Answer:A. The release of calcium ions causes myosin and actin to attach to each other.
The contraction of skeletal muscles takes place by induction of a nerve impulse, which produces a movement and the interaction of the filaments containing proteins named as actin and myosin. This interaction of filaments is regulated by proteins called tropomyosin and troponin present on the actin filaments. The motor nerve causes the depolarization of the muscle membrane sarcolemma. This triggers the sarcoplasmic reticulum to release calcium ions. This calcium binds to troponin and thus allows the tropomyosine strand on the actin filament to displace so that the part of the actin where myosine head needs to be attached remain uncovered. Binding of the actin myosine filament results in contraction.
Hence, the release of calcium ions causes myosin and actin to attach to each other causes muscle contraction.
Answer:
Explanation:
B. có nhiều hệ sinh thái khác nhau trên trái đất. mỗi hệ sinh thái có một đặc tính riêng và chúng có thể kết nối, tác động qua lại với các hệ sinh thái khác
No they have a negative charge Protons have a positive charge... I remember because P in Positive and P in Proton
The different types of plant tissues are:
1. Meristematic tissues - It is of three types: Apical, Lateral and lntercalary.
2. Permanent Tissue - It of two types: Simple and Complex tissues. Simple tissues are of three types Parenchyma, Collenchyma and Sclerenchyma.
Complex tissues are of two types - Xylem and Phloem.