🌱 PLANT CELL

A plant cell has several important parts. Each part has a special function that helps the cell work properly.

🧱 Cell Wall

• Gives the cell support and protection.

• Helps keep the cell’s shape.

🚪 Cell Membrane

ANIMAL CELL

Questions

1) How does mitochondria make energy

2) How does ribosomes make proteins

🧫 animal Cell

A cell is the basic unit of life. Our body is made of many cells.

🔬 Main Parts

• Cell membrane — Controls what goes in and out.

• Cytoplasm — Where many cell activities happen.

• Nucleus — Controls the cell and stores DNA.

1. Giraffe is the tallest animal

2. giraffe have purple tongue

3. giraffe drink a lot of water

1. A rattlesnake has a rattle on its tail.

2. It shakes its tail fast.

3. The rattle makes a sound.

4. The sound says , "stay away"!

5. It helps the snake stay safe

Breathing is the process of taking in oxygen and removing carbon dioxide from your body.

Here's how it works:

1. Inhale (Breathe in):

   • Your diaphragm (a muscle below your lungs) contracts and moves downward.

   • Your chest expands, and your lungs fill with air.

   • Oxygen from the air passes into your bloodstream.

What is muscle contraction

A muscle contraction happens when muscle fibers become shorter and generate force.

• During contraction: Muscle fiber pulls together.

• The muscle becomes shorter or develops tension.

• Mucles move when Bones pull on them through tendons.

• Energy is used.

💪 Muscle Contraction and Relaxation

💪 Muscle Contraction

Muscle contraction is the process in which a muscle becomes shorter and thicker to create movement. It starts when the brain sends a signal through a nerve to the muscle. The muscle then begins to work, and tiny proteins called actin and myosin slide over each other. This makes the muscle shorten. The shortened muscle pulls the tendon, which pulls the bone, causing movement.

😌 Muscle Relaxation

Muscle relaxation is the process in which the muscle returns to its normal length after movement. The brain stops sending the signal, so the muscle stops pulling. The muscle fibers return to their normal position, the tendon stops pulling the bone, and the muscle is ready for the next movement.

🌟 Simple Process

Muscle contraction and relaxation are two continuous processes that allow the body to move, breathe, maintain posture, and keep organs working. During muscle contraction, muscle fibers receive a signal from the nervous system. Calcium ions are released inside the muscle cells, allowing the proteins actin and myosin to slide past each other. This makes the muscle fibers shorter and thicker, producing force. ATP (adenosine triphosphate) provides the energy needed for this process. During muscle relaxation, the nerve signal stops, calcium ions are pumped back into storage, and the actin and myosin separate. The muscle fibers return to their original length, becoming longer and thinner. Contraction and relaxation always work together. For example, when you bend your arm, the biceps contracts while the triceps relaxes, and when you straighten your arm, the triceps contracts while the biceps relaxes. These processes are essential not only for walking, running, and writing but also…