Organisms And Evolution Flashcards
1
Q
Why do we sample
A
To get data and extrapolate an idea of what is going on in the population
2
Q
What must we consider when taking samples
A
Its the sample unbiased Is it representative The number of samples Accuracy and precision Designing your sampling Equipment Quantitative and qualitative Identification in your sample
3
Q
How can a sample be unbiased
A
It can be structured and randomised
4
Q
What makes a sample representative
A
You can justify assumptions and use statistics to extrapolate to the whole population
5
Q
Why is the number of samples important
A
Generally the more samples collected the more reliable the survey
However the closer you look the better the sample but that may limit the number of samples you can take
6
Q
Accuracy
A
A sample is accurate if it is close to the truth
7
Q
Precision
A
A sample is precise if it obtains similar results
8
Q
What does designing your sampling involve?
A
Pilot studies and early observations so the large sampling is done on the correct things
9
Q
Define quantitative
A
Numerical data
10
Q
Define qualitative
A
Data based on judgment
11
Q
You’re data is only as good as the —– made in a sample
A
Identifications
12
Q
What is important in choosing equipment?
A
Balancing cost, complexity, accuracy, training and time
13
Q
For health and safety, what must be considered about terrain
A
How much the land goes up and down (what is underfoot)
What you will need to traverse
How difficult it will be to work in
(Eg a cultivated field will have easy terrain
14
Q
For health and safety, what must be considered about weather conditions
A
The effects and dangers of the prevailing weather conditions
The possible extremes and their likelihood
15
Q
For health and safety, what must be considered about isolation
A
(Not a likely issue in urban areas)
How do you know exactly where you are (sampling has to have positional data)
How quickly could someone come to your aid
Communication?
Nearest settlement?
16
Q
For health and safety, what must be considered about contact with harmful organisms
A
Anything that can do harm eg bacteria, insects, larger animals
17
Q
Point counts
A
Involves the observer recording all individuals from a fixed point. This can be compared to other count locations or with data from the same location gathered at other times
18
Q
Quadrat
A
One of the most common methods for sampling organisms that are sliw moving or stationary
The frame is laid down and a direct count of what is in the frame or a percentage can be estimated
Only the squares containing the plants you are studying can be counted
19
Q
Randomised sampling
A
Quadrats are often thrown to try to get a random sample. This is still not a truly random sample and other methods can be used to improve the randomisation
20
Q
Line transect
A
A line (eg rope attached to a stake at either end) is laid out. At specific points along the line or across the whole line you record what is present or the presence or absence of a particular species
21
Q
Belt transects
A
Uses two parallel lines and records the plants at given points
Using a quadrat at each section will give more accurate data
22
Q
Quadrat and transects are used for
A
Sessile or slow moving organisms
23
Q
Pit fall traps
A
For mobile animals Can vary in size, access (fall triggered by size) Baited or not Result of the fall (lethal or not) Only effective for animals on ground
24
Q
Sweep nets
A
Used for sampling in air or water
25
Water sweep nets
Often designed to allow water to flow out while collecting the organisms
26
Flight intercept traps
Fine black or white mesh that the insects fly into. Simplest design is just a screen
27
Malaise traps
Large tent like traps to catch flying insects
28
Pan traps
Can tempt flying insects. These are brightly coloured shallow dishes with a liquid that has low surface tension (eg soapy water) insects will be attracted to the colour, fly in and drown
29
Camera traps
For animals which are difficult to capture and where you want to avoid contact.
These cameras are activated by the animal at it approaches, normally using motion sensors or triggers like breaking a light gate
30
Scat sampling
Sampling the feaces can give you information such as the number, the range, the dna, the food and diet ant the health of the animal
31
Wjen sampeling wild organisms it is essential to....
