semester exam review Flashcards
in which area of biology is DNA most likely to be studied
information and heredity
What is science
an organize way of gathering and analyzing evidence about the natural world
everything we know about the natural world
what is the first step of the scientific method
State the problem
what is a theory
when evidence from numerous experiments supports the hypothesis
what is data
The info you collect during your observations
what is a hypothesis
a proposed scientific explanation for a set of observations
what are the goals of science
to provide natural explanations for natural events in the world, understand patterns to make predictions about future events
how many variables should you test at one time
1
what is the basic unit of length in the metric system
meter
what questions cannot be answered in science
questions outside the natural world
why do all scientists the metric system
it is convenient to all use the same system and easier to convert without conversion factors
what types of molecules will not dissolve in water
Nonpolar molecules
what is the mass number
the average weight of all isotopes of that element
protons and neutrons
if an atom loses electrons what charge would have
positive
what are Van der waal’s forces
when molecules move together the slight positive and negative regions can create attraction
how is a suspension different from a solution
a solution has a solute being dissolved in a solvent
suspension is a mixture of water & non dissolving particles
The electrons located in an atom
in the electron cloud
what is the atomic number
number of protons or electrons in the atom
on the pH scale what is the most acidic number
0
how does the ion concentration of a base differ from an acid
acids have more hydrogen ions
bases have more hydroxide ions
explain why water is polar
water molecules attract to each other in hydrogen bonds
what is a compound
substance formed by the chemical combination of 2 or more elements in a definite proportion
what is an isotope
atoms of the same element that have the same number of protons but different numbers of neutrons
what type of electrons participate in bonds
valence
what is a covalent bond
when 2 atoms share an electron to become stable resulting in formation of molecules
what are the functions of proteins
structure in hair, muscles, bones
enzymes speed up chem. reactions
transport
fight diseases
what macromolecule are normally hydrocarbons
lipids
what is an endergonic reaction
a chem. reaction in which heat energy is absorbed
what can cause a protein to lose its shape
denaturation from pH
salinity
temperature
what carbohydrate makes up plant cell walls
cellulose
in a chemical reaction where are the reactants located in terms of the arrow
before the arrow
what is a monosaccharide
simple sugars consisting of 1 carbon ring
What is a catalyst
substances that speed up the rate of chemical reactions by lowering the amount of activation energy
what is activation energy
The amount of energy needed to get a chemical reaction started
what is a monomer
small molecules that can form into a polymer
what type of saccharide is sucrose
disaccharide
how many covalent bonds can carbon form
four
what is the function of wax on plant leaves
it is a water proof coating on plants
what type of organic molecule is cholesterol
steroid
what three things happen in a chemical reaction
Old bonds break
molecules rearrange
New bonds form
what is the function of the cell membrane
it separates a cell from its environment
how much more visible are details when viewing an electron microscope
1000x
what type of material can easily pass through the cell membrane
lipids
what is the role of protein channels and pumps
to move molecules in and out of the cell
Who invented the first compound lens microscope
Zacharias Janssen and his father Hans
how are active and passive transport different
active transport – cells may need to move against concentration gradient
passive transport – molecules move from high to low concentration gradient using no energy
what had to be invented before the discovery of the cell
microscope
what type of environment do animal cells prefer
isotonic
Who discovered and named cells
Robert Hook
what causes a cell to lyce in freshwater
there is more water than solute in the cell and it ruptures
what did Verchow conclude
cells come from pre-existing cells
what is osmosis
diffusion of water through a selectively permeable membrane
Who observed the first living cell
Robert Hook
what type of image does a scanning electron microscope produce
3-D image of surface of specimen
what type of cell do bacteria have
prokaryote
what is the function of smooth ER
it makes membrane lipids and detoxifies drugs
what is homeostasis
relatively constant internal, physical, and chemical conditions organisms contain
what is the function of centrioles
they help organize cell division
what is a tissue
A massive cells designed for a specific purpose
what is found inside the nucleus
DNA, chromatin, nucleolus
what is the function of the lysosome
digests lipids, carbs and proteins, and gets rid of worn-out organelles
what organelle contains cristae
The inner membrane of mitochondria
what makes ribosomes
nucleolus
