Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Semester 2 Exams > APS 123 - Beckermans Lectures > Flashcards

APS 123 - Beckermans Lectures Flashcards

1
Q

What are the six key processes that drive distribution and abundance?

A 
Births
Deaths
Extinction
Colonisation
Immigration 
Emigration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The growth of a unitary organism is _________

A

Determinate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Coral reefs and bryozoan collonies are examples of _______ organisms and their growth is _________

A

Modula

Indeterminate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a life history?

A

Describing when events occur within an organisms life cycle

Death, reproduction, somatic growth rates, birth, maturation and death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two key reproductive patterns

A

Semelparity - big bang reproduction: large number of offspring produced in one reproductive event

Iteroparoty - organisms reproduce several eggs during reproductive episodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the dormant phase of an ephemeral species life history

A

Seeds lay dormant
Reproduce when conditions are ok
Complete life cycle in a few weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Site in south Africa with huge plant diversity, give stats about it.

A 
9000 species
70% endemic 
5% of south africa 
44% of plants in south africa 
0.05% of total earth but 3% of global plants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

High adult mortality favours which type of reproduction?

A

Favours reproducing once and early - semelparity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In a life table what is Lx?

A

Survival to that age

Take value at age x and divide by value at age zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define Sx

A

Age specific survival
Survival between two years
Take value at age x and divide by value at x-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define Mx

A

Age specific reproductive value - must be measured independently

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is fecundity?

Why only females

A

Number of female babies / reproductive females

Only females generate the input into a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is R0? How do you work out the population level net reproduction rate?

A

The net reproductive rate
= LxXMx
Survival times the number of offspring produced
Population level = the sum of all the R0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

R0 = 1
R0 < 1
R0 > 1
What is happening in the above situations

A

=0 population replaces itself
>1 population growing
< 1 population declining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define generation time

A

Average time between births of individuals and the birth of their offspring
(Sum of (age x Lx x Mx))/R0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define a trade off give a specific example

A

Negative relationship between two variables
E.g. Reproduction vs survival
- as annual fecundity increases so does the winter mortality rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How can you increase population growth?

A

Increase Survival
Increase reproduction
Decrease generation time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Fx

A

Fertility

Fx = Sx X Mx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the count the babies model of measuring fertility

A

Count the new borns
Adults need to have been born for the babies to reproduce, Sx related to adult survival prior to reproduction.
Fertility at age 2 = the fecundity at age two multiplied by the survival chance from age one to 2
Hence F2= m2Xs1
A general equation: Fx = Sx-1 X mx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe the count the fledgling method

A 
Count them at age one 
See babies that survived one year so S0 
Multiply the chance of surviving the first year by the fecundity of the desired age
Fx=S0 X Mx
No need to vary Sx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Fertility rates can be put into a matrix and from this a dominat eigenvalue is calculated what does this value represent?

A

Population growth rate ( symbol is upside down y i.e. Lambda

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is significant about the method of finding population growth rate via a matrix?

A

Tells you at what age population growth rate is the fastest, so you can implement conservation statagies for these ages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

When does exponential population growth occur?

A

Few individuals
No limiting environmental factors
No restrictions on energy and hence reproduction and growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Give the equation for change in population size per unit time

A

dN/dt = bN -dN
Change in population per unit time = per capita birth rate time population size - per capita death rate times population size

Can be simplified to
r=b-d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Give the definitions of the following
r
R0
Lambda

A

r = intrinsic rate of increase
R0 basic reproductive rate
Lambda = population growth rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the limit to exponential growth?

A

Carrying capacity = k

Density increases = per capita respurces decrease = births decrease and deaths increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In the logistic equilibrium graph where would you find the carrying capacity?

A

Where birth and death lines cross

28
Q

What type of feedback prevents unlimited population growth

A

Negative feedback

29
Q

Show the logistic growth equation

Deconstruct the equation and explain it

A

dN/dt = rN(1-N/K)
dN/dt = change in number per unit time
rN = exponential phase - where numbers are low
The k component adds in density dependant negative feedback which is taken from the exponential phase. But makes it relative to changes in N, disproportionate loss where density increases

30
Q

Why is the human population not logistic?

A

Altered our carrying capacity with health care and agriculture

31
Q

What are the three assumptions of the logistic growth model?

A

Linear density dependancy
Population approaches carrying capacity smoothly
K is constant - year to year variation

32
Q

What size should the population start at if it will fit the logistic model?

A

Small size

33
Q

What traits are associated with high density dependance ?

A

Large offspring
Few offspring
Delayed reproduction
Long lived

34
Q

What traits are associated with low density depednace?

A

Small offspring
Early reproduction
Small and short lived

35
Q

What is the competitive exclusion principle?

A

No two species can share the same resource

36
Q

What is a fundamental niche and a realsied niche?

A

Fundamental - intrinsic requirements of a species on its own
Physiological and ecological limits - abiotic or weather
Biotic limits- food and habitat

Realised niche
How other species effect the niche
When competitors are present

37
Q

Give the equation for population growth taking interspecific competition in to account
Deconstruct the equation

A 
rN1 X (K1 - N1 - alphaN2)/K
All that without out N2 is density dependant interspecific competition, the alpha N2 is the interspecific competition coefficient
38
Q

At carrying capacity in the absence of Predator population growth is 0 manipulate the interspecifc competitom equation into the form of a straight line equation at this point.
Explain how this equation works in absence and presence of another species

A

Set it equal to 0
Multiply both sides by K
Divide both sides by rN

N1=K1 - alphaN2

In the absence of another species alphaN2 = 0 hence N1=K1 which makes sense
Where N2 is present the population is reduced by some function of N2 population size

39
Q

There is a _______ decrease in carrying capacity with an increase in _______specifc competition

A

Linear decrease

Interspecific competition

40
Q

How can coexistence occur between two species?

