Question

Differentiate between fresh weight and dry weight of plant tissue.

Answer 1

Growth refers to an irreversible increase in the size of the cell, organ, or whole plant. It can be viewed concerning plant height, the diameter of the stem, the volume of tissue, increase in cell numbers, fresh weight, and dry weight, etc. The increase in volume and mass of the plant occurs due to an increase in the mass of the cytoplasm and cell walls.

Complete answer:

| DRY WEIGHT| FRESH WEIGHT
---|---|---
Definition| Refers to all constituents of plants except water.| Refers to the weight of plants just after the harvest.
Heating technique | Used| Avoided
Reliability | More reliable as it excludes fluctuating water concentration | Less reliable

Measuring of dry weight includes
Step 1 – Remove the plants from the soil and wash off any loose soil present.
Step 2 – Blot the plant so that any free moisture present on the surface gets removed.
Step 3 - Set the oven on low heat, place the plant inside overnight.
Step 4 - After taking it out, let them cool down in a dry environment.
Step 5 – Once the plants cool down, weigh them on a scale. You’ll get the readings in milligrams.

Measuring of fresh weight includes
Step 1 – Remove the plants from the soil and wash off any loose soil present.
Step 2 – Gently blot the plant with the help of a soft paper towel to remove any free moisture present on the surface of the plant.
Step 3 – Immediately weigh the plants since plants contain water, so delaying the weighting procedure might lead to some drying and produce inaccurate data.

Note: Use of Ziploc bags is a way to avoid moisture if you don’t so then the plant will take up the water from the humid environment. Air-dry weight is the weight of the substance after drying to equilibrium with the atmosphere.