trace the path of a protein in a cell
ribosome, rough ER, golgi, out of cell
what is the function of microtubules and microfilaments
they support and transport
Microfilaments are made of actin
microtubules made of tubulin and move chromosomes during cell division
what’s the levels of organization from simple to most complex
cells, tissues, organs, organ systems, organisms
where does the Calvin cycle take place
Stroma
how does light intensity affect the rate of photosynthesis
speeds up the rate by exciting of electrons to a certain degree until all are excited
what did ingenhousz conclude
light is needed in photosynthesis
what are Grana
stacks of thylakoids
what type of plant is corn
C4
how does the amount of carbon dioxide affect the rate of photosynthesis
it will increase the rate but only up to a point
what is the end product of the Calvin cycle
sugar
what is the ultimate source of energy
sun
what is the difference between a C-3, C4, and CAM plant
C3 converts CO2 into a 3C molecule G3P
C4 converts CO2 into a 4C molecule
CAM stores CO2 at night then uses during day
how is energy released from ATP
The bond between the 2nd and 3rd phosphate breaks
what is another name for the Calvin cycle
light independent
what is the function of pigments
captures light
what is the starting molecule for glycolysis
glucose
what is the starting molecule for the Krebs cycle
Pyruvic acid
what is the net yield of ATP during cellular respiration
38
how efficient are we at cellular respiration
38%
what does aerobic mean
it needs oxygen
why is NADH needed in fermentation
so glycolysis can continue
what stage of cellular respiration creates water
ETC
what are the delivery trucks that bring a electrons to the ETC
NADH, FADH2
why is food important
it provides us with the chemical building blocks we need to grow and reproduce, source of raw materials to make new cells, energy
what is fermentation
converts pyruvic acid into other compounds, anaerobic respiration
what are the sources of energy during exercise
ATP already in muscles, lactic acid fermentation, cellular respiration
where does cellular respiration take place
glycolysis – cytosol
kreds cycle – matrix
ETC – cristae
what happens during glycolysis
one molecule of glucose is broken into a 2 3C molecule called pyruvic acid
what process is used to make wine
alcohol fermentation
describe bacterial chromosomes
spherical and singular
when do spindle fibers form
prophase
what happens during cytokinesis
cytoplasm divides
when do chromosomes line up in the middle of the cell
metaphase
what are the two main stages of cell division
mitosis and cytokinesis
what can lead to cancer
mutations of genes that alter the expression of growth factors
carcinogens (tobacco, radiation)
some families at high risk due to genetics
some bacteria and viruses(HPV)
how does contact between cells affect the rate of the cell cycle
it slows the cell cycle back to normal rate
what is cancer
disorder in which some of the body cells lose the ability to control growth
what happens during Interphase
G1, S, G2, and G0
what is the cell plate
it is like the cleavage furrow in plant cells
what happens during G1, G2, S, & M phases
G1 – makes proteins
S – DNA is copied
G2 – copies organelles and gets ready to divide
mitosis – chromatids split, cells divide
The cleavage furrow marks the end of telophase and the beginning of
cytokinesis
what happens during anaphase
spindle fibers pull the centromere’s apart allowing the sister chromatids to separate
List the stages of mitosis in order
prophase, metaphase, anaphase, telophase
what is the difference between haploid and diploid
diploid has two sets of chromosomes
haploid has one set of chromosomes
what happens during crossing over
homologous chromosomes exchange segments of DNA
when do tetrads form
prophase 1
how is mitosis different from meiosis
mitosis – one cell division, produces diploid, two identical daughter cells, homologous pairs don’t line up
meiosis – two cell divisions, produces haploid, 4 genetically diverse cells, homologous pairs line up
what happens during meiosis to increase genetic diversity
crossing over
what process produces gametes
cytokinesis 2
what is a tetrad
homologous pair of chromosomes that went through synapsis
what 2 structures make seminal fluid
seminal vesicles and prostate glands
where is the epididymis located and what is its function
in the testes where the spermatids mature
where the ovaries located and what is their function
at the end of each oviduct. They are reproductive organs that produce eggs
when does puberty start
ages 9 through 15. One year earlier in females
what are the three parts of the sperm and their functions
Head – contains DNA and enzymes that allow entry into egg
mid piece – contains energy releasing into mitochondria
tail – locomotion
where does fertilization take place
oviduct
what is the function of the placenta
gives oxygen and nutrients to embryo
helps embryo get rid of waste
what hormones cause the gonads to mature
follicle stimulating and lutinizing
when is the fetal heartbeat detectable
months 4 to 6
what does a blastocyst look like
A hollow ball of cells
what does the amniotic sac look like
membrane that surrounds embryo and contains amniotic fluid
what produces testosterone
testes