A

Where the interspecific competition is greater than intraspecific competition

41
Q

What are the four possible outcomes of coexistence

A

Competitive exclusion for species 1
Competitive exclusion for species 2
Stable equilibrium - where inter>intra
Unstable - k outside other lines

42
Q

Give examples of direct methods of competition

A

Overgrowth
Chemical
Territorial - defensive
Encounter - events over a specifc resource e.g. Fighting over food

43
Q

Where the isolines of two interspecifc competition lines dont cross what happens?

A

Which ever species has the higher carrying capacity wins

44
Q

Give some direct forms of competition

A

Exploitation - depleting resources
Pre emptive - using space depleting space
Scramble and contest - interference

45
Q

Give five reasons why predation is important?

A 
Structure and dynamics of commitmities
Evolution - behaviour physiology etc
Agriculture- pest contol
Conservation - predator control
Biodiversity
46
Q

Give some examples of prey defenses

A 
Colouration
Morphology 
Spatial arrangement
Batsian (harmless mimics poisonous) and mullerian (harmful mimic other harmful) mimics
Camoflauge - crypsis
47
Q

How can you test if an animal forages optimally?

A

They would eat what they encounter therefore you could gather contents of the gut, contents if not optimal should be in proportion to the abundance of organisms in the environment

48
Q

What are the three factors involved in prediciting animal diet choice.

A

The objective - e.g. Reduce time and maximise energy
The currency - time and energy
Constarints - search time and amount of energy gained

49
Q

Describe how the contingency model of foraging works

A

An organism will add prey choosing the most profitable ignoring search costs until the cost of searching and handling items is greater than the profit of the new prey

50
Q

How do we know that consumers are choosey?

A

Profitability does not equal availability
Yet consumers are choosing the most profitable items
Hence they are foraging optimally

51
Q

What is meant by the functional response when referring to predator prey relationships?

A

How the predators consumption rate varies with prey density

- plotting consumption on the y axis and prey density on the x axis

52
Q

Describe the type one functional response

A

Type one is a linear relationship
- the gradient of the line = prey mortality rate
- therefore mortality rate is constant
Doesnt seem likely - digestive constraints i.e. If predator eats 10% of a size 100 population it eats 10, to keep this rate the same it would have to eat 1000 in a 10,000 size population

53
Q

Describe the type 2 functional response

A

Attempts to capture the idea of digestive capacities
- non constant
- steep at low prey density
- then plateaus
Death rate does not increase as prey density increases hence this model doesnt follow the rule of density dependance
- mortality rate increases then decreases with density

54
Q

What is the type three function response

A

Mirrors type 2 for the first portion
But implements the idea that with increasing density organisms are easier to spot winde less space inbetween
- slope and therefore mortality is steepest in the middle
Mortality increases then decreases with density

55
Q

Which functional response would allow a movement towards stable communities?

A

Type 3 as it has an element of negative feedback

56
Q

Which functional response is the most common? What does this suggest?

A

Type 2

  • inverse density dependant mortality
  • suggests predators are destabilising
57
Q 
Which of the following will lead to a stable community?
Type1 FR and logistic growth
Type 1 FR and exponetial growth
Type 3 FR and exponetial
Type 2 and logistic
A

A,C and D

58
Q

For coexistence to occur there must be a source of ____________ this can either be ________ or _________

A

Negative feedback

Functional response 3 or logistic growth

59
Q

Similar to how coexistence occurs between two competitors for coexistence to occur between predator and prey can occur when?

A

Intraspecific competition is stronger than the effects of predation

60
Q

Describe using Paine’s 1966 study how predation can work to add structure to a community. Also breifly describe Tansleys study on rabbits that came to similar conclusions

A

Paine looked at rocky intertidal communities
Muscles were the dominat competitor and were predated on by piaster fish
- in the absence of predation the diversity dropped to one or two species because the muscles could outcompete the others
With predators the diversity remained at 18

Tansley saw that if rabbits were excluded from a grassland habitat then the diversity went down. Rabbits ate the dominat competitor

61
Q

When will predation increase biodiversity?

A

Where the predators predate on the dominat competitor

62
Q

When would predators reduce biodiversity?

A

When they are generalist competitors

63
Q

What are the three possible effects of predation on a community?

A

Keystone predation = diversity increases
Generalist predation = diversity decreases
Change the ranking of biodiversity but not the diversity

64
Q

What is a trophic cascade?

A

Pattern of interactions between predator and prey and resources

65
Q

Describe the otter story in terms of a trophic cascade

A

High otter abundance
Eat sea urchins so low urchin abundance
Urchins eat kelp so high kelp forest density

Overfishing = not enough fish for killer whales

  • killer whales turn to otters
  • more sea urchins
  • reduced density of kelp forests

Hence an organism 4 trophic levels away is determing the kelp forest biomass

66
Q

A test was done with spiders with glued mouths, these couldnt kill the grasshoppers. The glued spiders had a similar effect on veg abundance than normal spiders, what is happening here?

A

The spiders are causing a change in behaviour of the grasshoppers, the grasshoppers are less active and therefore dont move. Without moving they cant eat the grass

Semester 2 Exams (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions