Mobility
All living organisms move.
· Bacteria, single-celled algae move with the help of flagellum.
· Protozoa. Amoeba moves with the help of pseudopodia. Paramecium moves with the help of cilia.
· Multicellular animals move with the help of muscles.
The earthworm moves when the muscles contract: the segments get longer and shorter; the body gets thicker and thinner.
Fish move with the help of tail fin. Dolphins and cachalots use their tails to move up and down in water.
Some animals move when they react. Squids, scallops squeeze gills and push out water very fast which makes them move.
Waterfowl use swimming membranes to swim.
Penguins use wings to swim.
Birds use wings to fly. But not only wings help the birds to fly: streamline form, light skeleton, air bags, well-developed flying muscles.
Most vertebrates are walking animals: lower limbs (legs) support them. Insects have 3 pairs of limbs.
Mammals can be divided into 3 groups according to their style of walking on their limbs:
· Plantigrade (mammals walk on feet: bear, humans)
· Digital walking (mammals walk on toes: cats, dogs)
· Hoofed (mammals with hoofs: horses, deer)
Plants move too but only partially: only flowers and leaves.
Algae – водоросли
Flagellum – жгутик
Protozoa – простейшие
Amoeba – амеба
Pseudopodia – ложноножка
Paramecium – инфузория туфелька
Cilia – реснички
A muscle – мышца
An earthworm – дождевой червь
To contract – сокращаться
A tail fin – хвостовой плавник
A cachalot – кашалот
A tail – хвост
To react – реагировать
A squid – кальмар
A scallop – морской гребешок
To squeeze – сжимать
Gills – жабры
To push out – выталкивать
Waterfowl – водоплавающие птицы
A swimming membrane – перепонка
A wing – крыло
A streamline form – обтекаемая форма
A light skeleton – легкий скелет
An air bag – воздушный мешок
Well-developed – хорошо развитый
A vertebrate – позвоночный
Walking animals – ходильные жив.
Lower limbs – нижние конечности
A mammal – млекопитающее
Plantigrade – стопоходящий
A human – человек
Digital – пальцевой
Hoofed – копытный
A deer – олень
Partially - частично