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Quickie Questions - Alive and Living - Other

Date Answered Questioner (age, location) Question Answer

January 14, 2010arelii (age 14, dallas tx) is it true that it rained frogs some where? Well, I haven't witness one myself, but read this article!
January 8, 2010ibrahim (age 13, uk ) will life on earth end oneday? when will that day be?

does evrtthing have a beginning andd an end?
explain life on earth? will it end or survive?
Well, a star with a mass similar to our Sun and in the last phase of its life is a red giant. At this point, the Sun will have expanded to cover all the interior planets, including the Earth. But before that, in about 1.1 Gyr (1 100 000 000 years) from today) the Sun will be 10% brighter and this extra solar energy will cause the Earth's atmosphere to dry out. Under such conditions, surface life on Earth will probably be exterminated.
January 7, 2010lauran (age 15, texas) which scientist discovered molds? Molds are fungi that are found virtually everywhere. No a single scientist discovered them. One of the most important discovery related with molds was the discovery of penicillin, attributed to Scottish scientist Alexander Fleming in 1928.
January 5, 2010lauren (age 15, england) do protists eat and if so what do they eat? Protists eat by phagocytosis. Plant-like protists (e.g. algae) produce their own food. Animal-like protists ingest bacteria, other protists, and particles they find in the water. Fungal-like protists feed on dead or decaying organic matter, bacteria, and sometimes other fungal-like protists (found on: and
January 4, 2010jahnavi.s (age 7, india) what is exobiology?;how is milky way born? It is defined as the branch of biology concerned with the effects of outer space on living organisms and the search for extraterrestrial life (
January 4, 2010Siobhan (age 14, America) What are the steps in which proteins are made in cells? In a process called translation! Before this, a mRNA is created using DNA template (transcription). The mRNA then binds to the two parts of ribosome, tRNA, and translation allows the amino acids made in this process to bind to each other to form proteins, which can go through additional configurations in order to be active. More information can be found here and here.
October 16, 2009LAILA (age 12, PEKAN) WHY MARS DOES NOT HAVE LIVING THINGS ? Life, as we know it, requires of very especific conditions to exist. Earth seems to be just right for living creatures, at the perfect distance from the sun for lots of water. Mars is not. See our web page The Goldilocks Theory for more information.
September 30, 2009Lucy (age 13, Australia) What is the most inhabitable planet other than Earth? The only planet where life has flourished is Earth, from the rest of the planets in our Solar System, only Mars has, more or less, the right distance from the Sun.
September 30, 2009Marlene (age 15, Philippines) What are the 2 divisions under kingdom Monera ? Kingdom Monera is divided in Division Eubacteriophyta, Division Archaebacteriophyta, and Division Cyanophyta.
September 28, 2009Tankiso (age 21, South Africa) "why does the human so interllegent than other species in our environment" This is too compex a topic for this section. Maybe this article will help you.
August 20, 2009Joy (age 68, Georgia) If your body is a mass; and mass is energy; and if energy never dies what happens to it when you die? While the body descomposses, the atoms that form it are just freed to form new bonds and create new elements and molecules.
August 19, 2009charles Yi (age 13, tokyo,japan) How did life started on Earth? From an interview with Andrew Knoll, a professor of biology at Harvard and author of Life on a Young Planet: The First Three Billion Years of Life: "The short answer is we don't really know how life originated on this planet. There have been a variety of experiments that tell us some possible roads, but we remain in substantial ignorance. That said, I think what we're looking for is some kind of molecule that is simple enough that it can be made by physical processes on the young Earth, yet complicated enough that it can take charge of making more of itself. That, I think, is the moment when we cross that great divide and start moving toward something that most people would recognize as living." Read the interview here.
August 10, 2009Allison (age 22, USA) Humans have been here for a long long time right...Did humans evolve from something? IF so, what did we evolve from and what will we be after we do? Evolution, the process of change through time, applies to many things: languages plants, animals, including humans. We have a comprehensive web page dedicate to this topic. Please, visit Evolution and the links therein to learn much on this topic. I especially recommend the Evidence of Evolution Exploratour.
July 22, 2009alicia (age 29, tx/usa) what are five pieces of evidence that support microevolution? Microevolution is changes in the gene pool of a population over time that result in changes to the varieties of individuals in a population such as a change in a species' coloring or size. This process happens through Gene mutation, Gene flow, Genetic drift, and Natural selection. Our web page Evidence of Evolution, Microevolution: Individuals Don’t Evolve, Populations Do offers detailed information on this topic.
