Lecture 2 Flashcards
what is diversity
= differences between living things
what is the definition of life
life is capable of:
growth
reproduction
functional activity: movement, response to stimuli, metabolism, catabolism, excretion…
adaption: change over time in response to the environment
is a rock alive
a rock growth no reproductivity no activity no adaptation no
no
is a prion alive
a prion growth no reproductivity no activity no adaptation no
no
is a coral alive
a coral growth yes reproductivity yes activity yes adaptation yes
yes
is a virus alive
a virus growth no reproductivity uses host machinery activity no (don’t respond to stimuli, don’t have their own metabolism) adaptation yes
accepted as not alive
what is a prion
PrPc^c—a normal protein
PrP^sc—disease-causing form of prion protein
infectious agents
composed of a protein that can fold in multiple ways
one way of folding is transmissible to other prior portions
what disease might a prion cause
mad cow
aka Creutzfeldt-Jakob
what is a virus
infection agents
composed of a handful of parts
they use machinery within the cells thy infect to replicate
highly adaptable
what is biological diversity
scientists refer to the variety within and among living species as biological diversity
what is a kingdom
aka domains, taxonomic category of the highest rank, each kingdom groups together all forms of life having certain fundamental characteristics in common
what is a species
a group of individuals that regularly breed together
until about 50 years ago, how were organisms classifies
organisms were classified based on observations of behaviour, shape, size, etc
what was is the father of modern taxonomy
Carl linneaus
what did carl linnaeus do
classified plants, animals, minerals
what did linnaeus conclude about plants
organisms that were immobile and apparently made their own food
what did linnaeus conclude about animals
organisms that could move about and relied on other organisms for food
how many kingdoms were there in 1969
5 kingdoms
in 1969 how did scientist organize organisms
categorized organisms according to cell type and method of obtaining energy
what were/are the 5 kingdoms
plants, animals, fungi, protista, bacteria
what changed with the addition of molecular characteristics
later adapted to 6 kingdoms and 3 domains with the addition of molecular characteristics
what are the 3 domains
bacteria, archaea and eukaryotes
what does the term prokarya include
prokarya is a term for both bacteria and archaea
what are Prokarya
is further broken down into; bacteria, archaea
single celled and do not have membrane bound organelles
what are Eukarya
plants, animals, fungi, protesta
multicellular and have membrane bound organelle
what is significant about the organelles of prokarya
single celled and do not have membrane bound organelles
what is significant about the organelles of Eukarya
multicellular and have membrane bound organelle
what are traits of Prokarya— Bacteria
mostly single-celled forms
some form colonies or filaments
cell wall contains peptidoglycan (this is one thing that takes them different from archeae)
diverse lifestyles, some can make their own food
what are traits of Prokarya— archaea
mostly single-celled forms
cell wall lacks peptidoglycan (this is one thing that makes them different from bacteria)
similar to eukaryotes in genome organization
many species live in extreme environments
what are traits of Eukarya— plants
multicellular
make own food
largely stationary
what are traits of Eukarya— fungi
multicellular
rely on other organisms for food reproduced by spores
body made up of thin ailments called hyphae
what are traits of Eukarya— animals
multicellular
rely on other organisms for food
mobile for at least part of life
what are the origin of divergence
DNA and RNA sequences change over time as a result of mutations
what are Bacteria and Archaea
single celled organisms, free living or colonial
cells are small, do not have membrane bound organelles (e.g. a nucleus, mitochondria, or chloroplasts)
numerous; there are more bacteria in your mouth than the number of humans who have ever lived
extremely adaptable; live in harsh environments
what was the ver first organism
prokaryote
what was the Sequence of events led to the Eukaryotes— from prokaryote to eukaryote in 3 steps
step 1— acquiring a nucleus
step 2— acquiring mitochondria (chemical energy production)
(all protists, plants, animals, fungi)
step 3— acquiring chloroplasts (light based energy production)
all photosynthetic organisms (plants, some protists)
how did the mitochondria get into the cell
was absorbed
Domain Eularya— protists
what are the animal cells like
animal-like
ciliates (hair-like)
flagellates (long tail)
amoebas (pseudopodia)
Domain Eularya— protists
what are the plant cells like
diatoms (glass shell) brown algae (multicellular) green algae (uni, multi-cellular)
Domain Eularya— what were the origins of multicellularity
slime mold (colonial) brown algae (multicellular) green algae (uni, multicellular)
define evolution—
change over time
define change—
inherited characteristics of a population become different
what are inherited characteristics—
allele frequencies
what are population—
a group of individuals living in the same geographic area
what is time—
usually ling, as in millions of years
what is the official definition of evolution—
change in the inherited characteristics of biological populations over successive generations
what is the study of evolution interested in
HOW and WHY these changes occur
what are 2 mechanisms that evolution can occur
natural selection and genetic drift
what is natural selection
non-random evolution
who came up with natural selection
alfred russel wallace
charles darwin
both independently and (almost) simultaneously came up with the theory of the evolution by natural selection, an idea that was both novel and heretical at the time
what was it that Darwin and Wallace put forward
evolution by natural selection
first insights about evolution by natural selecton came from what
1) there is phenotypic variation
2) Variation is heritable
what is a phenotype
is the observable characteristics of an organism, it’s the expression of the genotype
what does phenotype include
it can include morphology, development, behaviour, even products of behaviour
what is Phenotypic variation—
means that there is variation in the observable characteristics
how do we know Variation is heritable
we know this because of modern genetics
darwin and wallace knew about it from dogs
what did thomas malthus observe
Resources grow LINEARLY
populations grow EXPONENTIALLY
what did malthus argue
malthus argued that without population controls (e.g. reproductive restraint) war, famine and disease would put a ceiling on population growth)
this will lead to a “struggle for existence” as individuals compete for resources
what is the 3rd observation in evolution by natural selection
“struggle for existence” as individuals compete for resources
what are the 4th and 5th points observed for evolution by natural selection
4) some variants will be more successful in this struggle
5) those individuals with such an advantage will survive (longer) and reproduce (more)
what do we call an individual’s ability to survive and reproduce
we call an individual’s ability to survive and reproduce its FITNESS
because the variation is heritable, there will be more of those successful variants in the next generation
selection is acting on what
selection is acting on phenotypes, not genotypes
