<span>Human genetics is the study of inheritance as it occurs in human beings. Human genetics encompasses a variety of overlapping fields including: classical genetics, cytogenetics, molecular genetics, biochemical genetics, genomics, population genetics, developmental genetics, clinical genetics, and genetic counseling.</span>
1. In the heart, an action potential originates in the (E) sinoatrial node.
The cardiac action potential is a term referring to the change in the membrane potential of heart cells causing the heart to contract. Cardiac action potentials are created by a group of specialized cells capable of generating automatic action potentials and are located in the right atrium of the heart. These cells are called sinoatrial node and sometimes are referred to as the natural pacemaker of the heart. This characterization originates from the fact that sinoatrial node continuously provides action potential and sets the rhythm of the heart function.
2. The sequence of travel by an action potential through the heart is (A) sinoatrial node, atrioventricular node, atrioventricular bundle, bundle branches, Purkinje fibers.
As explained above, the cardiac action potential originates from the sinoatrial node. This action potential then travels through the atrioventricular node, which belongs to the electrical conduction system of the heart and is located between the atria and the ventricles. It is responsible for the electrical connection between the right atrium and the right ventricle. The action potential then travels to the atrioventricular bundle (or bundle of His), another part of the electrical conduction system of the heart. The atrioventricular bundle transmits the electrical impulses from the atrioventricular node to the bundle branches. The bundle branches then send the signal to the Purkinje fibers which send the electrical impulses to the ventricles, causing them to contract.
3. The correct answer is A.
The generation of an action potential in the sinoatrial node causes the contraction of the atria. When the action potential passes from the sinoatrial node to the atrioventricular node, it slows down. This causes the transport of the electrical impulse from the atria to the ventricles to slow down. This delay enables the blood (from the contraction of the atria) to fill the ventricles before their contraction.
4. This statement is true.
The interventricular septum is a structure which divides the two ventricles of the heart and it is composed of two branches, the left bundle and the right bundle branch. When the action potential reaches the interventricular septum, it then travels to the apex of the heart from where it travels upwards along the walls of the ventricles and the ventricular contraction begins.
5. This statement is true.
The bundle branches gradually become Purkinje fibers located in the interior of the ventricular walls. Purkinje fibers are specialized cells and are responsible for conducting cardiac action potentials from the bundle branches to the ventricular walls. This signal transduction causes the muscle of the ventricular walls to contract.
Since we were given only one point, we have to test each exponential function for the point
Since exponential functions are of the form
, The correct option is between option A and option C.
For option A,
On substitution, we have;
.
Since the point satisfied the exponential function
, the exponential function goes through it.
Hence the correct answer is option A.
No need to test for option C again.
Answer:
The two compounds that correspond to waste products of cellular respiration are H₂O and CO₂.
Explanation:
The cellular metabolic waste products, specifically from cellular respiration are water (H₂O) and carbon dioxide (CO₂), from the oxidation of glucose into energy.
The process of <u>cellular respiration occurs in the mitochondria of eukaryotic cells and consists of a series of chemical reactions</u> where, from a glucose molecule, energy is obtained in the form of ATP molecules.
Obtaining H₂O and CO₂ from glucose can be summarized with the schematic reaction:
<em>C₆H₁₂O₆ + 6O₂ → 6H₂O + 6CO₂</em>
This summary indicates that a glucose molecule, when oxidized, produces as waste 6 molecules of water and 6 molecules of carbon dioxide. To reach this process all the reactions of the oxidative phosphorylation occur and 24 molecules of ATP are obtained for each molecule of glucose.
For the other options it is important to mention that:
- <em><u>C₆H₁₂O₆</u></em><em> is the substrate from which cellular respiration takes place.
</em>
- <em><u>ATP </u></em><em>is the final product of cellular respiration, translated into energy to be used by the cell.</em>
For most athletes, the period in their
yearly training cycle during which it is recommended to begin calorie restriction
so as to lose significant amounts of stored body fat is the off-season or early
in the preseason. Restriction of energy intake late in the preseason when
there is rigorous training or during season when there is competition may impede training, recovery,
or performance.
