Bio 30 Final review Unit D Flashcards
(43 cards)
What is Natural selection
The processes through which populations of living organisms adapt and change
What is genetic drift
A mechanism of evolution in which allele frequencies of a population change over generations due to chance
What is gene flow
“gene migration” or “allele flow” is the transfer of genetic material from one population to another
What is non-random mating
occurs when the probability that two individuals in a population will mate is not the same for all possible pairs
What is the bottleneck effect
“genetic bottleneck” is a sharp reduction in the size of a population due to environmental events like natural disasters, or human activities. This reduces the genetic variation of a population
What is the Founder effect
The loss of genetic variation that occurs when a population is established by a very small number of individuals from a larger population
What is Migration and how does it affect the gene pool
Migration is when a population of a species moves from one populated area to another. The larger the number of migrant individuals and the greater the difference in allele frequencies the greater the effect the migrants will have on changing the genetic constitution of the resident population
What are Mutations and what effect do they have on the gene pool
Mutations are a genetic defect resulting from an error in DNA replication. They are a strong force for introducing new alleles and a weak force for changing allele frequencies
What is geographic isolation
This is when members of the same species are separated geographically
What is reproductive isolation
This is when populations of the same species experience Drastically different changes in allele frequencies resulting in them no longer being able to reproduce
How can geographic isolation lead to reproductive isolation
When populations of the same species are separated geographically, The environmental pressures of the two populations will be different. This means that natural selection will favour different traits based on the location of the population; this causes the gene frequencies of the populations to change over time. Eventually, the gene pools of the populations will change enough that members of each respective location can no longer mate.
How do mutations result in a changing gene pool?
If a mutation provides a benefit, natural selection will begin to favour the mutated trait and it will become more commonplace in the gene pool.
What are the types of competition
-Interspecific competition: competition between different species
intraspecific competition: competition between the same species
What is Gause’s principle
Gause’s principle is founded on the idea that if two species that occupy the same ecological niche are in one ecosystem, one species will be “dominant” over the other and the less fit species will be outcompeted
What is symbiosis and the different types
An interaction or “relationship” between two species
-commensalism: a biological relationship between two species in which one organism benefits and the other is neither harmed nor benefits
-Mutualism: A relationship between two species where both will benefit in some way
-Parasitism: A relationship between species where one organism, the parasite(who benefits) lives on or inside another organism(the host) and harms it in the process
What are the Defense mechanisms
Mimicry: evolved resemblance to another organism or object, can involve morphological, physiological and behavioural traits
Camouflage: a tactic used to disguise their appearance, usually to blend into their surroundings. used to mask location, movement and identity
Protective toxins: some organisms are able to release and inject toxic chemicals to defend themselves from danger
What is the difference between mimicery and camouflage
If an organism uses mimicry, it is trying to be perceived as something else. If an organism uses camouflage, it is trying to not be perceived at all
What are the two kinds of succession and the difference between them
Primary Sucession: The changing of an environment with no life to a complex community
Secondary Sucession: the return in stages to a stable climax community in an area that’s lost its vegetation but not its soil
What is a population
A group of organisms of the same species that live in the same habitat at the same time.
What is a community
all organisms of various species that share a habitat at the same time
What is an ecological niche
An organism’s role in an ecosystem (place in the food web, breeding area, time of day when most active)
What are the different kinds of population distributions
Clumped: individuals in a population are more concentrated in certain parts of the habitat
Random: Individuals are spread throughout a habitat in an unpredictable and patternless matter
uniform: Individuals are equally spaced throughout the habitat
What are the biotic factors that affect population growth
Gender ratio
Mate avalibity
gestation period
estrous period
clutch or litter size
fecundity
What are the abiotic factors that affect population growth
-food supply
-availability of shelter
-water supply
-law of the minimum: growth of a population is controlled by its least available resource
-sheldfords law of tolerance: some species can only thrive in a certain range of abiotic factors
-density dependant factors
-density-independent factors
