Midterm 1 Flashcards
(143 cards)
1
Q
What are the 5 steps to the scientific method
A
- Make observations
- Form a question (has to be testable)
- Propose a hypothesis (has to be testable and falsifiable)
- Test your hypothesis (with experimental manipulation)
- Asses: reject or accept all or part of the hypothesis. The start over again at step 1
2
Q
What’s a testable question?
A
A testable question is one that’ll allow you to set up an experiment to learn the answer and should be measurable
3
Q
What’s the best and easiest way to turn a question into a hypothesis?
A
By forming an “If..then…because” statement
4
Q
Does science always go through the steps of the scientific method?
A
It often doesn’t exactly go through the steps of the scientific method as science often involves luck and surprises. The scientific method steps often also don’t always go in the usual order
5
Q
What are some common issues with data collection?
A
- Correlation vs Causation
- Sample size
- Sample bias
- Internal & External validity
6
Q
Does correlation = causation?
A
No, a correlation just means there’s a relationship between 2 variables but it does not necessarily mean that one causes the other.
Things that are correlated can be causally related but we can’t assume that they’re causal from their correlation.
Often there is a 3rd variable influencing the 2 variables in the correlation which could be the cause for the relationship.
7
Q
What’s an issue that could arise with sample size in data collection?
A
Only using one example or a sample size of 1 or a very small sample size to describe a phenomena/situation (ex: only tossing a coin once) -> not sufficient enough to properly describe
8
Q
What’s an issue that could arise with a correlational study in data collection?
A
People will sometimes assume that correlation = causation
9
Q
Describe the issue of sampling bias in data collection
A
Instead of having a representation of various groups, you sample just from one group or another
10
Q
How does a study have internal validity?
A
If it is well-designed (so there’s a reasonable sample size and the researched is manipulating the right variables) and if it’s free from biases or confounds
11
Q
What are examples in a study that demonstrate that it has internal validity?
A
- The same selection criteria is applied to everyone
- The study is double blind
12
Q
What does a study being double blind mean?
A
When the participants in a study don’t know what group they’re in or what treatment they got
13
Q
What are viruses made of (what’s their basic construction)?
A
They’re made of genetic material (bundles of RNA and DNA) covered in layers of proteins and lipids
14
Q
What is the genetic material of a virus used for?
A
Viruses use their genetic material to make copies and pass their genes along
15
Q
How does a study have external validity?
A
If it’s not too specialized relative to the general population. If it is representative of the general population and has more diversity
16
Q
What are questions to ask yourself regarding scientific data visualization/presentation?
A
- Any irregularjities with the y-axis?
- What data are included?
- What’s being compared?
- What’s being plotted?
- Who’s paying for it/who funded the study?
17
Q
What are issues that could occur in data presentation regarding the y-axis?
A
Manipulation of the scale of the y-axis to make a particular point (making differences in data seem very large or very small)
18
Q
What are issues that could occur in data presentation regarding the data that’s included?
A
A headline might make you jump to conclusions before actually exploring the data and noticing what’s creating the illusion that the headline is correct
19
Q
What are issues that could occur in data presentation regarding what’s being compared?
A
Something can seem big when compared to something smaller or can seem small when compared to something much bigger
20
Q
What are issues that could occur in data presentation regarding who’s funding/paying for the study?
A
- Biases can be involved and could manipulate how the data is presented
- Government or Unbiased Sources are usually good
- Industry or Partisan sources are usually bad
21
Q
What makes a good science media source?
A
- Clear links/reference to original research
- Description of the data (how it was collected not just interpretation)
- Interviews with the authors of the study
- Interviews with other scientists not involved in the study
22
Q
What’s diversity?
A
Differences between living things
23
Q
What’s the broadest biological diversity category?
A
Alive VS not alive
24
Q
What is life capable of?
A
- Reproduction
- Growth
- Functional activity
- Adaptation
25
What's considered functional activity in lively beings?
- Movement
- Response to stimuli
- Metabolism
- Catabolism
- Excretion
26
What's adaptation?
Change over time in response to the environment
27
Do things need to have all 4 of the characteristics to being alive to be considered alive?
Yes, having only one characteristic still means you're not alive
28
What's an example of something that's alive?
A coral
29
What's some examples of things that are not alive?
- A rock
- A prion
- A virus
30
Can viruses reproduce?
Viruses can't reproduce but they can use a host machinery within the cells they infect to copy/replicate themselves
31
What's biological diversity?
The variety within & among living species
32
How are organisms classified?
We divide them up into a series of different hierarchical groups
33
What are the broadest taxonomic categories, after life?
Domains and Kingdoms
34
What do kingdoms group together?
