biology AOS 2 SAC

Asexual reproduction

Only 1 parent required to produce offspring (individual can reproduce).

Clones

Offspring are genetically identical to their parents.

Binary fission

A type of cell division used by prokaryotes where the parent cell splits into two, producing 2 identical daughter cells.

Mitosis

A type of cell division used by eukaryotes that results in two identical daughter cells.

Fission

The process where the parent cell splits into two, producing 2 identical cells called daughter cells.

Fragmentation

Occurs in multicellular organisms where cutting up into parts/fragmenting turns into its own organism.

Budding

A process where a small outgrowth (bud) develops on the surface of the parent and eventually separates to form a daughter organism.

Parthenogenesis

Also known as 'virgin birth', it is the ability to lay eggs that have not been fertilized, allowing an organism to grow from the egg.

Spore formation

Occurs in fungi and some protists where spores are formed by cell division and can germinate under favorable conditions.

Prokaryotes

Simple, unicellular organisms that lack membrane-bound organelles.

Daughter cells

The two identical cells produced from the parent cell during fission.

Cytokinesis

The process that follows mitosis, resulting in the division of the cytoplasm and formation of two daughter cells.

Hyphae

The filamentous structures of fungi where spores are formed at the tips.

Sporangium

A structure in fungi that stores spores until they are released.

Favorable conditions

Environmental conditions that allow for successful germination and growth of spores.

Unicellular organisms

Organisms consisting of a single cell.

Multicellular organisms

Organisms composed of multiple cells.

Advantages of Natural Asexual Reproduction

Only requires one parent, daughter cells are genetically identical to the parent, efficient form of reproduction, reliable.

Disadvantages of Natural Asexual Reproduction

No genetic variations in offspring, rapid population growth leading to competition for resources.

Artificial Asexual Reproduction

Cloning carried out by humans to select specific genetic information desired in the offspring.

Embryo Splitting

A method in animals where an early-stage embryo is separated and implanted into surrogate mothers, resulting in genetically identical offspring.

Nuclear Transfer

A cloning method where offspring are produced from adult cells by transferring a somatic cell into an enucleated egg cell.

Somatic Cell

Any body cell that is not a sex cell.

Enucleated Egg Cell

An egg cell from which the nucleus has been removed.

Electric Pulse in Nuclear Transfer

Delivered to encourage fusion of DNA and egg cell and to stimulate mitosis.

Genetically Identical Offspring

Offspring that are genetically identical to the original organism from which they were derived.

Surrogate Mothers

Mothers that carry embryos that are genetically related to another organism.

Clone

Give birth to the clone of Sheep A (offspring genetically identical).

Applications of Artificial Asexual Reproduction

Can be very selective about the genetic information of the offspring.

Reproduction Rate

Reproduce quickly and in larger numbers.

Potential of Artificial Asexual Reproduction

Replenish and restore endangered/extinct species.

Applications of Artificial Asexual Reproduction

Minimise impact on the environment by not relying on particular seasons.

Genetic Variation in Offspring - asexual reproduction

No genetic variation in offspring.

Health Effects of Cloning

Offspring often have adverse health effects including premature aging and defects to vital organs.

Tolerance Range

The zone in which an organism can survive is known as its tolerance range.

Behavioral Adaptations

The actions or activities of an organism that enable it to survive in its environment.

Seeking shelter

A behavioral adaptation in animals to protect themselves from environmental hazards.

Huddling to maintain body temperature

A behavioral adaptation in animals to conserve heat in cold environments.

Migrations

A behavioral adaptation where animals move from one region to another for survival.

Courtship behaviours

Behavioral adaptations in animals used to attract mates.

Nocturnal

A behavioral adaptation where animals are active during the night.

Structural adaptations

Physical features that help organisms survive in their environment.

Thick fur and blubber

A structural adaptation in animals that insulates against the cold.

Bright feathers

A structural adaptation in animals used to attract a mate.

Small ears

A structural adaptation in animals that reduces heat loss.

Wings

A structural adaptation in animals that assists in flight.

Claws

A structural adaptation in animals used for digging.

Physiological Adaptations

Adaptations related to the internal functioning of an organism's body.

Concentrated urine

A physiological adaptation in desert animals that conserves water.

Shivering

A physiological adaptation that helps maintain body temperature when cold.

Camouflage

A physiological adaptation that allows an organism to blend into its environment.

