Mediastinal shift occurs in Tension pneumothorax. A tension pneumothorax makes the lung to collapse and the heart, the trachea and the great vessels, to shift toward the unaffected side of the chest. When air moves out from a laceration in the lung and goes in the pleural space or infiltrate the pleural space over a wound in the chest wall the shift happens.
XX if female and XY is male
The question is incomplete. Th ecomplete question is as following:
All of the following protect the skin and mucous membranes from infection EXCEPT
A) multiple layers of cells.
B) tears.
C) saliva.
D) HCl.
E) the "ciliary escalator."
Answer: D) HCl.
Explanation:
- The epidermis, the outer layer of the skin provides waterproofing and serves as a barrier to infection and other laers also sustain any type of injury.
- Tears wash out foreign bodies which enter the eye. In addition, tears contain a substance called lysozyme which has an antibacterial function and works to prevent microbial invasion and infection.
- Saliva protects against infection, especially via the innate immune system. This mechanism is an important first-line protection against bacterial and viral infection
- The mucociliar escalator is within the conducting airways and is composed of mucus and cilia that transfer the mucus up and out of the lungs where it can be removed by coughing or swallowing,
Whereas HCL helps in the digestion process.
Hence, the correct option is D.
Hi,
The word mutation come from word mutate, that means to change. In Biology, a mutations means a change in the DNA sequence of an organism. Since DNA sequence encodes for proteins, when a mutation occurs in part of DNA (gene) it causes a different than usual protein which had to be expressed.
For example:
- There was a gene whose sequence was: AATGGGGCCC
- A single base mutation made the sequence as: TATGGGGCCC
Now how these mutations affect an organism in which they took place?
The answer is, mutations can be beneficial, harmful and even neutral.
A mutations is beneficial when the sequence changes in such a way that the new protein gives beneficial characteristics to the organism. For instance, a mutation occurs in the DNA of bacteria which enhances its resistance against antibiotics, so the bacteria can live longer. This is a beneficial mutation for bacteria. Sometimes, the mutations can be lethal and very hamrful. For instance, when a mutation occurs in the coding region of a gene for certain trait of organism like skin type, skin color. If mutation happens in coding region of skin type, in such a way that new protein formed is not correct, it can heavily harm. Like a mutation changes the skin color of people living in hot areas from from dark to pale color. The pale color is prone to more damage than dark color, therefore, these skins are easily burnt and can causes skin cancer and other skins problems to people. Similarly, some mutations can be neutral and they cause neither benefit, nor harm, no effect on organism. These are called silent mutations because the DNA sequence is changed in such a way that new protein is same as old protein. For example there is a gene having part CCG, after mutation it changes to CCA. Both will code for the same protein Glycine and will have no effect on overall phenotype of organism.
Hope it help!
Answer:
two nucleotides are deleted
Explanation:
Frameshift mutations arise when the normal sequence of codons is disrupted by the insertion or deletion of one or more nucleotides, provided that the number of nucleotides added or removed is not a multiple of three.
Because two nucleotides are deleted (2 is not divisble by 3), it would be a source of a frameshift mutation.
Hope this helped! :^)