Biology 1 (complete) Flashcards
where is non-nuclear DNA found
mitochondria
where are three places cilia is found
in the lungs (respiratory system), ependymal cells (nervous system), uterine tubes (reproductive system)
what is the difference between eukaryotic and prokaryotic flagella
e: whipping motion; microtubules made of tubulin
p: spinning motion; simple helices made of flagellin
smooth ER
lipid synthesis (CREATION ONLY, not metabolization)
rough ER
covered with ribosomes that transcribe proteins
peroxisomes
detoxify
nucleus
DNA is found here, and cannot leave
nucleolus
site of rRNA transcriptions and ribosome assembly
mitochondria function and structure
powerhouse
lysosomes
digests cell parts and does apoptosis
golgi apparatus
package and transport
endosymbiotic theory
mitochondria evolved from aerobic prokaryotes that were engulfed by a larger “host” prokaryote.
centrosome
organizes things and plays a role in cell division
what are the 4 kinds of membrane transport and which require atp
simple: no atp
facilitated: no atp
active: atp
secondary active: no atp
describe active transport
when something is being moved against the concentration gradient or electron potential
what kind of membrane transport is osmosis
facilitated
what is osmosis
diffusion of water across a semi-permeable membrane
distinguish between hypertonic, hypotonic, and isotonic
hypertonic: shriveled up cell because the solutions are more concentrated than the cell so water leaves it
hypotonic: too much water in the cell, cell can burst
isotonic: equal concentration solutions
what are tight junctions and where are they found
water proof barriers; epidermis of the skin
what are gap junctions and where are they found
tunnels between adjacent cells allowing exchange; cardiac tissues, smooth muscle tissue etc
what are adherens junctions and where are they found
strong mechanical attachments; found in epithelium and between cardiac muscle cells
what are desmosomes and where are they found
strongest cellular junctions, but not water proof; found in the tissues prone to stress like epidermis
function of: epithelial tissue
nervous tissue
connective tissue
epithelial: covers the body and lines cavities
nervous: neurons, astrocytes, Schwann cells etc
Connective: bone, cartilage, blood, lymphatic, fat etc
Which of the following is not classified as nervous tissue?
A. ependymal B. oligodendrocytes C. lymphatic D. microglia
C - connective tissue, not nervous
true or false: it is safe to assume that if it cannot be classified as epithelial tissue or nervous tissue, it is connective tissue
true
cell communication:
endocrine
hormone signaling; cell targets a distant cell through bloodstream (receptor is usually far away)
cell communication:
paracrine
signal molecules come from one cell and bind to receptors on the local area of other cells; cell targets nearby cell
cell communication:
autocrine
signal molecules come from one cell and bind to receptors on the same cell; cell targets himself
cell communication:
intracrine
signal molecules bind to receptors within the same cell that made them
what is an example of a signal molecule via intracrine
steroids
cell communication:
juxtacrine
signaling needs direct contact between two cells
cell communication:
nervous system
signaling is happening through neurons
In the cell division phase G0, which cells are considered ‘frozen’/do not divide?
fully differentiated neurons and cardiac muscle cells
what is apoptosis and what organelle is in charge of it
programmed cell death caused by lysosomes
when is apoptosis initiated
whenever cells are exposed to extreme heat, radiation, viral infection, DNA damage, or to remove healthy but unwanted cells
how many chromosomes do humans have before and after replication?
46 before 46 after
do the number of chromosomes differ before and after S-phase? if so, how?
no, both are 46
how many chromosomes are are in diploid cells? haploid cells?
46 in diploid, 23 in haploid
what is the purpose of chromosomes
package long DNA strands so they can be stored while the divisions are happening
actin filaments is how long?
7nm
how long are microtubules
25nm
how long are intermediate filaments
8-12nm
actin filaments are polymers of?
actin monomers
what is the structure of an actin filament
globular protein arranged in a helix
what is the function of actin filament
major contractile component of muscle cells
what is the function of microtubules?
they play a role in cell structure, organization, mitosis, and movement
what is the function of the intermediate filaments
they are the structural protein in eukaryotic cells
what are the three things the cell membrane is made up of (3 components of a phospholipid)
phosphate bond; glycerol backbone; fatty acid tails
what are the three types of membrane transport and explain how they work
uniport: when S goes through in just one way
symport: when S1 goes in and S2 goes in the same way
antiport: S1 goes in one way and S2 goes in the opposite way
which of these membrane transport methods qualify as “cotransport”?
