You subtract the number of protons and the mass to get the number of neutrons.
Answer:
c. Ductus venosus, vena cava, heart, ductus arteriosus, arteries
Explanation:
The circulatory system consists of the heart and blood vessels. In a fetus, the circulation of blood is different from circulation after delivery largely due to the fact that the lungs are not in use, rather, the fetus obtains oxygen and nutrients from the mother through the placenta and the umbilical cord.
Blood from the placenta is carried to the fetus by the umbilical vein. While some of this blood enters the fetal ductus venosus and is carried to the inferior vena cava, some others enter the liver. The blood from the inferior vena cava then moves into the right atrium of the heart. The foramen ovale, an opening between the right and left atrium in the fetus directs most of the blood flow from the right into the left atrium, thereby, bypassing pulmonary circulation. Most of the blood from the right atrium flows into the left ventricle and is pumped through the aorta to the rest of the body.
Some of the blood from the right atrium however, enters into the right ventricle and is pumped into the pulmonary artery. The ductus arteriosus which is a special connection between the pulmonary artery and the aorta in a fetus, directs most of this blood away from the lungs and into the arteries.
<span>If a child takes large steps which exceeds his or her length, it may mean that he is more advanced or he simply has more walking experience than a normal length walking child.
Increased step length it shows a sign of improvement in the development of walking. In addition, I can say that large steps are reflected more strength and also balance than he had previously been supposed for the infants who are training themselves on how to walk.</span>
Before starting the explanation in the amoeba sister video, they explain what DNA replication is. We can say that DNA, which in eukaryotic cells is located in the nucleus, contains all the genetic information of a being and its duplication process is important for cell growth, reproduction and repair.
<h3 /><h3>What is DNA replication?</h3>
A DNA molecule is made up of two strands that complement each other. For example, if we have an F and an F' strand, in the replication process the strands separate and are used as templates for the formation of complementary strands. Thus, the nucleotide sequence of F determines the sequence of a new F' strand, and F' indicates the composition of a new F strand.
<h3>DNA replication process</h3>
In the video of the amoebas sisters it is briefly explained that..
- DNA replication occurs in the 5' → 3' direction and the strands are separated by the action of enzymes, which break the bonds between the nitrogenous bases and unwind the strands, opening the double helix.
- As DNA uncoiling takes place, other enzymes act to catalyze the synthesis of two new sequences using the parent strands as a template. Each strand created joins an original strand of DNA. Therefore, the process is classified as semi-conservative.
- DNA is a double helix molecule and for its duplication to occur, the first step is to unpack this structure by the action of the DNA helicase enzyme. The helicase recognizes the origin of replication and works by breaking the hydrogen bonds in the nitrogenous bases A-T and C-G. This process occurs at several points and forms "replication bubbles".
- As the bonds unravel, it's like a zipper opening, so this step gives rise to a Y-shaped structure called the replication fork, the starting point of duplication.
- The primase enzyme is responsible for synthesizing a portion of RNA, called a primer. In this step, several primers are generated and are joined to the chain to start DNA synthesis.
- The DNA polymerase enzyme is the replication enzyme responsible for extending the new strand by adding the bases (A, C, G and T). This step is directed from the 5' end, with a phosphate group, to the 3' end, with a hydroxyl group. This phase is called continuous replication.
- Among the primers attached to the original strand, several pieces of DNA are attached and are called Okazaki fragments. As the sections will need to be joined later, this phase is called delayed.
- The exonuclease enzyme is responsible for removing the primers from the original strands after the formation of continuous and discontinuous strands. To avoid sequencing errors, a review and, if necessary, a correction is performed by another exonuclease.
- The enzyme DNA ligase causes the DNA fragments to be joined and the DNA sequenced into two continuous strands.
thus, in a simple way, how DNA replication occurs in the video of the amoebas sisters.
learn more about DNA in brainly.com/question/264225?referrer=searchResults
