Species on earth Flashcards
1
Q
What are the reasons why many species remain undiscovered
A
- small species
- endemic species
-haven’t investigated everywhere
2
Q
What 4 factors is population controlled by
A
- births
- deaths
- immigration
- emigration
3
Q
Equation to determine population size
A
past pop + births + immigration - deaths - emigration = current pop
4
Q
What factors affect birth rate
A
- age
- number of females
- number of offspring
- predation
- life cycle
5
Q
What factors affect mortality rate
A
- food availability
- presence of predators
- presence of disease
- water availability
6
Q
Define carrying capacity
A
- a species’ average population size in a particular habitat, without it becoming damaging
7
Q
Examples of density dependent factors
A
- disease
- competition
- food supply
- parasitism
8
Q
Examples of density independent factors
A
- fires
- earthquakes
- seasons
- flooding
- temperature change
9
Q
What is the sigmoidal population growth definition
A
- growth pattern in which an organisms population density rises slowly originally ina fresh setting
10
Q
What causes a population to increase
A
- increase prey = increase predators
- decrease predators = increase prey
11
Q
What causes a population to decrease
A
- decrease prey = decrease predators
- decrease predators = increase prey
12
Q
Examples of artificial population control
A
- culling of deer
- removal of invasive species
13
Q
What is meant by an r - selected species
A
- species that give birth to many young and have low parental involvement
14
Q
What is meant by a k - selected species
A
- species that give birth to less and have high parental involvement
15
Q
How do r and k populations differ in terms of their ability to recover after a drop in population
A
- r selected would recover quickly
- k selected could take years to show any kind of recovery
