochondria
_______ is the “post office” of the cell, known for sorting and sending proteins and lipids to their final destination.
Golgi
Prokaryotes do NOT have _____.
Membrane bound nuclei
_____ is a cell part responsible for maintaining cell shape, internal organization, and cell movement.
Cytoskeleton
Which type of junctions allows small molecules to pass between cells?
Gap
All of the following are associated with endocytosis EXCEPT
a. secretion of cell products
b. endocytic vesicles
c. phagocytosis
d. plasma membrane going in
e. bulk-phase uptake of materials
a. secretion of cell products
To be able to invade host cells, viruses need something to attach to, usually a cell membrane
Receptor
The concentration of glucose inside of a cell is higher than the concentration outside of that cell, yet glucose continues to enter the cell. This is an example of
Active transport
A charge difference across a membrane, like what happens with K+ and Na+, is known as the
Electrochemical gradient
Which of the following accounts for the cell membrane keeping out polar substances from the cell?
a. the hydrophilic phospholipid heads
b. the integral membrane proteins
c. the hydrophobic fatty acid tails of the phospholipids
d. the cytoskeleton
C. The hydrophobic fatty acid tails of the phospholipids
The carrier molecules (transporters) used in active transport are
Proteins
A single-celled freshwater organism is transferred to salt water. Which of the following is likely to happen?
a. the cell bursts
b. salt is pumped out of the cell
c. shrinking
d. enzymes flow out of the cell
e. all of these
c. shrinking
Which of the following is NOT likely to diffuse through a membrane?
a. glucose
b. oxygen
c. water
d. carbon dioxide
a. glucose
Which statement is NOT true?
a. membranes are often perforated by proteins that extend through both sides of the membrane.
b. some membranes have proteins with channels or pores that allow for the passage of hydrophilic molecules.
c. polar substances have an easier time passing directly through membranes than nonpolar substances do.
d. the current concept of a membrane can be best summarized by the fluid mosaic model.
E)
The lipid bilayer serves as a hydrophobic barrier between two fluid regions.
c. polar substances have an easier time passing directly through membranes than nonpolar substances do.
Which of the following would not affect diffusion?
a. molecular weight
b. concentration
c. color
d. temperature
c. color
In an enzyme-catalyzed reaction such as X + Y = Z, Z is the
Product
Intermediates are associated with which of the following?
a. antioxidants
b. dead cells
c. free energy
d. metabolic pathways
d. metabolic pathways
_______ reactions use energy to build complex molecules.
Anabolic
Which of the following binds to an allosteric site in order to change the shape of enzyme so that the substrate won’t bind to the active site?
a. cofactor
b. suppressor
c. activator
d. inhibitor
d. inhibitor
Typically, what molecule is causing feedback inhibition in a metabolic pathway?
The end product of the pathway
Enzymes increase the rate of reaction by lowering what kind of energy?
Activation
Essentially, the first law of thermodynamics says that
energy can neither be created nor destroyed
The second law of thermodynamics states that
energy tends to become increasingly disorganized
A reaction that releases free energy is known as a(n) _____ reaction.
exergonic
When a substrate binds to the active site of an enzyme, it changes the shape of the enzyme to help the reaction proceed. What is this model called?
induced fit
Plants need which of the following to directly carry out photosynthesis?
a. H2O
b. CO2
c. O2
d. lipid
e. both H2O AND CO2
e. both H2O and CO2
The final electron acceptor in aerobic respiration is
O2
Pyruvate is regarded as the end product of
glycolysis
Glycolysis typically takes place in the
cytoplasm
The oxygen released in photosynthesis comes from
water
Which of the following conditions is NOT required for Calvin Cycle?
a. carbon dioxide is present
b. the plant is exposed to light
c. RuBP is present
d. enough ATP
e. enough NADPH
b. the plant is exposed to light
The correct sequence of the three processes listed below is:
I – glycolysis II – oxidative phosphorylation III – citric acid cycle
I – III – II or glycolysis - citric acid cycle - oxidative phosphorylation
An organism that can produce its own food is called a(n)
autotroph
The citric acid cycle takes place in the
mitochondria
Four of the five answers listed below are catabolic processes for carbon compounds. Select the EXCEPTION.
a. Calvin cycle
b. citric acid cycle
c. fermentation
d. cellular respiration
e. glycolysis
Calvin cycle
Define biology
the study of life
Properties of life (8 characteristics that define life)
order, sensitivity or response to stimuli, reproduction, adaptation, growth and development, regulation, homeostasis, and energy processing.
Order
consists of one or more cells
Positive response to stimuli
movement towards a stimulus
Negative response to stimuli
movement away from a stimulus
Reproduction in single-celled organisms
duplicate DNA and divide it equally, divides to form two new cells
Reproduction in multi-cellular organisms
produce specialized reproductive cells that form new individuals,genes containing DNA are passed to offspring
What is adaptation?
