What is oogamy in fungi?

Which one of the following reactions represents the oxidising property of $H_2O_2$?

The locus of the centroid of the triangle with vertices at $(a \cos \theta, a \sin \theta)$,$(b \sin \theta, -b \cos \theta)$ and $(1, 0)$ is (where $\theta$ is a parameter).

Electrons from excited chlorophyll molecule of photosystem $II$ are accepted first by

If $4x^2 - 5xy + y^2 = 0$ represents a pair of lines with slopes $m_1$ and $m_2$,then the value of $|m_1 - m_2|$ equals

$A$ man fires a bullet standing between two cliffs. The first echo is heard after $3 \ s$ and the second echo is heard after $5 \ s$. If the velocity of sound is $330 \ m/s$,then the distance between the cliffs is .... $m$.