MIDTERM 1 KEY TERMS AND PRACTICE Flashcards
1What does LUCA stand for and what is its importance?
LUCA stands for last universal common ancestor.
- The current hypothesis is that LUCA existed about 4 billion years ago.
- LUCA is the last common ancestor of all cellular life which exists on earth today. After billions of years of evolution, LUCA diverged into the different forms of life through natural selection
what is horizontal gene transfer?
horizontal gene transfer is the movement fo genetic material between organisms in a way that does not invlve traditional reproduction. the significance of this is that it plays a huge role in the spreading of antibiotic resistance genes among bacteria
what is taxonomy and phylogeny?
Taxonomy: study organisms, name them, and put them into similar groups. (example: domain, kingdom, phylum,class, order, family, genus, species…)
Phylogeny: Deduce evolutionary relationships between organisms and put them into similar groups (example: the evolutionary relationship between humans and other primates.
what is conservation ecology?
conservation ecology is the study of how to protect and restore biodiversity, ecosystems and natural resources. it focuses on understanding the interactions between species, their environments, and human activiites to prevent species extinction and habitat destruction.
organisms are constantly interacting and we cannot intervene with the system without knowing of their interactions!
epidemic and pandemics
epidemic: a significant rise in disease above the rate which is normally expected in a local population
pandemic: a global epidemic usually one or more than one continent
what is SARS-COV-2 and COVID-19
the covid-19 pandemic in early 2020s was caused by the coronavirus.
- SARS-CoV-2 is the name of the virus(severe acute respiratory syndrome coronavirus 2)
- covid-19 is the symptom caused by the virus coronavirus disease. it is spiked protein sticks out and makes the virus look liek a sun
not the first coronavirus weve dealt with
There are seven different human host coronavirus are known to date including SARS-CoV-2
Four of these are not as problematic and been recognized since the early 1960s
Causative agent of COVID 19
About 61.2 million cases as of sept 2022, globally
6.2 million deaths, roughly 1% fatality rate
Tremendous damage to human society! A global pandemic!
SARS-CoV-1?
- severe acute respiratory syndrome coronavirus 1
Causative agent of 2002-2004 SARS epidemic
About 8000 documented cases across 29 countries
10% fatality rate
MERS-CoV?
- middle eastern respiratory syndrome coronavirus
- first reported in 2012 and multiple outbreaks since then
about 2500 cases documented until july 2022 roughly 30 countries with up to 35% fatality rate
mammals vs marsupials
Mammals
Nurture their young ling by feeding milk and have three groups
monotreme(lay eggs), marsupial, and placental.
Marsupials give early birth and nurture their youngling in theri bags for an extended period of time (like a kangaroo!)
They diverged from the other non-sacked mammals in early mammalian evolution!
what do primary producers do
Primary producers CONVERT CO2 into sugars (liek a tree)
what do other organisms do to the primary producers
Other organisms consume sugars produced by primary producers(like a deer), then consumers of the other organisms are like wolves
CO released from organic molecules through respiration and decomposition!
Energy is lost at EVERY STEP throughout this cycle
No such thing as 100% energy conservation
Carbon cycle cannot be closed or it’ll run out of energy!
what is geothermal energy vs sunlight
Geothermal energy is basically heat energy stored within earth’s interior. It is a renewable energy source that comes from earth’s core, when temperatures are high due to radioactive decay and residual heat.
It relates to sunlight as they are BOTH:
Renewable energy (naturally replenished and sustainable)
Sunlight influences surface level geothermal heat pumps
Summary: geothermal comes from inside earth, solar comes from sun!
Sunlight is the major source of energy which is supporting organisms from outside the earth.
Overall, we categorize organisms by:
How do they obtain energy(can they use sunlight directly or not?)
How do they obtain carbon(can they use CO2 directly or not?)
what are phototroph and examples of them? what are autotrophs and what are examples of them? what are photoautotrophs?
phototroph: uses light as energy source. example, plants, algae, and cyanobacteria!
autotroph: uses CO2 as carbon source plants and algae and cyanobacteria
photoautotrophs use light to make organic chemicals from CO2 (their fixed carbon then gets used to build their body).
