A.) organ\nB.) organelle\nC.) organ system\nD.) organism
131931
Depending on how picky you want to be, the answer could be A or C.  By definition an organ is always composed of two or more tissue types.  Many organs contain all four major tissue types:  epithelial, connective, muscle, and nervous.  So A is certainly correct.  Since organ systems by definition are composed of two or more organs, they must also be composed of more than one tissue type.\n\nB is not correct because an organelle is a constituent of a single cell, which lies beneath tissues and organs in the hierarchy of organizational levels in complex multicellular organisms.  D could be correct if the organism in question is complex enough to have organs and organ systems.  On the other hand, simple forms of life such as bacteria and protists are also organisms, but being single-celled they obviously have not reached the level of organization at which tissues and organs are found.
272576
B.\n\nDo your homework.
402124
1 ribosomes\n2 stimuli\n3 enzyme\n4 cytoplasm
427337
Endoplasmic reticulum = 1\nRibosome(s)                 = several\nNucleus                         = 1 but has an inner Nucleolus\nlysosome                      = several\ngolgi bodies                   = I think 1  :)\nmitochondria                 = as u said "mitochondria" & not mitochondrion, so there are several of them\nvacuole                          = several (unlike the plant cell which has one big vacuole)\ncheers
417348
organelle is a microscopic component of a cell...whereas a structure is refered to a cell..a whole cell and it's components
386964
"d" is the answer.\n\nGet an "A".
554092
1. Mitochondria\n2. Cilia\n3. Co-enzymes
504288
the mitochondria...i think
415288
Mitochondria is said to be a living organelle because it has its own DNA and it can reproduce separately from the cell it self (just like chloroplast). Mitochondria is a living cell inside another living cell. It has its own DNA (which is different from the cell's DNA) and has 2 layers of membrane: the outer layer has the same composition as the cell membrane but the inner layer has a different composition, unique to the mitochondria. There are evidence that at one point, mitochondria (as well as chloroplast) was a free living cell. That is why both mitochondria and chloroplast are called living organelles.\n\nPlatelets are said to be non living because they are not real cells, they are cell particles. They don't have nucleus and don't metabolize anything. They are more like free chemicals in blood.
546350
The heart is what pumps blood throughout the body, keeping all organs functioning. Blood flows to the body through arteries and blood flows back to the heart through veins. Its all one big system - the circulatory system.
503153
Cytoplasm is the area within the cell inside the plasma membrane (the membrane separate the cell to others) and outside the nucleus (the region contaning genetic materials DNA). Cytoplasm contains many internal organelles (internal structures) that are necessary for cell's functions.\nINternal organelles: Ribosome (needed to make proteins), Golgi complex, lysosomes (digest defective materials in cells, only found in animal cells),Endoplastic Reticulum (2 types: rough with ribosome attached and smooth without ribosome), central vacuole (store H2O, toxins, pigments, waste), Mitochondria (use to make energy for cell, mostly from glucose), chloroplast (needed for photosynthesis in plant cells only),cytoskeleton (connect organelles to each other and membrane, control cell movement, cilia and flagella (cell movements inside an organism).
181153
cell walls, a nucleus, and phytoplasm
182680
All the different cell components surrounded by the cell membrane that make up a cell. Many of these replicate as the cell replicates.\nwww.pub.ac.za/resources/glossary.html\n\nA specialized cytoplasmic structure of a cell performing a specific function.\nwww.epidemic.org/glossaryText/glossaryM-O.html\n\nMembrane-bound intracellular, cytoplasmic structures having specialized functions, eg, mitochondria, plastics, Golgi apparatus, lysosomes.\nwww.kumc.edu/gec/gloss.html\n\ncompartments within cells. Organelles are separated from the rest of the cell by a membrane, and they exist to separate certain functions of the cell and concentrate those functions to make them more efficient. The organelle systems of the cell include the nucleus, the mitochondrion, the secretory system (includes the endoplasmic reticulum, the Golgi apparatus, the endosomes, the lysosomes), and the peroxisome.\nwww.peroxisome.org/Layperson/definitionstext.html\n\nminute, intracellular structures serving a specific function in the life processes of the cell.\nwww.uwo.ca/pathol/glossary.html\n\nSpecialized organs within cells.\nwww.fisicx.com/quickreference/science/glossary.html\n\nCell components that carry out individual functions; eg, the cell nucleus and the endoplasmic reticulum. Subcellular structures (usually membrane-bound and unique to eukaryotes) that perform some function, eg chloroplast, mitochondrion, nucleus.\nblue.utb.edu/biology/Oliva/terms_and_definitions_for_quiz_1.htm\n\nLiterally, the term means "little organs." Inside a cell, there are various little structures that perform specific functions, much like the multicellular organs of our body do. In the cell, these include generating energy (the organelle is the mitochondrion), making proteins (the organelles are ribosomes and Golgi apparatus), and others.\npeer.tamu.edu/curriculum_modules/Cell_Biology/Glossary/gloslist.html\n\nOR-gan-NELLZ Specialized structures in eukaryotic cells that carry out specific functions. 5, 60\nwww.mhhe.com/biosci/genbio/life/glossaryo.mhtml\n\nSmall structures within a cell that maintain the cells and do the cells' work.\nwww.mindsci-clinic.com/neuro_jargon.htm\n\nIn cell biology, an organelle is one of several structures with specialized functions, suspended in the cytoplasm of a eukaryotic cell. Organelles were historically identified through the use of some form of microscopy and were also identified through the use of cell fractionation. \nen.wikipedia.org/wiki/Organelles ...you figure out the similarities :)
368045
1. periodic table (?), 2. nucleotides, bases,  3. fatty acids,  6. saturated fatty acid, trans fat,  8. energy (?), 12. adenosine diphosphate (ADP)
497842
1) DNA\n\n2) Chromosomes\n\n3) Genes
33986
chloroplasts, flagella, contractile vacuoles and the eye spot for starters.
183487
Skin, lungs, and liver.