Daily NEET MCQ- July 4, 2022 - NEET MCQ

A Russian chemist named Dmitri Mendeleev classified elements based on chemical and physical properties in ascending order of their atomic weights. The number of groups was 8 and there were 12 series.

At the time of Mendeleev, Germanium was not discovered. So he predicted Germanium’s properties and left a space for it, by naming it Aka Silicon. So he predicted Aka silicon’s atomic weight as 70, but the Germanium’s atomic weight is 72.

According to Russian chemist named Dmitri Mendeleev who got the credits for the development of the modern periodic table, the periodic functions of the atomic weights are the properties of respective elements.

At the contact surface of two bodies (here, fluid layers) molecular bonds are formed. When there is relative motion between them these bonds try to oppose it. This is how friction works. Therefore we can say it is an electromagnetic force as molecular bonds are considered to be electromagnetic forces.

Resistance force by a fluid on a body = 6πηrv, where η is coefficient of viscosity, r is radius of body & v is its velocity. This doesn’t depend on density.
Another way to think of this is to imagine a hollow and solid sphere of the same radius falling through air at the same speed. The resistance offered by air will be the same on both as they have the same surface area exposed and are moving at the same speed.

At terminal velocity, Mg = viscous force. Therefore, 0.001*10^-3*10 = 6πηrv ∴ v = 10^-5/ 6πηr = 10^-5 / ( 6π*1.8 X 10^-5*0.001) = 29.47 m/s.

Apart from the genomic DNA present inside the nucleus, the mitochondria possesses its own genetic material in the form of a single circular DNA molecule. This DNA codes for some mitochondrial proteins.

Apart from the genomic DNA present inside the nucleus, the mitochondria possesses its own genetic material in the form of a single circular DNA molecule. It also possesses 70S (prokaryotic) ribosomes.

Chromoplasts impart colours to the different cells of a plant such as yellow colour of a flower or a fruit. Elaioplasts store oils and fats, amyloplasts store starch and aleuroplasts store proteins.

Chloroplasts are plastids containing the green pigment chlorophyll, which is necessary to trap sunlight to carry out the process of photosynthesis. Chlamydomonas has only one chloroplast per cell.