Answer:
The statement is true
Explanation:
Hematopoietic stem cells give rise to myeloid progenitor and lymphoid progenitor and these two progenitors give rise to many immune cells. Dendritic cells are produced by both the progenitors and macrophages are produced by myeloid progenitor.
Both macrophages and dendritic cells are phagocytes. In phagocytosis, the foreing particles are injected by these phagocytes and they are destryoyed by the action of digestive enzymes present in these phagocytic cells.
Macrophages are present in tissue and if they are present in blood they are called monocytes. Therefore the statement is true.
Answer:
The type of mutation responsible for changing a base in the mRNA strand, without changing the coding aminoacid or protein, is called a <u>silent</u> mutation.
Explanation:
In a silent mutation occurs the change of a nitrogenous base in one of the codons that encodes an aminoacid, without changing the aminoacid or altering the structure or function of the protein to be synthesized.
In this type of mutations the change of the base does not mean the change of the aminoacid, because some aminoacids can be coded with more than one codon. In the case of Leucine, the codons that encode it are CUU, CUC, CUG or CUA, so even if a base changes, the final protein will be the correct one.
For the other options:
- <u><em>Missense</em></u><em>: the change of the base in the DNA chain implies the change of the codon in the mRNA and of the encoded aminoacid, in that way a structural and functional alteration of the synthesized protein occurs. </em>
- <u><em>Nonsense</em></u><em>: the change in the nitrogenous base in the DNA leads to the coding of a termination codon, so that the protein is ultimately incomplete.</em>
- <u><em>Insertion</em></u><em>: in this case there is the addition of more nitrogenous bases to the DNA chain, with respect to the original one.</em>
Answer:
B- environmental factors do most of the “selecting.”
Explanation:
Natural selection is the environment that the organism lives in, and the process which that organism changes by.
Artificial selection is when humans intervene and create an organism that isn't suited for their specific environment, but rather for the humans own liking.
Think of breeding dogs to be smaller, or more fluffy and adorable. These are not traits to help them survive in where they original environment was.
Answer:
Answered below
Explanation:
Head injuries may be penetrating head injury or closed head injury.
A major concern for health professionals regarding intracranial injuries resulting from closed head traumas, is the management of intracranial pressure. Elevated intracranial pressure have negative effects on the brain and immediate management of raised intracranial pressure is important to avoid cerebral edema, intracranial hematoma, brain herniation and even death.
The usual procedures in the management of head injury include elevating the head to about 30 degrees. This position promotes cerebral venous drainage and decreases intracranial venous pressure and intracranial pressure as well.
This is helpful because when the patient is left in the horizontal position, the intracranial pressure becomes significantly higher and the have fatal consequences.
PHYSICAL DEVELOPMENT involve growth and changes in ......... Physical development in humans starts from infancy up to late adolescent. Features of physical development include: development of motor skills, puberty, development of muscle and physical coordination, etc.
