Answer:
The three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart.
Explanation:
In Anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.
Generally, the cardiac cycle occurs in two (2) stages;
I. Diastole : in this stage, the ventricles is relaxed and would be filled with blood.
II. Systole: at this stage, the muscles contracts and thus, allow blood to be pushed through the atria.
All amphibians and reptiles except for crocodiles (having four-chambered heart) have three-chambered hearts, which typically comprises of a partially divided ventricle and two atria.
Hence, the correct statement about the three-chambered hearts of amphibians and nonbird reptiles is that, the three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart due to the partially divided ventricle.
Answer:
Equal amounts of DNA contain equal proportions of nitrogenous bases.
Explanation:
According to Chargaff's rule, the nitrogenous base pairs (Purines and pyrimidines) have an equal ratio (1:1) in the DNA of all the organisms. More precisely, the amount of adenine is equal to thymine and the amount of guanine is equal to cytosine in the DNA of all the organism. A-T base pair has two H-bonds while G-C base pair has three H-bonds.
Answer:
mRNA must start membrane protein in the cytoplasm and, after that, continue it in the rough ER.
Explanation:
Protein synthesis is initiated when mRNA meets a free ribosome, the primary structure for protein synthesis. Ribosomes can be found in the r<em>ough endoplasmic reticulum</em> or floating in the cytosol. They read the mRNA code and add the correct amino acid using transference RNA to build the protein.
The <u>rough endoplasmic reticulum</u> is in charge of the synthesis and transport of the membrane proteins. It is also in charge of the latest protein modifications after transduction. Synthesis of membrane proteins <u>starts in the cytoplasm</u> with the production of a molecule portion known as a signal sequence. This portion leads the synthesizing protein and associated ribosome to a specific region in the Rough endoplasmic reticulum where it continues the protein building.
Membrane proteins are synthesized in the endoplasmic reticulum and <em>sent to the Golgi complex in vesicles</em>, where it happens the final association of carbohydrates with proteins. Finally, protein is transported <em>from the Golgi complex to its final destiny, the membrane. </em>
It totally depends upon whether modification is being done in somatic cells or germ cells. Somatic cells modification is ethically accepted because it doesn't pass from one generation to another generation but germline modification is considered as unethical because the modification will pass on to the next generation leading to the persistence of modification in future generations. The problem with genetic modifications is that the impacts of modifications are unpredictable, rather than being fruitful they may lead to lethal mutations so if it occurs in just somatic cells, then even if it is lethal/harmful, it will be confined to only that individual but if a lethal mutation occurs in germ cells then it will pass on to the subsequent generations and it will persist in all future generations.
According to natural selection process, the trend that will occur is that the number of organisms with harmful characteristics will decrease while organisms with neutral or beneficial traits will increase in the plant population
<h3>What is natural selection?</h3>
Natural selection is the process by which organisms with favorable features and characteristics that enable them to adapt to their environment survive while those with unfavorable traits die off.
In a changing environment, it will be observed that the organisms with the most favorable traits will be the most dominant in the environment.
Therefore, for the Year 5 and Year 10, the most likely trend that will occur is that the organisms with harmful characteristics will be decreasing in the plant population while organisms with neutral or beneficial traits will likely be increasing in number.
Learn more about natural selection at: brainly.com/question/14385908
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