Movement

Blood

Heart

Nerves

Gonads

Muscle

Kidney

B3.3.1
Adaptations for movement as a universal feature of living organisms

Movement is an essential function of life and all living organisms must possess adaptations to allow for movement

Organisms can display various levels of mobility and are broadly classed as being either sessile or motile

Sessile organisms are permanently attached to a surface and lack the capacity to move independently

Examples of sessile organisms include some prokaryotes (e.g. biofilms), certain animals (e.g. sponges), most fungi and all plants

Motile organisms have the ability to move independently, using their own metabolic energy

Examples of motile organisms include some prokaryotes (e.g. E. Coli), most protists (e.g. amoeba) and the majority of animals

Motile organisms have higher metabolic rates and increased nutritional requirements, while sessile organisms are more susceptible to predation

B3.3.9
Reasons for locomotion

Locomotion describes the movement of a motile organism from one location to another

Motile organisms have many different reasons for locomotion and may possess specific adaptations to suit these purposes

Reasons for locomotion may include:

Foraging for food – Worker bees spend a significant portion of their adult lives foraging for the hive
Avoiding danger – Squid expel water from the mantle cavity to achieve a jet propulsive escape from predators
Searching for mates – Salmon may swim from the ocean to freshwater rivers in order to reproduce
Travel / migration – Many species of birds will migrate long distances each year in response to the seasons

B3.3.10
Adaptations for swimming in marine mammals

Swimming is a form of locomotion employed by marine mammals that involves the propulsion through water using limbs

Marine mammals have evolved from terrestrial ancestors and so possess specific adaptations to support swimming

Examples of adaptations for swimming include:

Flippers – Front limbs have adapted to form broad, flattened flippers that support manoeuverability underwater
Airways – Dorsal blowholes that can be sealed allow for periodic breathing between dives
Streamlining – Streamlined body shapes encounter less resistance when moving through viscous fluids (water)
Tail / fluke – Fluke tails are adapted for up and down movement which enhances propulsion underwater