Evolution is Happening

Question 1

who is georges cuvier and what is he known for?

Answer 1

french scientist that studied fossils

Question 2

strata

Answer 2

specific layers of rock that can be used to infer the age of the layer

Question 3

who is lamark and what is he known for?

Answer 3

french biologist that recognized species do change over time

he is known for his incorrect mechanism of evolution –> he believed species changed over evolutionary time

Question 4

who is charles darwin and what is he known for?

Answer 4

known to have discovered the theory of evolution by natural selection

he believed in unity –> many species resemble one another and all life is descended from a common ancestor

Question 5

what is diverse modification and give an example

Answer 5

species in different environments are different but may look similar or related

ex. finches on diff islands look the same but are different

Question 6

natural selection

Answer 6

the process through which populations of living organisms adapt and change

–> organisms produce many more offspring than the number to survive
–> organisms must compete to survive

Question 7

heritable

Answer 7

a trait that can be passed down to offspring

Question 8

descent of modification

Answer 8

traits are passed down from generation to generation and sometimes undergo changes/ modifications over time

Question 9

phenotype

Answer 9

physical characteristics

i.e. shape, size, behaviour and functoin

Question 10

genotype

Answer 10

specific combo of genes and alleles

Question 11

what are the two requirements of a genotype

Answer 11

1. traits must be expressed (genetic makeup)
2. traits must be heritable

Question 12

what are the sources of variation?

Answer 12

mutation and meiosis

Question 13

what are the 3 different mechanisms of meiosis

Answer 13

recombination: chromosomes cross and exchange sections

independent assortment: offpsring receive one of each chromosome at random from the parent

fertilization: combining two parental genomes

Question 14

what are agents of selection and give an example

Answer 14

environmental feature that consistently produces differential survival

ex: heat, drought, salinity

Question 15

what are selective pressures? what are the two types? give examples

Answer 15

selective pressure is how intensely the environment is selecting a trait

1. biotic: living pressures
   ex. prey, predators
2. abiotic: non-living pressures
   ex. rainfall, temperature, nutrients

Question 16

fossil records

Answer 16

evidence for evolution where you can see species change gradually through time

Question 17

comparative embryology

Answer 17

distantly related species have similar embryonic stages (due to shared ancestry)

Question 18

biogeography

Answer 18

the distribution of related species matches evolutionary theory

Question 19

vestigial structures

Answer 19

some traits have no current function and are slowly disappearing

Question 20

genomics

Answer 20

DNA is more similar between closely related species

Question 21

artificial selection

Answer 21

selectively bred traits to produce desired phenotypes

Question 22

resistance in pests

Answer 22

pests have become resistance to our methods of control

Question 23

viruses

Answer 23

infectious particles made up of nucleic acid and a protein coat (capsid)
- extremely small and simple particles
- contains one or more RNA or DNA molecules
- can be enveloped in a membrane or not
- requires another organism in order to replicate

Question 24

do viruses follow the central dogma: DNA–>RNA–>protein

Answer 24

some but not all

Question 25

do viruses contain genetic information in DNA

Answer 25

some but not all

Question 26

do viruses have a metabolism

Answer 26

no

Question 27

do viruses have membranes made of lipids

Answer 27

no

Question 28

do viruses respond to stimuli

Answer 28

yes

Question 29

host

Answer 29

the organism infected with the virus

Question 30

host range

Answer 30

number of different species a virus can infect

Question 31

specialist

Answer 31

viruses that can infect only a single host species

Question 32

generalist

Answer 32

viruses that have a ride range of hosts

Question 33

what are the steps to viral replication?

Answer 33

1. virus attaches to the outside of host call 2. virus injects nucleic acid into host 3. virus hijacks the cell machinery to replicate its own components 4. viral components come together to form new viruses 5. virus is ejected from cell to infect other hosts

Question 34

lytic cycle

Answer 34

the final step in viral replication bursts open and kills host cell - virulent phages

Question 35

lysogenic cycle

Answer 35

viruses do not kill the host cell and continues to be produced by host cell - temperate phages

Question 36

what is HIV?

Answer 36

human immunodeficiency virus, which is an RNA virus but is a retrovirus

Question 37

what are the steps to how retroviruses work?

Answer 37

1. viral capsid, containing HIV RNA and viral proteins attaches and fuses to the cell membrane 2. capsid contents are released into the cytoplasm 3. HIV codes for reverse transcriptase 4. HIV cDNA is integrated into the host cell genome by viral integrase 5. the host machinery for transciption and translation is hijacked by the virus 6. new, replicated, HIV RNAs and long strand proteins are packaged into viral capsides 7. viral protease cuts bonds between the long strnad proteins to form active HIV proteins/enzymes

Question 38

do retroviruses have high mutation rates?

Answer 38

they have high mutation rates because reverse transcriptase lacks proofreading activity (removal of incorrectly incorporated nucleotides from the primer terminus before further primer extension)

Question 39

reverse transcriptase

Answer 39

an enzyme that uses RNA as a template to make DNA

Question 40

integrase

Answer 40

an enzyme that cuts host DNA

Question 41

antivirals

Answer 41

has a high number of side effects compared to antibiotics because viruses rely on host immune system --> try to target virus specific processes

Question 42

why does the effectiveness of antiviral therapies decrease over time?

Answer 42

- they apply a selection pressure (certain phenotype more favourable) - random mutations - over time, the viral population becomes entirely resistant

Question 43

AZT

Answer 43

a drug that is a nucleoside analog and gets mistaken as thymidine bc they're shaped very similarly

Question 44

zoonotic disease

Answer 44

a disease that can spread and are shared between animals and humans

Question 45

why is identifying pathogen (virus) reservoirs (infectious host organism) difficult

Answer 45

each pathogen (virus) has a unique reservoir

Question 46

endemic

Answer 46

when a pathogen is existing in its natural area or within its natural organism at a steady state level

Question 47

epidemic

Answer 47

a widespread occurrence of a particular pathogen within a short period of time

Question 48

pandemic

Answer 48

a fast, widespread occurrence of a particular pathogen over a significantly large area (multiple countries or across continents)

Question 49

scientific theory

Answer 49

coherent set of testable hypothesis that attempt to explain factors about the natural world - must be testable!!!

Question 50

variational

Answer 50

species evolving over generational time

Question 51

transformational

Answer 51

an individual growing over one lifetime

Question 52

unfalsifiable assertion

Answer 52

there are no cases under which it could be false - not having enough proof