Counter current system

A physiological adaptation that exchanges heat between arteries and veins.

Sweating

A physiological adaptation that evaporates heat to increase heat loss.

Antifreeze proteins

Proteins that prevent freezing in organisms, a physiological adaptation.

Phototropism

A behavioral adaptation in plants that is a growth response to light.

Geotropism

A behavioral adaptation in plants that is a response to gravity.

Chemotropism

A behavioral adaptation in plants that is a response to chemicals.

Thigmotropism

A behavioral adaptation in plants that is a response to touch.

Sickle cell anaemia

A physiological adaptation in humans where red blood cells change shape, providing malaria resistance.

September to October (poorneet)

A season where temperatures are getting warmer, it is still wet and rainy, lilies and yan daisies start to flower, and tubers are ready to be eaten.

December (garrawang)

A season marked by the readiness of kangaroo and apple fruits for harvest, along with an abundance of other animals.

Applications of structural adaptations

Utilisation of biological structures to inspire human materials and devices

e.g. such as Velcro mimicking hooks in fibers.

Indigenous Knowledge

Traditional understanding and practices of Indigenous peoples based on observations of their environment, organisms, and climate.

Water holding Frogs

Frogs that survive dry periods by storing water under their skin, burrowing into soil, and secreting a hard mucus cocoon to prevent water loss.

Stringray

A fish with a sharp barb at the end of its tail, where damage occurs when teeth are pulled out.

Interactions between species

The complex network of relationships and interdependencies between species in ecosystems, which can have beneficial, neutral, or harmful effects.

Symbiosis

Interaction between two organisms of different species living in close proximity, with varying benefits.

Mutualism (+/+)

A relationship where both organisms benefit, such as photosynthetic algae living inside coral tissue.

Commensalism (+/0)

A relationship where one organism benefits while the other is neither significantly harmed nor benefited, like cattle egrets following cape buffalo.

Amensalism (0/-)

A relationship where one organism experiences negative effects while the other is unaffected, such as hoofed animals trampling grasses.

Parasitism (+/-)

A relationship where one organism (the parasite) benefits at the expense of the other (the host), which is harmed but not killed.

Endo parasite

A parasite that lives inside the host.

Exo parasite

A parasite that lives on the outside of the host.

Community

The different organisms that live/working together in an ecosystem.

Niche

A smaller section of the ecosystem.

Keystone Species

Species who have a significant influence on ecological communities.

Keystone Species Example

Elephants are a keystone species, and can alter the entire structure of the vegetation in those areas into which they migrate.

Yellowstone National Park - key stone species

Keystone species - The wolf.

Effect of Increased Elk Population - in Yellowstone when the wolves were taken away

More elk meant that more plants were being eaten.

Elk Behavior Without Wolves

Elk were not constantly on the move and stayed in one location for much longer.

Decline of Plant Species

Plant species such as aspen and riverside willows declined in numbers.

Beaver Population Decline

The lack of beaver dams had a negative impact on aquatic plant and animal life.

Energy Flow in Ecosystems

Energy flows in 1 direction through ecosystems and is not recycled.

Producers (Autotrophs)

Capture and transform radiant energy/inorganic compounds into chemical energy.

Energy Transfer

Chemical energy made by producers is available for both the producer and for all other consumer organisms in the ecosystem.

Glucose

Required for cellular respiration to produce ATP (energy cells organism use).

Consumers (Heterotrophs)

Obtain energy from eating organic matter.

Types of Heterotrophs

Characterized by what they eat and the manner that they obtain that food.

Food Chains

Feeding relationships (and energy transfer) shown in food chain diagrams.

Food Chain Direction

Arrows show the direction of the flow of energy.

1st Order Consumer

E.g. Grasshopper - 1st order consumer.

Food Webs

More complex version of food chains.

Producers in Food Webs

Producers are located at the base of the food web.

Trophic levels

The feeding level of an organism within a community.

Energy flows through an ecosystem

Energy transfer between trophic levels is not 100% efficient.

10% rule

A rough rule of thumb for transfer of chemical energy between trophic levels is that ~10% of energy going into one trophic level is available for transfer to the next trophic level in the form of organic matter in tissues.

Food Chain Energy Flow

Energy is lost as heat from each trophic level via respiration.

Consequences of Trophic Levels

The number of trophic levels is limited (most to about 3 levels).