The probability is 1/16 that a gamete will receive only paternal chromosomes. In life
cycles that alternate between haploid and diploid stages, fertilization doubles
the number of chromosomes per cell, The pairing of chromosomes along
their lengths , which is essential for crossing over is referred to as synapsis
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.
Which combination of characteristics in a population would provide the greatest potential for evolutionary change?
a. large population, few mutations
b. small population, many mutations
c. small population, few mutations
Small population, many mutations are the combination of characteristics in a population would provide the greatest potential for evolutionary change.
b. small population, many mutations
<u>Explanation:</u>
Stabilizing selection in development is a kind of common choice that supports the normal people in a populace. In little, reproductively detached populaces, extraordinary conditions exist that can create fast changes in quality frequencies absolutely autonomous of transformation and normal determination.
Natural Selection prompts a transformation change when a few people with specific qualities in a populace have higher endurance and regenerative rate than others and give these inheritable hereditary highlights to their posterity. The power of Natural Selection aside, populace size is as yet a factor to be considered.
Answer:
False
Explanation:
Toxoplasma is a congenital disease that is characterized by mild muscle aches, tender lymph nodes, etc. and in some immuno-compromised individuals, seizures and coordination loss may occur. I
The disease is caused by a protozoan known as <em>Toxoplasma gondii </em>and its infection is usually by eating foods (usually meats) that contain the cyst of the organism or making contact with cats that are infected in addition to infected mother-baby transmission, especially during pregnancy.
<em>Hence, humans can contract the organism not just by exposure to an infected cat but also by eating meats that contain the cysts of the organism.</em>
Answer:
contractile vacuole.
Explanation:
Contractile vacuole is an organelle which is damaged from the antibiotic and as a result the cell burst. The main function of contractile vacuole is to regulates the quantity of water inside the cell. If the contractile vacuole is damaged so it does not regulate water required by the cell as a result more water enters inside the cell which results in the bursting of the cell.
