Q201 Final Exam
How is the base sequence of a DNA molecule transcribed into the base sequence of a mRNA molecule?
sense strand
gel electrophoresis
seperates DNA fragments on their bases of electrical charge and size
overexploitation
species diversity declining due to over-use (elephants killed for tusks)
epidemic species
species that are unique to a specific geographic area (an island, nation, zone, etc.)
promoters
specific signals found in the base sequence of the DNA molecule that TELL THE RNA POLYMERASE WHICH STRAND OF DNA MOLECULE IS SUPPOSED TO BE TRANSCRIBED
DNA Fingerprinting
-STRs used to produce these Uses: Forensics/criminal cases, Paternity cases, Immigration cases, Endangered species/wildlife poaching, Purebred/thoroughbred animals
RNA polymerases role
enzymes that synthesize RNA
We find evidence of the first stone tools associated with which hominin species? What do we call the types of tools that they made?
-Homo heidelbergensis/Archaic Homo sapiens (AHS) -Acheulian tradition
transfer RNA
-acts as an adapter between the mRNA and the growing protein chain. -recognizes nucleotides triplets in the mRNA molecule and carries the correct amino acid to the ribosome
ribosomal RNA
-composed of ribosomal RNA plus proteins- consists of a large and small subunit. -PROTEIN SYNTHESIS occurs here, AMINO ACIDS JOINED TOGETHER TO MAKE PROTEIN
key characteristics of Homo habilis
-larger brain -stone tools -smaller teeth
Lamarck's thinking
-shown to be incorrect -believed in transformism, species change over time into new species -ex: giraffes necks are long because they stretched them hard to reach leaves and passed stretched necks onto their offspring
transcription
-synthesis of RNA from a DNA template *RNA molecules are complementary to the DNA* (Ex: A DNA = U RNA)
3 types of natural selection
1. stabilizing selection, an intermediate population is favored 2. directional selection, individuals at one end of the phenotypic range survive and reproduce more successfully 3. diversifying selection, individuals on both extremes of a phenotype are favored over intermediate phenotypes
Evidence for evolution
1.) Fossils 2.) Biogeography 3.) Comparative Anatomy 4.) Comparative Embryology 5.) Molecular Biology
what percent of energy goes to the next trophic level?
10%
what is the age of homo sapiens sapiens
195,000 years
hominins
7,000,000 years ago, found in Africa
To which genus did the earliest, well-known hominins belong?
Australopithecines
Evolution of the species Homo is associated with the development of which features?
Brain?
Casts
Dead organisms trapped in sediment decay & leave behind an empty "mold" that fills with minerals dissolved in water (ex: marine shells)
Semi Conservative DNA replication
Each strand of the old DNA molecule acts as a template (pattern) for the synthesis of a new, complementary DNA strand
Preserved organisms
Entire organisms/parts of organisms, including soft parts, may be buried in a medium that prevents bacteria and fungi from decomposing the organism (ex: fossilized leaves/insects in amber)
Evolution
Genetic change in a population or species across/between generations
Homo habilis, archaic Homo sapiens(Homo heidelbergensis), and modernHomo sapiens skull differences
Habilis: 630 cc 50% size of modern humans, skull is lower in the back compared to modern humans Archaic/heidelbergensis: 1200cc 90% size of modern humans, higher rounded skulls
Artificial Selection
Humans provide the selective pressure by choosing the individuals that will breed
Inherited vs acquired characteristics
Inherited: a characteristic that can be handed down genetically Acquired: a characteristic that has been produced based on personal efforts to make the change
intrasexual selection vs intersexual selection
Intra: physical combat or displays between members of the same sex as they compete for a mate Inter: individuals of one sex select their mate based upon certain characteristics
Leading strand vs. lagging strand (differences in the way in which each is replicated)
Leading: synthesized continuously in a 5' to 3' direction Lagging: synthesized as a series of fragments called Okazaki fragments, which are later joined together by DNA ligase
Two Perspectives of Evolution
Macroevolution: Change in the FORM/BEHAVIOR of organisms between generations Microevolution: Change in the GENE FREQUENCIES between generations
Petrified Organisms
Minerals dissolved in ground water seep into tissues of dead organisms, and replace organic matter
What types of tools did the Neandertals make?
Mousterian ex: spears
elongation
RNA grows LONGER. New RNA molecule peels away from DNA and DNA double helix closes up again
initiation
RNA polymerase ATTACHES TO PROMOTER and begins to SYNTHESIZE RNA, using ONE STRAND of the DNA molecule as a template
termination
RNA polymerase reaches a terminator sequence in the DNA molecule and stops making RNA. New molecule is released
differences between the Robust and Gracile australopithecines
Robust: larger temporal, shorter snout, flatter forehead, smaller front teeth, larger molars Gracile: smaller temporal, longer snout, steeper forehead, larger front teeth, smaller molars These two species split because of the dropping temperatures in Africa
Diet of the Robust australopithecines vs. Homo habilis vs. Homo erectus vs. Neandertals, and how each obtained their food.
