In humans, the placenta is essential to the embryo for RESPIRATION, NUTRITION AND EXCRETION.
The placenta refers to an organ in the uterus of pregnant mammals that is responsible for nourishing and maintaining the unborn baby through the umbilical cord. Th placenta has many functions but primarily it plays critical roles in the nutrition, respiration and excretion of the fetus. Its other functions include: production of hormones, production of immunity for the fetus for prevention from infections, etc. <span />
Two main factors that must be taken in consideration are temperature and the pH level.
The temperature shouldn’t be too low as it slows down the rate of reaction, meaning that the enzyme will work slower, but also not too high as it will cause the enzyme to denature (stops working as it should).
The pH level is pretty much the same, shouldn’t be not too low nor too high.
<span>Planaria have a huge regenerative power because of the presence of adult stem cells called neoblasts. If you cut Planaria into pieces, each piece can regenerate into a complete organism and that’s a form of asexual reproduction. Cells which are located on the wound site proliferate to form a blastema-mass of cell that will grow into a new organ. Those cells will differentiate into new tissues and regenerate the missing parts.</span>
<span>The similar thing is happening with starfish.</span>
Answer: Stomata plays very crucial roles in plants. During photosynthesis, gas exchange takes place via the stomata. Water also evaporates from plants through the stomata. In plants, most of the stomata are usually on the bottom of the leaf IN ORDER TO PREVENT EXCESSIVE LOSS OF WATER.
During the day, the sunlight falls on the leaf directly and draws water from the plants. Locating the stomata at the underside of the leave reduces the amount of water that can be lost through excessive evaporation. Also, locating the stomata on the underside of leaves prevent the leaves from taking in too much water during rainfall.