June 2, 2009sasha (age 13, U.S.) how is it possible for animals to live in the deepest parts of the ocean Through very radical adaptations! For example, this article describes some of the special adaptations for living in extremely high pressure, low light conditions.
April 21, 2009claire (age 12, MO) Why is Earth the only planet that supports life and how do we know that other planets can't support life? Earth is the only planet that supports life in our solar system. Scientists keep looking for extraterrestrial life everywhere. One of the most widely accepted theory to explain life on earth is called The Goldilocks Theory.
April 16, 2009chris (age 16, oakcliff, tx usa) why don't we know if there is other life on other planets yet?????:)))))) Because the search for extraterrestrial life includes looking for life forms different from our own. It would be easy to spot a human-like life form (or a life form like those on Earth), but something different would be much harder.
April 15, 2009india (age , uk) What Facts Do You Know About Evolution, how the world was created ? I think it would be easier if you take our Evidence of Evolution Exploratour. There you will find many facts and evidences of the evolution.
April 13, 2009monique (age 11, NSW) what is in the earths biosphere and send me back 2 things that are in the biosphere. The biosphere is all life on our planet. This includes all the things that are living as well as the remains of those that have died but have not yet decomposed. The biosphere includes life on land and in the oceans - multitudes of plants, animals, fungi, protists, and bacteria. Much more information on our wb page The Earth's Biosphere.
March 23, 2009Angus (age 16, Vietnam) what is your opinion on a wildfires Wildfires are frequently seem as beneficial to the wilderness, as many plant species are dependent on the effects of fire for growth and reproduction. However, large wildfires often have detrimental atmospheric consequences, can cause human and material lost, and can triger other adverse effects.
February 26, 2009x VirjiniAx (age eleven, ON) how do we come from monkeys? This is a very complex topic that escapes the reach of this section. But visit our web page Evolution to find a comprehensive discussion on this topic.
February 24, 2009Rasha (age 10, Kentucky , U.S.A) How is it possible that the world could end in 2012? There is no scientific reason for such a disaster and extinction to happen!
February 24, 2009claire (age 11, missouri) What are some common examples of eubacteria? Some Eubacteria can cause problems for human health. For instance, Streptococci bacteria cause strep throat. If Staphylococci bacteria gets into a cut in your skin it can cause an infection that is called a staph infection. Bacteria such as E.coli and Salmonella are sometimes found in undercooked meat and eggs and can make people sick. Other bacteria are beneficial to human health, such as those found in yogurt.
February 19, 2009rowena (age 19, philippines) how does comet help the earth to produce life? New theories propossed that life began in space, and specifically in the hearts of comets, rather than on Earth. More information here.
February 17, 2009Rachel (age 12, North Dakota) When food spoiles, does fungi grow on it? Fungi are a group of microbes, which grow like plants but get their food by breaking down dead material. They include the moulds and mildews which are responsible for rotting and decay. More information here.
February 17, 2009Kwame (age 12, Connecticut) Can youu give informatoin on this type of archaea? Thermoplasmatles Thermoplasmatales: NCBI Taxonomy ID: 2301 NCBI Taxonomy Rank: Order A phylogenetically distinct line of Archaea contains three thermophilic and extremely acidophilic prokaryotes, Thermoplasma, Ferroplasma, and Picrophilus. These organisms are among the most acidophilic of all known prokaryotes and, in the case of Picrophilus, even capable of growth below pH 0. Taken from the text Brock Biology of Microorganisms (10th ed.). Madigan, M.T., Martinko, J.M., and Parker, J. 2003. Prentice Hall. 456p. For more information visit the website Thermoplasma.
February 12, 2009jarmila (age 12, philippines) why can't the mars cannot sustain life? Scientists are still looking for life outside our planet. There is no final answer to this question yet.
February 12, 2009jarmila kaye (age 12, philippines) why can't the mars cannot sustain life? Scientists are still looking for life outside our planet. There is no final answer to this question yet.
February 6, 2009Clive (age 42i, Ireland) Is there intelligent life other than us out there Scientists haven't found a final proof of extraterrestrial life, but they keep looking.
February 5, 2009gautam (age 19, bihar/india) another heavenly bodies apart from earth has been detected with liquid at its surface. what are the possibilities of the existence of life there? Life, as we know it, requires the existence of water, and this is one of the most important characteristics looked by scientists in other system's planets. The real possibility is hard to estimate, but it is a good start to be able to find water in other celestial bodies.
