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91 terms

barrett Biology Semester 2 Final

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Indicator Species
species that indicate or provide a sign of the ecosystem's quality
eutrophication
to process by which a body of water becomes enriched in dissolved nutrients that stimulate the growth of aquatic plant life --> depletion of dissolved oxygen
Bio magnification
the way that pollutants move throughout an ecosystem (i.e predator eating prey that contains a pollutant, dolphins and mercury)
sustainability
practice in which natural resources are used and managed in a way that meets the current needs without hurting future generations (i.e global fisheries)
umbrella species
A surrogate species selected with the assumption that protection of its habitat will serve as an "umbrella" to protect many other species; often a species with large or specialized habitat requirements or which is easy to count.
what is smog?
type of air pollution caused by sunlight interacting with pollutants made by fossil fuel emmisions
what is ground level ozone?
NO2 produced in fossil fuel combustions reacts with O2 to create O3 (ozone) --> causes asthma, emphysema
what is acid rain?
produced when pollutants in the water cycle cause pH to drop below normal levels
explain the greenhouse effect
earths atmosphere traps solar radiation --> caused by presence of gases (co2, H20, vapor) --> allow incoming light to pass through but absorb heat radiated back from the earth's surface
give examples of evidence of climate change
sea levels rising, global temperature rising, icecaps melting, flowers blooming earlier, animals migrating later
albedo
the fraction of the total sunlight striking a surface that gets reflected from that surface (albedo that is high, near 1, is very bright)
positive feedback
A produces more B, which produces more A
negative feedback
A produces B, which stops or lowers the production of A
what is the purpose of negative feedback?
to maintain stability (homeostasis)
what are the storage polysacharides in animals?
glycogen
what are the storage polysaccharides in plants?
starch (amylose)
what are the structural polysacharides in plants>
cellulose
what are the structural polysacharides in animals?
chitin
dehydration synthesis
take out water to join two sugar molecules, makes it bigger
hydrolysis
to split water, makes big sugars smaller
4 stages of the water cycle
transpiration, evaporation, condensation, evaporation
explain the carbon cycle
plants acquire co2 through their leaves --> photosynthesis --> co2 returned through respiration --> decomposition recycles carbon to the soil and back to the environment
explain the nitrogen cycle
most animals cannot get nitrogen on their own, must get it from plants --> animals eat these plants and incorporate them into their body
photosynthesis equation
6CO2+H20+light --> C6H1206
respiration equation
C6H12O6-->CO2+H2O
where is light energy converted into ATP?
thylakoid
where does respiration happen?
mitochondria
how do prokaryotic cells divide?
binary fission
how many steps are in binary fission? what are they?
2, DNA replicates, cell splits
chromosomes
super coiled DNA
chromatin
loose spaghetti like DNA
chromatid
half of a chromosome
what are the phases of the cell cycle?
Growth 1, Synthesis, Growth 2, Mitosis, Cytokinesis
mitosis
type of cell division that results in two daughter cells, each the same type as the parent nucleus (occurs in body cells only)
interphase
DNA replicates, prepares for division
prophase
DNA supercoils into chromosomes
metaphase
chromosomes line up along metaphase plate
anaphase
centromeres are pulled apart
telophase
cleavage furrow, 2 new daughter cells
somatic cells
body cells
gametes
sex cells
autosomes
all chromosomes except sex chromosomes
purpose of a karyotype
to determine the chromosomes in a cell
how is a kariotype organized?
largest to smallest, matched up homologous pairs by size and bindings
non disjunction
chromosomes fail to separate during anaphase
what is the result of non disjunction?
aneuploidy
aneuploidy
having more or less than 23 pairs of chromosomes
meiosis
division of sex cells
end result of meiosis
4 haploid daughter cells
4 phases of meiosis
prophase I/II, metaphase I/II, anaphase I/II, telophase I/II
tetrad
2 homologous pairs of chromosomes, one from mom, one from dad
independent assortment
orientation of homologous pairs at poles is random --> leads to variation
spermatogenesis
production of sperm
oogenesis
production of egg (1 egg, 3 polar bodies [not useful])
fertilization (order of development)
zygote, embryo, fetus, baby
differentiation
process by which cells are directed to specialize into different tissues (stem cells to kidney cells, etc)
structure of DNA
sides are alternating sugar and phosphate units, rungs of the ladder are purine and pyrimadines held together by hydrogen bonds
how do the base pairs match up?
adenine to thymine, guanine to cytosine
backbone of DNA
phosphate, negatively charged
nucleotides
3 components: 5 carbon sugar (deoxyribose), phosphate, nitrogenous base
purines
adenine, guanine (double ringed [big word, short structure])
pyrimadine
thymine, cytosine (single ringed)
DNA replication
double helix unzips (helicase) --> replication fork --> pair new nucleotides to old ones --> DNA polymerase move along and pair
semi conservative (DNA replication)
have one old strand and one new strand of DNA
Mendel's Laws
Law of Segregation (genes segregate from eachother during egg or sperm formation), Law of independent assortment (homologous pairs are oriented randomly)
3 types of proteins
structural, signaling, enzymatic
what do enzymes do?
control and create chemical reactions
proteins are mad up of...
amino acids
amino acid
organic molecule, some humans can make, others they need through consumption (essential amino acids)
a _____ is chain of _______
protein, amino acids
amino acids held together by ____
peptide bonds
DNA is the blueprint, _________ is the product
proteins
central dogma
states that info flows in one direction (DNA --> RNA --> ribosomes)
3 processes of protein synthesis
replication, transcription, translation
transcription
DNA to RNA (same as matching, except T replaced with U)
types of RNA
mRNA
tRNA
rRNA
messenger RNA (carries info to ribosome)
transfer RNA (carries amino acids to ribosome)
ribosomal RNA (composes parts of the ribosome)
translation
instructions in mRNA to produce protein
start with start codon, end with 3 stop codons in case of a mutation
protein folding
after polypeptide chains are released from the ribosome they fold into more complex structures
mutation
change in organism's DNA
point mutations
result in a new codon
silent mutation
result in the same amino acid
missense mutation
result in a different amino acid
nonsense mutation
result in a stop codon
cancer is a result of
accumulated mutations that affect genes that control cell division
if the mutation occurs in _______ cells, it will not be passed on
body
Lamark's Theory of Evolution
characteristics can change over time (giraffes had short necks, since they had to stretch to get food they got longer necks)
Darwin and Wallace
natural selection (giraffes with different sized necks, the ones with longer necks survived -- pass on genes)
genetic drift
gene frequencies in a population are sometimes altered by chance
examples of evolution
peppered moths, evolution of bacteria, fossils, artifical selection
evidence of evolution
fossils, vestigial structures (appendix), homologous structures, embryonic development, similarity of genetic code
misconceptions of evolution
how can evolution create complex structures like the eye, isn't evolution still argued about, is my ancestor an ape