When epidermal growth factor (EGF)—the ligand for the epidermal growth factor receptor (EGFR)—binds EGFR
on the cell surface, the intracellular domain of the
receptor changes shape into an "active state." The
receptor then induces a cascade of kinases in the
cytoplasm, resulting in the activation of mitogen-
activated protein kinase (MAPK). One effect of EGFR
signaling is the stimulation of cell proliferation.
Overactive EGFR is frequently found in cancer cells.

One strategy for developing anticancer drugs is to target
the overactive signaling proteins found in cancer cells.
Antibodies are proteins made by immune cells that only
recognize specific biomolecules, called antigens.

The
major component of an anticancer drug is an antibody
that specifically recognizes and binds EGFR.

Which of the following will most likely happen when this
anticancer drug is applied to a tumor that has a high level
of EGFR?

O Tumor cells with active EGFR will increase and
MAPK activity in the tumor will increase.
OTumor cells with active EGFR will decrease and
MAPK activity in the tumor will increase.
O Tumor cells with active EGFR will increase and
MAPK activity in the tumor will decrease.
O Tumor cells with active EGFR will decrease and
MAPK activity in the tumor will decrease.

question#1

ans:

cell is the basic unit of organization of all living things. cells are often called the building block of life and it is the smallest unit of life. the study of cell is called cell biology. cell consists of cytoplasm enclosed within membrane, which contain bio-molecules such as proteins and nucleic acid.

two third of cell is water, which means that two-third of your whole body is water. the rest is the mixture of molecules, mainly proteins, lipids and carbohydrates.

question#2

ans:

organ:

an organ is a group of tissues specialized to form a functional unit. an example is the heart in animals.

organ system:

an organ system is a group of several organs whose functions are synchronized to release an effective action in a living organism. an example is digestive system.

question#3

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#4

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system—working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#5

our body works because of the interactions that happen between organs and organ systems.  

for example:  

the heart to regulate blood flow throughout the body. the blood carries oxygen and nutrients to the cells and carries carbon dioxide and waste away from the cells. body systems work together in maintaining a constant internal environment. when this balance is disrupted, the body systems may not function properly, and human health can suffer.   you start to feel bad.

. ph changes the ability of them he enzyme to dissolve in water.