Video Transcript
The given diagram shows the basic
structure of a seed. What is the main role of the seed
coat? (A) To act as the site of cellular
respiration in the seed. (B) To act as a protective
coating. (C) To determine the shape of the
plant that is produced. Or (D) to provide the nutrients for
the seed to germinate.
This question is asking us to
determine the function of a particular part of a seed, the seed coat. Let’s quickly review what a seed
actually is and then figure out the functions of the different structures it
contains.
A seed is a structure that contains
the embryo of a flowering plant, which is capable of developing into a new
plant. Seeds act as a safe place for a
plant embryo to maintain a period of dormancy until conditions are optimal for their
growth. The plant embryo at this stage is
little more than a tiny embryonic root and one or two embryonic leaves.
Seeds often contain a food store
full of starchy carbohydrates. These large carbohydrates can be
broken down into smaller sugars. The sugars can then be broken down
themselves to release energy through cellular respiration. Energy helps the embryonic plant to
grow until it has developed enough to access light. Light allows a plant to
photosynthesize so that it can make its own sugars.
Most seeds are also surrounded by a
tough seed coat. This protects the developing embryo
and helps to prevent it from drying out. Knowing this, we can answer this
question correctly. The main role of the seed coat is
best described by answer option (B): to act as a protective coating.
