Answer: Cytotoxic T cells
Explanation:
A Cytotoxic T cell is a cell whose activation is mainly aimed at destroying cells that are infected by virus. It is a type of white blood cells that destroys cancerous cells or cells that are impaired especially by viruses. A Cytotoxic cell is also known as T-killer cells, Cytolytic T cells, T lymphocyte.
Cytotoxic T cells destroy target cells by prearranged apoptoses.
Answer:
Gravity
Explanation:
When its altitude is matched by the pull of the Earth's gravity, a satellite circles Earth. The satellite will fly off into orbit in a straight line or crash down to Earth without this equilibrium.
By juggling two things, a satellite retains its orbit: its velocity (the speed it takes to travel along a straight line) and the gravitational force on it that the Planet provides. To resist the greater gravitational force, a spacecraft orbiting closer to the Earth needs more velocity.
Answer:
A cell wall is a structural layer surrounding
of plant cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism
