Which of the following is an incorrect pair regarding lichens?

The transformed equation of $3x^2 + 3y^2 + 2xy = 2$,when the coordinate axes are rotated through an angle of $45^{\circ}$,is

What is produced when $Mg$ burns in $CO_2$?

When a wave travels in a medium,the particle displacements are given by $y = a \sin 2\pi (bt - cx)$ where $a, b,$ and $c$ are constants. The maximum particle velocity will be twice the wave velocity if

Magnetic induction at the centre of a circular loop of area $\pi \ m^2$ is $0.1 \ T$. The magnetic moment of the loop is ( $\mu_0 = \text{permeability of air}$ ).

Which group of organisms was the first to exist on Earth among the given options?