Scoring Guideline for Short FR Question 2 4 points maximum 2. Endocrine signals are specific and can impact cells that are a relatively long distance away from the secreting endocrine gland. Choose an endocrine pathway and describe how cells communicate using endocrine signals. In your description include the identity of an endocrine gland or cell, the signaling molecule produced by that structure, the target cell and the resulting action or function of the signal pathway. Secretory cell or gland (1 pt) Signal molecule (1 pt) Target cells (1 pt) Action (1 pt) Thyroid Calcitonin Bone cells (osteoclasts) Induces deposition of calcium into the bones Parathyroid PTH Bone cells Causes an increase in calcium in the blood stream Beta cells of pancreas Insulin Muscle cells and a variety of cells Binds with insulin receptor trigger in entry of glucose into the cells Alpha cells of islets of Langerhans Glucagon liver Cause the conversion of glycogen to glucose Leydig cells Testosterone Various including testicular cells, muscle cells, follicles Ovarian cells, (theca interna cells) Estrogen Ovaries, mammary glands, uterus, bones Anterior pituitary Growth hormone Bone, muscles, liver, cartilage Stimulates development of secondary sex characteristics, sexual activities Reproductive organs, development of secondary sex characteristics, Regulate cell growth, differentiation, apoptosis, and reorganization of the cytoskeleton
Scoring Guideline for Short FR Question 3 4 points maximum 3. Cells can communicate directly through cell-to-cell contact or indirectly through chemical signaling. Describe each type of communication and give an example of how the membrane of the cell is involved in each. Type of Communication 1 point for each correct description Cell-to-cell communication involves direct contact with communicating cells. Chemical signaling involves the indirect use of chemical signals secreted by one cell and received by and causing a response in a target cell. Example of how the membrane of the cell is involved 1 point for describing each component s role (any relevant example should earn credit) Plant cells may have direct cytoplasmic contact through plasmodesmata lined by a shared membrane. Animal cells may have direct cytoplasmic contact through gap junctions lined by a shared membrane. Insulin attaches to a receptor embedded in the membrane of a target cell. The membrane of secretory pancreas cells release insulin through exocytosis.
Scoring Guideline for Short FR Question 4 4 points maximum 4. Biological recognition is important in many processes at the molecular, cellular, and organismal levels. Explain how the process of recognition occurs in target cells in response to TWO specific types hormones using a specific example for each hormone type. 1 point each for choosing a hormone from each category (protein vs. steroid) 1 point for explaining process of recognition in target cells using a specific example The specific receptor is embedded in the cell membrane at the cell surface; the protein hormone doesn t get into the cell, thus a 2 nd Protein (Peptide) Hormone messenger (camp, etc.) must be involved in delivering the signal that triggers a response Specific Protein (Peptide) Hormone Examples (others possible) prolactin (PRL) acts on mammary gland and promotes lactation adrenocorticotrophic (ACTH) insulin antidiuretic hormone (ADH or vasopressin) oxytocin Steroid Hormones testosterone estrogen acts on adrenal cortex and regulates growth hormone causes liver cells, skeletal muscle and fat tissue to take up glucose from the blood; inhibits the release of glucagon primary functions are to retain water in the body and to constrict blood vessels involved during and after mammalian childbirth; causes uterine contractions during labor and breastfeeding Specific Steroid Hormone Examples (others possible) Generally the receptor is inside the cell; hormone crosses the cell membrane since lipid soluble. Recognition of hormone is specific to receptor (specific proteins). Affects transcription In men, testosterone plays a key role in the development of male reproductive tissues such as the testis and prostate as well as promoting secondary sexual characteristics such as increased muscle, bone mass, and the growth of body hair. Estrogens are used as part of some oral contraceptives, in estrogen replacement therapy for postmenopausal women, and in hormone replacement therapy for trans women.