“fit” to the environment, consequence of evolution by natural selection
What do adaptations enhance of individuals exhibiting them?
reproductive potential
Are adaptations constant or do they vary?
adaptations vary
What do gene instructions direct?
cellular growth and development
Why do offspring exhibits characteristics of their parents?
From the DNA or genes that get passed on during reproduction
What is regulation as a property of life?
complex organisms requiring multiple regulatory mechanisms to coordinate internal functions
Example: circulatory system carries oxygen throughout the body, delivers nutrients to cells
What is homeostasis?
the ability of an organism to maintain constant internal conditions
What is energy processing as a property of life?
All organisms use a source of energy for their metabolic activities.
Example: plants capturing light energy from the Sung and converting it into chemical energy in food
What is the smallest and most fundamental unit of matter?
atom
What is an atom?
nucleus surrounded by electrons
What do atoms combine to form?
a molecule
What is a molecule?
chemical structure consisting of at least two atoms held together by a chemical bond
What are macromolecules?
large molecules formed by combining monomers, biologically important
Example: DNA
What are monomers?
molecules, smaller units
What are organelles?
small structures in cells that perform specialized functions
What is the smallest fundamental unit of structure and function in living organisms?
cell
Why aren’t viruses considered living?
they are not made of cells; they have to invade and hijack a living cell
What are prokaryotic cells?
single-celled organisms lacking organelles surrounded by a membrane and do not have nuclei surrounded by nuclear membranes
What are eukaryotes?
organisms with membrane-bound organelles and nuclei
What are organs?
collections of tissues grouped together based on a common function
Are organs found in:
a. plants only
b. plants and animals
c. animals only
b. plants and animals
What is an organ system?
functionally related organs
What are organisms?
individual living entities
What are microorganisms?
single-celled prokaryotes and single-celled eukaryotes
What is a basic unit of matter consisting of a dense central nucleus surrounded by a loud of negatively charged electrons?
atom
What is a molecule?
a phospholipid, composed of many atoms
What is an organelle?
structures that perform functions within a cell
Differentiate between organisms, populations, and communities
in a park, each person is an organism. together all the people make up a population. all the plant and animal species in the park compromise a community
Describe the levels of organization from smallest to largest
atom - molecule - organelles - cells - tissues - organs - organ systems - organisms - populations - communities - ecosystem - biosphere
Which of the following statements is false?
a. tissues exist within organs which exist within organ systems
b. communities exist within populations which exist within ecosystems
c. organelles exist within cells which exist within tissues
d. communities exist within ecosystems which exist in the biosphere
b. communities exist within populations which exist within ecosystems
What is applied science?
a form of science that solves real-world problems
what is basic science?
science that seeks to expand knowledge regardless of the short-term application of that knowledge
What is a control?
a part of an experiment that does not change during the experiment
What is deductive reasoning?
a form of logical thinking that uses a general statement to forecast specific results
What is descriptive science?
A form of science that aims to observe, explore and find things out
Define falsifiable
able to be disproven by experimental results
What is a population?
collectively, all the individuals of a species living within a specific area
What is a community?
set of populations inhabiting a particular area
What is an ecosystem?
all the living things in a particular area together with abiotic, or non-living, parts of that environment
What is the biosphere?
collection of all ecosystems, represents zones of life on earth include land, water and portions of he atmosphere
What is evolution?
the process of gradual change during with new species arise from older species
How many levels are in the current taxonomic system?
8 levels
What are the 8 levels of the current taxonomic system?
species, genus, family, order, class, phylum, kingdom, domain
What are the 3 domains of life?
Eukarya, Archae, and the Bacteria
What organisms are in the domain eukarya?
fungi, plants, animals, and protists
What are archae?
single-celled organisms without nuclei, includes many extremophiles living in harsh environments
What are bacteria?
single-celled organisms without nuclei
Are classifications permanent?
No, they will change when new information becomes available
What are bionomial names?
consists of genus name (capitalized) and the species name (lowercase)
What is a phylogenetic tree?
diagram showing evolutionary relationships among biological species based on similarities and differences in genetic or physical traits or both
What do the internal nodes of the phylogenetic tree represent?
represent ancestors and points of evolution when an ancestor diverged to form two new species
What does the length of the branch on a phylogenetic tree represent?
estimate of relative time
define neurobiology
study of the nervous system
define paleontology
study of life’s history by fossils
define zoology
study of animals
define botany
study of plants
define ecologist
specialist studying the interactions of organisms in their environments
define physiologists
specialist studying the workings of cells, tissues, and organs
define science
knowledge about the natural world
What is the scientific method?
method of research with defined steps that include experiments and careful observation
What is a hypothesis?
suggested explanation for an event, which can be tested
What is a scientific theory?
generally accepted, thoroughly tested and confirmed explanation for a set of observations or phenomena
What are scientific laws?
