What is the function of the nucleus?

The nucleus is the control center of the cell — it houses the cell's DNA and directs all cellular activities including growth, metabolism, and reproduction The nucleus produces energy for the cell through chemical reactions The nucleus breaks down waste materials and recycles them The nucleus controls what enters and exits the cell

Why are mitochondria called the 'powerhouse of the cell'?

Mitochondria convert energy from glucose and oxygen into ATP (adenosine triphosphate) through cellular respiration — ATP is the fuel currency every process in the cell uses Mitochondria are called the powerhouse because they contain the cell's DNA Mitochondria produce proteins that power the cell's other organelles Mitochondria store chemical energy in the form of glucose for later use

What does the cell membrane do?

The cell membrane is a selectively permeable barrier that controls what enters and exits the cell, maintains the cell's internal environment, and enables communication with neighboring cells The cell membrane provides rigid structural support, like a building's outer walls The cell membrane is only present in animal cells — plant cells use their cell wall instead The cell membrane produces energy by letting certain molecules flow through

What is the role of ribosomes?

Ribosomes are the cell's protein factories — they read messenger RNA instructions and assemble amino acids into proteins Ribosomes store and release energy in the form of ATP Ribosomes control cell division by duplicating the nucleus Ribosomes digest old or damaged proteins and recycle their components

What does the endoplasmic reticulum (ER) do?

The ER is a network of membranes that folds and transports proteins (rough ER, studded with ribosomes) and produces lipids and detoxifies chemicals (smooth ER) The ER is where DNA replication takes place before cell division The ER surrounds and destroys invading bacteria inside the cell The ER stores ATP produced by the mitochondria

What is the Golgi apparatus and what does it do?

The Golgi apparatus is the cell's post office — it receives proteins from the ER, modifies and packages them, then ships them to their final destination inside or outside the cell The Golgi apparatus generates ATP alongside the mitochondria The Golgi apparatus copies DNA before cell division The Golgi apparatus is found only in plant cells

What are chloroplasts and where are they found?

Chloroplasts are organelles in plant and algae cells that carry out photosynthesis — converting sunlight, water, and CO₂ into glucose and oxygen Chloroplasts produce green pigment for camouflage and are found in all cells Chloroplasts are a type of mitochondria specific to plant cells Chloroplasts are found in animal cells and help digest green vegetables

What are lysosomes and what happens inside them?

Lysosomes are membrane-bound sacs filled with digestive enzymes that break down worn-out organelles, bacteria, and cellular debris — they are the cell's recycling and waste-disposal system Lysosomes store ATP produced by the mitochondria for use during high-energy activities Lysosomes are only found in plant cells and help break down the cell wall Lysosomes produce proteins used to repair damaged DNA

What is the function of the large central vacuole in plant cells?

The central vacuole stores water, maintains cell pressure (turgor pressure) to keep the plant rigid, stores nutrients and waste products, and helps the cell grow by expanding with water The central vacuole is where photosynthesis takes place in the plant cell The central vacuole is the plant cell's equivalent of the animal cell's nucleus The central vacuole produces hormones that control plant growth

What is the cell wall and which organisms have it?

The cell wall is a rigid outer layer outside the cell membrane that provides structural support and protection — found in plants (cellulose), fungi (chitin), and bacteria (peptidoglycan), but not in animal cells The cell wall is found only in plant cells and is made of the same material as the cell membrane Animal cells have a cell wall made of protein, which is why skin is tough The cell wall replaces the cell membrane in organisms that have it