A. uniport
B. symport
C. antiport
both symport and antiport
give examples of nervous tissue
brain, spinal cord, and nerves
give examples of muscle tissue
cardiac muscle
smooth muscle
skeletal muscle
give examples of epithelial tissue
lining of GI tract organs and other hollow organs
skin surface (epidermis)
give examples of connective tissue
fat and other soft padding tissue
bone
tendon
what are the 4 main phases of the cell cycle
G1, S, G2, Mitosis
what happens in the G1 phase of the cell cycle
G1 is known as the growth phase; most of cell life is here, they are making organelles and proteins
what happens during the S phase of the cell cycle
S phase is the synthesis phase; DNA is replicated here (goes from 23 pairs to 46 pairs)
what happens during the G2 phase of the cell cycle?
the preparation of mitosis happens here, making of microtubules occurs
what happens during the mitosis phase of the cell cycle?
this is where active cell division occurs
when does interphase occur and what is it?
interphase occurs in G1, S, and G2.
interphase is when cell growth happens but not cell division
what is G0?
a phase when there is no more cell division (ex. neurons)
what are the 4 phases of mitosis
prophase
metaphase
anaphase
telophase
what happens during prophase
DNA condenses into the X shape; centrosomes migrate to each side; nuclear membrane breaks down
what happens during metaphase
sister chromatids line up in the middle and attach to the microtubules
what happens during anaphase
sister chromatids are pulled apart, making them chromosomes now
what happens during telophase
DNA starts to unwind and the nuclear membrane begins to form
true or false: the splitting of the cells is also known as cytokinesis
true
what is the starting and ending result of mitosis
starts with 46 chromosomes for humans; the end result is 2 identical daughter cells, each with 46 chromosomes
what is the starting and ending result of ALL parts of meiosis
starts with 46 chromosomes; after meiosis 1, there will be 2 daughter cells that are different from parent cells, each with 23 chromosomes each; after meiosis 2 there will be 4 daughter cells
where does crossing over occur
meiosis 1 - prophase 1
what are the 4 DNA bases
adenine, guanine, cytosine, thymine
which bases bind with which bases (DNA bases?)
thymine with adenine
guanine with cytosine
in terms of DNA bases, which have 2 H bonds and which have 3 H bonds
guanine and cytosine have 3 H bonds
adenine and thymine have 2 H bonds
what is the function of a N-H bond in the DNA base?
it is there to attack sugars
split DNA bases into purines and pyrimidines
purines: adenine & guanine
pyrimidines: cytosine, thymine, and uracil
what are the three kinds of repair mechanisms for DNA
base excision, mismatch repair, nucleotide excision
what kind of damage is associated with base excision?
spontaneous damage
what kind of damage is associated with mismatch repair
DNA copy errors
what kind of damage is associated with nucleotide excision
chemical radiation
explain what proofreading is in terms of DNA repair?
DNA polymerase exhibits a substantial proofreading function that catches and repairs most mismatched base pairs on the spot
explain what mismatch repair system is in terms of DNA repair
enzymes that scan newly copied DNA and locate, excise and replace mismatched base pairs missed by the proofreading of DNA polymerase
explain what base excision is in terms of DNA repair
base portion only is excised first via a DNA glycosylase; other enzymes then remove the sugar-phosphate backbone; then DNA polymerase and ligase replace the nucleotide
explain what nucleotide excision is in terms of DNA repairs
excision of an oligonucleotide that includes several bases on either side of the error. DNA polymerase and ligase replace the missing segment
what is the southern blot
used to verify the presence/absence of specific DNA sequence; also indicate the relative size of restriction fragments
what is the northern blot
used to verify the presence/absence of specific RNA sequence; also indicate the relative size of restriction fragments
what is the western blot
used to verify the presence/absence of specific protein sequence; also indicate the relative size of restriction fragments; probes used are radiolabeled antibodies rather than nucleotide sequences
what is the eastern blot
similar to a western blot but it is used to verify post-translational modification; probes bind to lipids, carbohydrates, and phosphates
what is the Hardy Weinberg equation?
p^2+2pq+q^2=1
p+q=1
in the Hardy-Weinberg equation, what does the “p” represent? what does the “q” represent?
p= frequency of the dominant allele
q= frequency of recessive allele
which kind of gram cell has the thicker layer of peptidoglycan?
gram positive
what is the lytic cycle known as?
the reproductive cycle of a bacteriophage
true or false: the lysogenic cycle kills bacteria
false: lysogenic cycle does not kill bacteria
what does the lysogenic do/result in?
many copies of the viral DNA
what are lysogenic phages known as and what are lytic phages known as?
lysogenic: temperate
lytic: virulent
what is a flagella
lash-like appendage that protrudes from the cell body
what is cilia
slender protuberances that project from the much larger cell body
in simple diffusion, what kind of molecules are more likely to go through the gradient?
non polar & hydrophobic
when it comes to the transport of Na+/K+, what kind of membrane transport (from the 4) needs to be used?
