<span>Lamarck believed that organisms could acquire characteristics during their lifetime, that they could pass down to their offspring, but Darwin did not believe these traits could be passed down. Darwin proved that the species adapted to their environment through natural selection. Meaning only the one that could adapt to the changes would survive. </span>
The frequency increases.
Here's an easy way to think about this. The wavelength is the distance from crest to crest, or trough to trough -- equivalently, it's the distance the wave travels in one period. This means that the speed of the wave is the wavelength divided by the period, or <span><span>v=<span>λT</span></span><span>v=<span>λT</span></span></span> . But the frequency is just the reciprocal of the period, so <span><span>v=λf</span><span>v=λf</span></span>. Clearly, if v increases and the frequency stays the same, the wavelength must increase by an equivalent factor.
Answer:
peptide antigens by MHC class II molecules
Explanation:
Helper T cells are activated by peptide antigens by MHC class II molecules. These antigens express on the surface of antigen-presenting cells (APCs). After activation, the T helper cells divide and secrete cytokines to assist the immune response.
