All Lectures Flashcards
(116 cards)
1
Q
What is the name of our current Epox
A
Anthropocene
2
Q
What are the 5 problems with counting species
A
- inaccessible habitats
- definition of a species
- cryptic species
- complex life cycles
- sampling bias
3
Q
What is the estimated number of species one earth?
A
8.7 million
4
Q
What percent of terrestrial and marine species is unnamed?
A
86% and 91%
5
Q
true or false: If an organism is in the same class it has to be in the same order? if an organism is in the same family it has to be in the same genus
A
FALSE
FALSE
6
Q
Which of the following are false and why?
a. bacteria are unicellular and prokaryotic
b. bacteria have a cell wall
c. Protista can be unicellular or multicellular
d. Protista can be autotroughs or heterotrophs
e. Fungi are unicellular and heterotrophic
A
e. is false because fungi are multicellular, although they are heterotrophs.
7
Q
Identify what groups are in the 3, 5 and 6 kingdom system
A
3 - bacteria, archea, eukarya
5 - monera, protista, plate, fungi, animalia
6 - bacteria, archea, protistsa, lante, fungi, animalia
8
Q
Provide some reasons for a classfiication system
A
- logical universal names
- allows us to deduce relationships
9
Q
Describe what the difference is between alpha, beta and gamma diversity.
A
alpha diversity is the number of different species in a habitat. Beta diversity is the difference in species between two areas. Gamma diversity is the diversity of a landscape or all areas combined (aka regional diversity)
10
Q
what is an endemic species
A
those species found exclusively in an ecosystem
11
Q
Identify some problems with using species diversity in conservation
A
humans actually introduced many mammals to NZ, so the overall mammal diversity increased. BUT man unique species were lost… So need to focus on those species found exclusively within an ecosystem when dealing with conservation
12
Q
Biodiversity hot spots are based on what 3 aspects?
A
- number of species present
- number of those species found exclusively in an ecosystem (endemism)
- degree of threat they face
13
Q
What are the 4 criteria for natural selection according to darwin?
A
- more individuals are produced each generation than survive to reproduce (reproduction)
- variation
- fitter individuals contribute more offspring to subsequent generations (variation in fitness association with variation of characteristics)
- heredity
14
Q
Fitness is defined as?
A
Probability of reproduction
15
Q
The big band occurred ____ billion years ago.
A
13.75
16
Q
the earth formed __ billion years ago
A
4.54
17
Q
first evidence of cellular life is ____ billion years ago
A
4
18
Q
what is the period before life called
A
hadean earth
19
Q
what are the 3 basic functions needed for life
A
- heredity
- compartmentalise
- metabolism
20
Q
What is the edicaran fauna?
A
before this was only single-celled organisms. now basic multicellular organisms. first animals to be able to move.
21
Q
What occurred in the Cambrian explosion
A
Edicarian fauna died out, modern groups of organisms arose. Appeared quickly with lots of diveristy.
22
Q
What is characteristic of the Ordovician, Silurian and Devonian era’s?
A
- rise in diversity of marine life - fish and amphibians
23
Q
When did the 5 mass extinctions occur
A
- at the end of the ordovian
- end of the late devonian
- end of the permian
- end of the triassic
- end of the creactious
24
Q
what occurred in the carboniferous period?
A
- plants colonised the land and insects diversified
- increase in oxygen
25
what occurred in the Mesozoic era
age of reptiles!!! dinosours, birds, mammals made first appearance, flowers diversifying
26
describe the Cenozoic era
dinosaurs died, mammals and birds flourished
| primates appeared!!
27
What is the order of the 8 era's that tanya covered
1. precambian
2. edicarian fauna
3. cambian explosion
4. ordovian, silurian, devonian
5. carboniferous
6. permian
7. mesozoic
8. cenozoic
28
What is wallace's line
Divides the countries which are once joined together. Groups of organisms on either side of the line resemble those on their side. biogeography as support for evolution.
