Answer:
Following are the two advantages of endoplasmic reticulum.
1) Endoplasmic reticulum is an organelle of the cell which is responsible for the production of protein for the cell. This protein is sent to the Golgi apparatus where it is modified and used by the cell where it is needed.
2) Endoplasmic reticulum also helps in the removal of toxic substances from the cell. If these toxic substances are not removed, it causes damage to the cell.
Carbon dioxide and oxygen cannot pass through but move in and out
Plasma Membrane is the answer
Similarities
Both plant and animal cells have eukaryotic origins
Both have common organelles like the nucleus, mitochondria and ribosomes
Both are surrounded by a cell membrane
differences
plant cells have a regular defined shape while animal cells have an irregular shape
plant cells have a cell wall while animal cells lack a cell wall
plant cells have a chloroplast for photosynthesis while animal cells do not have a chloroplast
Answer:
a. heart development.
Explanation:
As the third week of fetal development starts, the process of formation of blood vessels begins. Also, the splanchnic mesoderm in the head end of the embryo forms heart on days 18 and 19. Since it develops heart, this part of the mesodermal cells is called the cardiogenic area. The underlying endoderm sends the induction signals to these mesodermal cells to form a pair of endocardial tubes that gradually develop into a single primitive heart tube.
This primitive heart begins to beat by the end of the third week of development. Therefore, any drug that affects fetal development during the first 20 days of the pregnancy might affect the development of the heart.
