$CH_3-CH_2-CH=O$ $\xrightarrow[(2) H^{+}]{(1) \text{Tollen's reagent}} X$ $\xrightarrow[(2) \text{dry distillation}]{(1) Ca(OH)_2} Y$
$Y$ is:

Identify the correct statements from the following: $(i)$ The cryptozoite ingests food and becomes spherical. $(ii)$ Sporozoites enter the human blood. $(iii)$ Two stages of the life cycle are observed in Plasmodium. $(iv)$ The cryptozoite transforms into cryptomerozoites.

Which has the maximum number of molecules among the following?

Flatworms are:

$A$ particle is moved from $(0, 0)$ to $(a, a)$ under a force $\vec F = (3\hat i + 4\hat j)$ along two paths. Path $1$ is $OP$ and path $2$ is $OQP$. Let $W_1$ and $W_2$ be the work done by this force in these two paths respectively. Then

$A$ speaker emits a sound wave of frequency $f_0$. When it moves towards a stationary observer with speed $u$,the observer measures a frequency $f_1$. If the speaker is stationary,and the observer moves towards it with speed $u$,the measured frequency is $f_2$. Then: