Final Bio Exam

How ploidy change in meiosis?

Once two daughter haploid cells are formed in meiosis 1 now meiosis 2 can take place where it converts to four unique daughter cells w/ 23 chromosomes

Meiosis 1 to Meosis 2

diploid (2n) to haploid (n) then haploid to haploid

What makes daughter cells unique?

crossing over, independent assortment, recombination of gamates

Calculate gametes

2^x x=heteoygotes (e.g.,Bb)

Phenotype

3:1

Genotype

1:2:1

How hybrid explains meiosis

The segregation of unlinked genes result in a greater number of games combination which result in crosses. This happens on the opposite chromosomes

Linked genes happen

one the same chromosome

Evolution

change in allele frequency through time

Georges Cuvier

discover extinct species

* established the idea that organisms change through time
* Strata difference

Hutton

idea of uniformitarianism which supports the earth being really old due to the calculation that sedimentary rock forms at a slow rate

Lyell

The principle of geology where he put superposition idea and uniformitarianism together

Lamarck

(disproven) still hd hierarchy ideology but believed that organisms change over time and pass on traits

malthus

population thinking, as population increases agriculture decreases

Darwin was influenced by his own work such as:

His book BMS and his experiments of pigeon breeding

fossil

remaining organism in sedimentary rock

what is fossils found in?

sedimentary rock which replaces carbon with minerals

Are fossil dated?

comparing fossil strata gives us the **relative age**

but

Radiometric dating give up the **absolute age** of the fossil

Why are fossil incomplete?

Due to many organisms not being in an environment where they’re bones don’t get kept in good condition, prey, decomposion, fossils get lost.

Homology

similar traits in two organisms due to common ancestor

How does homology relate to synapomorphy + phylogenetic trees?

Usually organisms share similar traits in a phylogenetic tree due to common ancestor and the phylogenetic tree is a representation of relationships due to common ancestry.

Phylogenetic tree are contructed by synapmorphys which is also where traits are shared between taxa.

Synapmorphies

used to construct phylogenetic trees

* trait that is shared by two or more taxa and derived through evolution

Differential fitness

different individuals in a population that have different fitness

how does understanding homology show the pattern of evolution, while differential fitness shows the process?

Homology shows evolution because it shows a trait being shared through while differential fitness shows how the fit survives to pass on the trait to survive

dominant

appear in both F1 and F2 phase (expressed)

recessive

doesn’t appear in F1 but appears in F2 (expressed later)

Darwins postulate

Variation must exits

traits need to be heritable

more individuals born than survive and reproduced

different fitness

Where do heritable variation originate?

thought mutations

Natural selection, fitness, and adaptation relationship

natural section leads to adaptation which is a trait that increases fitness

How natural variation needed for selection?

Some variation benefit individuals with certain traits that better suit the environment than others

How will population respond to climate change and other treats to biodiversity?

High eugenic variability allows for evolution while low genetic variability will allow extinction

Allele frequency

p+q=1

genotype frequency

p2+2pq+q2=1

Hardy W Assumptions

Mate randomly

Selection is not occurring on population

No drift

No emigration/immigration

No mutations

Directional selection

favors a specific direction

* reduces genetic variation
* Changes average value

Stabilizing selection

The center has the highest fitness and the extremes have low fitness

* no change in average value
* Reduces genetic variation

Disruptive selection

Extreme have higher fitness and the center has lower fitness

* increases genetic variation

Balancing selection

Genetic variation is maintained (fluctuating) usually due to other factors in environment.

Directional relating to Character displacement

when there is symmetric competition it causes the two species to evolve in opposite directions

Sexual selection

favors individuals with traits the organisms has which increases their ability to obtain mate

Natural section differ from sexual selection

natural section lead to differential reproductive success in an environment

Tension with natural section because of sexual selection

specific traits that may attract mates can also attract prey which decreases your fitness

Genetic drift

allele frequency change at random without repeat to fitness

* A person with good genes gets hit by a car
* Reduces genetic variability
* Leads to fixation and loss
* Affect smaller population more

Founder effect

group of individuals immigrated to a different area and established a new population

Genetic Bottle neck

caused by sampling error where a large population experience a sudden reduction in size

Gene flow

when individuals leave a population, joins another, and breeds

* increases genetic diversity
* Random respect to fitness phylogenetic tree

Biological (species concept)

a population that is reproductively isolated from other groups. interbreed is possible.

Morphospecies concept ( Species concept)

species have measurably different anatomical features from other groups

* arise if population are independent and isolated from gene flow

Phylogenetic (species concept)

species as the smallest monophyletic group in a phylogenetic tree

* evolutionary history of population
* Related by common ancestor

Why can there be no single definition of a specie

no concept works for a single species, all or interchange

Allopathic species

formation of new species in population that are geographically isolated from one another. (different place)

Sympatric species

the formation of new species in population that live in the same geographic area. (same place)

Reproductive barriers

Prezygote: prevent different species from mating successfully

Postzygote: offspring dies or do not reproduce

How are phylogenetic tested?

by hypothesis bases on a dataset

Why is no single phylogeny considered absolutely correct?

they are hypothesis

Mass extinction

fate of all species in extinction

* human are the strongest evolutionary factors currently operating at a global scale due to human activities

Sixth Mass extinction

By human impact which is caused by climate change, pollution, and loss of habitation

* causing change that’s too fast to adapt too

How do mass extinction events relate to adaptive radiation

adaptive radiation is a linage rapidly produces many descendants species with a wide range of adaptive forms and new niches

* Extinction events leads to adaptive radiation (a boom of species)

Fossil record

is punctuated by periods of extinction, followed by species over the next few million years

Why were we unable to determine just how vastly diverse bacteria is?

