Answer :Erwin Chargaff a Biochemist
Explanation:
He formulated the base paring of double helix of DNA. He reasoned that since the percentage of four DNA bases are of this proportions in human;
Adenine=30.9% and Thymine =29.4%;
Guanine=19.9% and Cytosine =19.8%
Then, the amount of adenine will always be equal to thymine,
And the amount of Guanine equals to cytosine based on this percentages of distribution.
(Adenine and Guanine are large, molecule of Purines, while thymine and Cytosine are Pyrimidine)
He concluded (although scientist believed, he did not explicitly stated this) that this should be the base paring patterns in DNA molecule. This is the first Chargaff Rule.
His second rule is that the DNA composition, in the relative amount of the four bases Adenine, Thymine, Cytosine and Guanine varies in proportion from one organisms to another. And this is the basis of molecular diversity.
Having the haploid number of chromosomes allows the zygote to have the correct number. If gametes weren't haploid, every generation of organisms would have twice as many chromosomes as their parents. I hope my answer has come to your help. God bless and have a nice day ahead!
I have searched everywhere, but I have not found the proposals of the question, but I will explain to you what is the endoplasmic reticulum so that you can answer it.
The endoplasmic reticulum is a eukaryotic organelle located in the cytoplasm.
The endoplasmic reticulum is a network of membrane tubules (often interconnected) scattered throughout the cytoplasm of eukaryotic cells. Its membrane, which alone represents more than half of the cellular membrane system, is in contact with the nuclear envelope.
The endoplasmic reticulum can be:
Granular (or rough) (RER) that is to say associated with ribosomes.
Smooth (SER).
The granular endoplasmic reticulum is the place of synthesis (in the associated ribosomes) of the proteins secreted outside the cell and of the proteins and lipids constituting the membranes of the cellular organelles. Golgi, lysosomes, mitochondria, nucleus, ribosomes, vesicles ...). It participates in the correct folding of the proteins that have just been synthesized.
The smooth endoplasmic reticulum participates in cellular metabolism, synthesizing lipids and storing calcium.
Biochemistry is the study of the actions of the main metabolic processes of living organisms, which are protein synthesis (DNA and RNA molecules, genetic codes and how they work, enzyme formation and function, etc), glycolysis (cellular respiration, aka the Krebs cycle/citric acid cycle to break down glucose molecules to release chemical energy and oxydative phosphorylation, the use of that chemical energy to form ATP molecules in which the chemical energy is put in a form the cell can use, and lipid chemistry (the study of the pathways in which fatty acids are formed into lipids and fat molecules and cholestrol formation and function).
Essentially, biochemistry covers the chemical reactions necessary for cellular and organism metabolism
Answer:
Nervous stimulus action for muscle contraction
Explanation:
Nerve stimulation is sent to the sarcolemma, which are motor nerves at the neuromuscular junction (junction between the terminal part of a motor axon with a motor plate), after which nerve endings implant in the sarcolemma and form plaque on the surface of muscle fibers, which in turn transmit stimulus to the musculature.
Then, an electrical current (from the stimuli) is generated, it propagates through the muscle cell membrane, reaches the cytoplasm and triggers the muscle contraction mechanism.
