Pituitary dwarfism is caused by problems arising from the pituitary gland. The pituitary gland, also called the hypophysis, is a gland at the base of the brain that produces many different hormones. This gland is divided into the anterior (front) and posterior (back) halves. The anterior pituitary produces six hormones: growth hormone, adrenocorticotropin (corticotropin), thyroid stimulating hormone (thyrotropin), prolactin, follicle stimulating hormone, and lutenizing hormone. The posterior pituitary gland only produces two hormones: antidiuretic hormone (vasopressin) and oxytocin.
The growth process begins in the lower part of the forebrain in a small organ called the hypothalamus. The hypothalamus releases hormones that regulate the production of other hormones. When the hypothalamus releases growth hormone-releasing hormone (GHRH), the anterior pituitary is stimulated to release growth hormone (GH). Growth hormone then acts on the liver and other tissues and stimulates them to secrete insulin-like growth factor-1 (IGF-1). IGF-1 directly promotes the development of bone and muscle, causing bones to grow in length, and muscles to increase protein synthesis (make more protein).
Since growth is a complex phenomenon, it may be slowed down or stopped by abnormalities arising at any point in the process. Thus, dwarfism can result if there is a deficiency in any of these hormones, if there is a failure in the receptor cells receiving the hormonal stimuli, or if the target cells are unable to respond.
At its most basic, pituitary dwarfism results from decreased production of hormones by the anterior pituitary. When none of the hormones of the anterior pituitary are adequately produced, this is called panhypopituitarism. A common form of pituitary dwarfism is due to deficiencies in the production of growth hormone (GH). When less GH than normal is produced during childhood, an individual's arms, legs, and other structures continue to develop in normal proportions, but at a decreased rate.
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When prolonged and excessive rainfall the more water percolates and the water table (below the earth surface/soil) rises. The higher the water table the more the possibility increases for a spring to form in the sense that it would now be easier for the water to find a means of escaping the underground through perhaps a crack or a cave, etc.
Answer:
b. mRNA from DNA
Explanation:
Transcription is the process of synthesis of RNA using a DNA template strand. The process of transcription occurs inside the nucleus in eukaryotes as their DNA is present in the nucleus.
The process includes unwinding of DNA double helix to expose the DNA template strand. The enzyme RNA polymerase binds to the specific start sites on the DNA template strand and starts making its RNA copy.
The newly formed RNA undergoes modification in eukaryotes before serving as a template for protein synthesis. However, in prokaryotes, the process of transcription and translation can occur simultaneously.
C. Energy processing from corn biofuels is not energy efficient.
