The child is more susceptible to diseases than the father because the father has already gained a slight immunity towards the lead by loving in the house longer than the child (assuming the father has lived in the house longer)
The correct answer is B !! Both are interdependent thus forming a mutualistic association !!
As both can not live without each other thus making obligate !!
so They share obligate mutual association !! Go with B !!
<span>By filtering the air so that the lungs so the lungs don't get infected</span>
<span>When the surface layer was dug up, the permafrost was exposed. When the weather warmed, this exposed permafrost would have melted and become soggy, causing the ground underneath the tracks to shift.</span>
Answer: b - Chondroblasts within the cartilage divide and secrete new matrix
Explanation: Chondroblasts are derived from two sources; mesenchymal cells within the center of chondrification and chondrogenic cells of the inner cellular layer of the perichondrium (coverings that lie over most cartilage).
At the chondrification centers, the cartilage forming cells (Chondroblasts) begin to secrete the components of extracellular matrix of cartilage. As the amount of matrix increases, the Chondroblasts become separated from each other and they are located in small cavity within the matrix called lacunae.
Concurrently, the cells differentiate into matured cartilage cells called chondrocytes.