A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate.
Answer:
The first layers of earth are very loose, unconsolidated layers called soil, which is pretty easy to dig into, but as we go deeper we reach the bedrock, which is the hardest part of the soil profile, which is made of hard rocks and matter.This makes it harder to dig more and more deeper.
Explanation:
the answer is chemical reaction
Learning that occurs
when an organism makes a connection between two events is called "Associative
learning".<span>
The process involves associating various details or events to
learn a particular fact or information. For example one cannot imagine one eye
of his/her father, whenever he/she will imagine the whole face of their father
will make sense to mind and not single eye.</span>