Minimise impact on the community an habit
Especially when dealing with rare species and habitats
Some habits will also have specific legislation to protect them in place
32
Name 3 taxonomic groups
Nematodes
Arthropods
Chordates
33
How can animals be classed in the feild
Classification guides and keys
Observations and data that can be used with these later can be recorded
Expects often are able to rely on their own expertise
34
How can animals be classed in the lab
DNA analysis, protein markers and other cellular structures or molecules can be used
Particularly useful where visual identification is not clear or where differences between species are determined at cellular levels
Can be used in tracking species diversity and identifying individuals
35
Taxonomy
Taxonomy classified organisms by shared characteristics. This allows biologists to decide the name of a particular species
E.g panthera tigris
The more similar the full name the more similar the characteristics of the organisms
36
Phylogenetics
The use of sequence data, morphology and protein structure has allowed more detailed maps of the relationships between organisms to be produced. These are called phylogenetic trees or a phylogen
Helps map out relationships that can be obscured by divergent or convergent evolution
37
Divergent evolution
A shared common feature that has been adapted to serve different functions
38
Convergent evolution
Animals possessing similar features/ that are adapted to similar niches but come from different evolutionary paths
39
Model organisms
Species that have been studied extensively
40
How do indicator species help to monitor environmental impact
Either by presence or abundance
Understanding the tolerances of a particular species can mean you can use them as indicators for the environment or the community
A species that is absent/present shows they are susceptible/being favoured to some factors in the environment and
41
How can population size be determined
Sampling
A direct count of the population within a particular area can be used to give a whole population
Mark and recapture can be used
42
Mark and recapture
Involves capturing a sample of the population, marking and releasing the sample
After an interval of time a second sample is captured
43
What is the formula to estimate the total size of a population
N=MC/R
44
In N=MC/R, what is N
Population
45
In N=MC/R, what is M
Number captured and marked (1st sample)
46
In N=MC/R, what is C
Number captured and marked (2nd sample)
47
In N=MC/R, what is R
Number recaptured (mark caught in second sample)
48
What assumptions are made in using mark and recapture
All individuals have an equal chance of capture
No immigration or emigration in time interval between 1st and 2nd sample
Marked individuals can mix fully and randomly with the total population
49
Describe the marking method of banding
Bands with an individual identifier are attached to the individual
If it will not be possible or appropriate to physically recapture different colours can be used for removing identification
50
Describe the marking method of tagging
Tags used for remote tracking (radio transmitter)
51
Describe the marking method of surgical implementation
Tags can be implanted to prevent them interfering with the animal
For example so the don't interfere with the streamlining of fush
52
Describe the marking method of painting
Animal is painted with non toxic biodegradable paints
Paint must not block skin surfaces for heat regulation, secretion or respiration
Impact of sent and colour must be considered
53
Describe the marking method of hair clipping
A clearly identifiable section of hair is removed
54
What is escherchia coli
A bacterium
55
What is caenirhabditis elegans (C. Elegans)
Nematode
56
What is arabidoopsis thaliana
Flowering plant
57
What is drosophila melanogaster
Arthropod
58
Name three chordates
Mouse
Rats
Zebrafish
59
Ethogram
A detailed list of all the behaviours in a particular species with clear descriptions of each behaviour
60
Describe a behaviour flow diagram
Arrows show moving from one to another
| Thickness of arrow gives idea of frequency
61
What are the three main methods of sampling when using an ethogram
Occurrence sampling
Focal sampling
Scan sampling
62
Occurence sampling
Note the number of times a particular behaviour occurs by any of the animals present
Good for rare behaviours
Or when studying particular sub group
Does not give indication of the amount of time given to behaviour
63
Focal sampling
One particular individual is tracked through the time, noting every behaviour
Useful for allocating time budgets and pooling information from lots of individuals will give a lot of data
Very intense way of sampling
64
Scan sampling
At specific time intervals, noting what each animal is doing and where they are
Can be helped with te use if photographs
65
Anthropomorphism
A problem when studying animal behaviour
| It is important to treat information in a scientific manner and not attribute human characteristics to non human species
66
Name three things that aid objectivity
Latency
Frequency
Duration
67
Latency
The time between a stimulus and response
68
Frequency
How often a particular behaviour occurs
69
Duration
The length of time a particular behaviour lasts
70
Tume budget
The time allocated to particular behaviours in a given time frame
71
Evolution
The change over time in the proportions of individuals in a population differing in one or more inherited traits
72
Name three ways Alleles can change in evolution
Natural selection
Sexual selection
Genetic drift
73
Natural selection
Non-random
Acts on genetic variation in populations when populations produce more offspring than the environment can support
Individuals with variations better suited to their environment tend to survive longer and produce more offspring passing on the advantage to the next generation
74
Sexual selection
Non random
The non-random process involving the selection of alleles that increase an individual's chances of mating and producing offspring
May lead to sexual dimorphism
Can be due to male-male rivalry and female choice
75
Genetic drift
Random
Chance events cause unpredictable fluctuations in allele frequencies from one generation to the next.
More important in small populations as alleles are more likely to be lost from the gene pool
76
Describe the effects of bottleneck and founder effects on genetic drift
A gene pool is altered by genetic drift because certain alleles may be under-represented or over-represented and allele frequencies change
77
Where selection pressures are strong...
The rate of evolution can be rapid
78
Describe the hardy-Weinberg (hw) principle
In the absence of evolutionary influences, allele and genotype frequencies in a population with remain constant over the generations
79
Fitness
An indication of an individual's ability to be successful at thriving and reproducing
80
Absolute fitness
The ratio between the number of individuals of a particular genome after selection to those before selection
81
Relative fitness
The ratio of the number of surviving offspring per individual of a particular genotype to the number of survivors offspring per individual of the most successful genotype
82
Co-evolution
The process by which two or more species evolve in response to selection pressures imposed by each other
A change in the traits of one species acts as a selection pressure on the other species
Frequently seen in pairs of species that have a symbiotic relationship
83
Impacts of a symbiotic relationship
Can be positive (+) negative (-) or neutral (0) for the individuals involved
Mutualism, commensalism and parasitism are types of symbiotic relationship
84
Red Queen hypothesis
In a co-evolutionary relationship, change in traits of once species can act as a selection pressure on other species. This means that the species in these relationships must adapt to avoid extinction
85
Costs of sexual reproduction
Males unable to reproduce
| Only half of each parents genome passed to offspring, disrupting successful genomes
86
Benefits of sexual reproduction
Ought-weigh cost due to an increase in genetic variation
Provides the raw material for adaptation giving a better chance of survival under changing selection pressures and predators and parasites
Ubiquitous in higher organisms
87
Benefits of Asexual reproduction
Maintaining the genome of the parent is successful in stable narrow niches or when re-colonising disturbed habitats
Offspring can be produced more often and in larger numbers
88
Name two examples of asexual reproduction
Vegetative cloning in plants and parthenogenesis in lower plants and animals
89
Parthenogenesis
More common in cooler climates disadvantageous to parasites or regions of low parasite density or diversity
90
Horizontal gene transfer
Not able to adapt easily to changes in environment (mutations can occur that enable adaption to occur)
Organisms that reproduce Asexually often also have mechanisms of horizontal gene transfer between individuals to increase variation for example the plasmids of bacteria and yeasts
Allows faster evolution
91
Gove some examples of asexual reproduction
Spider plants and strawberry plants produce runners
| Some lizards are capable of parthenogenesis
92
Examples of cloning in plants
Runners
Tubers
Bulbs
Plantlets
93
Meiosis
Results in the production of two haploid gametes
Does not occur during asexual reproduction
Increases variation
94
Gamete mother cells
```
Only diploid cells capable of meiosis
Located in sex organs
In animals: sperm in testes
Eggs in ovaries
In plants: ovules in the ovary
Pollen in the anthers
```
95
Haploid cells
One set of chromosomes (n)
96
Diploid cells
Two sets of chromosomes (2n)
97
Before meiosis begins.....