All forms of life having certain fundamental characteristics in common
35
What are species?
A group of individuals that regularly breed together
36
Who is known as the father of modern taxonomy?
Carl Linneaus
37
How did Carl Linneaus initially classify things
He classified them into plants, animals and minerals
38
What classification system did scientists introduce in 1969?
A classification system of 5 kingdoms (plants, animals, fungi, protista, bacteria) which categorized organisms according to cell type and method of obtaining energy
39
What 6th kingdom appeared with the emergence of molecular characterization
Archaea
40
What are the 3 domains of the 6 kingdoms of organisms?
- Eukarya
- Bacteria
- Archaea
Bacteria and archaea being grouped together as prokarya
41
What is prokarya?
- Made up of bacteria and archaea
- Single-celled and don't have membrane bound organelles
42
What is eukarya?
- Made up of plants, animals, fungi, protista
- Single or multicellular and have membrane bound organelles
43
What are the functions of membranes?
They keep the things inside cells organized
44
What are membrane bound organelles?
Things inside the cells like mitochondria and chloroplasts
45
List the different hierarchical/classification groups for organisms from the broadest to the narrowest category
- Life
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
46
Describe bacteria and archaea
- Single-celled organisms
- Their cells are small (no membrane bound organelles)
- Numerous
- Can be extremely adaptable (live in harsh environments)
47
Describe protists
- Mostly single-celled
- Diversity of lifestyles (plant-like types, fungus-like types & animal-like types)
48
Describe plants
- Multicellular
- Make their own food with chloroplasts
- Largely stationary
49
Describe fungi
- Multicellular
- Rely on other organisms for food & absorb things from the ground
- Reproduce by spores
50
Describe animals
- Multicellular
- Rely on other organisms for food
- Mobile for at least part of their life cycle
51
What do domains correspond to?
Domains correspond to divergences that happened very early in life's history
52
DNA and RNA sequences change over time as a result of what?
Mutations
53
How does the nucleus-first hypothesis explain how we went from prokaryote to eukaryote?
1. The prokaryote acquired a nucleus by absorbing one
2. The prokaryote then acquired mitochondria
3. Finally it acquired chloroplasts which explains the emergence of photosynthetic organisms (namely plants)
54
What's endosymbiosis?
When one ancestral prokaryote engulfed another prokaryote
55
Who put forward the theory of evolution by natural selection?
Charles Darwin and Alfred Wallace
56
What animals did Charles Darwin notice were different during his trip to the Galapagos Islands
- Iguanas
- Finches
- Tortoises
57
What did Alfred Wallace conclude after his trip to the Amazon?
That natural barriers can serve to separate species (islands being a great example of this)
58
The first insights of evolution by natural selection came from which observations?
1. That there's phenotypic variation
2. That phenotypic variation is heritable
3. There would be a "struggle for existence" as individuals compete for resources
4. That some phenotypes will be more successful in this struggle
5. That individuals with more of the successful phenotype will survive longer and reproduce more
6. There will be more individuals with the successful phenotype in the next generation
59
What's a phenotype?
The observable characteristics of an organism and the expression of genotype
60
What hypothesis did Thomas Malthus make about human populations?
He hypothesized that resources grow linearly and that populations grow exponentially, which would result in populations outgrowing their resources
61
What does an individual's "fitness" mean?
Their ability to survive and reproduce
62
What's a genotype?
Underlying genetic makeup
63
Mammals have how many copies of each gene?
2 copies
64
What are alleles?
Variants of a gene
65
Where do you need variation to have evolution/natural selection?
In the phenotype
66
Is selection intentional?
No, selection is not intentional. It's working with the existing genetic and phenotypic variation that's there as opposed to creating things from scratch
67
What is adaptation a consequence of?
Natural selection. Adaptations are traits that have evolved through natural selection
68
What are the different types of natural selection?
- Stabilizing selection
- Directional Selection
69
What's stabilizing selection?
When you have selection coming in from both directions resulting in most individuals being very close to the mean
70
What's directional selection?
When phenotypes that enhance reproduction and/or survival increase in frequency in subsequent generations
71
What's natural selection?
Heritable phenotypes that enhance reproduction and/or survival and have increased frequency in subsequent generations
72
What's evolution?
Change in the inherited characteristics of biological populations over successive generations
73
Who first identified sexual selection and why?
Charles Darwin and because he had a hard time reconciling natural selection with the range of traits he saw in animals (their traits would make them more attractive to predators)
74
What are the types of sexual selection?
