Life Cycle: Painted Lady butterflies undergo complete metamorphosis with four stages: egg, larva, pupa, and adult. Egg-Mint green, barrel-shaped eggs are laid singly on the leaves of host plants, and hatch in 3-5 days. Larva-The caterpillar has five instars over 12-18 days.Pupa-The chrysalis stage lasts about 10 days.Adult-Butterflies live for just two weeks. Special Adaptations and Defenses: The Painted Lady's mottled colors look much like military camouflage, and provide effective cover from potential predators.ainted Lady butterflies undergo complete metamorphosis with four stages: egg, larva, pupa, and adult. Egg-Mint green, barrel-shaped eggs are laid singly on the leaves of host plants, and hatch in 3-5 days.
Initiation of Muscle Contraction. Step 1) Neuromuscular Control. The axons of the nerve cells of the spinal cord branch and attach to each muscle fiber forming a neuromuscular junction. i). An action potential passes down the nerve. ii). The nerve releases Ca++ that results in the release of Acetylcholine (ACh) Step 2). ACh binds with the sarcolemma. Step 3). Muscle Fiber Action Potential. i).
Muscle contractions occur through the sliding of actin and myosin filaments past one another. The filaments themselves do not contract and the other elements of an individual sarcomere are not compressed. The sarcomere is able to contract without seriously bending or distorting itself. Contraction ends when the actin filaments on opposite sides of the sarcomere come into contact and the myosin comes into contact with the Z-lines forming the boundaries of the sarcomere. View the animation below, then complete the quiz to test your knowledge of the concept.