Answer:
No. They will need to repeat their experiment several times, since the weather and times were different both days.
Explanation:
When a scientific experiment is conducted, one independent variable shall be changed in each experiment at a time so that the results of the experiment are authentic and we can easily determine which independent variable caused a change in the dependent variable.
If more than one independent variable is changed in the same experiment, then it will be difficult to interpret that which variable caused the change.
<u><em>Similarly, Maria and her brother need to repeat their experiment several times with just changing one variable at a time. </em></u>
The correct answer is that "the T cell enters a state of anergy".
The activation of T cells requires two signals: (1) antigen specific signal presented by an antigen presenting cell (either a macrophage or a dendritic cell) that activates t cell receptors and (2) co-stimulatory signals that is not antigen specific but rather found in the plasma membrane of the antigen presenting cell (i.e. CD28). In the absence of a co-stimulatory signal, the t cell will enter a state of anergy or the inability to produce an immune response toward an offending antigen.
Answer: Directional selection
Explanation:
In the population genetics, directional selection is the mode of selection during which the extreme phenotype are favored more than the other phenotype.
This causes the allele frequency to shift towards the time in the direction of that particular phenotype.
Here, in the question the acid tolerant plant species is favored over the other phenotype.
Hence, the correct answer is option D
<span>static friction I'm pretty sure</span>