Exam 1 (Key Notes) Flashcards
What came first life or O2?
life
What came first land plants or land animals?
Plants
What led to the Perminan mass extinction at the end of the Cenozoic period/Cambrian explosion?
Formation of Pangea
What came first dinosaur extinction or first mammals?
First mammals
What came first Atlantic ocean opens or dinosaurs extinction?
Atlantic ocean
What came first humans or wooley mammoth extinction?
Humans
What is different about uracil compared to thymine?
Thymine has an extra H3C attatched which makes it more stable and found in DNA
What is different about cytosine compared to uracil and thymine?
Cytosine has NH2 on top whereas uracil and thymine have oxygen on top
Difference between guanine and adenine?
Guanine has O attached and adenine has NH2 attatched
What is on 3’ carbon of sugar in nucleotide?
OH
Where is double bonded O from phosphorous in nucleic acid polymerization?
On the right. Facing “inwards”
Where is hydrogen attached to the carboxyl group of the non-ionized amino acid?
To the single bonded oxygen
Non-polar amino acids (R)
look for hydrocarbon groups and sulfur
no oxygen
uncharged, hydrophobic
Polar amino acids
look for partial charges and oxygen
hydrophilic, will form hydrogen bonds
Electrically charged acidic amino acids
look for negative charge
look for carboxyl groups
hydrophilic, will give up protons
Which amino acids are acidic?
Aspartic acid and glutamic acid
Which amino acids are basic?
arginine, histidine, lystine
Electrically charged basic amino acids
look for positive charge
look for NH
hydrophilic, will attract protons
Intermediate forms
gradual stages between simple and complex structures
ex: development of the human eye
Transitional fossils
Intermediate forms in the fossil record
cannot assume a direct think between derived and ancestral species
Sister taxa
tips that are directly related by a single common ancestor at a node
Cladogram
only info is branching pattern and order, branch length provides no information
time is indicated by ancestors and descendants
Phylogram
branch length indicates level of divergence
there is time associated with it
Synapomorphy
shared derived homologous traits
a shared trait that sets a clade away from other clades
Precambrian era
life was unicellular and not diverse
oxygen was virtually absent until photosynthetic bacteria
early animals form later
Importance of the development of predators
sparked the Cambrian explosion
it is now an arms race to develop to survive
leds to shells, teeth, and claws
Adaptation
a heritable trait that increases the fitness of a particular individual relative to those lacking the trait
Fitness
the ability of an individual to produce surviving fertile offspring relative to other individuals in the population
Monohybrid cross
crossing plants that differ in only one trait
Particulate inheritance
suggests that hereditary determinants maintain their integrity from generation to generation
Principle of segregation
the two alleles of each gene pair must segregate into different gamete cells
Hardest bonds to break
non-polar covalent
More hydrogen ions in a solution indicates
lower pH (more acidic)
The particle theory of inheritance
hereditary traits act like particles (units) as they are passed from generation to generation
chromosomes are these particles
Law of independent assortment
character traits are not connected but are inherited independently
What are chromosomes composed of?
DNA and proteins
Bacteriophage
Hershey and Chase experiment
Bacteriophage only inject hereditary material into the cell
this will tell us whether DNA or proteins are the genetic material (cannot just study chromosome replication, since DNA and proteins are both in chromosomes)
How is DNA stabilized?
By hydrogen bonds and hydrophobic interactions in the interior
When is amino group most likely to be ionized?
In low pH
When it is more acidic, NH2 is more likely to act as a base and pick up one of the many hydrogen ions floating around
Disulfide bond
stabilize secondary and tertiary proteins
they are very strong
Codominance
simultaneous expression of the phenotype associated with both alleles in a heterozygote
Incomplete dominance
heterozygotes display a phenotype that is intermediate between the 2 homozygous parents
