🌱BIO153 TT1 Notes

Horizontal gene transfer

 the movement of genetic material between organisms that is not through the transmission of DNA from parent to offspring

Taxonomy

classification of organisms through naming and grouping

Phylogeny

the study of evolutionary relationships between organisms 

Conservation ecology

 the study of how to protect the Earth's ecosystems, biodiversity, and natural resources through sustainable management and practices

Epidemic

 significant rise in occurrence of a disease, above the rate which is normally expected within a population 

Pandemic

epidemic on a global scale (more than one continent) 

MRSA

Methicillin-resistant Staphylococcus aureus, source of several infections in humans 

Bacteria

free living cells

Virus

non-living collection of molecules, need a host to survive

How do survival mechanisms develop?

as the result of evolution

What are the two basic requirements for survival?

carbon and energy

How is carbon sourced?

from CO2 in the atmosphere

Primary producers

organisms that produce their own food through photosynthesis (converting CO2 into sugars) and form the base of the food chain

How are sugars produced by plants passed through the food chain?

by organisms consuming the plants

What is carbon used to make?

organic molecules

How is CO2 released from organic molecules?

through respiration and decomposition

Autotroph

obtain energy from non living sources such as CO2 and sunlight

Phototroph

use light as an energy source through photosynthesis 

Photoautotroph

uses light energy to make organic molecules from CO2 (cyanobacteria, algae, plants)

Heterotroph

obtain energy from consuming other organisms

Chemotroph

obtain energy stored in chemical reactions by oxidizing electron donors in their environments

Chemoheterotroph

 consume organic carbon made by photoautotrophs (majority of fungi and animals, some heterotrophic microbes such as E.Coli)

Prokaryotic

cells without a nucleus and membrane-bound organelles 

Eukaryotic

cells with a nucleus and organelles

How is binomial nomenclature formatted in text?

The first letter of the genus name is capitalized and the entire name is italicized

How is binomial nomenclature formatted in handwriting?

underline the entire name

Which taxa are written in non-italics?

All of them except for genus/species

What is the mnemonic for hierarchical classification in taxonomy?

Dumb King Philip Cries Out For Goodness Sake

What are two things that a phylogenetic tree shows?

how organisms are connected and their pattern of descent

What does a phylogenetic tree NOT infer?

that a taxon evolved from a neighboring taxon

Branch point

the point on a phylogenetic tree where the common ancestor diverges into different species

Dichotomy

a branch point where the common ancestor diverges into exactly two lineages

Polytomy

 a speciation event showing a common ancestor diverging into more than two species at once

Root of the tree

represents common ancestor of all taxa in the tree

Sister taxa

organisms that share an immediate common ancestor that is not shared by any other group 

Basal taxon

outlier group that diverges from all other members of the tree early in the history of the group and has not branched out

Cladistics

philosophical approach that states that organisms should be classified using ancestral relationship as the primary structure (eg. cheetahs are considered cats because it shares common ancestry with other cats) 

Phylogram

a type of phylogenetic tree where the length of branches correspond to the amount of evolutionary change or genetic distance between species

What do the branch points on a phylogram correspond to?

the time when speciation occurred

What are three physical traits used to classify organisms?

morphological, biochemical, and genetic

Homology

similar traits in organisms shared through common ancestry (eg. mammals producing milk)

Analogy

 similar traits in organisms without common ancestry

Orthologous genes

common ancestor diverges into two species, both species inherit the same genes from their ancestor, and the homologous genes can now begin to evolve differently

(homologous genes found in different species)

Paralogous genes

a gene makes a copy of itself within the same species, and the two copies of genes can begin to evolve differently

(homologous genes found in the same species)

Clade

a group of organisms that share a common ancestor and all of its descendants, used to refer to immediate relatedness

Monophyletic group

a clade where all members are descendants of their most recent common ancestor 

Paraphyletic group

a clade where all members are descendants of their most recent common ancestor, but there are more descendants of that ancestor which were not included

Polyphyletic group

a clade which includes members belonging to a different evolutionary lineage

what is the difference between a phylogram and a cladogram?

a cladogram does not show the amount of time between generations

maximum parsimony

states that phylogeny trees with the fewest evolutionary relationships are the most preferred

What does the carbon cycle need to keep running?

energy from an external source

Molecular clock

assumes that the time of evolution corresponds to the number of mutations you find between homologous genes

Derived characteristic

traits that appear in the most recent common ancestor

Ancestral characteristic

traits that are inherited from most recent ancestors

What is the difference between paralogous genes and orthologous genes?

Paralogous genes arise from gene duplication and are found in the same species, orthologous genes arise from speciation and are found in different species.