Genetics and NYS lab biodiversity

Genes are inherited from our parents:

  • Every organism requires a set of DNA (coded instructions) for specifying its traits

  • For offspring to resemble their parents, there must be a reliable way to transfer information from one generation to the next. Heredity is the passage of these instructions from one generation to another

  • DNA is contained in genes, located in the chromosomes in the nucleus of each cell

DNA replication:

  • In all organisms, the coded instructions for specifying the characteristics of the organism carried in DNA, a large molecule formed from subunits arranged in a sequence with bases of four kinds

  • The chemical and structural properties of DNA are the basis for how the genetic information that underlies heredity is both encoded in genes and replicated by means of a template

Protein synthesis:

  • Cells store and use DNA. The genetic information stored in DNA is used to direct the synthesis of the thousands of proteins that each cell requires

  • The work of the cell is carried out by the many different types of proteins the cell makes, such as enzymes and hormones

  • Protein synthesis occurs in the ribosome of the cell

  • Protein molecules are long, usually folded chains made from 20 different kinds of amino acids in a specific sequence. This sequence influences the shape of the protein. The shape of the protein determines its function

Mutation and recombination of genes:

  • Mutations and the sorting and recombination of genes during meiosis and fertilization result in a great variety of possible gene combinations

  • Any alteration of the DNA sequence is a mutation

  • Mutations may occur as random chance events or be caused by such agents as radiation and chemicals

  • When they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to other body cells only

  • Inserting, deleting, or substituting DNA segments can alter genes. This can change the shape and function of the protein built from this gene

Gene Expression:

  • Gene expression can be changed by the environment

  • Even though the DNA in each body cell of an organism is essentially identical, many body cells are very different from one another. This is because different parts of the DNA are used in different types of cells, and are influenced by the cell’s environment and past history

Genetic engineering:

  • For thousands of years new varieties of cultivated plants and domestic animals have resulted from selective breeding by humans for particular traits

  • In recent years new varieties of farm plants and animals have been genetically engineered by manipulating this DNA to produce new characteristics

  • Human genes can be inserted into bacterial DNA to produce hormones or enzymes missing in the human body

  • Different enzymes can be used to cut, copy, and move segments of DNA. Characteristics produced by the segments of DNA will be expressed when these segments are inserted into new organisms, such as bacteria

  • Commonly used to make insulin for individuals with diabetes

  • Cloning is the production of identical genetic copies

  • Knowledge of genetics is making possible new fields of health care

  • Finding genes which may have mutations that can cause disease will aid in the development of preventive measures to fight disease

  • Substances, such as hormones and enzymes, from genetically engineered organisms may reduce the cost and side effects of replacing missing body chemicals

  • As a result of evolutionary processes, there is a diversity of organisms and roles in ecosystems. This diversity of species increases the chance that at least some will survive in the face of large environmental changes. Biodiversity increases the stability of the ecosystem

Purpose of Gel electrophoresis: To separate DNA fragments based on size. The more DNA “bands” in common, the more closely related the two species are

How to complete Gel electrophoresis: Obtain colored paper strips representing portions of DNA molecules. The sequence of bases are representative of molecules isolated from botana curus and species X, Y and Z. An enzyme will be used to cut between C and G of the sequences to produce different sized portions of the DNA. These will be placed on a simulated gel plate to compare the relatedness of botana curus to X, Y and Z

Purpose of Paper chromatography: procedure used to separate plant pigments. The more pigments in common, the more closely related the species

How to complete paper chromatography: Using clean, separate pipettes for each sample, transfer two drops of each plant extract to a piece of chromatography paper, two cm above the bottom. Label the top of the paper with the proper sample names. Place the paper into a cup of water, 1 cm deep. The water should NOT touch the spots of plant extract. Keep checking the sample to make sure the water does not reach the labeled top part of the paper. When the water is done rising, check the color and relative amounts of pigments and record this in the data table

Purpose of translating DNA to make a protein: Change DNA sequence into mRNA sequence, then use the genetic code table to determine an amino acid sequence

KEY POINTS:

  • The diversity of life on the planet has been created through the process of evolution by the means of natural selection

  • Through natural selection, organisms have evolved to lessen competition, and therefore fill a wide array of niches. This biodiversity increases the stability of ecosystems.

  • Biodiversity has important benefits to mankind, including development of new food sources and medicines; as well as beneficial, free, ecosystem services. Ecosystem degradation and destruction lead to the loss of genetic biodiversity and increases the chance that an ecosystem will become less stable and collapse

ANALYSIS

  1. This lab has 7 tests used to determine the relatedness of 4 plant samples. Remember that scientists use a variety of evidence to determine evolutionary relationships, including cells types, structural morphology, DNA, behavior, embryology, and fossils. The more criteria that are shared between organisms, the more likely they are closely related

  2. Relatedness can she shown using a “branching tree diagram”, or cladogram. Organisms that are closely related are next to each other on the same branch. More distant relations are further apart on the branch

  3. Botana Curus shares the most characteristics with Sample Z, making this sample the most closely related. These characteristics included the presence of Enzyme M, the same pigments blue, yellow, and pink, scattered bundles, no difference in the amino acid sequences, and the same DNA banding pattern

  4. The evidence that should receive the most emphasis when determining the relatedness would be the genetic sequence, as many things can look similar structurally (convergent evolution), but would be unlikely to share the same DNA sequence if they are not truly closely related

  5. The loss of even a single species (extinction) can have major implications for mankind and natural ecosystems

  6. Scientists use gel electrophoresis to separate DNA fragments. Negatively charged DNA molecules migrate through the gel like material towards the positively charged pole. The smaller molecules migrate more rapidly through the gel than the larger ones do