Answer:
Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
Explanation:
Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen-presenting cells (APCs). Once activated, they divide rapidly and secrete cytokines that regulate or assist the immune response.
Answer:
Differentiate between tricuspid valve and bicuspid valve
<u><em>The tricuspid valve is positioned between the right atrium and right ventricle, whereas the bicuspid valve is located between the left atrium and left ventricle. Furthermore, the tricuspid valve has three cusps, whereas the bicuspid valve has only two. Valve that connects the heart's left atrium and left ventricle.</em></u>
hope this helps!
Explanation:
LUMINOSITY
The energy that is emitted by the star per unit time is called luminosity of a star
<em>Luminosity of a Sun:-</em>
<em />
<em> 3.8 × 10²⁶ W.</em>
<em />
<em>SI unit :-</em>
<em />
<em> It is measured in Watts</em>
<em />
<em> The brightness of a star as seen from the earth means that the brightness of star from 32.6 light-years away ( from earth)</em>
<em />
<em />
The classification of the characteristics and examples based on the model of speciation that is being described are as follows:
- <u>Allopatric Speciation:</u> speciation that is based on geographic isolation.
- <u>Sympatric Speciation:</u> organisms are reproductively isolated by postzygotic mechanisms and evolve into different species.
- <u>Allopatric Speciation:</u> organisms in different locations are subject to different selective pressures and evolve into different species.
- <u>Sympatric Speciation:</u> speciation that does not require geographic isolation.
- <u>Sympatric Speciation:</u> bread wheat evolved from two species of wheat with different chromosome numbers.
<h3>What is speciation?</h3>
Speciation can be defined as an ecological and biological process through which new species of a living organism are formed, especially due to isolation of a part.
<h3>The types of speciation.</h3>
In Science, there are five (5) major types of speciation and these include the following:
- Allopatric Speciation
- Peripatric Speciation
- Parapatric Speciation
- Sympatric Speciation.
- Artificial Speciation.
Read more on allopatric speciation here: brainly.com/question/4493180
#SPJ1
<u>Complete Question:</u>
Classify the following characteristics and examples depending on what model of speciation is described.
Allopatric Speciation Sympatric Speciation
Speciation that is based on geographic isolation
Organisms are reproductively isolated by postzygotic mechanisms and evolve into different species
Organisms in different locations are subject to different selective pressures and evolve into different species
Speciation that does not require geographic isolation
Bread wheat evolved from two species of wheat with different chromosome numbers