29
```
Major transitions?
replicating molecules to ____
independent replicators to ___
RNA as gene and enzyme to _______
prokaryotes to ______
asexual to ______
protists to ______
solitary individuals to ____
primate societies to ____
```
```
replicating molecules to populations of molecules in compartments
independent replicators to chromosomes
RNA as gene and enzyme to DNA and protein
prokaryotes to Eukaryotes
asexual to sexual populations
protists to animals, plants, fungi
solitary individuals to colonies
primate societies to human societies
```
30
Give an example of how each of the following are characteristics of major transitions:
a. entities going from independent transition to only being able to replicate in a host
b. division of labor
c. new ways of transmitting information
a. mitochondria
b. ants
c. CNS
31
Describe what the morphological species concept is and identify the pros and cons.
relies on similarity in morphology (shape) between species.
pros:
- easy to measure
- use fossils
cons:
- phenotype differences may be due to environment
- cryptic species - may miss these
- hard to identify those who look different between life stages e.g. jellyfish
32
Describe what the Biolgoical species concept is and identify the pros and cons.
two groups of organisms are separate species if:
- they are not able to hybridize
- hybrid offspring are infertile or have low fitness
pros:
- intuitive
- works in many cases
- may reveal cryptic species
- widely accepted
cons:
- species that form fertile hybrids don't fit BSC
- difficult to test in many asses: i.e. testing in labs?
- only applies to sexual organisms
33
Describe what the phylogenetic species concept is and identify the pros and cons.
Phylogeny based on DNA sequencing and morphology. Individuals sharing a common ancestor are designated species.
Pros:
- deal with a sexual
- detect cryptic species
- includes ideas from morphological and BSC
cons:
- genetic analysis expensive
- requies sepcialise equiptment.
34
What are the pre-zygotic mechanisms of isolation that prevent hybridization with other species?
- temporal separation (mate at different times of year)
- ecological separation
- behavioural separation (different courtship behaviours)
- mechanical
35
What are the post-zygotic mechanisms of isolation that prevent hybridization with other species?
- hybrid inviability - don't develop to reproductive maturity
- hybrids are sterile
- F2 hybrids are infertile
36
Compare cladogenesis vs aginogenesis
cladogenesis is when a single lineage splits into two i.e. A into A and B
Angiogenesis is when there is gradual change of a species over time i.e. species A changes into species B
37
What is allopatric, parapatric and sympatric speciation
speciation due to:
allopatric - no gene flow
parapatric - some gene flow
sympatric - major gene flow
38
what is a clade?
a group of organisms related by descent.
39
what is a synapomorphy? give an example
shared, derived trait e.g. hair in mammals
40
what is a plesiomorphy? give an example
ancestral, general trait e.g. eggs in mammals
41
What is an autapomorphy? give an example
once, derived trait e.g. live birth in koala
42
what is a monophyletic group
a group of animals that includes an ancestor and all of their descendants aka clade aka linage
43
what is a paraphyletic group
group of animals that includes ancestor and some of their descendants
44
what is a polyphyletic group
Group of animals that share a trait, which is not present in the common ancestor of all descendants
45
Are DNA strands 5' to 3' or 3' to 5' ?
5' to 3'
46
what direction does DNA polymerase work in
5' to 3'
47
what is a major difference in the genes of eukaryotes and prokaryotes. propose a reason why.
Genes in Eukaryotes are separated by non-genomic DNA, however genes of prokaryotes are squashed together and sometimes even overlap. prokaryotes rely heavily on fast replication.
48
After transcription the mRNA is processed/modified. what does this involve (3 processes)?
- capping: modify 5' end
- polyadenylation: add a nucleotide to the 3' end = poly a tail
- splicing: removal of introns from final RNA. Exons are stuck back together. Exons are expressed.
49
What are 2 benefits of diploidy
- allows normal phenotype despite defective allele
| - allows homeostasis - ability to function normally in different environments.
50
if AABB x aabb were crossed - what is the phenotypic ratios (shown as a genptpe) of the F1 and F2 generations?
- will need to do punnet square
```
F1 - AaBb
F2 -
1: aabb
3: Aabb
3: aaBb
1: A_B_
```
51
What is the classic phenotypic ratio of a dihybrid cross if genes are not linked?
1:3:3:9
52
Describe what a test cross is
Mate unknown with recessive parent to determine genotype of unknown.
53
what is a backcross
mate F1 hybrid to recessive parent or dominant parent in order to increase useful traits in a population.
54
What is recessive epistasis and give an example
Epistasis is where one gene affects the expression of another gene. For example the B_ genotype codes for black fur, and bb genotype codes for brown fur. However a second gene A is necessary for the deposition of the pigment colour. So if B_A_ = black dog, B_aa = yellow dog, bbA_ = brown dog, bbaa = yellow dog.
55
what is a quantitative characteristic
characteristic that is not controlled by a single gene but by many genes and the environment e.g. schizophrenia.
56
explain how crossing over allows us to calculate the distance between genes and the centromere.