Each chromosome replicates forming two identical chromosomes help together by a centromere
98
Meiosis 1
The diploid mother cell divides into two haploid cells
99
Meiosis 2
The two haploid cells divide to form four haploid gametes
100
Homoglous chromosomes
Pairs of chromosomes of the same size, same centromere position and the same genes at the same local
Although the genes are the same the chromosomes may he different
Each inherited from a different parent( 1paternal and 1 maternal
101
Independent assortment
During meiosis 1 homoglous chromosomes pair up along the equator of the cells in q random and independent manner
Results in the production of gametes with varying combinations of maternal and paternal chromosomes
102
The number of different combinations produced by an independent assortment can be calculated using the formula...
2^n where n is the haploid number
103
What is the purpose of independent assortment
Results in new combinations of alleles and increased variation
104
Crossing over
During meiosis one when homoglous amazons pair up the inner nonsister chromatids and cross over at points called chiasma
swapping genetic material results in the re-combination of alleles
105
Linked genes
Genes on the same chromosome are said to be linked
The greater the distance between linked genes, the greater the chances of crossing over and the greater frequency of recombination
106
Recombination frequency
Indicates a distance between linked jeans
107
Gene mapping
Recombination frequency can be used to mark the position of linked genes on a chromosomes
108
Sex determination
Sex chromosomes decide whether an individual is male (xy) or female(xx)
Males are hertogametic
109
Sry gene
Responsible for the development of male characteristics
110
Non-genetic (environmental) sex determination
Occurs when the sex of an organism can be altered during a sensitive period of development due to external factors such as temperature
111
Temperature dependent sex determination (Tsd)
Where are the temperature experienced by the embryo during this temperature sensitive period of incubation determines sex
Most prevalent in reptiles
112
Sex changes can occur as a result of
Change in size
Social interaction including competition
Parasite infection
113
Sex ratios
The ratio of males to females in a population
Usually 1:1
The sex ratio of vertebrates can divide from 1:1 when influenced by resource availability and parental quality
114
Sex allocation theory
The ability to shift offspring sex ratios represent an evolutionary adaptation for getting more offspring into the next generation, thus increasing fitness
115
External fertilisation
In which both types of gametes are shed into the water and the sperm swim or are carried by currents to the eggs
116
Internal fertilisation
In which eggs are retained within the reproductive tract of the female until after they have been fertilised by sperm inserted into the female by the male
117
What organisms use external fertilisation
Animals in aquatic environments
| Almost all aquatic invertebrates, most fish, many amphibians
118
What organisms use internal fertilisation
Land animals
119
External fertilisation advantages
Low energy cost of reproduction
Offspring need no parental care
Less energy used in courtship
Large numbers of offspring produced
120
External fertilisation disadvantages
Restricted to wet environments
| High chance offspring will not survive
121
Internal fertilisation advantages
High chance offspring will survive
| Able to reproduce on land
122
Internal disadvantages
High energy cost of reproduction
Parents have to care for, protect and provide
Nourishment for their offspring
Less young produced
123
R selected organisms
Occur in unstable environments, density dependent
Small, low energy reproduction, many offspring, earlier maturity, short life, each individual reproduces only once, die early, short generation
124
K selected organisms
Occur in a stable environment, density dependent
Large, high energy reproduction, late maturity requiring long parental care, long life, reproduce multiple times, high survival, long generation
125
Monogamy
One male mates with one female
Form life long pairs
Chosen strategy when young are venerable and require care from both parents
126
Polygamy
An animal has more than one mate
127
Polygyny
One male gets exclusive mating rights with multiple females
| In some species only one of a few males in a group of females will mate
128
Extra-pair copulation
A strategy used by females to avoid the sexual conflict caused by polygyny
Occurs as it is a disadvantage to the females for male choice to be limited
129
Polygamy
When a female gets exclusive mating rights to multiple males
130
Courtship
Specialised behaviours that attracts a member of the opposite sex and leads to mating
131
Sexual selection
Mutual attraction is an important factor in mating
| The presence of a particular trait among members of one sex can make them somehow more attractive to the opposite sex
132
Conspicuous physical traits
Bright colouration, increased size, striking adornments and elaborate courtship make animals more visible to predators but grant greater success in obtaining mates
133
Sexual dimorphism
A physical difference between males and females other than sex organs
A product of sexual selection
134
Energy used in sperm production in comparison to egg production is relatively...
