Answer:
Troponin and calcium ions.
Explanation:
Troponin is a component of thin filament along with tropomyosin and actin. It is a protein complex to which calcium binds and start the production of muscular force.
Calcium also playing a very important role in muscle contractions, it binds with troponin and helping to move tropomyosin.
When calcium ion attached to troponin, then conformational changes occurs in troponin shape and moves which allow tropomyosin going away from its inhibitory position from the myosin-binding sites on actin. After this, the energized myosin head starts binding to the actin molecules and starts the cross bridge cycle, which helping in shortening the muscle's fiber.
Answer:
The power of the objective lens multiplied by the power of the ocular lens
Explanation:
Option (III) .Cephalization, the clustering of neurons and interneurons in the anterior part of the animal, is apparent in <u>Planaria.</u>
What is planaria?
- Planaria is a genus of planarians in the family Planariidae.
- When an individual is cut into pieces, each piece has the ability to regenerate into a fully formed individual.
- Currently the genus Planaria is defined as freshwater triclads with oviducts that unite to form a common oviduct without embracing the bursa copulatrix and with an adenodactyl present in the male atrium.
- The testes occur along the whole body.
- Planaria originally have habitats in dark, murky water which results in such sensitivity .
- They are also sensitive to other stimuli such as chemical gradients, vibration, magnetic and electric fields .
- Their central nervous system includes the anterior (head, brain and eyes) and middle (abdominal trunk and pharynx).
To know more about planaria, refer:
brainly.com/question/1917416
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