Virus Structure Viruses are not plants, animals, or bacteria, but they are the quintessential parasites of the living kingdoms. Although they may seem like living organisms because of their prodigious reproductive abilities, viruses are not living organisms in the strict sense of the word.
Plant Cell Structure Plants are unique among the eukaryotes, organisms whose cells have membrane-enclosed nuclei and organelles, because they can manufacture their own food.
Chlorophyll, which gives plants their green color, enables them to use sunlight to convert water and carbon dioxide into sugars and carbohydrates, chemicals the cell uses for fuel. Like the fungi, another kingdom of eukaryotes, plant cells have retained the protective cell wall structure of their prokaryotic ancestors.
The basic plant cell shares a similar construction motif with the typical eukaryote cell, but does not have centrioles, lysosomes, intermediate filaments, cilia, or flagella, as does the animal cell.
Plant cells do, however, have a number of other specialized structures, including a rigid cell wall, central vacuole, plasmodesmata, and chloroplasts. Although plants and their typical cells are non-motile, some species produce gametes that do exhibit flagella and are, therefore, able to move about.
Plants can be broadly categorized into two basic types: Vascular plants are considered to be more advanced than nonvascular plants because they have evolved specialized tissues, namely xylem, which is involved in structural support and water conduction, and phloem, which functions in food conduction.
Consequently, they also possess roots, stems, and leaves, representing a higher form of organization that is characteristically absent in plants lacking vascular tissues. The nonvascular plants, members of the division Bryophyta, are usually no more than an inch or two in height because they do not have adequate support, which is provided by vascular tissues to other plants, to grow bigger.
They also are more dependent on the environment that surrounds them to maintain appropriate amounts of moisture and, therefore, tend to inhabit damp, shady areas.
It is estimated that there are at leastspecies of plants in the world today. They range in size and complexity from small, nonvascular mosses to giant sequoia trees, the largest living organisms, growing as tall as feet meters.
Only a tiny percentage of those species are directly used by people for food, shelter, fiber, and medicine. Nonetheless, plants are the basis for the Earth's ecosystem and food web, and without them complex animal life forms such as humans could never have evolved.
Indeed, all living organisms are dependent either directly or indirectly on the energy produced by photosynthesis, and the byproduct of this process, oxygen, is essential to animals. Plants also reduce the amount of carbon dioxide present in the atmosphere, hinder soil erosion, and influence water levels and quality.
Plants exhibit life cycles that involve alternating generations of diploid forms, which contain paired chromosome sets in their cell nuclei, and haploid forms, which only possess a single set.
Generally these two forms of a plant are very dissimilar in appearance. In higher plants, the diploid generation, the members of which are known as sporophytes due to their ability to produce spores, is usually dominant and more recognizable than the haploid gametophyte generation.
In Bryophytes, however, the gametophyte form is dominant and physiologically necessary to the sporophyte form.
Animals are required to consume protein in order to obtain nitrogen, but plants are able to utilize inorganic forms of the element and, therefore, do not need an outside source of protein. Plants do, however, usually require significant amounts of water, which is needed for the photosynthetic process, to maintain cell structure and facilitate growth, and as a means of bringing nutrients to plant cells.Guard cells are able to control how open or closed stomata are by changing shape.
They are like an inflatable set of doors that make the opening between the two cells wider or narrower. Modifying the shapes of cells to influence function: By Edward R.
Winstead. March 1, Scientists have developed specialized glass surfaces for growing cells that allow them to control and modify the shapes of cells and their nuclei.
Cells come in many shapes and sizes. Some cells are covered by a cell wall, other are not, some have slimy coats or elongated structures that push and pull them through their environment.
(Deoxyribonucleic Acid) contains all the information for cells to live, perform their functions and reproduce.
Inside the nucleus is another organelle. Well, the muscle cell is long and skinny, therefore it can pass by things easier. Muscle cells have many mitocondria to break down the energy to preform that function. Oct 17, · Best Answer: Cheek cells are flat like tiles or roofing shingles.
They are a perfect shape for making a covering over the inside of the ashio-midori.com: Resolved. Regrettably, most animal cells grown in culture lose their normal morphology and become blob-like, although careful quantitative analysis has shown that cultured cells still have defined shapes in the sense that they only take on a subset of the total set of bloblike shapes.
9 Growing cells in 3-D cultures might help to elicit more diverse cell.