Biology 9 and 10 - ACTUAL Flashcards
genetic diversity
a measure of the genetic variation among individuals in a population
Why is genetic diversity important?
Protects longevity of species by reducing susceptibility to sudden environmental change. The population has a higher chance of containing alleles that are better suited too survive environmental challenges.
Advantages of sexual reproduction
- increases genetic diversity allowing for recombinant offspring
- improves disease resistance by promoting presence of different alleles
- combining genetic material from 2 gametes reduces chance of offspring inheriting genetic disorder that is carried by one parent
disadvantages of sexual reproduction
- the cost of male progeny
- time, energy and reserves takes to find a mate
- risk of transferable diseases associated with sexual intercourse
- risk of losing offspring to outside influences (embryo damage)
Oviparity vs. Viviparity
ovi: eggs are released into external environment and embryo develops from nutrients inside yolk
vivi: embryo develops inside mothers body and is born after gestation period
sexual reproduction in angiosperms (flowering plants)
- Flowering plants produce and release pollen (the male gamete).
- Pollen is carried by a pollinator to the flower of another plant, collected by the stigma of the flower, and fertilises the ovule (the female gamete).
- Pollinators can either be biotic (living organisms such as insects) or
abiotic (non-living methods such as wind and water).
What is asexual reproduction?
the production of offspring without the fusion of gametes.
Advantages of asexual reproduction
- grows faster
- offspring are identical clones of parent (important for organisms that’s phenotype is fine tuned to survive in a particular environment
- does not require organism to mate with so doesn’t have to be mobile
- requires little parental investment and removes need to protect fragile offspring
Disadvantages of asexual reproduction
low genetic diversity so may suffer during rapid environmental change
TYPE OF AR: binary fission
asexual reproduction in prokaryotes and certain
species of eukaryotes, which results in the generation of two
identical cells.
TYPE OF AR: budding
formation of buds which grow and split away from the
main organism to develop into another separate organism.
TYPE OF AR: fragmentation
breaking of fragments from an organism which can
regrow back into a whole organism.
TYPE OF AR: Vegetative propagation
reproduction of plants with roots or leaves
breaking away from the original plant and independently growing into
a new plant.
TYPE OF AR: Sporogenesis
formation of spores which are dispersed into the
environment where they can grow into an organism.
TYPE OF AR: Parthenogenesis
Formation of an embryo from a female gamete
alone, without the need for a male gamete to fertilise it.
what are reproductive cloning technologies
human interventions which artificially produce genetically identical clones of an organism
reproductive cloning technologies: animals: somatic cell nuclear transfer
- Enucleation - removal or destruction of the nucleus from the donated
egg cell - Extraction - the donated somatic cell’s nucleus is extracted
- Insertion - the donated somatic cell’s nucleus is inserted into
the enucleated egg cell - Development - the developing embryo is implanted into a
surrogate mother
3 types of reproductive cloning technologies: plants
- Tissue culturing - growth of plant cells on a growth medium in
sterile conditions. - Plant cuttings - production of new plants from fragments
such as the stem or root from the original plant. - Plant grafting - attachment of a rootstock and scion together
to produce a clone.
Types of symbiotic relationships
Mutualism (+, +), Commensalism (+, 0), Parasitism, (+, -), Predation (+/-), Amensalism (0/-), competition (-/-)
Types of Competition
intraspecific and interspecific
intra: between same animal species for same food source
inter: between different animals for same food source
What is a Apex predator?
Apex predators have no natural predators and are at the top of the
food chain.
keystone species
The effects of a keystone species on an ecosystem are greater than
expected relative to its population size.
What is an ecosystem engineer?
Ecosystem engineers create, significantly alter, or maintain the
structure of an environment.
population distribution
The range of geographical areas that members of the population are found in
Population size
the total number of individuals within a population
population density
a metric for the number of individuals per unit area
levels of ecological organisation
cell, organism, population, community, ecosystem
