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Bio 30 > Population and Community Dynamics > Flashcards

Population and Community Dynamics Flashcards

1
Q

Whats a population

A

Same species at same place in same time
> specific time ex. July 2020
> Species can have variety not identical

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2
Q

Whats a gene pool

A

all of the allels for all of the genes in a population at any one time
> all alleles: BB, Bb and bb genotypes all at one time

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3
Q

Who’s Darwin, what did he find and what does it mean

A

Fount out abt Natural Selection:
> that new variants of species arise continually
> those that can thrive adapt and produce more offspring lead to changes in population, those who cant die off
> Mandels work helped explain this

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4
Q

What is the Hardy-Weinberg Principle and show
> what 5 conditions must be met

A

Model that shows wether evolution has occurred in a population
Allele gene frequency will remain same (no evolution) as long as :
1- Very large population
2- Random mating
3- No mutations
4- No migration
5- No natural selection

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5
Q

Formula for calculating allele frequency and what each letter represents

A

p+q=1.00
p- dominant allele
q- recessive allele

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6
Q

Formula for calculating genotype frequency and what each letter represents

A

p^2 + 2pq + q^2
p^2- frequency of homozygous dominant individuals
2pq- frequency of heterozygous individuals
q^2 - frequency of homozygous recessive individuals

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7
Q

What are the causes of Gene Pool Change ?

A

Micro evolution: gradual change in gene (allele) frequency with a population
> Mutations, Genetic Drift, Gene Flow, Non random mating, Natural selection

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8
Q

What are Gene pool change mutations
> most occur?
>how inherited?
>Benefit?

A

Original source of genetic variation
> Most occur within somatic cells and die within individual
> inherited if in gametes
> can provide selective advantage

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9
Q

What is gene pool change genetic drift
> 2 genetic drift situations: Founder and Bottleneck what are they and differences

A

Changes in a gene pool in a small (sub) population due to chance events that change allele frequency with
> Founder: small number of individuals colonize a new area = gene pool dosent contain all genes from parent population
> Bottleneck: results from rapid decrease in population size caused by natural disasters or hunting > loss of gene pool diversity

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10
Q

What is the Founder effect

A

A gene pool change = genetic drift when a small number of individuals colonize a new area and the new gene pool dosent contain all equal representation of all genes from parent populations

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11
Q

Whats the Bottleneck effect

A

A gene pool change= genetic drift situation where it results in a rapid decrease in population size caused by natural disasters or hunting causes loss of diversity

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12
Q

Whats the gene pool change of gene flow caused by

A

Caused by immigration or emigration that decreases or incrases genetic diversity

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13
Q

Whats the gene pool change of non random mating and benefits/disadvatages

A

When idividuals with certain more desired characteristics mate, those characteristics increase chance of mating
> more homozygous individuals produced in interbreeding
> harmful allels more likely expressed

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14
Q

Whats the gene pool change cause of natural selection

A

> Some individuals will produce more offspring then others: cause grater fitness and selective advantage

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15
Q

What is succession
> the two types

A

Gradual change in the vegetation of an area: little biodiversity to stable larger biodiversity
1- Primary succession
2- Secondary succession

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16
Q

What is Primary succession

A

Gradual change in the vegetation of an area- from an area with no community previously existing (no soil just rocks) > weathering of rocks produces soil - Slow process

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17
Q

What is secondary succession

A

Community is partially or completely destroyed - fast process as significant soil and seeds exist
ex. forest fire

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18
Q

Whats Climax community

A

A point reached in succession with stable point with not much change

19
Q

What are the 2 stages of succession

A

Pioneer stage and Climax stage
> Pioneer is when species (small- grasses) enter and grow , starting vegetation > create microclimate for other species > when they die they increase soil and water storage for larger species
> Climax stage: stable plant community lots of diversity- not much change max reached

20
Q

Types of populations:
> what do they each mean

A

Open population: changes in birth, death, immigration and emigration > natural

Closed Population: changes in birth and death only, no immigration or emigration (cant leave/enter) > rare

