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.
A. The concentration of water should be higher on the outside because it allows water to slow into the cell to balance the concentration.
Answer: 16s rRNA subunit is an universal target, all bacteria have it, it has conserved regions that allow the design of primers to detect all bacteria, it can also be amplified through variable regions, it is a multicopy gene which increases the detection sensitivity, 16S rRNA genes are easy to obtain from a bacterial isolate.
Explanation:
<u>16S rRNA is the component of the minor subunit (30S) of the prokaryotic ribosomes</u> that binds to the Shine-Dalgarno sequence. The genes that encode it are known as 16S rRNA genes, and <u>it is one of the most studied and characterized gene, used for phylogeny reconstruction and in various databases</u> mainly because of their low rates of evolution. It evolves at relatively constant speeds which allows to infer phylogenetic relationships.
This subunit is an universal target because it is part of the translation process, therefore it is present in all bacteria. Then, since 16S rRNA genes are ubiquitous, there can not be translation without it, so all bacteria have it. It is composed of conserved and variable regions, and these conserved regions allow the design of primers to detect all bacteria. But it can also be amplified through variable regions where the differences in the sequence of the bases allow the determination of several species. Even more so considering that it is a multicopy gene, which increases the detection sensitivity. However, not all the regions are equally good at differentiating between species. Also, because of the complexity of DNA-DNA hybridization, 16S rRNA gene sequencing is used to identify bacteria and assist with differentiating between closely related bacterial species.
16S rRNA genes are easy to obtain from a bacterial isolate, providing information to identify it, through the use of 16S rRNA databases that are available.
The softest mineral is talc with a hardness of 1 Mohs scale.
Answer:
The correct option is <em>A. Two molecules are formed, each with one original side</em>
Explanation:
When a DNA is duplicated, initially the bonds between the complementary DNA strands are broken. Each strand serves as a template to generate a new strand. Nitrogenous bases are added complementary to both the templates and two new strands are generated. In this way, two new strands are formed with each being complementary to one of the original strands. This method is known as the semi-conservative method of DNA replication.
