Answer:
The correct answers are:
1. closing
2. the ventricles and arteries,
3. a constricted trachea
Lub is the first sound of a heartbeat and is mentioned as S1. It is usually produced due to the closing of tricuspid and and mitral or bicuspid valves present between atria and ventricles.
Tricupsid is located between atrium and ventricle of the right hand side and mitral valve is located between atrium and ventricle of the left hand side. They prevent the back flow of blood from ventricles to their respective atria.
Dub, being the second sound is written as S2. It is produced due to the closing of pulmonary (located between right ventricle and pulmonary artery) and aortic valves (located between left artery and aorta).
These valves prevent the back flow of blood from arteries into the ventricles.
The time between the two sounds is often taken as the measure of the diastole i.e. ventricular filling.
Wheezing refers to a high-pitched sound produced when a person breathes, especially during exhale. It is caused by constriction of the airways or inflammation. It is considered as a symptom of various diseases such as asthma, COPD, allergies, bronchitis etc.
14: Operons allow prokaryotes to replicate DNA at the appropriate time.
Operons are specific regions of genes that are linked to a singular process. They ensure that the expression of these genes does not go unchecked and only occurs when necessary. Two key examples of this in humans are the lac operon and trp operon.
15. The central dogma of molecular biology is:
DNA to RNA to Proteins
Protein Synthesis occurs in 3 steps.
First our DNA is translated into RNA. Next the RNA is sequenced into Amino Acids by reading the corresponding 3-Base Codons. These Amino Acid sequences form various protein structures.
So white blood cell’s(WBCs for short) main job is to fight infections.
They do this by swallowing the infection.
You see,WBCs do not have a permanent shape.this means that they enlarge and decrease size of parts of their body.So they grow two long arm like structures called pseudopodia which swallow the infection.(pseudopodia means false feet).
You can see the process in the photo I attached from google
<span>Please remember that spring tides occur approximately twice a month, when the earth and moon and sun are about co-linear. That is about at full moon and about at new moon.
Neap tides occur at half moons, when the moon is off to the side of the line between earth and sun. I hope this can help</span>
