Question

Which of the following are found exclusively in plant cells, exclusively in animal cells, and in both?
Nucleus, centrosomes, Golgi bodies, leucoplasts, cell coats

Answer 1

Hint: Cytology, cell biology, or cellular biology is defined as the branch of science that deals with the study of cells. Cells are the smallest unit of life. Cells are considered the functional, structural, and biological unit of all living organisms.

Complete answer: Organisms are classified based on the number of cells they are made up of. There are unicellular and multicellular. Unicellular organisms such as bacteria are made up of a single cell, whereas multicellular organisms consist of numerous cells and include plants and animals. Cells are of two types. There are eukaryotic cells and prokaryotic cells. Eukaryotic cells are mostly multicellular and have a nucleus and a definite nuclear membrane, mitochondria, chloroplast, cell wall, and nucleic acid present in them. Fungi, protozoa, plants, and animals are some organisms that are included in eukaryotic cells. Mitochondria are referred to as the powerhouse of the cell as it produces adenosine triphosphate (ATP), the energy molecule.

Plant cell:

Plant cells are eukaryotic cells which means that they have a defined nucleus and cell organelles present in them. The cell wall in plant cells is composed of pectin, hemicellulose, and cellulose. The vital role of the nucleus is to store hereditary information and genetic material which is necessary for metabolism, growth, and cell division. Plant cells consist of membrane-bound organelles called plastids. Plastids have their own DNA. They synthesize molecules, part takes in the photosynthesis, and stores starch. Some of the characteristic plastids include chloroplast and leucoplast. Chloroplast consists of chlorophyll, a green-colored pigment that converts sunlight energy into chemical energy, which is utilized by the plants to derive food from carbon dioxide and water. This process is called photosynthesis. Leucoplasts on the other hand are found in non-photosynthetic plants. They store lipids, proteins, and starch. Golgi apparatus or Golgi bodies are involved in the transportation of synthesized macromolecules to various cell parts. Centrosomes are present in the plant cell, but unlike animal cells, they do not have centrioles and are much simpler. Many plant cells are equipped with large central vacuoles. These are known to maintain the cell turgor, digest waste proteins, organelles, store useful phosphorus and nitrogen and control molecule movement between sap and cytosol.

Animal cell:

Animals are all multicellular and have very complex functions and features. All cells have different characteristics and functions. For instance, human cells are highly specialized and perform different functions from one another even though they all are human cells. Unlike plant and fungi cells, animal cells do not have a cell wall. They have a thin layer of outer covering called the plasma membrane which separates the cell from the environment. The cells sometimes could be living in an environment with a lot of physical stress which would require the cell to be equipped with an extra layer of protection or padding. This is where the glycocalyx, a thick outer covering enriched with carbohydrate, comes in. The glycocalyx is composed of a layer of secreted mucus, this is present in the urogenital tracts, respiratory tract, and gastrointestinal tract. It also consists of oligosaccharides of glycolipids and glycoproteins.
Animal cells do not comprise of chloroplasts, and they have very small vacuoles that assist in the transport and storage of molecules. Every animal cell does not have the same type of cell organelles because all cells have distinct and specialized functions. Animal cells are eukaryotic cells therefore they comprise a nucleus that consists of the hereditary information and genetic material necessary for cell division, metabolism, and growth. The genetic material is called DNA. DNA stands for deoxyribonucleic acid. The nucleus is enveloped in a nuclear membrane that separates it from the cytoplasm of the cell. The nuclear membrane allows the entry and exit of molecules through the nuclear pore present in them. Animal cells consist of Golgi bodies also known as the Golgi apparatus. These receive proteins from the endoplasmic reticulum which they distribute to various parts of the cell.
Unlike plant cells, animal cells consist of a centrosome. The centrosome is a cellular structure that facilitates the process of cell division. The centrosomes duplicate and move towards the opposite sides of the cell before cell division. They react with chromosomes during mitosis when the nuclear membrane breaks down to produce spindle fibres.
With respect to the particulars provided, one can conclude that plant cells consist of a nucleus, Golgi apparatus, leucoplasts, and to some extent centrosomes. Animal cells on the other hand lack leucoplasts but consist of a nucleus, centrosomes, Golgi bodies, and cell coats also known as glycocalyx.

Note: Robert Hooke first discovered cells in 1665. In 1839, Mathias Jakob Schleiden and Theodor Schwann developed the “cell theory” stating that all organisms are composed of one or more cells. It has been estimated that cells first appeared on earth at least 3.5 billion years ago.