Some produce O2 as a byproduct of photosynthesis
- cyanobacteria, algae, and plants are all photoautotrophs, meaning they use light energy to convert CO2 into organic molecules through photosynthesis!
How do they work?:
Absorb light energy (use chlorophyll or similar pigments) to capture sunlight
Fix carbon: convert CO2 into glucose using calvin cycle
Build their body: use organic molecules to grow and produce biomass!
what are chemotroph and heterotrophs? what are chemoheterotrophs?
Chemotroph: use chemicals (such as organic ones) as an energy source
Heterotroph: use organic molecules as a carbon source
Chemoheterotrophs consume organic carbon made by photoautotrophs
Vast majority of fungi and animals are chemoheterotrophs as well as heterotrophic microbes like E. Coli.
(ex, white tailed deer, eastern coyote, animals, fungi, etc.)
prokaryotes vs eukaryotes and unicellular vs multi cellular
Eukaryotes: Cells WITH a nucleus plus organelles. (compartmentalization of cellular processes such as storage of genetic material, energy production and photosynthesis
Prokaryotes: cells WITHOUT a nucleus and other membrane-bound organelles
UNICELLULAR ORGANISMS
(one cell does essentially everything, bacteria, protists, yeast…)
MULTICELLULAR ORGANISMS
(many cells work together with specialised functions: humans, trees, fungi)
what are some rules for binomial nomenclature?
The species name includes both names of the binomial(for example, cougar is Puma concolor, not just concolor!
Both genus and species names are ITALICIZED and underlined if handwriting
First letter of Genus is ALWAYS capitalised!
Genus name can be abbreviated after the first appearance in the paper, report, or article! So like, Puma concolor can be P. Concolor later on…
what is each layer of classifcation (domain kingdom phylum) called?
taxon, plural taxa
what is the ICZN, ICN, ICNP and ICTV responsible for
International code of zoological nomenclature (ICZN) ← naming animals!
International code of Nomenclature for algae, fungi, and plants (ICN OR ICNafp)
International code of nomenclature of prokaryotes (ICNP) ← naming bacteria and archaea!
International committee on taxonomy of viruses (ICTV) ← name viruses!
what is cladistics and how does it relate to taxonomy and phylogeny
Cladistics is an approach for systematics saying that organisms should be classified using ancestral relationships as the primary criteria.
Cladistics refines taxonomy by ensuring that classifications reflect evolutionary history, not just physical similarities.
Cladistics builds phylogenetic trees that show these relationships based on common ancestry.
whats a branch point? dichotomy?
a branch point is the common ancestor diverging into two different species
dichotomy is a branch point whwere the common ancestor diverges into exactly two lineages
what is sister taxa and basal taxa?
sister taxa is two groups of organisms that shae an immeadiate common ancestor and are eachothers closest relative (diverge from same branch point, more closely related to eachother than any other group)
basal taxon: the earliest diverging lineage in phylogenetic tree, meaning it split off first from common ancestor
what are some properties of phylogenetic trees
Property 1: a phylogenetic tree ONLY shows how each organism is connected to one another UNLESS otherwise noted.
Other features of the tree, such as the length of each branch ,contain NO ADDITIONAL INFO like the degree of similarity between organisms UNLESS otherwise noted.
Therefore, the basic phylogenetic tree can be drawn in different shapes without changing its meaning!
Property 2: the tree shows patterns of descent. This may not always correspond how similar organisms look or behave
cetaceans(whales/dolphins) and seals look similar, as they are both marine mammals. However, cetaceans and seals do not share an immediate common ancestor.
Property 3: the tree does not infer that a taxon evolved from a neighboring taxon. (so in the lizard/chimp/human tree it doesn’t mean they evolved straight from the neighbour, what is suggests is that once upon a time, there was a common ancestor of chimps and humans but they diverged into those diff species later on)
The common ancestor of chimps and humans is different and does not exist today!
cladograms vs phylograms
A basic phylogenetic tree only shows how each organisms are connected to one another UNLESS otherwise noted
PHYLOGRAMS: phylogenetic tree which addition information are represented, typically by the lengths of each branch
Branch length may correspond to the amount of genetic change, amount of time, etc
cladogram: a tree diagram that shows the relationships between organisms based on shared characteristics, but does not show evolutionary time or genetic differences. phylograms do.
