The mitochondria are the powerhouses of the cell. They extract energy by breaking down nutrients and converting carbohydrates to ATP. The citric acid cycle and electron transport chain take place within the mitochondria.

Some of the main differences between plant and animal cells are the presence of a cell wall in plant cells, which maintains a regular and rigid cell shape, and chloroplasts, which are the sites of photosynthesis in plant cells. By contrast, animal cells do not have a cell wall, allowing their cell shape to be more irregular and more dependent on cytoskeletal filaments. Animal cells do not perform photosynthesis and therefore do not have chloroplasts. Some, not all, animal cells contain many small vacuoles. 

A centriole is a cylindrical structure present in pairs in most eukaryotic cells. They are composed of microtubules arranged in nine triplets and play a role in mitosis and meiosis. During these processes, the centrioles are replicated and each pair migrates to a cell pole. From the centrioles, mitotic spindles emanate to attach to the centromeres of sister chromatids located at the metaphase plate. 

The Golgi apparatus is composed of compartments that are organized into a cis and a trans face. The cis face receives proteins from vesicles originating from the endoplasmic reticulum. After fusing with the Golgi apparatus, the proteins are modified and move through the folds, or cisternae, of the Golgi to the trans face. At the trans face, the modified proteins are organized and transported by vesicles from the Golgi apparatus to their final destinations.

Ribosomes, the sites of protein synthesis, are found through the cytoplasm, and in eukaryotes, on the endoplasmic reticulum. Ribosomes are assembled in the nucleolus, where rRNA (ribosomal RNA) is transcribed. Ribosomes are made of rRNA and protein, so the ribosomal proteins are synthesized on the rough endoplasmic reticulum, and are transported into the nucleolus to be assembled into ribosomes.

Smooth ER lacks ribosomes and functions in diverse metabolic process such as synthesis of lipids, metabolism of carbohydrates, and detoxification of drugs and poisons. Rough ER contains ribosomes on its surface and functions in protein synthesis. Bacteria lack endoplasmic reticulum since it is membrane-bound.

While most of a cell's DNA is located in the nucleus, some DNA is found in the mitochondria and chloroplasts. The DNA found in plasmids supports the endosymbiotic theory. The cytoplasm of eukaryotes does not contain free floating DNA like in prokaryotes.

Extranuclear genes, also known as cytoplasmic genes, are genes located outside the nucleus. They can be found in other parts of the cell, such as the mitochondrion, chloroplasts, and other plastids. Each of these organelles is thought to have originally been an independent prokaryotic cell, ingested by another cell, known as the endosymbiotic theory. Each of these organelles has its own DNA and works in cooperation within the nuclear DNA. 

Ribosomes are organelles composed of two subunits of ribosomal RNA and proteins. There are two types: free ribosomes, which are found in the cytosol of the cell, and bound ribosomes, which are bound to the rough endoplasmic reticulum. Their primary purpose is to synthesize proteins. Messenger RNA will bring amino acids to the ribosomes, where proteins are then synthesized. The endoplasmic reticulum is an organelle that is composed of bounded tubules and sacs and is continuous with the nuclear envelope. It is composed of two parts: the smooth endoplasmic reticulum and the rough endoplasmic reticulum. The smooth endoplasmic reticulum synthesizes lipids, metabolizes carbohydrates, stores calcium, and detoxifies the cell of drugs and poisons. The rough endoplasmic reticulum, studded with ribosomes, aids in protein synthesis. The mitochondrion is bound by a double membrane; the inner membrane has many infoldings called cristae. This increases the surface area of the organelle and therefore increases productivity. Known as the “powerhouse of the cell,” the mitochondrion creates ATP for the cell through a process known as cellular respiration. Peroxisomes are specialized metabolic organelles bound by a single membrane. They contain enzymes that transfer hydrogen atoms from substrates to oxygen, producing hydrogen peroxide. Hydrogen peroxide is then converted to water. The Golgi apparatus is a stack of flattened membranous sacs. Its purpose is to modify proteins, carbohydrates, and phospholipids. Polysaccharides are also synthesized here. Besides synthesis and modification of these macromolecules, the Golgi apparatus also sorts products and sends them to other parts of the cell through vesicles. 

Organelles, for the most part, are too small to be clearly defined by a simple light microscope. Although, larger organelles may be seen with a light microscope, they cannot be well-studied using them. An electron microscope can achieve remarkable magnification and resolution. Some electron microscopes can even resolve individual molecules or atoms. Also note that an egg (chicken, human, ostrich etc.) is a single cell. We can study the nucleus (yolk) with the naked eye, but this is a special case, and the question does not provide us any information that would make this a reasonable assumption.