Answer :
Sure, let's fill in the blanks in a detailed, step-by-step manner.
1. (a) Plate moves due to convection current.
Explanation: The motion of tectonic plates is driven by convection currents in the mantle. These currents are a result of the heat from the Earth's interior causing the magma to move.
(b) When the magma under the plate is heated up, it expands and rises. The magma spreads out beneath the plates and is dragged along, causing the plates to move away from each other.
Explanation: As magma heats up, it becomes less dense and rises towards the lithosphere. This rising magma then spreads out horizontally, dragging the tectonic plates with it, which causes the plates to move away from each other.
(c) When the magma under the plate cools down, it sinks, causing the plates to be dragged towards each other.
Explanation: When magma cools, it becomes denser and sinks back down into the mantle. This downward movement can pull the tectonic plates along with it, causing them to move towards each other.
(d) The repeated heating and cooling of magma cause continuous convection currents in the mantle and cause the movement of plates.
Explanation: The constant cycle of heating and cooling of magma in the mantle establishes a continuous flow of convection currents, which drives the motion of tectonic plates.
2. There are three types of plate boundaries:
(a) Convergent boundary is where plates move towards each other.
It is also known as a destructive boundary as the crust is melted and destroyed.
Explanation: At convergent boundaries, two tectonic plates move towards each other, which can lead to one plate being forced underneath another (subduction) or the plates colliding and crumpling to form mountains. This process often results in the destruction of the crust.
(b) Divergent boundary is where plates move away from each other. It is also known as a constructive boundary as new crust is created.
Explanation: At divergent boundaries, tectonic plates move apart, and magma rises from below the Earth's surface to fill the gap. As the magma cools, it forms new crust, hence, it's called a constructive boundary.
(c) Transform boundary is where plates slide past each other.
It is also known as a conservative boundary as no crust is destroyed nor created.
Explanation: At transform boundaries, tectonic plates slide horizontally past each other. These boundaries are characterized by strike-slip faulting and do not typically destroy or create crust, which is why they are known as conservative boundaries.
Thus, the complete filled-in text would be:
1. (a) Plate moves due to convection current.
(b) When the magma under the plate is heated up, it expands and rises. The magma spreads out beneath the plates and is dragged along, causing the plates to move away from each other.
(c) When the magma under the plate cools down, it sinks, causing the plates to be dragged towards each other.
(d) The repeated heating and cooling of magma cause continuous convection currents in the mantle and cause the movement of plates.
2. There are three types of plate boundaries:
(a) Convergent boundary is where plates move towards each other.
It is also known as a destructive boundary as the crust is melted and destroyed.
(b) Divergent boundary is where plates move away from each other. It is also known as a constructive boundary as new crust is created.
(c) Transform boundary is where plates slide past each other.
It is also known as a conservative boundary as no crust is destroyed nor created.
1. (a) Plate moves due to convection current.
Explanation: The motion of tectonic plates is driven by convection currents in the mantle. These currents are a result of the heat from the Earth's interior causing the magma to move.
(b) When the magma under the plate is heated up, it expands and rises. The magma spreads out beneath the plates and is dragged along, causing the plates to move away from each other.
Explanation: As magma heats up, it becomes less dense and rises towards the lithosphere. This rising magma then spreads out horizontally, dragging the tectonic plates with it, which causes the plates to move away from each other.
(c) When the magma under the plate cools down, it sinks, causing the plates to be dragged towards each other.
Explanation: When magma cools, it becomes denser and sinks back down into the mantle. This downward movement can pull the tectonic plates along with it, causing them to move towards each other.
(d) The repeated heating and cooling of magma cause continuous convection currents in the mantle and cause the movement of plates.
Explanation: The constant cycle of heating and cooling of magma in the mantle establishes a continuous flow of convection currents, which drives the motion of tectonic plates.
2. There are three types of plate boundaries:
(a) Convergent boundary is where plates move towards each other.
It is also known as a destructive boundary as the crust is melted and destroyed.
Explanation: At convergent boundaries, two tectonic plates move towards each other, which can lead to one plate being forced underneath another (subduction) or the plates colliding and crumpling to form mountains. This process often results in the destruction of the crust.
(b) Divergent boundary is where plates move away from each other. It is also known as a constructive boundary as new crust is created.
Explanation: At divergent boundaries, tectonic plates move apart, and magma rises from below the Earth's surface to fill the gap. As the magma cools, it forms new crust, hence, it's called a constructive boundary.
(c) Transform boundary is where plates slide past each other.
It is also known as a conservative boundary as no crust is destroyed nor created.
Explanation: At transform boundaries, tectonic plates slide horizontally past each other. These boundaries are characterized by strike-slip faulting and do not typically destroy or create crust, which is why they are known as conservative boundaries.
Thus, the complete filled-in text would be:
1. (a) Plate moves due to convection current.
(b) When the magma under the plate is heated up, it expands and rises. The magma spreads out beneath the plates and is dragged along, causing the plates to move away from each other.
(c) When the magma under the plate cools down, it sinks, causing the plates to be dragged towards each other.
(d) The repeated heating and cooling of magma cause continuous convection currents in the mantle and cause the movement of plates.
2. There are three types of plate boundaries:
(a) Convergent boundary is where plates move towards each other.
It is also known as a destructive boundary as the crust is melted and destroyed.
(b) Divergent boundary is where plates move away from each other. It is also known as a constructive boundary as new crust is created.
(c) Transform boundary is where plates slide past each other.
It is also known as a conservative boundary as no crust is destroyed nor created.