The closer two genes are on a chromosome, to each other the smaller the rprobaility of a reconbination event. So we can use this to determine how far genes are from the centromere. Take the number of recombinants/total progeny and x 100.
57
When calculating the map distance with sodoria, what do you need to do.
divide the map distance by 2.
58
Compare the mitochondrial genome versus the nuclear genome and what kind of ifnormation can be gained from each.
mitochondria:
- phylogenetics
- short term evolution - mutates faster and sloppier polymerase
nuclear:
- phylogenetics deep in time
- understand gene function
- diversity of animals and humans
- polymerase much more effective at not making mistakes
59
What is a telomere and how does it contribute to aging
repeated sequence at the end of a chromosome. with every replication the telomere gets shorter and shorter. so finite number of times the cell can divide - one reason we age.
60
what are transposable elements
sequences in our genome which are not transcribable. they cut themselves out and move around the genome.
61
What are minisatellites and how to they end up in our genome?
about 300 base pair sequences are repeated over and over. Usually viral origins - infested an ancestral monkey.
62
What is a microsatellite?
about 2-3 base pair units repeated over and over
63
Describe the process of the polymerase chain reaction.
1. the DNA to be ampliied is mixed with deoxyribonucleases and a thermal stable DNA pol i.e. taq polymerase
2. the mixture is heated to break the H bonds in the DNA, forming single-stranded molecules
3. the mixture is then cooled sufficiently to allow the DNA primers to anneal at each end fo the segment to be copied
4. taq polymerase then synthesises the complementary strand of DNA, using the primer as the starting point
5. repeat steps 3-6 as many times as want.
64
SOme applications of PCR?
- amplify microsatellites - Microsatellites are molecular markers in genetics - maternity and paternity testing.
- introduce specific mutations to DNA
- amplify genes from particular animals for sequencing
- amplify ancient or degraded DNA
- amplify from minute samples e.g. forensics
65
Explain the processes of DNA sequencing
1. DNA is heated to break apart into single string
2. Test tube with - DNA single strand + primer DNA + deoxyribonucleases + 1% ddATP etc. Do for each base, so 4 test tubes.
3. the sequencing will stop once the ddATP molecule binds, hence stopping when it encounters an A - but only sometimes. so this creates many different sized strands - stopping at A. Do for each base
4. put into electrophoresis gel and read sequence
66
What is a transcriptome and what can it tell us.
Transcriptome is is the set of RNA molecules produced by an organism or group of cells. It can tell you what genes are being expressed in the organism.
67
What are restriction enzymes and how can we use them?
They are enzymes developed by bacteria to cut out sequences of DNA that don't belong to them. We can use them to cut out specific sequences in the genome.
68
What is the name of the molecule that joins DNA back together
DNA ligase
69
briefly outline the cloning process
1. digest plasmid and DNA to be closed with same restriction enzyme, and then join with DNA ligase
2. introduce recombinant vectors into host cells by transformation
3. select recombinant closing using antibiotic resistance. media contains antibiotic - so only those cells that contain the antibiotic (which we inserted before) will grow. some of these 'positive clones' will contain segments of the target DNA (successfully transformed)
4. to identify and select the clones with recombinant DNA - if the lac gene was disrupted by the new gene the blue gene or lac gene doesn't function, so the bacteria is white. so select all white bacteria.
70
Describe CRISPR and its potential applications
bacterial immune system has protein called CAS9, which picks up viral DNA and cuts it. CAS9 can cut out any DNA sequence, unlike restriction enzymes which only cut a specific target sequence. CAs9 cuts at a specific DNA target specified by the guide RNA. so we can manipulate the guide RNA, and therefore use this CAS9 to cut out any sequence e want. so we can cut and then replace with another gene.
Applications:
- remove or add any gene from crop plants and domestic animals
- potentially alter human embryos (unlikely)
- hugely useful for function genomics
- target retrovirus sequences in donor animals - so we can use pig hearts for transplants
- antimicrobial therapies
- anticancer therapies.
71
What are the 5 asumptisn of the hardy weinberg equation
- random mating
- large population
- no migration
- no mutation
- no natural selection
72
If the initial allele frequencies of a gene are:
A = 0.9
a = 0.1
Determine the genotypic frequencies and the phenotypic frequencies
(will need to work out)
genotypic:
f(AA) = 0.81
F(aa) = 0.01
F(Aa) = 0.18
phenotypic:
domiannt A_ = 0.99
recessive aa = 0.01
73
if the frequency of cystic fibrosis (homozygous recessive condition - aaa) in Australia is 1/2500 births, what is the frequency of carriers in the population?
