Is a geared cycle better than non-geared cycle?
Geared bicycle is better for long rides and is recommended strongly for hilly terrain. It preserves lot of one’s energy for a much longer ride than it would be possible on a single speed bicycle.I have peddled for 160KM in single speed bicycle at an average speed of 12Km/Hr with considerable variation in altitude and took almost 14 hours to complete the track. I was completely exhausted near the end of journey.And with geared hybrid bicycle , I have peddled the 160KM in 9 hours (including 1 hour for breakfast & rest) at an average speed of 20KM/Hr and still had enough energy & day light to cover another 60KM.Geared Bicycle:Pros:No worry of chain slip and losing balance as a result of it.Easy maintenance.Saves lot of time & energy.Provides good acceleration if riding in city traffic.Easy riding even with extreme altitude variations.Cons:Any damage to derailleurs proves costlier to repair/replace especially the rare ones which are more vulnerable and exposed.Caution:Avoid momentary loss of balance in geared bicycle by checking that the gear numbers matches with the derailleur position before pedaling. Bunch of idiots always like to play with it when the bicycle is parked.Prefer single speed for normal use within city limits where main intention is to burn fat or if you don’t have a need to invest little more on geared bicyle.
1. Describe the major events that occur during the eukaryotic cell cycle. How many phases can it be divided in
Wikipedia, lol? The eukaryotic cell cycle is typically divided into 3 major stages, and these stages are further broken down. I'll give you an overview: 1. Interphase. This basically just the cell's life when it's not really doing anything. Simply put, growth and normal activity. However, there is a point in interphase that is important to the cell's division- synthesis, or the S phase (the rest of Interphase are the G phases, for growth- the period before S is G1 and the period after S is G2.) During the S phase, DNA synthesis, the DNA of the cell is replicated, thus doubling the amount of chromosomes. This is needed, or else in the next stage, when the cell divides, you'll end up with 2 cells with half the amount of DNA. 2. Mitosis: This is the dividing of the cell. There are generally five stages: prophase, prometaphase, metaphase, anaphase, and telophase. I'll spare you the details, but basically, in this stage, the cell starts splitting, and becoming two. 3. Cytokinesis: This is the instant in time when the cell actually divides. Basically, mitosis is like pulling the cell apart, and cytokinesis is the rip! that gives you two new normal (hopefully) cells, which then go on to interphase and grow etc. Of course, this is just mitosis. Meiosis, a different process, is more complicated, and actually produces 4 sex cells from one cell instead of 2 normal cells from one. And the sex cells are haploid, meaning they have half the number of DNA as other "normal" nonreproductive cells, because when two sex cells join, you get one full DNA normal cell, which becomes offspring. Thats basically the gist of it. Just remember, interphase, mitosis, cytokinesis, OR G1 (growth), S (DNA replication), G2 (more growth), Mitosis (splitting), Cytokinesis (split). Of course, interphase is WAY longer than the other stages, and cytokinesis takes only a moment. Hope that helped.
During which phase of the cell cycle does the amount of DNA in a cell remain at the 4 C level if the initial amount is denoted as 2 C: only G2 or both M and G2?
A cell cycle is divided into G1,S,G2 and M phase. G1 or first growth phase is followed by S phase or synthesis phase. DNA replication occurs in S phase and DNA amount doubles up i.e., a cell with 2C DNA in G1 phase will now have 4C DNA. G2 phase is the second growth phase where DNA content remains 4C. M phase is the phase where DNA content either regains 2C level(mitosis) or become halved i.e. 1C(in meiosis).SO The Answer is only G2
Summarize what happens to chromosomes during the stage of the cell cycle in which the nucleus divides?
in prophase they condense. in metaphase they line up at the equator. in anaphase they break apart at the centromeresand move in opposite ends. in telophase the cell breaks in two and the chromosomes are now seperated into 2 new cells. BOOYA 4 YEARS OF COLLEGE AS A BIO MAJOR FINALLY CAME TO GOOD USE
Can you recommend me a good Cell Biology or Molecular Biology textbook?
Just my views. I own 3 molecular cell biology texts: Becker's, Lodish's, and Cooper's. Of those 3, Becker's is the best one for learning molecular cell biology. "The World of the Cell: 7th Edition", by Wayne Becker. http://www.amazon.com/World-Cell-7th-Way... I do not own Albert's text, but the graphics I have seen from it (there is a CD for sale at Amazon that you can see some of the graphics) are crude, and better are the graphics in Becker's. Becker's book does not have as high of a rating at Amaxon as Alberts, so if you go just by ratings, then Albert's is the way to go. But I don't know about the Amazon reviewers that rated Becker's a 1, saying things like it was was a bunch of disorganized facts and/or that they could not follow the material in it. Those people are in sad shape since Becker's book explains things much better than either Cooper's or Lodish's: and if someone can't follow Becker's, they had better just give up on cell biology. NOTE: If you join the Scientific American Book Club, you can get BOTH Becker's AND Cooper's molecular cell biology texts - and one other book of your choice - for something like $10, with a minimal obligation thereafter.