These minerals are quartz, feldspar, mica, and usually hornblende. Granite forms as magma cools far under the earth's surface. Because it hardens deep underground it cools very slowly. This allows crystals of the four minerals to grow large enou
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.
Answer:
The correct answer will be- true and structural specializations
Explanation:
The evolution of life on earth has suggested that life has moved from the simplicity to complexity or from single-celled organism to multicellular organism.
This multi-cellularity is achieved through the property of called cellular differentiation and specialization. as the cellular complexity increases, therefore, cellular demands like the use of energy, food, water and other variables increased.
This lead to the formation of the organ and organs system specializes to perform specific functions like the digestive system and another biological system.
Thus, true and structural specializations are the correct answer.
Gaseous atoms and plasmic ions expand in all directions.