February 3, 2009Alvaro (age 95, H-town) Why is their life on earth? It is called The Goldilocks Theory: Just as Goldilocks found the porridge that was just right, the Earth seems to be just right for living creatures. The Earth seems to be the perfect distance from the sun for lots of water.
January 26, 2009justin (age 9, alabama/america) is the escosystem changing Ecosystems are constantly changing. Changes can be brought by both natural and man-made causes.
January 26, 2009justin (age 9, alabama/america) what plants and animals live in the escosystem Many similar ecosystems form a biome. Follow these links to learn more about the plants and animals that live in each one: Tundra, Taiga, Temperate forest, Tropical rainforest, Desert, Grassland, and Ocean biome.
November 11, 2008yaudat (age 8, San antonio, tx) Why the Sun's ray are more of a danger than in the past? As Earth's protective ozone layer is thinning, levels of harmful ultraviolet radiation are expected to rise. See this article for more information.
November 7, 2008kim (age 14, philippines) what is life? Here is our What is Life page. Artificial life does not yet exist, but there are many people who are working toward creating it someday.
November 6, 2008STEPHANIE (age 19, CALIFORNIA) is it true that when an eclipse happens pregnant women should put something red around their bellies to prevent the eclipse from eating their baby???
please answer as soon as possible very curious.
oh and another question when was the last eclipse?
and the next one going to happen??
No, this is just a myth. The only danger during eclipses is to look directly to the Sun without adequate protection. This could irreversibly damage our eyes.
November 6, 2008nishi (age 10, india) what is a stem? It depends on the context, but in general stem is a slender or elongated structure that supports a plant or fungus or a plant part or plant organ.
November 3, 2008rebekah (age 14, usa) what do heterotrophs eat? Heterotrophs are organism that requires organic substrates to get its chemical energy for growth and development.
November 3, 2008cya (age 13, india) why do people have different types of hair like wavy,straight,curly etc? and why do people have different hair colour? For the same reasons we all have different facial characteristics, skin color or feet size: our genetic information produced by the combination of our parents genes.
October 31, 2008CRETIA (age 18, FL) WHAT IS LIFE Here is our What is Life page. Artificial life does not yet exist, but there are many people who are working toward creating it someday.
October 21, 2008miss akma (age 16, malaysia) is that true that one day humans can live at mars because i just read that fact in a book that told the humans can go to the mars using a LIFT???thank you for answering my question.... Scientists are studying all planets in our system and beyond. There is still not a clear winner for our second home, and in any case, our technology is not adavanced enough to make a planet habitable for humans.
September 30, 2008Karol (age 58, Tennessee) I have been looking at phylum rotifera / phylodina / diatoms. The information is astounding, with one exception: What is the samllest multi-celled creature, an aprx how many cells does it consist of? An example of very small organism is found among the green alga Volvox and its relatives. The ranges of sizes go from the single cell Chlamydomonas to the 16-cell Gonium, Eudorina, and finally to the largest species of Volvox, which may consist of 50000 or more cells. This page offers an extensive discussion on this topic.
September 18, 2008Davin (age 12, Indonesia) I think the alive in the earth is comes from others planet and evolution to many creatures,is that true? That is one of the main stream theories about the origin of life in our planet. It is known as exogenesis.
September 17, 2008aditya (age 16, india,kerala) 1.Is there life in mars? is this universe formed?
3.Is there life in darwin 4?
4.i have to a nasa scientist
if you are having orkut account plz join our community called -tt nasa kids
My email
No, so far scientists haven't found life outside Earth.
September 12, 2008avneet (age 13, india) will the life on earth be extincted after 20-40 yrs? No, there is no reason for that extinction to happen!
September 8, 2008immaculate (age 17, south africa) where do live come from after the bigbang Your question requires a detailed answer beyond the scope of this section, but here is a good discusion on this topic.
September 5, 2008Candy (age 13, Philippines) why is it that blue green algae belong to the kingdom eubacteria while the ordinary algaes belong to the kingdom protista The basic difference is that cyanobacteria, also called blue-green algae, are formed by prokaryotic cells, which have no nucleus or organelles enclosed within membranes. Species in the Eubacteria domain have prokaryotic cells. On the other hand, ordnary algaes are formed by eukaryotic cells (cells with a nucleus and organelles surrounded by membranes), and are members of the Kingdom Protista, part of the Eukaryota domain.
August 19, 2008abinaya (age 16, chennai/ india/) if there is any change in the universe The universe is always changing. Nothing stays the same. From atomic reactions to galaxies, there are always changes occurring.
July 3, 2008Cholo (age 17, South Carolina) 3 examples of organic substances? An organic substance is a complex carbon-containing substance; often produced by a living organism: for example, sugar, honey, alcohol.
July 2, 2008Sean (age 12, NC U.S.) In biomes located on land, abiotic factors are used to classify the differnt biome types. What are these abiotic factors? Abiotic components are the nonliving components of the biosphere. Chemical and geological factors (like rocks and minerals), and physical factors (temperature, weather, etc), are abiotic components.
June 24, 2008CHELSE (age 11, PENNSYLVANIA) HOW DO FUNGI CELLS DIFFER FROM PLANT CELLS ? HOW ARE THEY ALIKE Fungi have cell walls (like plants) but the cell walls are composed of chitin. The cell walls of plants and some protists are composed of cellulose.
June 23, 2008DURRIYA (age 21, PAKISTAN) what is the relation between hydrosphere and biosphere? The intearction between the hydrosphere and the biosphere is very complex and dynamic, but there is an element that can't be miss: animals necessitate water for metabolic processes or, in other words, without water there will not exist life as we know it.
May 29, 2008urja (age 12, india maharashtra) are we humans progressed enough to find all the remaining secrets of the universe?? No by far! Scientists keep studying the universe, life, etc. to understand them more and more. There are so many things that we still don't know!
April 30, 2008rahul (age 11, kerala/india) is there life in other planets Scientists have not found extraterrestrial life, but they keep looking!
March 27, 2008Tifani (age 27, north carolina, usa) How many comets, meteors, etc. can be realated to the apperance of life on earth? You will find here information on this topic.
March 18, 2008Jenn (age 14, USA) What is the difference between a procariotic cell, and a eukariotic cell? Prokaryotic cells have no nucleus or organelles enclosed within membranes. Eukaryotic cells have a nucleus and organelles that are surrounded by membranes. Each organelle does a specific cell function.
March 18, 2008hillary (age 11, canada) could there be other "creatures" in another glaxie? Scientists have not found extraterrestrial life, but they keep looking!
March 17, 2008brandon (age 14, ca usa) is ther life in the entire Universe Well, yes, on our planet. Scientists have not found extraterrestrial life, but they keep looking!
February 13, 2008Nripendra (age 21, Nepal) Can life exists in the universe forever? I believe life will always evolve under the right conditions.
February 13, 2008Nyoka (age 13, Qld Australia) Do you think Aliens are real,and that they can survive/live on other planets So far, the efforts to find extraterrestrial life have not been successful.
February 4, 2008brittany (age 15, mississippi united states of america) how do you contrast archea bacteria and eubacteria? The Domains of Life are Archaea (very primitive forms of bacteria), Eubacteria (more advanced forms of bacteria), and Eukaryota (all life forms with eukaryotic cells including plants and animals). OPlease, visit our web pages Archaea and Eubacteria for further information on them.
January 25, 2008radwa (age 14.5, egypt) is there any life on other planet corresponding to earth in other galaxy? So far, the efforts to find extraterrestrial life have not been successful.
December 27, 2007jimmy (age 12, Australia) Is there any life in space besides earth? So far, the efforts to find extraterrestrial life have not been successful.
December 17, 2007cdabney (age 8, California USA) what is the difference between a biome and an ecosystem? There are several definitions for both, among them: Biome: A living community characterized by distinctive plant and animal species and maintained under the climatic conditions of the region. Ecosystem: a functional unit consisting of all the living organisms (plants, animals, and microbes) in a given area, and all the non-living physical and chemical factors of their environment, linked together through nutrient cycling and energy flow.
December 10, 2007candy (age 27, philippines) why are cells called the building block of life The Cell Theory states that all living things are made of cells, which are the basic units of life, and that cells come from other cells. More information in our web page Cells Introduction.
November 5, 2007kenneth (age 13, philippines) can we still breath at the peak of Mt. Everest?"because they said that we can't breath because atmosphere is composed of carbon-dioxide...but for me we can still breath because the atmosphere has 4 layers the first is the troposphere which is the nearest to the ground and contains air we breath so it means we can still breath(for my own explaination only)... At 10,000 to 14,000 feet, the available oxygen is only 60 to 70 percent that of sea level. As you climb higher and higher, it gets harder to breathe.
October 15, 2007omon (age 18, sydeny) compare and contract the past and presentenviroment of archaea I believe you will find the information you are looking foe in our web page archaea.
September 24, 2007Courtney (age 12, Alabama) More than 2 billion years ago what produced oxygen? Plants created the Earth's oxygen-rich atmosphere. Over one billion years ago, in Earth's early ocean, the most complex life was bacteria surviving by extracting chemical energy from minerals. But then, a bacteria made an extra-ordinary evolutionary leap by learning to live on sunshine and water. This ability to extract energy from the abundance of sunlight and water was a great advantage, and these evolutionary innovators proliferated and spread. Extracted from Ancient Forests. The Balance of Life.
August 17, 2007mary (age 70, ohio) are cell phones safe during a electrial storms? In general, no metallic objects should be used during electric storms, including cell phones.
August 15, 2007Partha (age 11, India) Can there be life in other conditions other than the conditions found on earth, if yes then why are scientists not looking into this also? Life has been found under very harsh conditions, like around hydrothermal vents or vent chimneys at the bottom of the oceans. Scientists study these (different) life forms to understand better the origin and evolution of life.
July 23, 2007Ethan (age 10, newbury) how many life forms are on mars So far none, but we keep looking!
July 21, 2007ruchika (age 15, faridhabad/india) where,when and how the cysts are formed in the life of a amoeba A special membrane is secreted under adverse conditions to protect the amoeba. This membrane is called a cyst membrane. This “encystment” occurs to keep the amoeba alive until it reaches an adequate area.
July 21, 2007Yvette (age 13, Zambales, Philippines) can we consider rock as a living thing? In a very broad sense, life is a condition that distinguishes organisms from inorganic objects. Following this definition, a rock is not considered a living thing.
July 18, 2007jim (age 36, california usa) how important it's a manta ray fossil? All fossils contribute to the study of our past. I believe they are all important.
June 28, 2007kendra (age 15, ny) can life as we know it be found on venus?? please answer its due soon. The average temperature on Venus is 457 oC (855 oF). This temperatures are extreme for life as we know it.
May 10, 2007brandon (age 9, new yok ) describe how living how living things are divided into groups Living things are divided into three groups based on their genetic similarity. The three groups are: Archaea: very primitive forms of bacteria. Eubacteria: More advanced forms of bacteria. Eukaryota: All life forms with eukaryotic cells including plants and animals. For a more detailed information, visit our web page Classification of Living Things.
May 5, 2007kiwi (age 16, canada) how does kingdom protista affect us? Members of the Kingdom Protista are the simplest of the eukaryotes. Protistans are an interesting assemblage of organisms classified for what they are not. Protistans lack characteristics shared by plants, fungi, and animals, but they're not bacteria. Essentially, this Kingdom is home for the "leftover" organisms that couldn't be classified elsewhere! Protists are used in toothpaste, scouring pads, filters, puddings, salad dressings, and others. Protists also cause amoebic dysentery, African sleeping sickness, malaria, plant blights, red tide (from dinoflagellates), and others.
February 12, 2007fairy (age 17, alaska) does eubacteria have cell walls Eubacteria, also know as “true bacteria”, are microscopic prokaryotic cells. They don't have nucleus or organelles enclosed within membranes, but they do have cell walls. For more information visit our web page The Domain Eubacteria, and for a diagram of prokaryotic cells visite Cells.
January 21, 2007Marissa (age 15, Florida) What are some examples (organisms) of Autotrophs? Examples of autotrophs are plants and algae. More information about autotrophs is available at our page Autotrophs.
January 5, 2007aleashia (age 14, alaska/u.s) where can i find pictures of each of the five kingdoms? You can start your search in our site. A good starting point could be our web page Classification of Living Things. I believe you will find many useful pictures and information.
November 12, 2006nick (age 15, arizona) What kind of scientific degree do you have?
How many years did it take you to get your degree?
How many hours a week do you work?
Could you describe a typical day at work?
Do you enjoy being a biologist?
You can find information about the Windows to the Universe team at this page Thank you for using Windows to the Universe!
September 24, 2004Hazel (age 13, philippines) What are examples that fall in the classification of Kingdom Protista? A one-celled amoeba and sea kelp are both examples of organisms that are under the Kingdom Protista.
November 10, 2003brittany(age 13, Illinois, USA) What is microbacteria ranae? Mycobacterium ranae is a bacterium that sometimes causes disease in frogs (rana is the Latin word for frog). It is spread through the water, and enters the frog through skin abrasions or cuts.
January 31, 2003 Ariannas (age 12, Florida, USA) What do living things need nitrogen for? Living things depend on nitrogen because our bodies need amino acids, DNA, RNA, vitamins, and other small molecules to live, and these molecules all contain nitrogen atoms.

November 22, 2002 Chris (age 14, Texas, USA) What are the producers and consumers of the tundra ecosystem? Even though vegetation is limited in the tundra ecosystem and there are no trees, producers include lichens, mosses, grasses, and bushes. Consumers can be abundant and include herbivores such as caribou and musk oxen, and carnivores such as polar bears. Visit our tundra section for more information about tundra ecology.

July 31, 2001 Rachel (age 15, Australia) What factors and conditions influence biodegradability? Biodegradability is determined by a lot of different factors. One of the most important is the number and variety of microorganisms growing in the area in question, and the abilities of these organisms to deal with chemicals that are not normally found in nature (these chemicals are sometimes called xenobiotics). Other important factors include the temperature of the environment, the pressure, the chemistry of the environment (oxygen availability, pH, and other factors like this), and even less obvious factors like how isolated the environment is (for example, is there moving water or air that would replenish the environment, or would toxic byproducts eventually build up and poison any microorganisms).
July 23, 2001 Steven (13, New South Wales, Australia) I am doing a science project about a'life-bubble' in space and I need to know what types of things I am going to need to sustain life and how to do it, could you please help me? The most basic things needed to support human life are oxygen, food, and water. To be supported in space people would also need to be kept at a good temperature (probably 60-90 F or so), and pressure would also have to be regulated.

