The answer is sliding filament.
Muscle fibers are made up of myosin and actin filaments that straddle one another in alternating sequence. The myosin has myosin heads that act on the actin and enable the myofibrils to slide across each other in opposite directions. This causes the muscle to shorten hence contract. This is an energy-requiring process (hence hydrolyses ATP) and also requires calcium ions. In an animation, the myosin would seem to ‘walk’ on the actin filament.
The correct answer is phototrophism.
Phototrophism is said to be the growth of a plant toward a source of light.
It is response to the stimulus of light and is seen when a plant bends towards the direction that light is coming from. Response by plants to a stimulus is called tropism. The word or prefix "photo" means or refers to light. Therefore phototropism simply means response to light.
Phototropism can be especially evident in the jungle where the jungle floor gets very little light. If a tall tree falls to the ground, it leaves a gap in the canopy through which sunlight streams to the ground. Many jungle plants growing on the ground will bend towards the gap and rapidly grow towards the source of light.
Answer:
14. Carcinogenic
15. Not sure. I believe it is monoclonal antibodies.
Some keep flying for decades, while others end up on the scrap heap