I think c and d is the best answers
Answer:
In intravenous ossification, bone develops directly from sheets of mesenchymal connective tissue. In endochondral ossification, bone develops by replacing hyaline cartilage. Activity in the epiphyseal plate enables bones to grow in length. Modeling allows bones to grow in diameter.
Explanation:
Gene duplication, mutation, or other processes can produce new genes and alleles and increase genetic variation. New genetic variation can be created within generations in a population, so a population with rapid reproduction rates will probably have high genetic variation.
Answer;
C. A wall of stones and mortar
This would act as a model describing the cell membrane.
Explanation;
A cell membrane is made up of a phospholipid bilayer with embedded proteins.
A cell membrane hold the different components of the cell together and to protect it from the environment outside the cell. It acts as a boundary between the inside environment and the outside environment of a cell.
It regulates the materials that enters and exits the cell; through selective movement of substances in and out of the cell.