21
Q

What is population growth: biotic potential

A

> highest possible growth rate, no limits, resources are abundant, exponential growth ( j shaped curve on graph) , birth> death

22
Q

Life Strategy: R selected is what

A

-Exponential growth (J-curve)
-increase population size rapidly
- Many offspring and low parental care
- Short lifespan and small organisms

23
Q

Life strategies: K selected is what

A
  • Logistic growth ( S- curve)
  • Few offspring: slow growing with lots of parental care
  • Larger size organisms and long lifespan
24
Q

What is a carrying capacity

A

Maximum stable population size that a particular environment can support over a long time

25
Q

What’s environmental resistance

A

Biotic and abiotic factors that limit population size and result in a logistics growth (S curve)

26
Q

What are density independent factors that limit population growth

A

Abiotic - non living factors that effect everybody in a population
ex. weather conditions , flood, drought etc.

27
Q

What are density dependent factor that limit population growth : intraspwcific vs inter specific

A

Biotic - living factors
1- Intraspecific competition: within individuals of the same species

2- Interspecific competition: between individuals of a different species

28
Q

What is intraspecific competition

A

density dependent biotic factor within individuals of the same species

29
Q

What are interspecific competitions

A

Density dependent biotic factors between individuals of different species

30
Q

What does N, D and A or Vrepresent in equation D= N/AorV for size and densityy of populations

A

N-Population size # of organisms
D- population density
V/A- per area or volume

31
Q

Changes in population size formula
what do variables represent

A

🔺N= (B+I)-(D+E) or Nfinal-Ninitial
B- births I- immigration
D- deaths E- emigration

32
Q

Growth rate calculates what
> Formula and variables

A

How quickly a population size is changing
> gr= 🔺N/🔺t or (Nfinal- Ninitial) / (Year final - year initial)
have to calc 🔺N and t🔺 for it

33
Q

Cgr - growth rate per capita us calculating:
> formula and variables

A

Amount of population size has changed in relation to its original size expressed as a percentage (x100)
> cgr= 🔺N/N or (Nfinal - Ninitial) / N initial

34
Q

How does a Growing population pyramid look

A
  • Increasing offspring
  • Wide base
  • more births than deaths
    🔺shape
35
Q

How does a Stable Population graph look

A
  • Rectangular shape
  • about the same proportion of people each age category
  • slightly more young than old
  • death/birth even
36
Q

What does a declining population graph look like

A
  • Skinny narrow base
  • Inverted triangle
  • more older individuals that young
37
Q

Species Interactions types (4)
> what are they
> how much energy is passed

A

Predator vs Prey or Producer vs Consumer are same thing just when prey is plant

Competition: Intraspecific (within same species) or interspecific (between diff)

Symbiosis: Parasitism (+/-) , Mutualism(+/+) or Commensalism (+/o) neutral - o

10% energy is passed as you go up foodchain

38
Q

Defence Mechanisms types:
1- Cryptic colouration
2- Protective colouration
3- Mimicry colouration

A

1- Camouflage, helps organisms blend in to surroundings to avoid predators

2- Bright colours that give warning to predators of poisonous or bitter taste

3- Looking like a species that’s poisonous or harmful even if they aren’t

39
Q

What type of interaction is mutalism

A

both benefit from relationship (+/+) between diff species

40
Q

What type of interaction is commensalism

A

One organism benefits other is neutral/ unaffected (+/o)

41
Q

What type of interaction is parasitism

A

(+/-) one organism benefits while other is negatively affected but not dead

42
Q

Whats the defense mechanism cryptic colouration bc

A

camouflage that helps organisms blend into surroundings to survive

43
Q

whats protective colouration

A

defense mechanics that looks bright and dangerous giving attackers watning of danger

44
Q

whats mimicry defense mechanism

A

looking like another dangerous species to trick attackers even if ur safe

Bio 30 (11 decks)

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