i have a question in biology??
913933
Because of the covalent bonds between water molecules. Because water's polar, the molecules are very attracted to each other. It's important because it allows for things such as capillary action, which can be seen in plants absorbing water through their roots and having the water "climb" up the plant against the force of gravity.
477782
Genetics and evolution.
980794
Simple Biology, ask your doctor.
499299
Doesn't get much simpler than this website, have fun!\n\nhttp://www.biology4kids.com/files/cell_main.html
147158
Interesting question for the science section
892480
True, in fact observations that the offspring from parents of different species (where offspring are possible) are sterile was one of the key lines of evidence that lead Darwin to evolution by natural selection. ie. that once two populations of the same species become different enough, they can't interbreed thus stay separate.  \n\nIt is now established though, through many observations, that bacteria have and do pick up chunks of DNA from unrelated species of bacteria. A lot of their DNA is very mobile. I guess it depends on what you call 'kind'.
826685
You might try posting this question in the general biology area, it seems to get a bit more traffic than over here. Good luck.
416340
I would have to answer that you're asking the wrong question!  \n\nThe explanation of how a plant or animal can develop asexual reproduction isn't going to help you better understand incremental changes via evolution; what you really need to understand is how a plant or animal can develop sexual reproduction. \n\nLooking at the first, microbiological life, asexual reproduction - i.e. cell division or 'budding' -  was the first and most essential form of reproduction. It took century upon century for more complex life to develop and specialize; and, for the mechanisms of sexual reproduction to develop and become established. \n\nThe change from asexual to sexual reproduction would indeed have been  massive, but it doesn't follow that it had to be sudden. When scientists look at species and evolution, they will generally say that one species was more successful at adapting to their environment than another. \n\nIt seems that the ancestors of many plants and animals developed sexual reproduction mechanisms, and they were more successful in competing with other animals for food/territory, over an extended period of time. The less successful ones died out long ago.\n\nSo - it may not be totally accurate to say, "reproduction either works or it doesn't." A better statement would be, "evolutionarily speaking, changes in species over time may cause one method of reproduction to become less successful than another."  \n\nHaving said that: there are other scientists who agree that evolution isn't always slow and gradual; they argue that sometimes evolution happens occasionally in a sudden and dramatic way, when one species splits to become new species - generally the new species are created when one population becomes separated by geographic boundaries. \n\nI'd strongly suggest reading the Wikipedia article (linked below) on Stephen Jay Gould for an evolutionary point of view which counters the slow evolution methodologies advocated by Dawkins; as well as the articple on evolution itself - which looks at the development of the understanding of evolutionary principles and their historical context.
1012471
(A) protozoa\n(B) protozoa are eukaryotes (have membrane bound organelles), bacteria are prokaryotes (no nucleus, organelles, etc)\n(C) there are thousands of protozoans in Kingdom Protista (maybe even millions)\n(D) Protozoans are animal like because they are motile (some have flagella and/or cillia), SOME of them cannot produce their own food (via photosynthesis), so they have to get food from their environment, and some are sexually reproducing organisms.\n(E) via sexual reproduction\n\n(F) next time pay attention in class :)
577147
This article answers your question.\n\nhttp://www.hhmi.org/cgi-bin/askascientist/highlight.pl?kw=&file=answers%2Fgeneral%2Fans_043.html
275559
UPDATE: I've just read your comment so I'm leaving the difficult stuff below. \nFirst things first:\nProbably you know (but it's worth repeating) that the genetic information in each cell is kept as DNA. This DNA is able to copy parts of itself as RNA. RNA in turn builds proteins. Our bodies are not made only of proteins, but proteins are the ultimate regulators of what our body looks like and how it works. So, if a gene in your DNA synthesizes a specific RNA, and this in turn can make a particular protein, this protein will have to do with the way you look and function. Another person with a somewhat different "variety" of the same gene, will have a different appearance and/or function. Each gene codes for one protein, so it takes a really large amount of genes to code for all of them (and this is VERY simplified, the interactions are much more complex).