Answer:
A callus is a hardening of skin, keratin is the protein which is abundant in callus. Skin is a protective layer against a external environment. Outer layer of skin consist of keratin which is also found in hair. Callus is the accumulation of dead cells result due to friction and pressure exerts on the part in which they are present. The keratin component (keratinocytes) remains undifferentiated in these dead cells which causes hardening in callus.
Answer:
A. passive transport by diffusion
Explanation:
Diffusion and osmosis are both types of passive transport. They do not require energy. Diffusion is the general term for the process. Osmosis is the diffusion of water molecules.
Many small, uncharged molecules can cross the cell membrane by diffusion. Oxygen and carbon dioxide are examples of two small molecules that pass the cell membrane by passive transport.
Larger or charged molecules require energy to cross the cell membrane. This is achieved by active transport.
Explanation:
Worms are invertebrate animals with bilateral symmetry. Worms have a definite anterior (head) end and a posterior (tail) end. The ventral surface of worms and other organisms is the bottom side of the body, often closest to the ground. The dorsal surface is located on the upper part of the body facing the sky. The lateral surfaces are found on the left and right sides of the body. Figure 3.35 compares bilateral symmetry in a whale shark and a swimming plychaete worm. Organs for sensing light, touch, and smell are concentrated in the heads of worms. They can detect the kinds of environment they encounter by moving in the anterior direction
4 cells will result. Each cell will have 20 Chromatids which is half a chromosome. once sexual reproduction takes place, these 20 chromatids will match with those from the other parent cell to form chromosomes
Lisa and Shirley, because upbringing has more of an impact than genes
