VCE Biology Unit 2 Outcome 2 - How do inherited adaptations impact on diversity?

Types of Asexual reproduction

fission

budding

vegetative propagation

spore formation

What is fission

When a parent cell divides into two

what is vegetative propagraion

occurs when a plant grows from fragmentation

e.g stem or root cuttings

what is sporogenesis

when spores form on an organisms surface & dispersed into surroundings

to develop into individual clones of the original

biological advantages of sexual reproduction

mixing of genetic information between two parents

random mating within a population

independent assortment of non-homologous chromosomes at metaphase I in meiosis

crossing over & recombination at prophase I in meiosis

biological disadvantages of sexual reproduction

time and energy needed

inefficient

dependence on vectors (carrier used to transfer genetic material into a cell)

risk to life, pregnancy problems

how have humans been using reproductive closing technology

to clone livestock

e.g dolly sheep in the 1990’s

what is somatic cell nuclear transfer (SCNT)

-technique in which the nucleus of a somatic (body) cell is transferred to the cytoplasm of an enucleated egg (an egg that has had its own nucleus removed).

involves: donated somatic cell (sheep 1) & donated egg cell (sheep 2)

EEID

enucleation: removal of nucleus from donated ell cell

extraction: somatic cells nucleus is extracted

insertion: somatic cells nucleus is inserted into the enucleated egg cell

development: cell begins to divide & development into embryo which is implanted into surrogate mother

what is embryo splitting

single early-stage embryo is divided into two or more identical, genetically identical embryos

what is plant tissue culturing/ propagation

runners: plant shoots off parent plant, end runner forms clone of the parent

suckers: new shoots that arise from underground roots

rhizomes: underground storage of starch (bulbs and tubers), genetically identical to parent

what is cutting (plants)

piece of parent is cut and planted in soil & grown into a full plant

what is grafting (plants)

tissues of plants are joined so as to continue their growth together

why is genetic diversity important within a species of population

gives species the chance to evolve over time with natural selection

structural adaptations to enable life in deserts

plants

• small leaves - reduces water lost through transpiration

• shallow, widespread roots - close to surface to quickly absorb any available moisture

• deep taproots - reach underground water sources far below the surface

animals

• large ears - act as radiators, helping to dissipate body heat

• small body size - higher surface-area-to-volume ratio, which aids in releasing heat more efficiently. 

physiological adaptations to enable life in deserts

animals

• efficient kidneys - kidneys that reabsorb water, producing extremely concentrated urine to minimize water loss.  e.g kangaroo rat

• metabolic water - Camels store fat in their humps, which can be metabolized to produce water as a byproduct

• nocturnal activity - animals are most active at night when temperatures are cooler, avoiding the harsh heat of the day

• burrowing - cooler and more humid environment

behavioral adaptations to enable life in deserts

animals

• seeking shelter - finding refuge in burrows, rock crevices

• estivation - enter a state of temporary dormancy, similar to hibernation, during the hottest and driest months to conserve energy and water. 

• nomadic lifestyles - animals moving long distances to find water and vegetation e.g desert elephants

structural adaptations to enable life in the cold

animals

• blubber - thick layer of fat, beneath the skin acts as a highly effective insulator for marine animals such as whales, seals, and polar bears. 

• thick fur & features - fur coats with an insulating underlayer of fluffy fur or hollow hairs that trap warm air

  e.g Emperor penguins use four overlapping layers of scale-like feathers for wind protection

• compact bodys - to reduce surface area to volume ratio, minimizing heat loss

• antifreeze proteins - Antarctic fish have developed antifreeze proteins in their blood to prevent ice crystals from forming and damaging their cells in extremely cold waters. 

physiological adaptations to enable life in the cold

vasoconstriction - blood vessels near the skins surface contract, reducing blood flow and heat loss to the environment, thus preserving core body temperature

behavioral adaptations to enable life in the cold

migration - moving long distances to find food and warmer

hibernation - enter a state of dormancy, dramatically slowing their heart rate, breathing, and metabolism to conserve energy.

microclimate creation - Animals create or select sheltered microclimates to protect themselves from the cold, like burrows or using existing structures

structural adaptations to enable life in marine environments

streamlines bodies - torpedo-shaped bodies that reduce water resistance, allowing them to move more quickly. eg sharks and dolphins

gills - specialized organs that extract dissolved oxygen from the water and release carbon dioxide.

echolocation - emitting sound waves to create a "sound map" of their surroundings, which helps them navigate and find prey. 

physiological adaptations to enable life in marine environments

skin absorption - absorb oxygen directly through their skin

endothermy - endothermic ("warm-blooded"), maintaining a constant internal body temperature regardless of the surrounding water temperature e.g whales

behavioral adaptations to enable life in marine environments

migration - such as salmon, migrate long distances to find food or suitable breeding sites. 

schooling - swim in schools to protect themselves from predators.  e.g fish

bioluminescence - attract prey in the dark ocean depths.  e.g anglerfish

types of symbiotic relationships

competition, mutualism, commensalism, parasitism, amensalism

what is competition

Two organisms compete for a limited resource. Both organisms are harmed in this relationship

Example: Two different species animal, competing for the same food source

what is mutualism

where both organisms benefit

what is commensalism

where one organism benefits while the other is unaffected.

what is parasitism

one organism benefits while the other is harmed.

what is amensalism

ONE organisms UNAFFECTED from the relationship. The other is HARMED.

Example: Animal walking over grassy terrain and damaging it

how can a keystone species change biodiversity around them

distribution, density, size of population

how has the knowledge of Aboriginal and Torres strait islander peoples knowledge contributed to the understanding of interdependencies between species

firestick farming

long-term observation

holistic perspective