This is known as parasitism.
In biology, parasitism is a relationship between species, where one organism, the parasite, lives on or in another organism, the host, causing it some harm, and is adapted structurally to this way of life.
It is probably the l<span>amellae.
The lamellae are sheets of bony matrix. This bony matrix is produced by o</span>steoblasts, which are cells that synthesise collagen<span> and specialised proteins like </span>osteocalcin<span> and </span>osteopontin. These are then the most important constituents of the bony matrix.
Answer:

Explanation:
We recognize that total occurrence equals new cases of disease over time divided by the number of people at risk at the onset.
Mathematically:

Given that:
Number of the population at risk = 1000 individuals
New cases during Jan 1 - Dec 31 = 60 because;
At 20 occurred on June 30 & 40 on Sept. 30) & no new cases were identified after that:
∴