(will need to work out)
1/25
74
What are the 5 agents of evolutionary change and how do they effect allele frequencies?
1. Mutations - minimal effects on allele frequencies
2. gene flow/migration - introduce new alleles or change allele frequencies
3. non-random mating/assortative mating - doesn't alter gene flow itself but will organise alleles into certain populations
4. genetic drift - population bottlenecks, finder effect - change allele frequencies. alleles can become fixed or lost.
5. selection - increase frequency of certain allele's and may result in loss of other alleles.
75
If these are the genotypic frequencies
MM - 28
MN - 129
NN - 195
What are the allele frequencie?
M?
N?
M - 0.2628
| N = 0.7372
76
If 68 people in the lecture can roll their tongue (aa; recessive) and 12 can't (A_; dominant), what is the frequency of the tongue rolling allele (a) and the non-tongue rolling allele (A)?
```
a = 0.092
A = 0.080
```
77
Describe the 3 types of natural selection
1. disruptive - population selected in 2 different directions
2. directional - population moving in one direction because they are selected or something
3. stabilizing selection - extremes are removed.
78
why are polymorphisms or variations maintained, or why do they occur.
heterozygote advantage
| neutral theory - many variants have no consequences, they don't effect phenotype. neutral mutation.
79
idefntify the 11 topics which couldbe discussed as evidence for evolution
1. hierarchical organisation of life
2. homology
3. genes and genomes
4. convergent evolution
5. embryology
6. vestigial organs
7. bodies are not perfect
8. vestigial forms
9. biogeography
10. fossil record
11. evolution in our lifetime.
80
What determines sex?
Presence of Y chromosome containing SRY gene determines if your male. If don't have SRY gene, female.
81
What occurs in the offspring following these sex chromosome abnormalities:
- 44AOY
- 44AXO
- 44AXXY
- 44AXXX
- 44AYY
- 44AOY - death
- 44AXO - female phenotype, turners syndrome, sterile, late sexual maturity, webbing of skin
- 44AXXY - male phenotype, kleinfelter's syndrome. sterile, small balls
- 44AXXX - female phenotype, fertile
- 44AYY - male phenotype, tall, aggressive, criminality
82
What are the costs of sex?
- two-fold cost - if every offspring was female, then rate of progeny would increase by 2 fold
- mate searching
- competition among males
- meiosis
- meiosis 2x of mitosis
- sexually transmitted diseases
83
What is anisogamy and why did it evolve?
Anisogamy is sexual reproduction by the fusion of two dissimilar gametes. It evolved because being a large gamete is advantageous because you have more resources and hence are more likely to survive. being small is advantageous because you can produce more. there is no advantage to the intermediate size.
84
What are some benefits of sex?
- DNA repair (but this occurs without sexual reproduction)
- prevents accumulation of mutations - Mullers ratchet - if get mutations sex allows the recessive mutations to accumulate and thus eliminate them, since these organisms die.
- tangled bank - want to reproduce with someone and produce offspring that won't compete with you, but still has some chance
- red queen - only way to beat pathogens is to produce genetically different offspring. nematodes example.
85
What links plant cells?
Plasmodesmata - microscopic channels which traverse the cell wall of the plant. enables transport and communication between cells.
86
what links animal cells?
- tight junctions - prevent fluid from moving across a layer of cells
- extracellular matrix
- desmosomes - fasten cells together in strong sheets
- gap junctions - similar function to plasmodesmata in plant cells
87
define:
- chemoheterotrophs
- chemoautotrophs
- prokaryotic organisms that metabolise organic substances for carbon and energy - many bacteria
- prokaryotic organisms which use chemicals like nitrogen, hydrogen, sulfur, iron and methane to create energy - e.g. nitrifying bacteria
88
define:
- photoheterotrophs
- photoautotrophs
- prokaryotic organisms that rely on sunlight for energy but use organic compounds as ready-made building blocks e.g. green and purple algae
- photoautotrophs - capture and store sunlight in the chemical bonds of ATP and carbohydrates e.g. cyanobacteria
89
what is the first law of thermodynamics
energy can only be transformed not created
90
what is the second law of thermodynamics. Give an example.
a process will only happen spontaneously if it increases the entropy of the universe as a whole. e.g. ATP --> ADP + P.
91
what is Gibbs free energy and how is it calculated?
a measure of the amount of usable energy. G final - G initial.
92
what is enthalpy and entropy
enthalpy refers to energy stored in bonds. entropy refers to the disorganisation of the molecules.
