<h2>Answer:</h2>
Following are the four combinations of active or inactive regulatory proteins that could be present anytime in the cell:
- Active repressor , Active activator
- Active repressor, Inactive activator
- Inactive repressor, Active activator
- Inactive repressor, Inactive activator
Clean coal is meant to drastically improve emissions, but no matter how much you treat it, it still creates an environmental impact
Answer:
The correct answer is case control study.
Explanation:
A study in which a comparison is made between the patients carrying the disease with the patients not carrying the disease is known as the case-control study. In the mentioned study, the one carrying the disease is termed as cases, and the one that does not possess the disease is termed as controls.
This form of study is generally done to predict the association between the disease and the risk factor. In case-control studies, only observation is done as no attempt is made to change the course of the condition. The prime objective of the study is to predict the exposure of the risk elements for the individuals present in two groups, that is, controls and cases. This form of study is also called case-referent studies or retrospective studies.
Earth is a planet, Zero planets on earth
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.
