Describe the structure and function of the following organelles: nucleus, endoplasmic reticulum, Golgi body, mitochondria, lysosomes, ribosomes, and centrioles

A cell organelle is defined as a cellular structure which has a specific function. The structure and function of these organelles as explained below.

Explanation:

--> NUCLEUS: This is the largest and most important cell organelle. It is enclosed by a double- layered nuclear membrane with many pores. The structure of the Nucleus makes it the 'control center' of the cell. This, it contains genetic materials( chromosomes) which controls the Production of a new cell or the whole organism itself and it controls the type and quantity of proteins( enzymes) produced in the cytoplasm.

--> ENDOPLASMIC RETICULUM(ER): this is a system of membrane-lined sacs that form channels throughout the cytoplasm. It's membrane is continuous with the nuclear membrane. There are two types of endoplasmic reticulum: rough and smooth. The rough ER packs and transports proteins made by ribosome while the smooth ER is involved in lipid and steroid synthesis.

--> GOLGI BODY: This is a stack of membrane-lined sacs. It is continuously formed at one end and broken off as bubbles or vesicles at the other end. These vesicles carry 'export materials' like enzymes and hormones which the cell makes.

--> MITOCHONDRIA: This is a sausage-shaped body surrounded by a double-membrane layer. The inner membrane is folded to form partitions which project into the inside of the mitochondria. The energy producing reactions of cellular respiration take place in the mitochondria. It is thus often called the cell's 'power- house'.

LYSOSOMES: These are small round sacs that contains digestive enzymes which break down structures and substances. They are also involved in the transport of materials in and out of the cell.

RIBOSOME: These are found on the surface of rough endoplasmic reticulum and are sites for protein synthesis of the cell.

CENTRIOLE: Two rod-like centrioles are found at right angles to each other in an animal cell. They are found near the nucleus and seem to be concerned with cell division.

the answers are as following:

1. c. double helix, nucleosome, coil, supercoil, chromosome

2. b. g2 phase, preparation for mitosis

3. d. interphase consists of the g1, s, and g2 phases

4. c. metaphase

5. a. chromosomes are duplicated before cell division so that each new daughter cell has a complete set