93
explain this equation: change G = change H - T change S
Gibbs free energy is the change in enthalpy (H) - the temperature times the change in entropy (S).
94
what is G when the reaction is spontaneous. Are spontaneous reactions exergonic or endergonic.
G is negative - i.e. energy is released. exergonic - releases energy.
95
is ATP --> ADP + P an endergonic or exogonic reaction
exergonic
96
What is the electron transport chain and what is its function?
It is a collection of embedded proteins and organic molecules in the phospholipid bilayer. Electrons travel through the chain and energy is released as electrons move downhill. The energy that is released produces ATP from ADP. Utilises biological protein carriers - NADH and FADH.
97
Why do cells tend to be small. How did eukaryotes get around this.
As volume increases the SA:V ratio decreases. If all energy is tied up into the membrane or surface area, and the demand for energy increases as the volume increases, at some stage the cell can't keep up due to the limitations in SA. Eukaryotes got around this through the use of a mitochondria - which was a bacteria engulfed by another cell. This increases the SA available for energy production so the cell can get larger. Also chloroplasts make own energy.
98
What is required for multicellularity to evolve?
- cells must adhere to other cells
- cells must communicate with each other
- cells must cooperate with each others
- cells must specialize
99
what is the difference between colonial and clonal multicellular organisms.
colonial = cells come together and stay together. clonal daughter cells come together (these are true multicellular organisms)
100
With multicellularity came changes. What are these 6 main changes and why did they occur?
1. large genomes
2. intercellular communication - need to communicate and coordinate cells over large distances
3. internal transport system - body volume increase, so simple diffusion not efficient. need internal transport system for chemical exchange with environemnt
4. efficient ingestion and digestion - need two openings for injection and excretion as larger
5. efficient gas exchange - increase volume to SA ratio limits passive gas exchange, simple diffusion not good enough. So need more intricate structure of gas exchange.
6. structural support
101
outline the alternations of generations
> sporophyte (2n) > spores (n) > gametophyte (n) > gametes (n) > zygote (2n) > sprophyte (2n)
102
Pollen grains are the male ______
microgametophyte
103
Explain what is meant by double fertilization
every pollen has 2 sperm --> one fertilises the egg to form the diploid zygote, the other sperm fertilise two polar nuclei to form the triploid endosperm, which will become a food source for the growing embryo
104
# Define:
- hermaphoditic plnts
- monoecius plants
- deoecious plants
- flowers containing both male and female organs
- plant that he v both make and female flowers
- Plants that have male or female flower.
105
what era was bilateral symmetry invented
Cambrian explosion
106
How are protosomes and deuterostomes distinguished
devlopment
107
what is the difference between cuticulata nad lophotrochozoan
cuticulata have an external protective covering produced by the organism itself (e.g. exoskeleton) vs lophotrochozoan which find their outer covering (e.g. hermit crabs)
108
What is broadcast spawning and give an example of an animal that undergoes this process.
occurs in the ocean when female and male gametes are released simultaneously from the same or different individuals. e.g. coral
109
What is spermcasting and give an example of an animal that undergoes this process.
mating releases sperm that are disposed to fertilise eggs retained by another individual. e.g. barnicles
110
what is eggcasting and give an example of an animal that undergoes this process
releasing eggs into the male. For example female seahorses release eggs into the males pouch. The male then releases sperm to fertilize the eggs.
111
What is external fertilisation and give an example of an animal that undergoes this process.
males attract females, females release eggs first, males then release sperm.
112
Explain the importance of the soma-germline separation and identify what animals have this separation.
true multicellular animals have this distinction.
- Eggs are arrested during their development until ovulation which prevents division - preventing mutations. - no cells in the soma can contribute to anything in the next generation, because our bodies die.
113
What are the 2 main challenges plants faced when moving on to the land
- water balance
| - gas exchange
114
What are some adaptations that plants evolved when moving into land
- cuticle - protective water resistant coating to minimize water loss and protect from UV radiation
- roots for extracting the water and dissolved nutrients from the soil
- vascular system for transporting water and nutrients to above-ground parts of the plant
- tissue for structural support
- stomata for gas exchange
115
what adaption allows plants to become large?
secondary growth - woody tissue produced by vascular cambium (from xylem). Bark produced by phloem.
116
Why did plants evolve diploidy?
- plants need to grow tall, but this leads to increase UV, which leads to increased rates of mutation. Therefore diploid is an advantage due to masking of defective allele.
