BIO FINAL Flashcards
steps of the scientific method
make observations, ask a question, form a hypothesis, test the hypothesis (experiment), draw conclusions, communicate results
scientific hypotheses
possible answer to a scientific question based on scientific knowledge
scientific law
is always true
scientific theories
broad explanation for events that are accepted to be true
control group
the aspects of an experiment that are maintained in order to keep the experiment controlled
dependent variable
the thing that is measured; examples: height of the plant, the temperature of the water
independent variable
the thing that is changed; examples: the growing medium, the type of liquid used to measure the plant
characteristics of living things
responds to environment, grows and develops, produces offspring, maintains homeostasis, has complex chemistry, and consists of cells
principles of biology
cell theory, gene theory, homeostasis, evolution
cell theory
- all living things are made up of cells
- all living things come from other cells
- all organisms start as a single cell
gene theory
characteristics of living things are controlled by genes
homeostasis
keeping things constant; the ability to maintain a balance
evolution
change in the characteristics of living things over time; happens through natural selection
properties of water
hydrogen bonds
pH scale
the lower the number, the more acidic it is; the higher the number, the more basic it is; 1-14
what is the main element in organic compounds?
carbon
carbohydrates
provides and stores energy, forms body structures
lipids
stores energy, forms cell membrane, and carries messages
proteins
help cells to keep shape, makes up muscles, speeds up chemical reactions, carries messages and materials
nucleic acids
contains instructions for proteins, passes instructions from parent to offspring, helps make proteins
structure of carbohydrates
made of many monosaccharides
structure of lipids
made of saturated fatty acids or unsaturated fatty acids
structure of proteins
made of amino acids; 20 different kinds found in living things; form a chain called a polypeptide
structure of nucleic acids
made up of nucleotides; form a chain called a polynucleotide
endothermic reaction
energy is absorbed
exothermic reaction
energy is released
how do enzymes speed up chemical reactions
their shape attracts the molecules that need to be paired together to the active site
what are some factors that affect enzymes?
pH level, temperature, and ionic conditions
first person to use the word “cell” to describe them
Robert Hooke
Leeuwenhoek
made microscopes that are very similar to modern light microscopes; found tiny animals that we now call bacteria
Schwann and Schleiden
proposed that cells are the basic building blocks of all things
Virchow
said that all cells come from other cells
prokaryotic cells do not have…
a nucleus
DNA in prokaryotic cells is stored…
in a single loop
the parts of a prokaryotic cell…
ribosomes, DNA, cytoplasm, plasma membrane, cell wall, capsule, and the flagellum
main parts of an animal cell
nucleus, cytoplasm, other organelles, cell membrane
organelles in an animal cell
mitochondria, golgi body, smooth endoplasmic reticulum, rough endoplasmic reticulum, ribosomes, lysosomes, and centrioles
plant cells have…
a central vacuole, chloroplasts, and a cell wall in addition to the other organelles in animal cells
cytoplasm
helps cell to keep shape and suspends organelles in place
nucleus
largest organelle, controls what proteins are made
mitochondria
create ATP for the cell
rough endoplasmic reticulum
provides a framework for ribosomes
smooth endoplasmic reticulum
its membrane forms vesicles that carry proteins away from the ER; also makes lipids and stores substances
ribosomes
where proteins are made
golgi body
processes proteins, packages them and sends them to different parts in the cell, also transports lipids
vesicles and vacuoles
sac-like organelles that store and transport materials
lysosomes
use enzymes to break down foreign matter and dead cells
which organelles are only found in plants?
cell wall, a LARGE CENTRAL vacuole, and plastids
cell wall
rigid layer that surrounds the cell to provide structure and allow water and nutrients to enter; often made of cellulose
large central vacuole
takes up the majority of the cell’s volume; stores materials, provides structure, and can even provide coloring
plastids
different types of organelles that are only found in plants
chloroplasts
provide the green pigment in plants, conduct photosynthesis
organization of cells
cells, tissues, organs, organ systems, organisms
phospholipid bilayer
hydrophilic head and hydrophobic tails; the tails face inward and the heads outward
centrioles
only found in animal cells; help to organize organelles before cell division
Why is no energy necessary for passive transport?
