Complete this concept map on animal movement.

Verified step by step guidance

1. Step 1: Animal movement requires both muscles and a skeleton. Fill in (a) with 'muscles' and (b) with 'skeleton'.
2. Step 2: The types of skeletons include hydrostatic skeletons, exoskeletons, and endoskeletons. Fill in (c) with 'exoskeleton'.
3. Step 3: Units of contraction in muscles are sarcomeres. Fill in (d) with 'sarcomeres'.
4. Step 4: Endoskeletons are made of bone and cartilage. Fill in (e) with 'bone and cartilage'.
5. Step 5: The sliding-filament model explains how myosin pulls actin filaments to shorten sarcomeres, enabling muscle contraction.

Key Concepts

Types of Skeletons

Animals utilize different types of skeletons to facilitate movement, primarily categorized into three types: hydrostatic skeletons, exoskeletons, and endoskeletons. Hydrostatic skeletons, found in organisms like jellyfish, rely on fluid pressure, while exoskeletons, such as those in insects, provide external support. Endoskeletons, like those in vertebrates, are internal structures that support the body and allow for greater mobility.

Antagonistic Muscle Pairs

Movement in animals is often achieved through the action of antagonistic muscle pairs, where one muscle contracts while the other relaxes. This coordinated action allows for precise control of movement, such as bending and straightening limbs. For example, in the human arm, the biceps and triceps work as antagonistic pairs to enable flexion and extension.

Sliding-Filament Model

The sliding-filament model explains how muscles contract at the molecular level. According to this model, muscle fibers shorten as myosin filaments pull on actin filaments, causing the muscle to contract. This process is fundamental to muscle function and is essential for all types of animal movement, from walking to flying.