Low however they are made in larger quantities
135
The r/k system
Organisms are categorised based on a level of parental investment and number of offspring produced
136
Ecological niche
Summary of requirements and tolerances of a species
137
Niche overlap leads to...
Competition
138
Niche overlap occurs when...
Different species have similar resource requirements and tolerances
139
Competition means that individuals have...
Less resources and hence lower survival chances
140
Fundamental niche
The full niche an organism could occupy if there is no interspecific competition
141
Partial nich
Occupied in response to interspecific competition
142
Competitive exclusion
Occurs due to interspecific competition where the realised niches of two species are very similar
Called competitive exclusion because one species declines to local extinction
143
Resource partitioning
Occurs due to interspecific competition Where the realised niches of the two species are sufficiently different
E.g individuals divide up a territory
144
Parasite
A symbiont that gains benefit in terms of nutrients at the expense of its host
145
The reproductive potential of the parasite is....
Greater than the host
146
Why do parasites have asexual and sexual phases
Asexual phase allows rapid build up of parasites but no variation
Sexual phase allows rapid evolution
147
Ectoparasite
Lives on surface of host
| Ticks, lice
148
Endoparasite
Lives within the host
| Tapeworm , plasmodium
149
What is meant by ‘many parasites are degenerate’
The host provides many of the parasites needs. Evolution has favoured the loss of non-useful organisms or structures. This means parasites have a narrow niche in which they can survive and breed
150
Vector
An organism which plays an active role in the transmission of their parasite (may also be a host)
151
Definitive host
Organisms on which or in which the parasite reaches sexual maturity
152
Intermediate host
Organisms required to the parasite to complete its lifecycle/ asexual stage of parasites life cycle
153
Transmission
Spread of parasite to host
154
Virulence
Harm caused to a host species by a parasite
155
More virulent parasites...
Have less chance for transmission
156
Why is distribution of a parasite in a hosts population not uniform
Variation in host health
Variation in host immune system
Variation in host exposure to vectors
Variation in host behaviour
157
Overcrowding of hosts increases...
Transmission rate
158
In malaria and schistosomiasis infected hosts are often incapacitated. The parasites increase the transmission rate using....
Vectors
| Water dispersal stages
159
Give an example of host behaviour being used to maximise transmission
Schistosomiasis parasite released into water so can infect humansas they wade in the water
160
Give an example of host behaviour being changed to maximise transmission
Rabies virus makes a dog more aggressive so it will bite and pass on diseases through saliva
161
Describe the lifecycle of malaria
Caused by plasmodium
Mosquito acts as vector and bites human allowing plasmodium to enter bloodstream
Asexual reproduction occurs in the liver in red blood cells
When red blood cells burst, gametocytes are released into bloodstream
Mosquito bites an infected human and gametocytes enter mosquito
They mature into male and female gametes allowing sexual reproduction
The mosquito infects another human
162
Describe the lifecycle of schistosomiasis
Caused by schistosomes
Reproduce sexually in human intestine
Fertilised eggs pass out with faeces into water where they develope into larvae
Larvae infect water snails where asexual reproduction occurs.
This produces a type of mobile larvae which escape the snail and penetrate the skin of a human, entering the bloodstream
163
Methods of transmission used with ectoparasites
Direct contact
164
Methods of transmission used with endoparasites of body cavities
Direct contact
| Contribution of intermediate host
165
Methods of transmission used with endoparasites of body tissue
Often transmitted by vectors
166
Transmission
The spread of a parasite toa host
167
Parasites can modify the hosts...
Foraging behaviour
Movement
Sexual behaviour
Habitat choice
168
Some parasites can suppress the hosts immune system. This allows parasites to....
Grow and reproduce more efficiently
169
Bacteria and viruses need....host species
One
170
Viruses can only replicate...