- Intrasexual selection (within a sex)
- Intersexual selection (between the sexes)
75
Describe intrasexual selection
- Within a sex
- When individuals intimidate, deter or defeat same-sex rivals
- There is territory defence, fighting and other direct competition
76
Describe intersexual selection
- Between the sexes
- Individuals make themselves more attractive to the opposite sex
- Driven by mate choice or male preferences
77
How do natural selection and sexual selection interact with each other?
Preferences for particular traits can drive changes in those traits (sexual selection), and natural selection could limit the degree to which sexual selection could push a trait
78
Describe the flashy sex
- Has evolved more elaborate traits (brightly coloured, larger or bigger than others) to impress opposite sex and find a mate
- The sex that has greater variance in reproduction
79
Describe the choosy sex
- More selective about who to mate with
- Greater investment in reproduction
80
Is it true that both males and females can be either choosy or flashy?
Yes, females can be flashy just like males can be flashy. There are some instances where both partners are choosy as they go by biparental care
81
How does Bateman's gradient explain why females tend to be choosy and males flashy
- He hypothesized that there is a relationship between mating success and reproductive success
- Females that can't increase reproductive success with more mating might focus on improving quality of offspring and hence become more choosy and attempting to choose a better mater
82
What are the 3 models to explain sexual selection?
- Direct Benefits
- Good genes/immunocompetence hypothesis
- Sensory bias/sensory exploitation
83
Explain the direct benefits sexual selection model
- Females or males gain something directly from their mate
- Ex: more or healthier offspring, more food, better nesting site, protection from predators
- Effect of this isn't necessarily heritable
84
Explain the good genes/immunocompetence hypothesis sexual selection model
- Some males are genetically more resistant to parasites or infection than other males
- These males would survive longer, have more offspring, be less likely to infect females and produce offspring that would also survive longer and reproduce more
- They need to produce a trait (usually show off an ornament) to show off their health and good genes
85
Explain the sensory bias and sensory exploitation sexual selection model
- Females have a bias for a sensory stimulus which result from the way their brain is set up
- Males then produce a signal that stimulates that part of the female sensory system
- Females usually mate with these males as they're attracted to their signal
- Signal doesn't indicate anything about the male "quality"
86
What's a phylogeny?
a history of organismal lineages as they change through time
87
What's a parsimony?
How to get to the pattern of trait expression in the descendants with the fewest changes
Most parsimonious = fewer changes
Least parsimonious = most changes
88
When did the tungara frog develop a preference for chucks?
The preference for chucks arise prior to the ancestor of all tungara species and hence appeared before chucks were in the vocal repertoire of the tungara frog
89
Why would ancestral females prefer chucks?
- Has to do with their auditory system and the way their ears are set up
- Frogs have 2 cochleas
- One part of the cochlea is especially sensitive to low frequencies which explains why chucks (which are low in frequency)
maximally excite this part of the ear of female tungara frogs
90
What is the cochlea?
What we use when we have to take in the sounds of different frequencies and turn these into action potentials in our brain
91
Who moved the idea of genetic drift?
Stephen Gould and Richard Lewontin
92
What did Stephen Gould and Richard Lewontin argue about natural selection
They argued that not every trait in species is an adaptation
93
How can we show that evolution is happening?
- Sexual selection
- Natural selection
- Genetic drift
94
What's the Hardy-Weinberg Equilibrium?
An equation that we can use to predict the frequency of genotypes from one generation to the next
95
What happens when you combine alleles in different ways?
You get different genotypes which then lead to different phenotypes
96
What does homozygous mean?
2 of the same allele (ex: GG or gg)
97
What does heterozygous mean?
2 different alleles (ex: Gg)
98
What does genetic drift mean?
- Evolution by chance/random evolution
- Effects are random
- Effects are stronger in small populations
99
What are 2 ways that genetic drift could result in big changes?
- Genetic Bottleneck
- Founder Effect
100
Describe genetic bottleneck
- An extreme example of drift where an event results in a big decrease in population size and genetic diversity
- You can get dramatic changes in allele frequency
- New population can look very different from original population
101
Describe Founder Effect
- When a few individuals randomly end up somewhere new (ex: on an island)
- Results in decrease in population size and genetic diversity
- Natural barriers separate these individuals from their population which prevents gene flow between them and their original population
- Leads to changes in allele frequencies
102
What's speciation?
- It occurs when gene pools are separated, gene flow is restricted and populations diverge genetically over time
- Can result from genetic drift, natural selection, sexual selection
103
Can different species mate with each other?
Yes, but they either won't be able to produce offspring or they will produce offspring that is neither viable nor fertile
104
What's reproductive isolation?
Mechanisms that prevent gene flow between members of different species
These mechanisms can be pre-zygotic or post-zygotic
105
What's a zygote?