Catch 2: wee only study what we can grow, if we cannot grow it then it didn’t exist

Why is bacteria important for biochemical cycles?

* bacteria produces N2 in atmosphere
* Endosymbiotic theory
* Allow photosynthesis

(bacteria share genes) Transfer by transformation

when bacteria naturally take up DNA from the environment that has been related by lysis (dead cells)

(bacteria share genes) Tranduction

when virus pick up DNA from one prokaryotic cell and transfer it to another cell

(bacteria share genes) Conjugation (sex)

When genetic info is transferred by direct cell-to-cell contract

* bacteria swap directly

Archaea

unicellular prokaryotes distinguished by cells wall made by polysaccharides, plasma, membrane, and ribosomes and RNA

What is Archaea related too?

closely related to eukaryotes than bacteria

Hypothesis regarding origin of life

indeterminable all are everyone common ancestor

Endosymbiotic plants

Theory that mitochondria and chloroplasts evolved from prokaryotes (bacteria) that were engulfed by host cells and taken up a symbiotic extinct in those cells

Endosymbiotic: Cyanobacteria

became chloroplast when it was engulf twice and eventually allowed for photosynthesis to occur in some organisms

Endosymbiotic: Protebacteria

become mitochondria, allowed a lot of ATP production, cellular respiration

Plant Graph

Green Algea: **GA**ly

Moses: **M**arried

Ferns: **F**or

Gymnosperms: **G**ood

Angiosperms: **A**pples

Plant Graph Traits

Stomata: **S**he

Vascular tissue: **V**en**T**s

Seed: **S**o

Flower: **F**requently

Seed adaptation to terrestral environment

1. protective waterproof cover (seed coat)
2. Nutrients and nutrient delivery
3. occurs in absence of water

Amniotic egg

* water proof covering shell
* Nutrients and nutrients delivery system
* Embryo
* Don’t need water to reproduce

What role do plants play in food webs & energy/matter flux in ecosystems

energy flow through photosynthesis due to plants

* plants are also the producers which provide energy in ecosystems through sunlight

Biochemical cycle (C,N,H2O)

The movement of nutrients and other elements between abiotic and biotic factors

What community interact with plants

bottom-up community structures of a food web if remove the bottom it will cause a collapse of species to go extinct at the top

What ecosystem service roles do plant play in?

all foods comes from plants, stabilize soil, and regulate temp.

* cellular respiration
* receive and release light energy
* root systems

Fungi related to mater and energy

unlike humans fungi are saprophytic meaning they eat dead stuff, particularly wood

Fungi are like humans because

if mutilcelluar organisms they are heterotrophs that digest and break down nutrients

Fungi Major role

* play role in carbon cycle which they fixate it by land plants
* Play a role in the nitrogen cycle which they fixate nitrogen to produce N2 +N3

Fungi can be parasitic

symbiotic relationship with other living organisms (+,-)

Fungi can be predatory (+,-)

Some fungi produce hyphae for prey to capture and take nutrients

Fungi can be mutualistic

two organisms work together each benefiting from the relationship

Ex: plants and fungi

Why is fungi sex unique?

Each individual is it’s own sex and can mate with whoever

* reproduction can become asexually or sexually
* Haploid dominate (mitosis)

What are animals

Multicellular; cells lack cells wall but have communication between cells and all differentiate in the jobs hey do inside the organisms

How animals differ from others

Can move, have internal digestion, nervous system, muscles

How are animals the **same** in matters of obtaining energy and reproduction?

Animals are heterotrophs, consume other organisms for energy like fungi

How are animals the **differ** in matters of obtaining energy and reproduction?

animals reproduce sexually and have amniotic eggs

plants produce their own food while we hunt for ours

Basal clade

Is the sponge of all animals (multicellular)

Chordates relating to vertebrates

* Notochord
* dorsal hallow nerve cord
* Pharyngeal slits
* Post-anal tail

what are amniotes?

are clade of tetrapod vertebrates compressing the reptiles, birds, and mammals

Primates classification

hands and feet, nails, and extensive parental care of offspring

Anthropoids classification

humans with forward facing eyes, large brains, and three color visons

Hominids classification

distinguished by large brains size not tail, and exceptionally large brains

Homonins classification

their bipedal (walk on two legs)

Why is humans evolution a radiation and not linear

Humans do not evolve from chimps but we do share a common ancestor with chimps. Humans evolve independently from the same common ancestor from chimps.

* Fossil record support this because it shows that humans had a common ancestor that lived in Africa

Hypothesis of how modern humans relate to one another

modern humans evolved in Africa and spread to other continents, replacing other homospecies

Range

geographic distribution of an organism (where a species can survive)

Niche

Tolerable conditions and the range of resources an organism can use. (the role a specie plays in it’s ecosystem)