D) Circulatory system is the one that transports nutrients to body cells.
Answer:
Tropomysin, calcium
Explanation:
Tropomysin is a protein that prevents muscle contraction hence acts as a contraction inhibitor. It wraps around the actin blocking the binding sites for myosin on the actin.
Muscle will only contract when they get a rush of calcium ions.
The calcium ions binds to troponin, the troponin changes its shape. The change in shape will remove tropomyosin from the binding sites allowing myosin to bind on the actin leading to muscle contraction.
Answer:
Mitotic phase
Explanation:
Cell cycle is composed of interphase and mitotic phase. Interphase is aphase of cell preparation. It is subdivided into:
- G1 (gap 1 phase)-the cell grows and becomes larger
- S phase- replication of DNA, duplication of centrosomes
- G2 (gap 2 phase)-proteins and oranelles are made
Mitotic phase is phase of cell division, chromosomes are separated, daughter cell get identical sets of chromosomes. It is followed by cytokinesis-separation of cytoplasm. Stages of mitosis are:
- prophase-condensation of chromatin into chromosomes, the nuclear envelope breaks down, mitotic spindle formation
- metaphase-the chromosmes line up (metaphase plate)
- anaphase-the siste chromatides move toward opposite cell poles
- telophase-the nuclear envelope forms again, cell division is almost complete
Answer: Rheumatoid arthritis
Explanation:
Rheumatoid arthritis is a disease which is a autoimmune disease which is usually associated with the pain and inflammation in the joints. This is the condition in which the person is not able to walk or sit for a longer period of time as it is painful.
The lysosomes is an enzyme that is found in the saliva and tears of human beings which helps in the degradation of the cell wall.
In case of autoimmune diseases the antibody present in the body destroys the cells of the body considering it as self antigen. Its concentration is found high in the people suffering from this autoimmune disorder.
Melanin provides pigmentation to the skin and it also provides UV ray protection (which is its role in the epidermis).
