Question

In the initial phase of mineral ion absorption, there is a rapid uptake of ions into ______ space of cells. Ions absorbed in this phase are ______ exchangeable. It is ___ uptake as it ____ the expenditure of metabolic energy.
A. Inner, not freely, actively, requires
B. Inner, freely, passive, requires
C. Outer, freely, passive, does not require
D. Outer, not freely, active, requires

Answer 1

The cell membrane plays an important role in the structure and metabolism of the cell. It allows only selective components to pass through it. These components are usually ions which maintain the equilibria in the cells by their charges. The usually needed ions in the cells are sodium and potassium.

Complete answer:
Mineral ion absorption in the cells in the process of movement of ions from inside to outside or vice versa to maintain the balance of charges and equilibrium. This may need energy depending upon the characteristics of the membrane and the transport.
Mineral ion absorption occurs into two phases - initial phase and the metabolic phase.
In the initial phase, the ions will enter outer space. This is a rapid and fast process. In this outer layer, they become freely exchangeable. Due to no need for energy, this becomes a passive uptake pathway.
In the metabolic pathway. The ions move to the inner space of the cell. The ions here do not move freely and need ATP for the transport. Thus this makes an active transport of the ions.

In the question, now let us fill the blanks –
In the initial phase of mineral ion absorption, there is a rapid uptake of ions into outer space of cells.. Ions absorbed in this phase are freely exchangeable. It is passive uptake as it does not require the expenditure of metabolic energy.

So, the correct option is option C: 'outer, freely, passive, does not require'.

Note: It is a chemiosmotic mechanism across the plasma and cell membrane. This diffusion takes place in the roots of the plants which need to uptake minerals from the soil. The ion absorption also occurs in the human body especially in the kidneys while filtering the blood.