substances are moving from an area of higher concentration to an area with a lower concentration
molecules that go into the cell by simple diffusion…
are often hydrophobic
osmosis occurs until…
the water concentration is the same on both sides of the plasma membrane (inside the cell and outside the cell)
if transport proteins help materials get through the membrane, it is called
facilitated diffusion
channel proteins
help water to get though the membrane so that they do not touch the hydrophobic tails; form a hole in the bilayer
carrier proteins
bind with certain ions or molecules and carry them across the layer
active transport is required when…
materials are moving from an area of lower concentration to an area of higher concentration
energy in active transport comes from this
ATP
sodium-potassium pump
sodium exits the cell, potassium enters the cell; both going from lower to higher concentrations
with vesicle transport the _____ does not matter
concentration; if the material is too large, vesicle transport is necessary
material moving into the cell
endocytosis
material leaving the cell
exocytosis
hypotonic solution
less solute in the solution than inside the cell (concentration in the solution
where do water molecules go in a hypotonic solution?
they go into the cell because there are less solute in the solution to block the way
isotonic solution
relatively equal concentration of solute in and outside the cell (concentration in the solution=concentration in the cell)
hypertonic solution
more solute in the solution than inside the cell (concentration in the solution>concentration in the cell)
where do water molecules go in a hypertonic solution?
they leave the cell because there is less solute in the cell to block the exit
why do cells divide?
to reproduce, to replace lost or dead cells, and to promote the growth of the structure they are a part of
what process do prokaryotic cells use to reproduce?
binary fisssion
what are the steps of binary fission?
- DNA replication; end up with two identical chromosomes
- each chromosome moves to a different part of the cell
- plasma membrane starts to grow down the center of the cell creating two new cells
what is being divided in mitosis?
the nucleus
what is happens during cytokinesis?
the cytoplasm divides and two daughter cells form
the mitosis phase of the cell cycle includes what two processes?
mitosis and cytokinesis
what three phases are grouped together in interphase?
G1, S, and G2
Growth Phase 1 (G1)
cell grows rapidly and prepares for division by making necessary materials; cell spends most of it’s time in this state
Synthesis (S)
cell’s DNA is copied through DNA replication
Growth Phase 2 (G2)
final preparations to divide are made
cell growth checkpoint
at the end of G1; checks whether cell is big enough and has the proper proteins
DNA synthesis checkpoint
during S phase; checks whether DNA has been replicated correctly
mitosis checkpoint
during the mitosis (M) phase; checks whether cell has divided properly, if so the cycle repeats with the new cells
structure of chromosome
two sister chromatids in an x-shape joined at the center by a centromere
phases of mitosis
PMAT; prophase, metaphase, anaphase, telophase
cytokinesis in animal cells
plasma membrane pinches to form two new cells
cytokinesis in plant cells
cell plate divides the two cells and new plasma membrane forms
asexual reproduction
single parent, offspring are identical with each other
sexual reproduction
requires two parents; gamete cells are formed and they unite to form the offspring
a zygote is a….
diploid cell because it has twice the number of chromosomes as a gamete
haploid cells contain…
half the number of chromosomes found in other cells of the organism
homologous chromosomes
are chromosomes that may have different DNA, but code for the same genes, hybrid chromosomes form from homologous chromosomes through crossing-over; provides offspring that are not genetically identical to the parents
prophase I
homologous chromosome pairs are formed and crossing-over occurs
metaphase I
homologous pairs line up at the equator
anaphase I
homologous pairs are pulled apart
telophase I
nuclear membrane reforms
meiosis I results in…
two haploid cells
prophase II
DNA condenses
metaphase II
chromosomes line up at the equator
anaphase II
sister chromatids are pulled apart
telophase II
nuclear envelope reforms; four haploid cells are produced
the haploid cells that result from meiosis II are also called…
gametes
generation
all the offspring from two parents
characteristic
a visible trait that can have different variations (ex: flower color)
trait
the different variations of characteristics (ex: purple flowers)
hybrid
the offspring of two parents from the same species
genetics
the science of heredity
why were pea plants good test subjects?
