SAC 5 (ecosystems) Flashcards
Abiotic factors
- metals, gases (O2), water
Biotic factors
- living or have lived (animals, trees)
Asexual Reproduction Definition
- is a type of reproduction that does not require the fusion of gametes
- offspring are genetically identical to the parent
Asexual Reproduction - Different Types
- binary fission
- budding (produced as bud/growth)
- vegetative propagation (part of plants being detached & developing)
- fragmentation
Asexual Reproduction - Advantages
- requiring only one parent, conserving energy
- organisms can quickly reproduced under favourable conditions
- advantageous in stable environments
Asexual Reproduction - Disadvantages
- does not produce genetic variation
- only genetic variation is mutation
- rapid population growth
Sexual reproduction
- can occur internally or externally
Internal Fertilisation
- is the process of fertilisation that occurs inside the body (oviparity, ovoviviparity, viviparity)
Advantages of Internal Fertilisation
- increased fertilisation probability
- mates are selective
- young is protected against predators, increased survival
External Fertilisation
- occurs outside the body of an organism, usually requires water
- spawning (leads to higher genetic diversity)
Adv & Dis of External Fertilisation
- increased genetic variation (adv)
- produce large number of offspring (adv)
- large amount of gametes are wasted (dis)
- desiccation zygotes (dis)
Surface-Area to volume ratio and heat loss
- small body = higher surface area: volume ratio (release heat)
- large body = lower surface area: volume ratio (maintain heat)
Adaptations
- a genetically controlled structural, behavioural or physiological feature that enhances the survival of organisms in a particular environmental conditions
Structural
- physical features (feathers)
Physiological
- body processes (respiration)
Behavioural
- the way an organism acts/actions performed (mating dance)
Carrying capacity of a habitat
- a species average population size in a particular habitat
Indigenous management techniques
- Fire (controlled burning to manage animal population and promote vegetative growth
- Hunting (hunting of particular species to control population density)
Interactions between ecosystems
- mutualism: both species benefit
- commensalism: one species benefits and other is not affected
- parasitism: one species benefits at the expense of another
Species richness
- Species richness is defined as the number of different species in a region – this is the total number of species (both plant and animal) that you counted for each location.
Species evenness
- Species evenness refers to how balanced the numbers of each species in a habit are. Instead, you evaluated the abundance of the species as low, medium, or high
Population density and size
- Population size is the number of species in a population
- Population density is the average number of species per unit of area or volume
Sexual v asexual reproduction in plants
- asexual reproduction: without seeds
- sexual reproduction: with seeds
Cloning-embryo splitting
- Remove DNA from donor ovum, so it has no DNA
- Nucleus from somatic cell is transferred to donor ovum
- Ovum is shock to stimulate mitosis
- Cell division until the embryo becomes a blastocyst
- Implant into surrogate mother
Cloning-somatic cell nuclear transfer
Uses a different approach than artificial embryo twinning, but still produces an genetic copy of an individual
Cloning-plants
- Cloning plants is just to take the cutting/clipping of a plant and grow it elsewhere on its own
Gene pool
- the combination of all the genes present in a reproducing population or species
Genetic diversity
- the biological variation that occurs within species
