In Mendel's studies with peas all characters observed had only two traits. He figured that there was complete dominance between the two factors responsible to produce those traits. This is because:
One of the alleles is dominant over the other.
An individual Tt:
C Expresses only the dominant trait
A true-breeding individual:
A. is always homozygous
There is a gene for flower color where the dominant allele F is blue and the recessive allele f is white. What is this individual's genotype? Ff
Heterozygous
What is the genotypic ratio (HH:Hh:hh) resulting from the following cross: HhxHh?
1:2:1
What is the phenotypic ratio resulting from the following cross: HhxHh?
3:1
A disease that is caused by an allele from a gene in chromosome 10 in humans is:
an autosomal disease
When Mendel did not know the genotype of a plant, he would cross it with a homozygous recessive plant and observe the phenotypic ratio of the offspring. He called this:
A test cross
Mendel's Law of Segregation states that:
alleles segregate into different gametes independant on the genotype
The Law of Independent Assortment states that:
Genes assort independent of other genes
The Law of Independent Assortment does not apply to:
Linked genes in general
Considering two genes that are not located in the same chromosome what are the possible types of gametes produced by an individual RrFf?
RF, Rf, rF, rf
Which gametes could be produced by an individual RrFf if these two genes are located in the same chromosome?
RF, rf
What are the 5 conditions required for Hardy-Weinberg equilibrium?
Mutations do not occur
Mating is random
No migration in or out
Population is infinitely large
Natural selection does not occur
Genetic drift differs from Natural Selection because:
Genetic drift is due to chance and may not necessarily result in the survival of the fittest individuals
When Norway rats and roof rats interbreed, the resulting embryo does not develop into a fetus. This is an example of:
Hybrid inviability
Coccus Bacteria
Spherical or elliptical
Bacillus Bacteria
Rod shaped
Spirillum Bacteria
Form of helix or spiral
Gram Stain
Differences in cell wall
Gram-Positive ends up purple
Gram-Negative ends up pink
Transformation
Acquisition of fragments of DNA from surroundings
Transduction
DNA fragments are transferred via viruses
Conjugation
Piece of DNA is transferred from one cell to another
Evironmental and Economical Importance of Bacteria
Nutrient Cycle
Photosynthesis
Fermented food
Production of vitamins, chemicals, and proteins
Sewage treatment
Algae
Photosynthetic
Examples:
Dinoflagellates
Diatoms
Seaweeds
Dinoflagellates
Two flagella
Produce bioluminescence
Red tide
Seaweeds
Green Algae
Red Algae
Brown Algae
Slime molds
Body resembles that of fungus
Engulf food
Water Molds
Diploid body as opposed to haploid body in fungi
Cell wall contains cellulose instead of chitin
Diploid Cells
Carry two alleles of each gene
Situations in which Mendel's probabilities do not apply
Linked genes
Crossing over
Sexual dimorphism
Males and females appear different
Fome differences make a male more obvious to predators
Sexual selection
Type of natural selection
Results from variation in the ability to obtain mates
Linnaeus
Gave scientific names to species
Hierarchical system of classification
Based on morphology
Mayr
Biological species concept
Considered reproduction and genetics
Example is a Mule
Ecological isolation
Different environments
example- ladybugs feed on different plants
Temporal isolation
Active or fertile at different times
Field crickets mature at different rates
Behavioral isolation
Different activities
Frog mating calls differ
Mechanical isolation
Mating organs or pollinators incompatible
Sage species use different pollinators
Gametic isolation
Gametes cannot unite
Sea urchin gametes incompatible
Hybrid inviability
Hybrid offspring fail to reach maturity
Hybrid eucalyptusseeds and seedlings not viable
Hybrid infertility
Hybrid offspring unable to reproduce
Liger infertile
Hybrid Breakdown
Second generation hybrid offspring have reduced fitness
Offspring of hybrid mosquitoes have abnormal genitalia
Modern extinctions
20-200 extinctions per year per million species
Phylogenies
Depict relationships based on evolution
Use multiple lines of evidence
Cladistics
Defines groups by distinguishing between ancestral and derived characters
Builds on the concept of homology
Homologous structures
inherited from a common ancestor
Ancestral character
Inherited attributes that resemble those of the ancestor of a group
Derived character
Features that are different from those found in the group's ancestor