The cell formed by the joining of 2 gametes (ex: egg & sperm)
106
What are pre-zygotic mechanisms?
- Any mechanisms that prevent egg & sperm from fusing together (any mechanism prior to this fusion)
- They do so by preventing interactions, mating or actual union of gametes
107
What are post-zygotic mechanisms?
Anything that happens after the fusion of egg & sperm
108
List the pre-zygotic isolating mechanisms
- Habitat isolation
- Temporal Isolation
- Behavioural isolation
- Mechanical isolation
- Gametic isolation
109
Explain habitat pre-zygotic isolation?
Two species living in different environments and hence never encountering each other
110
Explain temporal pre-zygotic isolation?
Two species breed at different times in the year
111
When does post-zygotic isolation occur?
- After the egg and sperm have fused and formed a zygote
- The zygote either doesn't survive or can't reproduce
112
List the post-zygotic isolating mechanisms
- Hybrid Inviability (offspring don't survive)
- Hybrid Infertility (offspring aren't fertile)
113
How does reproductive isolation happen?
- Through allopatric speciation (physical isolation)
- From being in different environments species can become very different which could lead to them not being able to reproduce or recognize each other
114
What are the 3 categories of symbiosis?
- Parasitism
- Commensalism
- Mutualism
115
What's parasitism?
a relationship between individuals where one individual benefits to the harm of the other
116
What's commensalism?
a relationship between individuals where one individual benefits and the other is unaffected
117
What's mutualism?
a relationship between individuals where both benefit from it
118
The interaction between humans and bacteria falls under what category of symbiosis?
Mutualism
119
What's a microbiome?
The totality of microbes in an environment
120
Why is bacteria useful in humans?
It influences:
- Metabolism
- Physiology
- Maturation of the immune system
- Energy balance
- Susceptibility to disease
- Behaviour
121
How early do humans start acquiring bacteria?
When in the uterus
122
What part of our body works great in repopulating our gut with useful bacteria?
The appendix
123
What are issues that come from being more likely to encounter bacteria due to urbanization?
- Encountering unfamiliar bacteria that doesn't interact well with your microbiome (ex: cholera)
- Getting good bacteria in the wrong place which leads to diseases (ex: pneumonia)
124
What kind of places are most susceptible to contracting cholera?
Places with poor sanitation and challenges with their infrastructure
125
When did antibiotics emerge?
When Alexander Fleming discovered penicillin from some mold in 1928
126
When did the first antibiotic resistant strain emerge?
1942/1943, the same year or a year after penicillin started being used widespread (used during WW2)
127
What are the 3 classes of antibiotics?
- Cell wall synthesis
- Nucleic acid synthesis
- Protein synthesis
128
What are ways that bacteria are antibiotic resistant?
- Drug modification
- Drug degradation
- Reduced drug accumulation within the bacteria
129
How can bacteria gain antibiotic resistant genes?
- From another bacteria (horizontal transfer)
- From viruses
- From dead bacteria
- From the environment
- Bacteria pass on resistant genes when they reproduce (by fission)
130
What is horizontal transfer in bacterias?
Plasmids are copied and transferred to other bacteria through a pilus
131
How do genes for antibiotic resistance spread rapidly?
- They can spread in the absence of reproduction
- Reproduction is asexual
- Reproduction is fast
- Generation time for bacteria is quick
132
What does this rapid spread of antibiotic resistance for genes result in?
Plenty of opportunity for mutation
133
What's the semisynthetic version of penicillin that created the MRSA resistant bacteria?
Methicillin
134
Are antibiotics effective against viruses?
No, they're only effective against bacteria
135
What do vaccines do to our bodies?
They train our immune system to recognize bacteria and infections
136
What courses of action do we take if we notice the appearance of a virus in humans with pandemic potentials?
- Quickly produce a vaccine
- Limit exposure and transmission
137
What are we attemtpting to do with vaccines?
Create heard immunity
138
What's heard immunity?
when a large part of a community is immune, the virus has limited hosts.
139
What's viral chatter?
A hint that there are viruses that are bubbling up below the surface that we might need to pay attention to
140
What do species do when faced with selection pressure due to climate change?
1. Show phenotypic plasticity
2. Evolve or adapt
3. Go extinct
141
What's phenotypic plasticity?
Some organisms can alter their phenotypes and express different traits depending on the environmental conditions
142
What's trophic mismatch?
when the timing of migration and breeding need to coordinate with the timing of food availability
143
What's the lombard effect?
- Humans will increase the amplitude and frequency of their speech when ambient noises increase
- Birds do this too with urban noise pollution