For longer time periods, waste products would need to be disposed of (this includes CO2 as well as body fluids).

July 11, 2001 Kim (15, USA) What is the significance of a coacervate in terms of chemical analysis? Coacervates are significant in study of the chemistry of life because they show that the molecules associated with life (proteins, lipids, carbohydrates) can form life-like structures without any special circumstances. This means that a lot of of the complexity in biochemical structures can be formed naturally with a pretty simple set of ingredients.
November 10, 2000 Kristy (age 11, Washington, USA) What is the difference between DNA and RNA? Both have a sugar/phosphate backbone and 4 nitrogenous bases. The sugar found in DNA is deoxy-ribose, while the sugar in RNA is ribose. Also, they share 3 bases (adenine, guanine, and cytidine), but DNA's 4th base is thymidine, while RNA's 4th base is uracil. That's why you'll see DNA is made up of G, A, C and T's when written out (guanine, adenine, cytidine and thymidine). RNA will be written as a string of G, A, C, and U's.
October 9, 2000 Sammy (age 16, Michigan, USA) What is your theory on how the dinosaurs became extinct? The most popular theory is that a large comet or meteor crashed into the Earth. This changed the climate so much, that the dinosaurs couldn't survive.
July 28, 2000 Fred (age 12, Canada) How many known kinds of monera are there? Since bacteria are included in the monera kingdom, there are perhaps thousands of types (maybe even millions!) of monera. Here's a partial listing if you're interested in any specific bacteria!
June 28, 1999 Neil (age 14, Minnesota) What is the largest known fungal colony? The largest fungal colony known is in Washington state. It covers over 1500 acres and started from one spore around 1000 years ago. A similar fungi in Michigan which covered 37 acres was estimated to weigh 110 tons, the same size as a blue whale.
June 25, 1999 Michelle (age 18, Mass.) What are the elements in living cells Six elements make up over 98% of living cells by mass. These six are oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Oxygen makes up a whopping 65% of our bodies by mass! Beyond these six, several others (potassium, sulfur, sodium, magnesium, chlorine, iron, and iodine) show up in small amounts but play very important roles.
March 12, 1999 Arnon (age 36, Oregon, USA) What is life? Is there artificial life? Can you give me a definition of life beyond the ability to reproduce? Are virus's alive? Here is our What is Life page. Artificial life does not yet exist, but there are many people who are working toward creating it someday.

Some people say viruses are half alive and half dead...however, the scientific view is that they are not alive at all, since they do not fulfill all the conditions for life. Viruses cannot respire, grow or reproduce on their own.

June 13, 1998 Steven (Age 26, Australia) What is the name of the creature that was half man and half goat, of which Pan was one? As far as I know, creatures that are half men and half goat are referred to as satyrs in Greek mythology and fauns in Roman mythology. Pan, the pastoral god in Greek mythology, is an example of a satyr.
December 2, 1997 Benjamin (Texas, USA)

Victor (age 14, Corvallis, Oregon, USA)
How old is the Sun? How old is Earth and what is the oldest known living life form known to man? How old is it? Most scientists agree that our solar system began to form about 4.5 billion years ago following the explosion of a star (called a supernova). This means that the Sun and all the planets, including Earth, are roughly the same age -- about 4.5 billion years old.

The oldest known organisms are "heterotrophic anaerobic bacteria". This simply means "bacteria that can't make their own food (like plants) and don't breathe oxygen". Fossils of these bacteria have been found in Australian rocks that date back to 3.5 billion years ago. Some types of these bacteria still survive today, including Clostridium, the bacterium which causes botulism (a type of food poisoning).

Last modified October 14, 2003 by Jennifer Bergman.

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