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Biology
In adults, over 90% of all cancers are either adenomas (adenocarcinomas) or carcinomas, including cancers of the skin, lung, colon, breast, and prostate. Which one of the four basic tissue types gives rise to most cancers? Give two reasons why this tissue is more likely to produce cancerous cells.
Skin cancer is the most common[footnoteRef:2]. Each year over 2 million people are treated for basal cell and squamous cell carcinoma in the United States alone. The next most common cancer type is prostate cancer. [2: http://www.cancer.gov/cancertopics/wyntk/skin]
The risk of skin cancer is increased by exposure to UVB radiation, whether by natural sunlight or tanning beds[footnoteRef:3]. Studies in skin-humanized mice show UVB induced DNA damage, p53 expression, and epidermal disorganization[footnoteRef:4], changes that would be expected to increase cancer risk. [3: http://www.cancer.gov/cancertopics/wyntk/skin/page5] [4: Garcia et al., 2010. Amer. J. Pathol., 177, 865-]
Genetics also plays a role on many levels[footnoteRef:5]. Persons with fair skin, blue or gray eyes, lots of freckles, or red and blond hair will tend to burn rather than tan when exposed to sunlight. The redness produced when the skin is sun burned is an indication of skin trauma, including DNA damage[footnoteRef:6]. An increased risk of developing melanoma and other types of skin cancer can run in some families as well. [5: http://www.cancer.gov/cancertopics/wyntk/skin/page5]...
Brittany and Joshua are physically normal but they have a daughter with galactosemia, an autosomal recessive disease. The daughter is homozygous recessive. What are Mary and Joe's genotypes?
An autosomal recessive disease can only manifest if an individual contains two mutated copies of the same gene. In the case of galactosemia the genes known to cause this disease are galactose-1-phosphate uridylyltransferase, galactokinase, or galactose epimerase[footnoteRef:7]. Since the parents are physically normal then both must be heterozygous carriers for the same mutated gene. [7: http://ghr.nlm.nih.gov/condition/galactosemia]
3. In recent years more mothers are breast-feeding their babies. At the same time, mothers have been protecting the skin of babies from sunlight, to reduce UV exposure. A side effect of this protection has been weak bones and other symptoms of rickets in breast-fed babies.
a. Mothers who are breast-feeding are told to give the babies Vitamin D, and to encourage young children to play outside. Why? The answer does not involve obesity.
The gradual shift from a primarily agrarian society to an urban one has reduced the amount of sun exposure children receive. When exposed to sunlight cholesterol (7-dehidrocholesterol) in healthy human skin is converted to vitamin D3[footnoteRef:8]. This vitamin is important for…
If a child lived in a northern climate their exposure to sunlight would be limited, especially when they would be wrapped head to toe in winter clothing for months at a time.
4. Jennifer was 17 years old and very short for her age (<5th percentile). The doctors determined that her body was not producing enough growth hormone. Prior to beginning growth hormone therapy, they ordered X rays. The X rays showed that her epiphyseal plates were completely ossified, and the doctors cancelled the hormone therapy, telling Jennifer it would not help her. Why did they decide it would not help Jennifer?
The epiphyseal plates are required for growth of the long bones in the body[footnoteRef:10]. Until sexual maturation is reached in humans, the epiphyseal plates continue to produce chondrocytes and bones are able to grow. Once sexual maturation is reached the epiphyseal plates are resorbed and longitudinal bone growth ceases. The process of resorption is also called epiphyseal plate fusion or ossification. Since Jennifer's X-rays showed ossification of the epiphyseal plates, she was no longer capable of longitudinal bone growth. The goal of hormone therapy would have been to stimulate the production of chondrocytes from the epiphyseal plates. [10: Welse et al., 2001. PNAS, 98, 6871-]
Attention-deficit/hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder that affects many children and often continues into adulthood. The biology of ADHD involves various factors, including genetics, neurotransmitter systems, brain structure and functioning, and environmental influences, all contributing to the disorder's wide range of symptoms. Genetic factors are believed to play a significant role in ADHD. Twin and family studies have consistently shown a heritable component to the disorder, with estimates suggesting
G Protein-Linked Receptors An organism must respond appropriately to its internal and external environments day after day in order to survive. The organism's cells respond to internal and external stimuli much like tiny computers that process numerous inputs and also produce numerous outputs in daily existence (Kennedy 2004). These stimuli are signals that come from the general environment or the cells of other or co-existing organisms, proximate or distant, and this
The responses will be tabulated into data sheet that exhibit the participants ease of remembering that facts. The coding will produce levels which showing the proportionate ability to remember. The data will then be input in a statistical program to give distributions and this will be subjected to a T-test to assess their significance level at 5%. The decision rule will be such that reject the null hypotheses if probability
killer whales. It has 6 sources. The following is a brief overview of the biological classification, diet, distribution and social behavior of the mammalian orcinus orca. The research also outlines the factors that are responsible for the decline in orcinus orca population around the world today. Special emphasis has been given to resident orcinus orca to demystify the concept that orcas are lethal to the fishermen and hence should be
1997). The basis of all plants' alternating generations and complex life cycles could be found in a common ancestor shared with fern species, even though ferns are no better reproducing sexually than moss are fully dependent on a saturated enough environment to perform a task that flowers have developed innumerable methods of getting done (Munster et al. 1997; Mehltreter et al. 2010). Conclusion The life cycles of moss and ferns are
Melanogaster Stubble Gene The author of this scientific report has been asked to offer a thorough review of the stubble gene if a D. melanogaster. Items that will be covered will be a brief overview of the stubble gene, an introduction to the gene, the basic biological process when it comes to the gene, the phenotypic characteristics of the gene, the mode of inheritance of the gene, at least two mutant