bio1120L midterm Flashcards
evolution
a change in allele frequencies through time in populations
5 criteria for genetic equilibrium
- no migration
- no mutation
- no genetic drift
- no natural selection
- random mating
formulas for calculating allele frequencies
p+q=1
p^2+2pq+q^2=1
how to find p
(2)AA+(1)Aa/# of individuals(2)
how to find q
(2)aa+(1)Aa/#of individuals(2)
how to find 2pq
2(pxq)
bottleneck effect
rapid reduction in a population size where only a few alleles survive
fixed allele
the only allele for a particular gene
how to calculate degrees of freedom
number of genotypes-1
four mechanisms for evolutionary change
what happens if they’re met?
- migration
- mutation
- natural selection
- genetic drift
microevolution
microevolution
evolution over a short time frame
macroevolution
evolution over a long period of time
what is speciation the bridge between
micro and macroevolution
what is a defining feature of speciation
reproductive isolation
define species
A population that can interbreed, produce fertile offspring, and is reproductively isolated from other species
limitation of bsc species definition
doesn’t apply to asexual organisms, some species can interbreed
allopatric speciation
species become geographically isolated
parapatric speciation
species diverge in semi isolated locations
sympatric speciation
species diverge in the same area
genetic drift
random change in allele frequencies
8 categories used to classify organisms
- Domain
- Kingdom
3.Phylum
4.Class
5.Order
6.Family
7.Genus
8.Species
node
branching point
clade
2 branches next to each other
Synapmorphy
similar characteristic in 2 or more species inherited from a common ancestor
systematics
the study of the kind and diversity of organisms and their relationships
will a significant change in allele frequency have an effect on genotypic frequency
yes because allele frequencies affect the number of genotypes present
what effect does natural selection have on genotypic frequency?
natural selection favors genotypes that are more likely to survive and reproduce
endosymbiont theory
mitochondria and chloroplasts originated as prokaryotic cells that got swallowed by a host cell
what are the distinguishing characteristics of bacteria?
bacteria is unicellular, doesn’t have a nucleus and reproduces through binary fission
what are the distinguishing characteristics of protists?
some protists can be multicellular, reproduce through mitosis, eukaryotic, aquatic
3 shapes of bacteria
coccus, bacillus, spirillum
How does a Euglena move around? How does it obtain food?
- flagellum
- photosynthesis or they can assimilate organic material heterotrophically
How does a Paramecium move around? How does it obtain food?
- cilia
- collects food particles in oral groove and deposits them into vacuoles
Why are autotrophic protists, like Diatoms, important?
they fix the most carbon dioxide into oxygen
Which kingdom represents the first group of organisms to exist on earth?
bacteria
Give an example of an autotrophic organism we saw
diatom or algae
Give an example of an heterotrophic organism we saw
paramecium
Give an example of an organism that can be either heterotrophic or autotrophic
euglena
Where do meiosis and fertilization occur in the life cycle of moss and ferns?
sporangium
Why are mosses and ferns found in moist habitats?
sperm must swim to reach the egg
Why is a fern considered more advanced than moss?
they have vascular tissue with xylem and pholem
What kind of habitat would we expect to find spore-bearing plants?
moist
Is the gametophyte or sporophyte phase dominant in mosses?
gameophyte
Is the gametophyte or sporophyte phase dominant in ferns?
sporophyte
Do the gametophyte and sporophyte phases live independently or dependently in mosses?
dependently
Do the gametophyte and sporophyte phases live independently or dependently in ferns?
independently
moss/fern life cycle
- spore
- gameophyte
- antheridium/archegonium
- fertilization
- zygote
- embryo
- sporophyte
- sporagonium
- spore mother cells
- meiosis->1.
Describe the sexual reproduction process in gymnosperms and angiosperms
both produce male pollen grains that travel to female ovules to fertilize them, forming seeds. They are heterosporous, they produce megaspores and microspores. same as moss just with 2 spores.
Why is the seed an advantage for life on land?
seeds protect the embryo
Why do pollen grains have wings?
they help with wind dispersal
What is the ploidy of tissue that nourishes a gymnosperm embryo?
haploid
Describe double fertilization
one sperm fertilizes the egg cell to form a zygote, the other sperm fuses with 2 polar nuclei to form an endosperm
What is the ploidy of tissue that nourishes an angiosperm embryo?
triploid
What happens to young cotyledons as a young seedling grows?
they absorb nutrients from the gameophyte tissue
what is a stamen
male reproductive structure. contains filament anther and pollen
what is a pistil
female reproductive structure. contains stigma, style, and ovary.
what is the phylum of moss
Bryophyta
what is the phylum of ferns
Pteridophyta
what is the phylum of gymnosperms
Coniferophyta
what is the phylum of angiosperms
Anthophyta