Robust: nuts, seeds, hard fruits, scavengers Habililis: meat scavengers Erectus: scavengers but probably more hunting Neanderthals: hunter, meat
Comparative embryology
The development of different organisms, closely related organisms have similar development patterns
Molecular Biology
Universal genetic code
restriction enzyme
enzymes that recognize specific base sequences in a DNA molecule and cut the DNA molecule at a specific site within that base sequence
ecosystem
a biotic community interacting with abiotic factors in the environment
sexual selection
a form of natural selection where individuals with certain traits are more likely than other individuals to find mates
codon
a group of three adjacent nucleotides in a mRNA molecule that specifies a particular amino acid in a protein, or specifies a start or stop signal
symbiosis
a physically close association between organisms of two or more species
plasmid
a small circular DNA molecule that is SEPARATE from the chromosome of a BACTERIAL CELL, into which a piece of foreign DNA can be inserted can be inserted and undergo replication
PCR (polymerase chain reaction)
a technique used produce millions of copies of a specific section of a DNA molecule uses: amplify DNA from crime scenes, paternity cases, immigration cases
gene flow
allele frequencies in a population can change when a population gains or loses alleles when fertile individuals move into or out of a population
selection
any pressure that causes one individual to die or not reproduce, while others having a different set of characteristics do survive and reproduce
bioaccumulation vs biomagnification
bioaccumulation: accumulation of toxins in an INDIVIDUAL organism biomagnification: accumulation of toxins in the food chain
messenger RNA
carries the genetic information FROM THE DNA in the nucleus TO THE RIBSOMES
genetic drift
chance events cause allele frequencies to fluctuate unpredictably from one generation to the next
Zygomatic arch
cheekbones
Comparative Anatomy
comparison of body structures in different species (ex: wing of bird)
requirements of natural selection
competition among individuals, heritable variation, selective pressures
FOSSIL evidence for evolution
complexity increasing through time or appearing/disappearing body parts
DNA double helix
double stranded line of sugar-phosphate backbone , A PAIRS WITH T, G PAIRS WITH C. Two strands are antiparallel
trophic structure
feeding relationships between organisms
value of biodiversity
foods, genes, biological control agents, natural products
diastema
gap between two teeth (with early hominins, was the space between canine teeth and front teeth)
bottleneck effect
genetic drift resulting from a drastic reduction in population size
founder effect
genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool is not reflective of the original population
mutations
heritable change in the nucleotide sequence of a DNA molecule
Which hominin species was the first to leave Africa?
homo erectus
what type of bond holds together strands of DNA?
hydrogen
3 Different Types of Fossils
impression, petrification, preservation
sagittal crest
ridge of bone running down the center of the top of the skull, used to anchor chewing muscles
where are toxins stored?
in fat (milk has a high fat content!!!)
BIOGEOGRAPHICAL evidence for evolution
individuals will resemble their relatives more than non-relatives in similar but distant places (example: ensantina salamander)
gene
linear sequence of NUCLEOTIDES in a DNA molecule that SPECIFIES THE LINEAR SEQUENCE OF AMINO ACIDS IN A PROTEIN
biomes
major ecosystem types occuring over a broad geographic area (Tropical Rain Forest, Temperate Deciduous Forest, Chaparral, Temperate grasslands, Deserts, Arctic Tundra, Coral Reefs, Hydrothermal Vents (deep sea vents), Rivers, Streams, Lakes, Wetlands)
sexual dimorphism
males and females have different appearance or size
what do we need to make a protein?
messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA)
Interactions
mutualism: both organisms benefit predation/grazing/parasitism: one organism benefits, one is harmed commensalism: one organism benefits, the other is not hurt nor benefits competition: both organisms are harmed
invasive exotic species
non-native species introduced intentionally or unintentionally
introns
non-protein coding sequences
monomer
nucleotides that consist of three parts: nitrogen base, 5 carbon sugar, and a phosphate group
Darwin's theory of natural selection
occurs when individuals that are better suited to survive and reproduce do so, leaving more offspring than their competitors in the next generation. (ex: The birds prefer the taste of the red bugs, so soon there are many green bugs and few red bugs. The green bugs reproduce and make more green bugs and eventually there are no more red bugs)
what type of bond forms between amino acids in DNA synthesis?
peptide bond
nucleotides are joined together by _________ bonds
phosphodiester
services provided by living organisms
pollinate plants, producing O2, filter water
community
populations of 2 or more organisms, living and interacting in an area
evolutionary theory
predicts life originated once, began with a simple single celled organism
DNA cloning
producing large numbers of identical DNA molecules- not possible until 1970s
exons
protein coding sequences
two types of biomes found on earth
terrestrial and aquatic
foramen magnum
the hole in the base of the skull through which the spinal cord passes
gene pool
the set of alleles present in a population
ecology
the study of biotic and abiotic interactions in the environment
translation
the synthesis of a polypeptide using the genetic information encoded in an mRNA molecule
bipedal
walks on two legs- hominid trait proof of it: Pelvic bones, leg structure (knee turned outward), laetoli footprints
Scientific Definition of Theory
well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment