A. Asexual reproduction is like cloning.
High melting point
Good conductors of heat and electricity
Lustrous (shiny)
Malleable (can be hammered)
<span>More than 50</span>. There are more than 7000 chemicals in cigarette smoke, 250 of which are known to be detrimental to health and 69 chemicals are carcinogenic (can cause cancer). Some of the carcinogenic chemicals in cigarette smoke are: Arsenic, Cadmium, Chromium, Formaldehyde and Nickel.
Nucleotide bases are added to DNA strands in a 5' to 3' direction.
What is DNA replication?
When a cell divides, DNA copies itself through a process called replication.
- Generally speaking, DNA replication involves uncoiling the helix, strand separation by rupturing the hydrogen bonds between the complementary strands, and synthesis of two new strands through complimentary base pairing.
- The origin of replication, which is a precise location in the DNA, is where replication starts.
- From the point of origin, DNA replication is bidirectional.
- The two parent DNA strands unwind and split apart at the origin of replication to generate two "Y-shaped" replication forks in order to start DNA replication.
- These unwinding enzymes are known as DNA helicases.
- The real location of DNA copying is at these replication forks.
- Proteins that destabilize helices bind to the single-stranded areas to prevent the two strands from rejoining.
- To reduce stress on the helical molecule during replication, enzymes known as topoisomerases cause breaks in the DNA and then reunite them.
- The hydrogen bonding of free DNA nucleotides with those on each parent strand results in the formation of new complementary strands as the strands continue to unwind and split in both directions around the entire DNA molecule.
- The new nucleotides are joined by DNA polymerases using phosphodiester bonds as they align themselves opposite each parent strand using hydrogen bonds.
- Deoxynucleotide triphosphates, which are made up of a nitrogenous base called deoxyribose and three phosphates, are the actual nucleotides that are aligning through complementary base pairing.
- Two of the phosphates are withdrawn to provide energy for bonding as the phosphodiester bond forms between the 3' OH of the previous nucleotide in the DNA strand and the 5' phosphate group of the next nucleotide.
- In the end, two identical DNA molecules are created when each parent strand acts as a template for the synthesis of a complementary copy of itself.
Hence, nucleotide bases are added to DNA strands in a 5' to 3' direction.
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Answer:
Explanation:
Over the past 250 year or two and a half centuries fossil fuels have been burnt at a very fast rate to meet the various human needs. These fossil fuels contains huge amount of carbon dioxide. And when these fossil fuels are burnt in power factories, power plants, cars etc. carbon moves from the fossil to the atmosphere. And since carbon dioxide is a greenhouse gas it traps more heat and hence there is a global temperature rise.
It is estimated that every year almost five and a half billion tons of carbon is released by burning fossil fuels. And since this amount of carbon dioxide is very huge for plants to convert all of them into oxygen via photosynthesis it leads to disbalancing in the carbon cycle that is more carbon dioxide is produced than the amount can be utilized which finally leads to rise in Earth's temperature as all of the extra carbondioxide ends up in Trapping more sun light.
