Answer:
acidic
Explanation:
anything below a 7 is acidic
anything above a 7 is basic
and 7 is neutral
Answer:
primary succession takes longer
Explanation:
Primary succession is built from the ground up, whereas secondary succession is built from an already existing civilization.
Step 1: Copy of one side of DNA strand is made (called mRNA, messenger RNA)
step 2: mRNA moves to cytoplasm, then ribosome
step 3: mRNA goes through ribosome 3 bases at a time
step 4: transfer RNA (tRNA) matches up with the open DNA bases
step 5: tRNA releases the amino acid at the top, which joins the chain of amino acids being produced
Answer:
Watson and Crick proposed the double helical model of DNA.
Explanation:
- This model says that DNA exist as double helix. It has two polynucelotide strands running in opposite direction i.e the strands are anti-parallel.
- Each polynucleotide strand is made up of several nucleotide liknked together by phophodiester bonds.
- The two strands are not coiled upon each other but the double strand is coiled upon itself around a common axis like the spiral stair case. Here base pairs forms the stairs and backbone of two strands form railing. Back bone contains sugar and phosphate.
- The base pairing is specific, adenine always pairs with thymine and guanine always pairs with cytosine. Thus if we see any base pair, it consists of one purine and one pyrimidine.
- The two strands of DNA thus show complementary base pairing.
- The strands are held together because of hydrogen bonding between the bases in opposite strand.
- One full helical turn involves ten base pairs and the base pairs are stacked 3.4 A apart.
- This form is called as B-form of DNA.
