Answer:
Climate change has been described as one of the biggest problems faced by humankind. Carbon dioxide is is the primary driver of global warming. Prof Joanna Haigh from Imperial College London explains why this gas has played a crucial role in shaping the Earth's climate.
Carbon dioxide (CO2) has been present in the atmosphere since the Earth condensed from a ball of hot gases following its formation from the explosion of a huge star about five billion years ago.
At that time the atmosphere was mainly composed of nitrogen, CO2 and water vapour, which seeped through cracks in the solid surface. A very similar composition emerges from volcanic eruptions today.
As the planet cooled further some of the water vapour condensed out to form oceans and they dissolved a portion of the CO2 but it was still present in the atmosphere in large amounts.
Answer:
The nucleic acid is a macromolecule present in living systems in the form of either DNA or RNA, whose molecule consists of many nucleotides which are linked with each other to form long chains. The presence of DNA or RNA in an individual promotes continuity of life. The variability and complexity of nucleic acid are dependent on its constituent molecules as, sugar, a phosphate group, and a nitrogenous base. However, two monocyclic nitrogenous bases were classified purines (adenine:A, guanine:G) and pyrimidines (thymine:T, cytosine:C, and uracil:U).
In addition, RNA is a single-stranded structure which differs from DNA in two aspects, the sugar content of RNA is ribose, and pyrimidine base uracil replaces the thymine base of DNA. A ratio between two strands of DNA can be calculated by using Chargrff's rule which states that "DNA from any cell of all organisms possess a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases'.
The purine to pyrimidine ratio in RNA with different bases is given below in the following table:
Presence of single strand in RNA does not follow chargaff's rule and alters the purine: pyrimidine ratio. The above ratio of each base in the given information is not equal, due to which the ratio of purines to pyrimidines is different. The ratio of DNA and RNA is not equal because DNA has its complementary DNA strand. However, bases in RNA might vary due to its single-strandedness property, but its ratio is dependent on the species.
Therefore, it can be concluded that the ratio of purines to pyrimidines is dependent on the species due to its genetic makeup. Hence, option (c) is correct.
Answer:
the central nervous system, cardiovascular, respiratory, and musculoskeletal systems
Explanation:
The answer would be A. thick filaments!
Humans benefit from the domestic dog because they reduce stress, they can prevent depression, and they can improve your health. Dogs benefit from humans because they love the bond they have with their owner.