Biology by Bradford
support
The subtopic in the middle and nine tasks round it: label five diagrams, complete a table, put a process in order and fill 42 gaps. The whole subtopic is higher level. Type into the blanks and check them, or print it on A4, Letter or A3 with an answer key.
| Example | Reason for moving |
|---|---|
| A cheetah sprinting after a gazelle | |
| A gazelle zig-zagging away from the cheetah | |
| A male moth flying upwind towards a female's scent | |
| Arctic terns flying between the Arctic and the Antarctic each year |
A species moves from place to place; a one, such as a coral or a barnacle, stays fixed but still moves parts of itself.
Number the steps in order.
Muscles pull on the bones through . The hip is a joint, so it can move in all three planes.
One of these nerve cells and all the cells it supplies form a : when it fires, they all contract together. Muscles that make fine movements, such as those that move the eye, have units.
Arthropods have a hard outside the body; vertebrates have an of bone inside it. Either way the skeleton anchors the muscles, and its parts act as that turn about the joints. The angle a joint can move through, its range of motion, is measured in degrees with a or from photos analysed on a computer.
1234When the muscle contracts, the two kinds of filament past each other and the sarcomere ; neither kind of filament changes length.
Muscle exerts force only when it : it can pull but never push. So muscles work in pairs: when one pulls, it stretches the other. Between the ribs, the and external intercostal muscles have fibres running in different directions, so they move the ribcage in opposite directions. The stretched layer stores in the giant protein , which helps its sarcomeres recoil and stops them overstretching.
A body cuts drag. The tail beats , not side to side as a fish's does, and the airway opens on top of the head, so a dolphin can breathe at the surface between dives.
| Example | Reason for moving |
|---|---|
| A cheetah sprinting after a gazelle | foraging |
| A gazelle zig-zagging away from the cheetah | escaping danger |
| A male moth flying upwind towards a female's scent | searching for a mate |
| Arctic terns flying between the Arctic and the Antarctic each year | migration |
A motile species moves from place to place; a sessile one, such as a coral or a barnacle, stays fixed but still moves parts of itself.
When the muscle contracts, the two kinds of filament slide past each other and the sarcomere shortens; neither kind of filament changes length.
Muscle exerts force only when it contracts: it can pull but never push. So muscles work in antagonistic pairs: when one pulls, it stretches the other. Between the ribs, the internal and external intercostal muscles have fibres running in different directions, so they move the ribcage in opposite directions. The stretched layer stores potential energy in the giant protein titin, which helps its sarcomeres recoil and stops them overstretching.
One of these nerve cells and all the cells it supplies form a motor unit: when it fires, they all contract together. Muscles that make fine movements, such as those that move the eye, have small units.
Muscles pull on the bones through tendons. The hip is a ball-and-socket joint, so it can move in all three planes.
Arthropods have a hard exoskeleton outside the body; vertebrates have an endoskeleton of bone inside it. Either way the skeleton anchors the muscles, and its parts act as levers that turn about the joints. The angle a joint can move through, its range of motion, is measured in degrees with a goniometer or from photos analysed on a computer.
A streamlined body cuts drag. The tail beats up and down, not side to side as a fish's does, and the airway opens on top of the head, so a dolphin can breathe at the surface between dives.