Final study guide

Final study guide - What are mutations and how are they...

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What are mutations and how are they caused? How are DNA mutations related to the genetic variation that is the basis of natural selection? Mutations are caused from a lack in genetic variation. This is very common in cases of species incest or between two organisms that are to genetically similar.-The main source of variation is mutation, which introduces genetic changes. These changes are heritable (can be passed on through reproduction), and may give rise to alternative traits in organisms. How many chromosomes do people have? In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females. What are the sex chromosomes? Sex chromosomes determine the sex of an organism. A human somatic cell has two sex chromosomes: XY in male and XX in female. A human germ cell has one sex chromosome: X or Y in a sperm and X in an egg. A. Females get one X from their mother and one from their paternal grandmother since all humans take an X from their mother. What can DNA sequencing tell us about how closely related different individuals (or populations or species) are? Part of the human genome project if we can identify the 25,000 genes in humans we can understand more about how and why humans are different What is the genome? Entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA. How does the complexity of an organism relate to the size of its genome? Most biological entities that are more complex than a virus sometimes or always carry additional genetic material besides that which resides in their chromosomes, Note that a genome does not capture the genetic diversity or the genetic polymorphism of a species. What was the purpose of the genetic information nondiscrimination act? Designed to prohibit the improper use of genetic information in health insurance and employment. The Act prohibits group health plans and health insurers from denying coverage to a healthy individual or charging that person higher premiums based solely on a genetic predisposition to developing a disease in the future. Also employers cant base decisions solely on that info. What are two general categories of genetically modified (GM) organisms? Animals and plants. There are also microbial. What are the two most common genetic modifications in crops today? Increasing the nutritional value of the crop and increasing the resistance of the crop to disease, drought, weather etc. (corn,soybeans,wheat most commom)
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Final study guide - What are mutations and how are they...

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