Inside a host cell
171
Viruses
Parasites that can only reproduce inside a host cell
172
Animal viruses have
DNA
| Protective coating
173
Retroviruses have
RNA
Protective coating
phospholipid membrane from host material
174
Viruses have outer surface....
Antigens which are used to attach to a host cell
175
Antigens on viruses can sometimes be detected as...
Foreign by host immune system
176
Describe DNA Viruses replication
Viruses antigens attach to host cell surface
Virus DNA genome is inserted into host cell
Virus DNA genome is replicated by hosts enzymes
Virus genes are transcribed to RNA and translated to make viral proteins
Virus particles are assembled and burst out of host cell
177
Retrovirus replication
Changes RNA into DNA
Viral enzyme called reverse transcriptase is used to form DNA
new formed viral DNA is inserted into the genome of the host cell
Viral genes can be expressed to form new viral particles
178
In an immune response to parasites by mammals the first line of defence involves
No specific defences: physical barriers
| Chemical secretions
179
Physical barriers
Epithelial tissue blocks entry
180
Chemical secretions
Mucus saliva and tears all contain hydrolytic enzymes which destroy bacterial cell walls
Low ph caused by secretions in the stomach, vagina and sweat glands denatures cellular proteins of pathogens to destroy them
181
Injured Cells release signal molecules this results in...
Enhance the bloodflow to the site bring antimicrobial proteins and phagocytes
182
Describe the process of phagocytosis
Lysosomes contain powerful enzymes to kill parasites by engulfing them and storing them inside a vacuole
183
Natural killer cells
Can identify and attach the cells infected with viruses releasing chemicals that lead to cell death by inducing apoptosis
184
Lymphocytes
White blood cells found mainly in lymph glands
Each lymphocyte is part of a clone So each lymphocyte has just one type of receptor protein on the surface
Receptor proteins bind to a specific antigen
185
Describe immune surveillance
Lymphocytes check the lymph fluid for antigens
| Lymphocytes only activate if it’s receptor blind to its antigen
186
What are the three types of lymphocytes
Killer T cells- induce apoptosis
Helper T cells
B cells- Produce antibodies
187
Antibodies possess regions where the amino acid sequence vary greatly between different antibodies. Variable region gives the antibodies....
It’s specificity for binding antigens
188
How do antibodies and inactivate parasites
When antigen binds to the binding site the antigen-antibody complex formed that can result inactivation of the parasite Rendering it susceptible to take a seat or can stimulate a response that result in cell lysis
189
Describe memory lymphocytes and the secondary immune response
Initial antigen exposure produces lymphocyte cells self specific for that antigens that can produce a secondary response when the same antigen enters the body in the future when this occurs Antibody production is enhanced in terms of speed of production, concentration in the blood and duration
190
Describe some strategies parasites have evolved to resist the immune system
Endoparasites can mimic host cell antigens and have a detection by immune system
Modify the hosts immune response reducing chance of destruction
Antigenic variation in subsequent generations involving. Evolving faster than the immune system can respond to new antigens
191
Epidemiology
Study of outbreaks and spread of infectious disease
192
Describe the difficulties in developing anti parasite medicines
Some Parasites are difficult the culture in the laboratory so there is no way to study the effects of treatment except using a host animal
Vaccines are difficult to develop as rapid antigen change after reflected in the design and the vaccine
I can also be difficult to find drug compounds that only target the parasite
193
What are some non medicinal ways of controlling parasites
Attacking other parts of the parasites lifecycle
194
Water born stages in a parasites lifecycle can be controlled by...
Civil engineering projects to improve sanitation
| Parasites not transferred from human waste or bathing water
195
Coordinated vector control
Reduces vector population and prevents vectors from infecting new hosts
196
What allows parasites to spread rapidly
```
Overcrowding (e.g refugee camps, many hosts close together with poor sanitation
Tropical climates (warmer so parasites can survive away from hosts and vectors reproduce quickly )
```
197
Parasite control allows
Reduced child mortality
Population wide improvement in child development and intelligence because kids are have more resources for growth and development
198
LECDs
Less economically Developed Country