fast growing and easy to raise
procedure
cross two different colored flowers (p generation)
F1 generation
all had the dominant trait
F2 generation
3 dominant : 1 recessive
dominant
if it is present in the genotype, the organism will have that trait
recessive
may be present in the genotype but will not always appear
homozygous
when the genotype is made up of all the same alleles (ex: RR, rr)
heterozygous
the genotype is made up of different alleles (ex: Rr)
genotype
the genetic makeup
phenotype
the physical trait
law of segregation
two factors controlling a certain trait and one is dominant over the other
law of independent assortment
factors controlling different traits are inherited independently of each other
incomplete dominance
dominant allele is influenced by the recessive allele
codominance
both alleles are expressed equally
multiple alleles
having more than two different alleles for a given traint (ex: blood type)
polygenic characteristics
controlled by more than 1 gene (ex: skin color)
sex-linked traits
travel on the X chromosome; if a male has an X chromosome that is dominant for the sex-linked trait then he will have that trait
Miescher
isolates nuclein
Chargaff
shows that the proportions of nitrogen bases in organisms is always the same
Avery
determined that DNA transmits genetic information
Hershey and Chase
also conclude that DNA is the genetic material
Wilkins and Franklin
take x-ray images of DNA
Watson and Crick
determine the 3-D structure of DNA
Griffith
discovered that genetic info could transfer between organisms
DNA is made up of…
two nucleotide chains; each nucleotide chain has a sugar/phosphate backbone and nitrogen bases are complementary to each other
where does DNA replication take place
replication forks
1st step of DNA replication
DNA helicase unwinds the DNA strand
2nd step of DNA replication
DNA polymerase adds complementary nucleotides to each strand
how is DNA replication semi-conservative?
it has one strand from the parent and one new strand
how is RNA different from DNA?
single strand instead of two, ribose instead of deoxyribose, uracil instead of thymine
mRNA
messenger; carries instructions for making proteins
tRNA
transfer; carries amino acids
rRNA
ribosomal; helps form ribosomes
transcription
takes place in the nucleus, uses DNA as a template to make mRNA strand, it leaves the nucleus
translation
reads the mRNA strand and makes a protein
point mutation
change in single nucleotide
silent mutation
codes for same amino acid
missense
codes for different amino acid
nonsense
premature stop codon
insertion
piece of a chromosome is inserted into another one
deletion
part of a chromosome is deleted
frameshift mutation
a change in nucleotides that changes what proteins will be made
nondisjunction
the failure of replicated chromosomes to separate
binomial nomenclature allows…
scientists to talk about the same species no matter their native language
scientific name includes
genus name + species name
taxonomic classifications (broad to specific)
domain, kingdom, phylum, class, order, family, genus, species
kingdoms in archaea
archaebacteria
kingdoms in bacteria
eubacteria
kingdoms in eukarya
protista, fungi, plantae, animalia
abiotic factors
physical, not living (ex: temperature, sunlight, rocks)
biotic factors
living (ex: animals, plants)
ecosystem
interactions among the organisms and the physical surroundings in a particular area
community
all organisms in an ecosystem
population
members of the same species living in the same area
1st trophic level
producers
2nd trophic level
herbivores
3rd trophic level
carnivores/omnivores
4th trophic level
top carnivore
food chains show…
a single path of energy through organisms
food webs show…
multiple paths of energy through organisms
the percentage of energy that is passed to each trophic level
10%
if a lower trophic level consumes a toxin…
the concentration of the toxin becomes higher as it goes up each trophic level
runoff
streams, rivers; flows across the surface of the earth
percolation
water settles beneath the surface of the earth
transpiration
plants release water which evaporates into the atmosphere
cellular respiration
releases carbon into the atmosphere
photosynthesis
removes carbon dioxide
ammonification
nitrogen from dead organic material returns to soil as ammonia
nitrification
making nitrate from ammonia
assimilation
process by which plants absorb nitrogen from soil
denitrification
nitrate is changed into atmospheric nitrogen gas
tropical rainforest
most diversity; great amounts of rain; humid
temperate deciduous forest
lots of trees; shed leaves
taiga
spruces and firs; lakes and marshes
tundra
coldest biome
grasslands
few plants except for grass
desert
hot, little rain
chaparral
found in cali; summers are very dry
freshwater
no salt
marine
salt
predation
predator eats prey
competition
organisms are competing for resources
mutualism
both species benefit (ex: bees and flowers)
commensalism
one species benefits and the other is unaffected (ex: hermit crabs and old shells)
parasitism
one species benefits while the other is harmed; some parasites will kill their host
