From the deepest to most superficial: pia mater, arahnoid, dura mater
March and January would be the most similar
Answer:
The history of the human evolution can be studied by the fossil and DNA evidence. The similarities and advancement in certain characters has revealed the human evolution.
Different evidences like change in the diet, locomotion, brain size, walking ability as compared with the present species and species appeared 6 million years ago. The human genetics evidence and different paintings explain the culture of earlier homo species.The H. sapiens species has highly advance character that help them to survive than any other hominid species. The neanderthals extinction might occur due to their aggressive behavior, low social ability and their large cranial size.
The cell’s nucleus contains chromosomeschromosomes: Rod shaped bodies found in the nucleus of cells that contain genetic information (DNA). made from long DNA molecules. The diagram shows the relationship between the cell, its nucleus, chromosomes in the nucleus, and genes.
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.