\n\nNow for the second part: the fact that you have several really long DNA strands in each cell (these DNA strands are what can be visualized as chromosomes under special circumstances) does not mean that every single little gene in your DNA will generate RNA and ultimately produce a protein. Only a part of the DNA is actually active (and it's a small proportion), the rest is just "there" and doesn't code. And the expression of the gene (=when the gene's information becomes visible) depends on the interaction with other genes, with other substances that are cellular regulators, and many environmental factors. \n\nExample: you know Siamese cats? they have a genetic constitution such that the dark color proteins are formed especially at the body parts that are colder. So usually you get a sand-colored cat with black legs, tail, and ears. But for this pattern to show, there has to be interaction with the right temperatures. If the cat is not exposed to these colder temperatures, the dark parts don't develop. Or maybe other proteins or regulators "got in the way" of the process. And you get a cat with no dark parts (or the opposite, a very dark animal from excess cold). \nAnother example: suppose a baby is born from tall parents; they in turn had tall parents, so it's highly probable that the baby has the "tall" potential. But if this baby is not well nourished during his/her development, he/she will not reach the height that he "potentially should" have had. \nCan you see the difference? The genotype is ALL the genetic information that you have, and the phenotype is the result of the combination of this genetic information with other factors: the person/animal/plant as it is realized. \nI hope this helps you, I'll be around :-)\n\nCheck this site, it's great:\nhttp://evolution.berkeley.edu/evosite/evo101/IIIA1Genotypevsphenotype.shtml\n-------------------------------\nThe genotype is the genetic information that the said individual carries in each of his/her body cells. Much of that information is never expressed (=becomes "visible" or translates into actual characteristics), and much genetic information can yield different characteristics depending on the interaction with many environmental factors (which occur both inside and outside the cell or organism in question). Thus, the final fully developed individual is the result of the genotype ("raw" genetic information) PLUS environmental/developmental factors; the characteristics of this final product, the real individual, constitute the Phenotype. \nFor instance, an individual with a perfectly "normal" genotype may develop many types of abnormalities due to problems during pregnancy, including drugs, lack of oxygen, etc. Identical twins have the same genotype (they come from a single cell) but are never completely identical; and of course they have different personalities. This is because of all the epigenetic phenomena that influence development. And it's also the reason why reductionist approaches that s
1037910
I don't know how breif this is...but check out this site:\n\nhttp://en.wikipedia.org/wiki/History_of_biology
424765
To keep it short, biology is life.  It's how we move, breathe, digest, and function.
1135493
Biology has become such a vast research enterprise that it is not generally regarded as a single discipline, but as a number of clustered sub-disciplines. This article considers four broad groupings. The first group consists of those disciplines that study the basic structures of living systems: cells, genes etc.; the second group considers the operation of these structures at the level of tissues, organs, and bodies; the third group considers organisms and their histories; the final constellation of disciplines focuses on their interactions. It is important to note, however, that these boundaries, groupings, and descriptions are a simplified characterization of biological research. In reality, the boundaries between disciplines are fluid, and most disciplines frequently borrow techniques from each other. For example, evolutionary biology leans heavily on techniques from molecular biology to determine DNA sequences, which assist in understanding the genetic variation of a population; and physiology borrows extensively from cell biology in describing the function of organ systems.
1048996
Hey Bud, have you ever taken a class in evolution?\n\n"You're logic is flawed. There is plenty of evidence to show small adaptations within a species. These small variations enable animals to adapt to their environments.\n\nBut to go from that to changes from one species to another is quite a blind leap of faith and poor science as well. " Poor science according to who?\n\nHow many small variations does it take to turn one species into another?  A few small genetic variations make slight changes in organisms.... a few more make more changes... a few more make even more changes, and eventually enough of these little changes of added up so that the 2 groups of organisms are no longer able to interbreed. Thus, a new species - evolution at work.\n\nPoor science is when people who have not studied evolution try to disprove it. You come up with some pretty wacky ideas. Evolution is not something that animals do on purpose to improve. There is no plan, purpose, or goal to evolution. An animal that adapts to his environment (after he is already born) like your example is NOT evolution. Evolution affects populations, not individuals, and it does not 'occur' after an organism is born. Evolution only occurs when the gene frequency in the population is changed, through natural selection, random mutation, drift, etc.
429454
hi, i work 4 a book company, and 1 of our regular books is on cell and molecular biology, if you email me, i can probably give you an answer on exactly what ur question is.
413968
http://dev.biologists.org/cgi/content/full/130/17/4123?ck=nck