Functions of skin. Protection: it protects against UV light, mechanical, thermal and chemical stresses, dehydration and invasion by micro-organisms. Sensation: skin has receptors that sense touch, pressure, pain and temperature. Thermoregulation: various features of the skin are involved in regulating temperature of the body. For example sweat glands, hair, and adipose tissue. Metabolic functions: subcutaneous adipose tissue is involved in production of vitamin D, and triglycerides. This diagram shows the layers found in skin. There are three main layers: the epidermis, dermis and hypodermis. There are also sweat glands, and hairs, which have sebaceous glands, and a smooth muscle called the arrector pili muscle, associated with them. Hairs are only found in thin skin, and not in the thick skin present on the fingertips, palms and soles of your feet.
As seen in Graph 1, a pie chart represents the total percentage of cells in each stage of the cell cycle. Interphase accounted for 95.31 percent of the cells, followed by prophase with 1.58 percent, metaphase with 1.27 percent, telophase with 0.95 percent, and anaphase with 0.87 percent. Graph 2. As seen in Graph 2, this pie chart represents the total number of minutes per cycle a cell spends in each stage.
Now weâre going to do an experiment to determine how much time cells spend in each phase of cell division. Letâs count the number of cells in some onion root tips during each phase, and use this information to answer the question. On this slide, there are 21 cells in interphase, 4 in prophase, 2 in metaphase, and 1 in telophase. Why are most of the cells in interphase? Recall that interphase makes up the majority of the cell cycle. Letâs look at another slide. In this slide, there are 16 cells in interphase, 1 in prophase, and 1 in anaphase. Go ahead and try characterizing the cells yourself. Good job! Good going! Youâve got it! Nicely done! Thatâs right! Sorry, thatâs not correct. This cell is in interphase.