describe how elements of nature will behave under certain specific conditions
What are natural sciences?
fields of science related to the physical world and its phenomena and processes
What are life sciences?
study living things
What are physical sciences?
study non-living matter
What is inductive reasoning?
form of logical thinking that uses related observations to arrive at a general conclusion
What is qualitative data?
descriptive
What is quantitative data?
consisting of numbers
What is deductive reasoning?
form of logical thinking that uses a general principle or law to forecast specific results
What does descriptive science aim to do?
to observe, explore, and discover
Hypothesis-based science
begins with a specific question or problem and a potential answer or solution to be tested
What are the steps of the scientific methods?
make an observation, ask a question, form a hypothesis , make a prediction, do an experiment, analyze results, determine if data supports hypothesis, report results or try again
What is a variable?
any part of the experiment that can vary or change during the experiment
What is a control?
part of the experiment that does not change
Define soluble
dissolves in water
Define insoluble
does not dissolve in water
key building blocks of the chemicals found in living things
carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus
Matter
occupies space and has mass
What are elements?
substances that cannot be broken down or transformed chemically into other substances
Smallest component of an element that retains all of the chemical properties of that element
atom
All atoms contain protons, electrons, and neutrons except:
Hydrogen which only has one proton and one electron
What is a proton?
positively charged particle that resides in the nucleus
What is the nucleus?
the core of an atom
What is the mass and charge of a proton?
mass of 1 charge of +1
What is an electron?
negatively charged particle that travels in the space around the nucleus
What is the mass and charge of an electron?
no mass, charge of -1
What is a neutron?
reside in the nucleus on atom
What is the mass and charge of a neutron?
mass of 1, no charge
What is the mass of an atom equal to?
the number of protons and neutrons of that atom
What is the atomic number of an element?
equal to the number of protons that the element contains
What is the mass number?
number of protons plus the number of neutrons in that element
What is the periodic table of elements?
chart of elements including atomic number and relative atomic mass of each element
What are isotopes?
different forms of the same element with the same number of protons but different number of neutrons
What elements have naturally occurring elements
carbon, potassium and uranium
Most common isotope of carbon
Carbon-12
What are radioactive isotopes?
an isotope that spontaneously emits particles or energy to form a more stable element
What is the half-life of an isotope?
the time it takes for half of the original concentration of an isotope to decay to its more stable form
How many electrons can be hold in the closest shell
2 electrons
What shell is filled first with electrons?
the closest shell to the nucleus
How many electrons can the second shell hold?
8 electrons
How many electrons can the third shell hold?
8 electrons
How are electrons arranged in the 2nd and 3rd shells?
arranged in four pairs
How are electron shells filled?
one position in each pair is filled with an electron before any pairs are completed
What do the rows of the periodic table represent?
rows correspond to the number of shells that the elements within that row have
What do the columns of the periodic table represent?
Increasing numbers of electrons from left to right
When is an atom most stable?
When its outermost shell is full
What are chemical bonds?
interactions between two or more of the same or different elements that result in the formation of molecules
What is the octet rule?
states that the outermost shell of an element with a low atomic number can hold eight electrons
What can an element do to satisfy the octet rule?
donate, accept, or share electrons
what is an ion?
an atom or compound that does not contain equal number of protons and electrons, and therefore has a net charge
What are cations?
positive ions that are formed by losing electrons
What are anions?
negative ions that are formed by gaining electrons
What is an electron transfer?
movement of electrons from one element to another
Name 4 types of bonds
ionic, covalent, hydrogen bonds, and van der Waals interations.
Which bonds have strong interactions?
ionic and covalent bonds
What kind of charge will an element have if it accepts an electron?
negative charge
What is an ionic bond?
a chemical bond that forms between ions of opposite charges
What are covalent bonds?
a type of strong bond between two or more of the same or different elements; forms when electrons are shared between elements
Which bond(s) dissociate in water?
a. ionic bonds
b. covalent bonds
c. both
a. ionic bonds
What type of bonds are used to form water?
covalent bonds
What are the two types of covalent bonds?
polar and non-polar
What are non-polar covalent bonds?
bonds formed between two atoms of the same element or between different elements that share the electrons equally
What are polar covalent bonds?
a type of covalent bond in which electrons are pulled toward one atom and away from another, resulting in a slightly positive and slightly negative charged regions of the molecule
Does oxygen have a slightly positive or negative charge in water?
slightly negative because the electrons spend more time near the oxygen nucleus
Does hydrogen have a slightly positive or negative charge in water?
slightly positive charge because electrons spend more time near oxygen than hydrogen nuclei
What are two frequently occurring weak bonds?
hydrogen and van der Waals interactions
What is a hydrogen bond?
A weak bond between partially positively charged hydrogen atoms and partially negatively charged elements or molecules
What are van der Waals interactions?
a weak attraction or interaction between molecules caused by slightly positively charge or slightly negatively charged atoms