Describe how, where, and when the first living cell came about? What is a geneti
ID: 300207 • Letter: D
Question
Describe how, where, and when the first living cell came about?
What is a genetic mutation and what are some causes of these mutations?
What are two major types of mutations and what effect can they have on protein activity?
Describe how cancer can be caused by mutations in certain genes?
Describe how recombinant DNA technology is used to clone organisims?
Describe how PCR reaction can be used to make many copies of a DNA sequence?
How is the PRC reaction important in determining parenthood or if a DNA sequence is from a GMO?
What is a transgenic organism?
Describe how our food is affected by transgenic organisms?
What is gene therapy?
Decribe how gene therapy could help genetic disorder? Give one specific example.
Describe the evolution from prokaryotic cells to eukaryotic cells to multicellular eukaryotic cells?
List and describe the evolution of land plants?
List and describe the evolution of vertbrates from invertebrates and chordates? Make sure to include the major characteristics of each vertebrate group?
Atleast 5 mass extinction have occurred througout the history of earth. Some scientists say we are now in the sixth mass extinction. Explain?
What are the three domains and give examples of an organism in each?
Name and describe three ways scientists determine how closely two organisms are related?
Give the complete classification for human from Domain all they way down to species?
Why do scientists assign a Latin name (genus and species) to evry species?
What is our (humans) Latin name?
Explanation / Answer
Describe how, where, and when the first living cell came about?
Life first emerged 3.8 billion years ago, some 750 million years after Earth was formed. At that time when life arose, the atmosphere of Earth was reducing i.e. it contained little or no free oxygen, having gases like CO2 and N2in addition to smaller amounts of H2, H2S, and CO. Such an atmosphere that had reducing conditions was favorable for the spontaneous formation of organic molecules, given a source of energy such as sunlight or electrical discharge. This has been demonstrated experimentally in the 1950s, by Stanley Miller; discharge of electric sparks into a mixture of H2, CH4, and NH3, in the presence of water, led to the formation of a variety of organic molecules, including several amino acids, (Cooper, 2000). The so formed organic molecules like; amino acids, proteins, and other hydrocarbons came together into a form called coacervates ( the first primitive cells, a spherical aggregation of lipid molecules making up a colloidal inclusion) in the warm primordial ocean.
What is a genetic mutation and what are some causes of these mutations?
A gene mutation is a permanent alteration in the DNA sequence that makes up a gene. Mutations range in size; they can be a single DNA (base pair) change or a change in a large segment of a chromosome that includes multiple genes.
Causes of mutations
DNA fails to copy accurately due to improper proofreading activity.
Mutation may also be caused by a mutagen i.e. an agent, such as radiation or a chemical substance. Common chemical mutagens are: sodium azide, psoralen, benzene etc.
Common radiation mutagens are: x-rays, gamma rays, alpha particles, ultraviolet radiation.
What are two major types of mutations and what effect can they have on protein activity?
Point mutation which is a change in one base of the DNA, depending upon the change it can be silent, nonsense, or a mutation leading to change in structure of the protein, e.g. point mutation in Sickle cell anemia or frame shift mutation, in which is there are insertions or deletions of a number of nucleotides in a DNA sequence that is not divisible by three, hence the whole reading frame changes e.g. thalassemia
Describe how cancer can be caused by mutations in certain genes?
Mutations in the tumor suppressor genes, i.e. the genes that:
Leads to the loss of the activity of these genes will leads to cancer.
E.g. of some tumor suppressor genes are: p53 gene and the Rb gene.