How is a Cell defined?

Question

Fill in the blanks

A cell is defined as ___. Cells were first described by the English scientist ___, who thought that they resembled the tiny rooms, or cells, where monks live. (Actually, ___ did not see living cells- just the ___ of dead cork cells.) Cells contain structures called ___. This term means tiny ___.

The discovery of cells and their internal parts was made possible by the invention of the ___ in the ___ century. During the next two hundrred years, the work of many scientists lead to the development of the ___theory. This theory can be summarized in three statements :

1.

2.

3.

Answer 1

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is sometimes called the building block of life.[1] Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an ostrich egg. In 1837 before the final cell theory was developed, a Czech Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells. All cells come from preexisting cells. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.[2]

The word cell comes from the Latin cellula, meaning, a small room. The descriptive name for the smallest living biological structure was chosen by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in.[3]

Each cell is at least somewhat self-contained and self-maintaining: it can take in nutrients, convert these nutrients into energy, carry out specialized functions, and reproduce as necessary. Each cell stores its own set of instructions for carrying out each of these activities.



Mouse cells grown in a culture dish. These cells grow in large clumps, but each individual cell is about 10 micrometres acrossAll cells have several different abilities:[4]

Reproduction by cell division: (binary fission/mitosis or meiosis).

Use of enzymes and other proteins coded for by DNA genes and made via messenger RNA intermediates and ribosomes.

Metabolism, including taking in raw materials, building cell components, converting energy, molecules and releasing by-products. The functioning of a cell depends upon its ability to extract and use chemical energy stored in organic molecules. This energy is released and then used in metabolic pathways.

Response to external and internal stimuli such as changes in temperature, pH or levels of nutrients.

Cell contents are contained within a cell surface membrane that is made from a lipid bilayer with proteins embedded in it.

Some prokaryotic cells contain important internal membrane-bound compartments,[5] but eukaryotic cells have a specialized set of internal membrane compartments. Material is moved between these compartments by regulated traffic and transport of small spheres of membrane-bound material called vesicles.

Anatomy of cells

There are two types of cells: eukaryotic and prokaryotic. Prokaryotic cells are usually independent, while eukaryotic cells are often found in multicellular organisms

to know more about cell detaled functions with diagrams go to http://en.wikipedia.org/wiki/Cell_%28bio...

The cell theory is a widely accepted explanation of the relationship between cells and living things. The cell theory states:

All living things are composed of cells.

Cells are the basic unit of structure and function in living things.

All cells are produced from other cells.

The cell theory holds true for all living things, no matter how big or small, or how simple or complex. Since according to research, cells are common to all living things, they can provide information about all life. And because all cells come from other cells, scientists can study cells to learn about growth, reproduction, and all other functions that living things perform. By learning about cells and how they function, you can learn about all types of living things.

hope this helped you ;)

Answer 2

As a biologist and a university lecturer in Anatomy and Physiology, I forbid anyone to answer this question.  The English scientist who first coined the term "Cell" is amongst the most famous scientists in all of science.  His famous cork experiments are absolutely everywhere on the net and the theory referred to in the question is amongst the most fundamental in all of biology.  Not being able to find those answers your self means you have no business having the answers since you clearly have no interest in science.

One of the most important parts of science is researching information and discovering things no one has ever seen before.  We do that by looking through the literature to see what has been done before us so we can then base our experiments on this work.  In other words you MUST know how to find existing information, especially work as fundamental and as widely reported as that needed for this question.

We can explain things you don't understand here, but but you should avoid just passing off work you can't be bothered doing to other people if you can since it escapes the purpose of such assignment questions, ie it is not having the answer that is important, it your ability to come up with the answer that is.