Biology Unit 2 AOS1 SAC Flashcards
sexual reproduction:
fusion of gametes from two different parents.
biological advantages of SEXUAL reproduction
- offspring have a great deal of variation
- high chance of individuals having a beneficial trait if environment changes.
- due to different phenotypes being present in the offspring there is likely to be less competition for resources.
biological disadvantages of SEXUAL reproduction
- considerable amounts of energy must be expended on the efforts to find and establish a mate.
- Only half of the parents genetic material ends up with the offspring.
zygote
a single cell formed from the fusion of gametes from two different parents
production of gametes
gametes are produced my meiosis - show considerable variation even from the one individual
asexual reproduction
occurs when only one individual gives rise to the next generation. usually offspring is identical to the parent and each other. (clones)
asexual reproduction examples
- binary fission
- budding
- spores
- vegetative reproduction
- fragmentation
biological advantages of ASEXUAL reproduction
- energy efficient
- no need to find a mate
- offspring are genetically identical to the parent-
- many offspring can be produced in a very short period of time
biological disadvantages of ASEXUAL reproduction
- offspring are genetically identical to the parent so if the environment changes and one individual is susceptible to the change, then all are.
- Mutations cannot be guaranteed to produce beneficial variation- most are harmful
- large numbers of offspring may result in fierce competition between them.
cloning
producing genetically identical copies of an individual organism.
two main forms of cloning in animals
- nuclear transfer
- embryo splitting
nuclear transfer
many problems
offspring
-offspring age very quickly and have many abnormalities
- aren’t identical because the mitochondria are from the egg donor.
embryo splitting
egg is fertilized using IVF. (procedure used to help get pregnant)
- zygote is allowed to divide
- the coat that stimulated the cell to divide is removed
- the cells are separated, and an artificial coat is placed around each of the separated cells.
- These cells divide and the bundles are implanted into different surrogate mothers.
adaptations
any characteristic of a living thing which helps it to survive and reproduce in its environment.
- can be structural, behavioral or physiological
structural
physical features or anatomical traits that help an organism survive in its environment
structural example
camouflage in animals like chameleons or polar bears.
structural- how chameleons avoid predators
has specialized pigment producing structures
physiological
internal body processes or functions that enhance survival or reproduction
physiological example
sweating or panting to regulate body temperature
physiological- how chameleons avoid predators
can produce different types/amounts of pigment to change color
behavioral
actions or patterns of behavior that organisms develop to survive and reproduce
behavioral example
migration of birds to warmer regions during winter
behavioral- how chameleons avoid predators
stays still when in danger
symbiosis
close relationship between two species
four main types of symbiosis
- parasitism
- mutualism
- commensalism
- amensalism
parasitism
one species benefits and the other is harmed
- a parasite often lives on or in its host
- host is harmed by the relationship
mutualism
both species benefit
commensalism
one species benefit and the other neither benefit or is harmed
amensalism
one species is harmed and the other neither benefit nor is harmed
- occurs because one species produces a chemical which harms the other species but the organism producing the chemical is not benefitted by the harm to the second species.
competition
a relationship where two organisms require the same resources
-intraspecific and interspecific
intraspecific
within species
interspecific
between species
abundance
the number of organisms of a particular species
some ecosystems have a lower abundance but higher species richness
predator-prey
the predator kills and eats the prey
distribution
how the members of a species are spread through a particular area
- uniform, random, clumped
density
the number of individuals per unit area.
keystone species
a species with a dramatically large effect on an ecosystem relative to its abundance
aboriginal and torres strait islanders knowledge:
- location of animal’s habitats
- food webs of an ecosystem
- seasonal patterns of movement
- nesting and breeding locations
- density and distributions of populations.
what aboriginal and torres strait islanders get from understanding the ecosystem
- harvest plants and animals in a sustainable manner
- on going supply for themselves
- conservation of the species