Na+ requires facilitated diffusion because it does not go against any concentration gradient
K+ requires active transport because it goes against the concentration gradient
what are the three steps of PCR
- denaturation
- annealing
- elongation
in PCR, what does denaturation do
heat is increased to separate the DNA strands
in PCR, what does annealing do
heat is lowered to allow primers to bind to the DNA strands
in PCR, what does elongation do
DNA replication occurs
why are PCR and DNA cloning done
further tests can be done such as southern blots
PCR results in…
increased DNA concentration exponentially
DNA 4 bases vs RNA 4 bases
DNA: thymine, adenine, guanine, cytosine
RNA: uracil, adenine, guanine cytosine
in terms of structure, what is the difference between DNA base structure and RNA base structure
DNA has a the extra OH which makes it a DEOXYribonucleic acid
how many strands does DNA have? RNA?
DNA has 2 and RNA has 1
location of DNA vs RNA
DNA: stays in the nucleus
RNA: exits nucleus and travels elsewhere in the cytoplasm
what are the three types of RNA
mRNA, tRNA, rRNA
what is the function of mRNA
messenger RNA: read by a ribosome in the process of synthesizing a protein
what is the function of tRNA
transfer RNA: helps to decode information present in mRNA sequences into proteins
what is the function of rRNA
ribosomal RNA: part of ribosome
what strands go from 5’—->3’?
template strands, anti coding strands, anti sense strands
what strands go from 3’—->5’?
mRNA
nontemplate strands
coding strands
sense strands
what are the start codon(s)
AUG
what are stop codon(s)
UAG,UAA,UGA
order these in the lac operon
Promoter
lacZ
lacY
lacA
Operator
lacl(regulator gene)
lacl(regulator gene)
promoter
operator
lacZ
lacY
lacA
what does the presence of lactose remove? what does that result in
removes the repressor
allowing RNA polymerase to function normally and transcribe mRNA
what is a mutation
any change in the DNA sequence
germ cell vs somatic cell
germ: gametes, sperm, eggs
somatic: everything else
what is cancer
uncontrolled division of mutated cells due to failure of cellular regulatory mechanisms
what is a phenotype
physical appearance of an organism as a result of its genes
what is a genotype
actual genetic makeup of an organism
law of segregation
alleles segregate independently of one another
law of independent assortment
genes located on different chromosomes assort independently
what is a wild type
normal genotype, usually used as a control against an altered genotype
chromosome of male vs female
male: XY
female: XX
what is codominance
blue + yellow = blue/yellow
what is incomplete dominance
blue + yellow = green
natural selection is
when mutations lead to a change in the gene pool. requires an individual to have a beneficial polymorphism and for individual to produce more offspring than normal
what are unlinked genes?
when genes are found on different chromosomes or far apart on the same chromosomes, they assort independently
what are linked genes?
when genes are close together/on the same chromosome
this means that the alleles already together on one chromosome will be inherited as unit more frequently than not
what is divergent evolution
for example, there was a wolf as a common ancestor. this resulted in a fox and a domestic dog
what is convergent evolution
there would be no common winged ancestor but through their respective ancestor there came a bird, butterfly, and bat
order these in taxonomy: largest to small
genus
order
family
species
kingdom
phylum
class
kingdom
phylum
class
order
family
genus
species
true or false: members of 2 different species can mate a produce a viable and fertile offspring
false
are fungi heterotrophs or autotrophs
heterotrophs
define heterotroph
ability to gain energy from other organisms
can fungi reproduce sexually?
yes; usually they reproduce asexually but under stressful situations they reproduce sexually
what is lichen
symbiotic relationship between fungi and algae
what is mycorrhizae
symbiotic relationship between fungi and plant roots
do virus have a shell?
yes, it is a protein shell; inside you will find genetic material
how do bacteria reproduce
binary fission
does binary fission increase genetic variation? what other things may increase genetic variation
no; transformation, transduction conjugation
what is transformation?
transduction?
conjugation?
transformation: genetic material is picked up from the environment
transduction: viral DNA is introduced into the bacterial cell
conjugation: genetic info is transferred from on bacterium to another via sex pilus
gram negative vs gram positive
in terms of: stain, membrane and wall
positive: thin cell membrane but thick cell wall; stain purple
negative: 2 membranes on either side of the thin cell wall; stain pink
