14: Operons allow prokaryotes to replicate DNA at the appropriate time.
Operons are specific regions of genes that are linked to a singular process. They ensure that the expression of these genes does not go unchecked and only occurs when necessary. Two key examples of this in humans are the lac operon and trp operon.
15. The central dogma of molecular biology is:
DNA to RNA to Proteins
Protein Synthesis occurs in 3 steps.
First our DNA is translated into RNA. Next the RNA is sequenced into Amino Acids by reading the corresponding 3-Base Codons. These Amino Acid sequences form various protein structures.
Answer:
Cell membrane as a semi permeable membrane.
Explanation
A semi permeable membrane is the one that would only allow water,ions and certain molecules to pass through it by diffusion while restricting other large molecules from passing through.
Details in the attachment.
Answer:
Metabolism consists of all the energy transformation reactions in an organism. (Ans. B)
Explanation:
Metabolism is defined as the total sum of the chemical reactions which synthesized in every cell of living things and provides energy for formation of new organic materials and vital processes (such as movement, growth, reproduction and development).
In living metabolism, enzyme mediated chemical reactions takes place. Energy which comes from nutrients and solar energy fueling multistep reactions and converting into the molecules which is necessary for maintenance and growth.
Answer:
Cross-bridges would form in the absence of an action potential from a motor neuron.
Explanation:
The injected calcium ions would bind to troponin. Troponin would make tropomyosin move away from the myosin-binding sites on actin. The presence of free binding sites on the actin would be followed by the contraction cycle. This would include hydrolysis of ATP to energize myosin heads and binding of these heads to actin to form cross-bridges. Therefore, cross-bridge formation would occur without any action potential if calcium ions are injected directly into the muscle.
