Mechanical stress applied to bone increases osteoblast activity in bone tissue, and the removal of mechanical stress decreases osteoblast activity.
Explanation:
Osteoblasts are cells , that are produced in the bone marrow and are responsible for formation of bones and bone matrix.
Whenever a mechanical stress is applied on the bones , a series of reactions are triggered. As a result the activities of osteoblast increases to synthesize more and more bone matrix to provide strength.
Again on the other hand a decrease in mechanical causes a decrease in the activities of the osteoblasts.
The two semilunar valves, the pulmonary and aortic valves, are closed, preventing backflow of blood into the right and left ventricles from the pulmonary trunk on the right and the aorta on the left.
C. cells . are the basic units of life
Answer:
Active genotype - environmental effects
Explanation:
There are primarily three types of co-relation between genotype and environment which are as follows –
a) Passive genotype –environment effect – This depicts the relationship between the genetic characteristics acquired by a child from his/her parents and the environment in which he/she is raised.
b) Reactive genotype –environment effect – This represents a relationship between genetically acquired behaviour from parents and the reaction corresponding to such behaviour.
c) Active genotype –environment effect – This represents a relationship between genetic tendency of an individual and the environment condition selected by an individual .
