AOS2 Biology

Abiotic factors

Properties of the environment that aren’t living

Biotic factors

Properties of the environment that are living

Individual

A single organism

Species

A group of organisms that are capable of interbreeding to produce fertile viable offspring

Population

A group of organisms of the same species that are living in the same location at the same time

Community

A number of different populations existing in the same location at the same time

Ecosystem

The interactions between biotic and abiotic factors in a given environment

Adaptation

An adaptation is a heritable change that makes an organism better suited to survive its environment

Structural adaptation

A physical feature that helps an organism survive in its environment

Behavioural adaptation

An action or activity of an organism that helps it survive in its environment

Physiological adaptation

Any internal function or metabolic process of an organism that helps it survive in its environment

Symbiosis

An interaction of two organisms of different species living in close proximity to each other

Mutualism

Both benefit

Commensalism

One benefits one is unharmed

Parasitism

One benefits the other is harmed

Food chains

Food chains show the energy transfer between tropic levels

Detritivore

Ingest dead material for nutrients

Decomposer

Release enzymes to break down dead material for nutrients

Keystone species

A species that has a larger than expected impact on an ecosystem

Asexual reproduction

Only one parent is required to produce offspring - offspring are genetically identical to parent.

Asexual pros

Rapid population growth

Single parent required

Every member can give birth

Asexual cons

no genetic variation

no new genotypes

can’t salt to new environments

Binary fission

Parent cell splits into two identical cells (Prokaryotic) E.g. All bacteria

Fission

Parent cell splits into two genetically identical cells e.g. amoebas

Budding

A small outgrowth develops then detaches off the parent e.g. sea sponge

Spore formation

Small lightweight capsules produced in large numbers dispersed e.g. black bread mould

Fragmentation

Fragment breaks of parent then grows e.g. Star fish

Parthenogenesis

Offspring produced from an unfertilised egg e.g. Komodo dragon

Vegetative propagation

Rhizome, bulbs, tuber, root propagation e.g. Chinese money plant

Cuttings

Part of the plant is removed then put into a suitable environment to grow (artificial) e.g. Chinese money plant

Grafting

Stem tissue of one plant is attached to the stem root of another plant (artificial) e.g.fruit trees

Tissue culture

Large numbers produced in a controlled environment (artificial) e.g. orchids

Embryo splitting

Splitting the cells of an embryo then put into a surrogate mother (artificial) e.g. Cows

Nuclear transfer

nucleus fused with egg then implanted into a surrogate mother (artificial) e.g. sheep