Which science presents the changes in the internal and external structure of plants from the perspective of evolution and phylogeny?

In which of the following reactions is $H_2O_2$ acting as a reducing agent?

Let $\overrightarrow{a}, \overrightarrow{b}, \overrightarrow{c}$ be the position vectors of the vertices $A, B, C$ respectively of $\triangle ABC$. The vector area of $\triangle ABC$ is :

Two tuning forks $A$ and $B$ produce $8\ Hz$ beats per second when sounded together. $A$ gas column $37.5\ cm$ long in a pipe closed at one end resonates in its fundamental mode with fork $A$,whereas a column of length $38.5\ cm$ of the same gas in a similar pipe is required for a similar resonance with fork $B$. The frequencies of these two tuning forks are:

The angle between the curves $y=\sin x$ and $y=\cos x$ is

Assertion : The isothermal curves intersect each other at a certain point.
Reason : The isothermal change takes place slowly,so,the isothermal curves have very little slope.