87 terms

Biology 1101: Exam 2

STUDY
PLAY
Law of Segregation
genes separate equally into gametes so offspring have an equal likelihood of inheriting any combination of factors
Law of Segregation Example
Only one copy of each gene is placed on each gamete during meiosis
Law of Independent Assortment
genes do not influence each other with regard to sorting of alleles into gametes; every possible combination of alleles is equally likely to occur
Law of Dominance
in a heterozygote one trait will conceal the presence of another trait for the same characteristic
genotype
heritable characteristics
phenotype
physical expression of characteristics
dominance
a trait that masks the expression of another trait when both versions of the genes are present in an individual
incomplete dominance
two contrasting alleles share phenotype in offspring
codominance
complete and simultaneous expression of both alleles for the same characteristic
x-linked
a gene present on the X chromosome but not the Y
The first x-linked trait to be identified
eye color in the fruit fly
wild type
the most commonly occurring genotype or phenotype in a population
continuous variation
range of small differences among individuals in a characteristic
Who discovered DNA transfers genetic info, not protein?
Griffith
Who found that DNA is a double helix structure?
Roselyn Franklin
Watson and Crick
scientists that combined DNA research
Chargaff
Scientist that predicted that there were four nucleotides present in DNA molecules; two paired with the other two in equal amounts (A/T and C/G)
What is the first function of DNA?
replication
When does DNA replication happen?
During the S phase
Does DNA replication happen before or after mitosis/meiosis?
before
The process of DNA replication
1. DNA unwinds
2. New bases are added to complementary parental strands
3.Primers are removed while new nucleotides replace them
4. DNA ligase seals DNA backbone
What is DNA made of?
Nucleotides
What are the three components of nucleotides?
deoxyribose, a phosphate group, and nitrogenous base
What are the four types of nitrogenous bases?
Adenine
Thymine
Guanine
Cytosine
Uracil
Nitrogenous base that RNA replaces Thymine with?
allele
alternate versions of the same gene
Transcription
the sequence of a gene is copied from DNA to RNA molecule
Where does transcription take place?
in the nucleus
Translation
the sequence of RNA is used to produce protein
Where does translation make place?
in the cytoplasm
RNA polymerase
enzyme that is responsible for opening the DNA strand
introns
non-coding sequences
exons
coding sequences
protein sequences consist of ____ amino acids
20
triplet codon
three-nucleotide sequence that defines amino acids
Start codon
AUG
What type of molecule provides info for making proteins in an organism?
DNA
dominant allele
allele that is expressed whenever it is present
a recessive gene can...
result in gain or loss of a function
seed shape
one sequence letter change
tay sachs
many sequence changes
mutations can...
change protein function in a neutral or positive way
Difference in Prokaryotic & Eukaryotic gene expression
prokaryotes transcribe everything while eukaryotes only transcribe exons
Difference in Prokaryotic & Eukaryotic gene expression 2
In prokaryotes transcription and translation happen at the same time
Difference in Prokaryotic & Eukaryotic gene expression 3
In Prokaryotes gene expression is regulated during transcription while eukaryotes always regulate gene expression
four mechanisms that can cause evolution
natural selection
genetic drift
migration
mutation
natural selection
a change in allele frequencies when one version of a gene has greater reproductive success than another
genetic drift
a random change in allele frequencies
evolution
when allele frequencies in a population change
sexual selection
selective pressures from social environment
intra-sexual
competition within one sex
inter-sexual
interaction between different sexes
mutation
a change in the DNA sequence of a gene
migration
the movement of individuals and their alleles from one population to another
microevolution
generational change
macroevolution
changes over a long period of time
types of macroevolution
mutation
genetic drift
gene flow
selection
allopatric speciation
geographic barriers that physically separate species
sympatric speciation
reproductive isolation of a population that coexist in the same area but separate by preference
homologous structure
similiar structure and function with evidence of common ancestor
analogous structure
similar function but different structure
example of analogous structures
birds wings vs bat wings
example of homologous structure
different birds wings
Tardi Gras
best survival organisms
Microbes
highest biodiversity
gram-positive bacteria
more susceptible to antibiotics
gram-negative bacteria
more resistant to antibiotics
how do bacteria reproduce?
asexually
What causes diversity in bacteria?
mutations
Conjugation
when bacteria connect and exchange DNA functions
What distinguishes protists from other microbes?
only protists have organelles
Protists
plant-like or fungi-like bacteria
three domains of life
bacteria, archaea, and eukarya
endosymbiosis
development of eukaryotes by engulfing of other cells that complete a function
You categorize types of life by ________
size
no endosymbiosis =
less diversity
Exceptions to Mendel's law
Codominance and incomplete dominance
requirements of natural selection
variation in traits
heritability of traits
differential reproduction and survival
polygenic traits
Some traits, like skin color and eye color, are coded for by several different genes.
antibiotic resistance
when mutations occur in bacteria after resisting an antibiotic for so long and cause the antibiotic to no longer be effective.
speciation
formation of a new species
phylogeny
working hypotheses of how organisms are related over time
node
where two branches come together
fitness
An organisms reproductive output compared to others in its population
beneficial protists
cheese, alcohol
What do prokaryotes help?
food production and chemical cycling
bioremediation
use of prokaryotes to break down chemical waste
YOU MIGHT ALSO LIKE...