Take home Bio quiz

UTANG NA LOOB LANG… wag naman kopyahin the answers here directly… grasp the thought, then write on your own words. and if you have better answers, kayo na lang magsagot by yourselves, and pwede niyo rin i-comment para helpful sa lahat... :>

Nasa book naman lahat.. and try niyo ring i-search about the topics para may references naman kayo..

1. (FORESICS /grp1) How are VNTRs used to make a DNA match?

(a) VNTR’s are repeated sequences of base pairs found in introns. They are highly variable between two individuals, especially those unrelated. VNTR’s are commonly characterized using the Southern Blotting. This results into RFLP’s used to identify a DNA fingerprint (shows variation in lengths; 4-6 VNTR loci are analyzed for forensic purposes).

2. (HGP/grp2) How are gene linkage maps and physical maps of the genome made?

(a)

3. (HGP/grp2) Briefly explain chromosome walking?

(a)

4. (AGRI AND FOOD/grp4) Give one method for inserting DNA into plant cells or animal cells and explain.

(a) (pick one lang :D)

DNA microinjection

• transfer of a desired gene construct from another member of the same species or from a different species into the reproductive cell
• the manipulated cell, which first must be cultured in vitro to develop to a specific embryonic phase, is then transferred to the recipient female

Retrovirus-mediated gene transfer

Retrovirus- virus that carry genetic material as RNA rather than DNA

• retroviruses used as vectors to transfer genetic material into the host cell, resulting in a chimera, an organism consisting of parts of different genetic constitution
• chimeras are inbred for as many as 20 generations until homozygous (carrying the desired transgene in every cell) transgenic offspring are born

Embryonic stem cell-mediated gene transfer

• isolation of totipotent stem cells (stem cells that can develop into any type of specialized cell) from embryos
• the desired gene is inserted into these cells
• cells containing the desired DNA are incorporated into the host’s embryo, resulting in a chimeric animal

5. (ECO AND EVO/grp5) How are DNA probes and PCR technology used for monitoring microorganisms in the environment (i.e. water quality tests)?

PCR analysis provides a sensitive and specific means to detect and monitor microorganisms in complex environmental samples. Possession of DNA probes representing harmful microorganisms was used to sample the quality of the environment. The samples that could be test included rainwater, tank water, and soil. The presence of the microorganisms in the sample indicates that the environment may not be suitable for other organisms.

6. (ECO AND EVO/grp5) How is DNA technology used to break the cycle of disease in nature (i.e. intervention in the life cycle of parasites)?

(a)

This is the specific way for malaria parasites-- By disrupting the potassium channel of the malaria parasite, a team of researchers has been able to prevent new malaria parasites from forming in mosquitoes and has thereby broken the cycle of infection during recent animal tests.

By genetically altering the malaria parasite through gene knock-out technology, a research team consisting of scientists at the University of Copenhagen-gen and John Hopkins University, Baltimore, has prevented the parasite from going through the normal stages of its life cycle and developing a cyst (egg-like structure or occyst), which spawns new infectious parasites." As it is exclusively the parasites from these oocysts that can infect new individuals, we were able to prevent the disease from being transmitted to the animals in our tests", explains Assistant Professor, Peter Ellekvist from the University of Copenhagen.

(b) Another example --- Bulls, on a farm in South Dakota, were genetically engineered by scientists at Hematech and Kirin to be prion-free, which likely makes them resistant to mad cow disease.

7. (ECO AND EVO/grp5) What are applications of DNA technology in taxonomic classification? How is it used to establish that a particular organism is, for example, a separate or a new species?

(a) Barcode of life

- accepts DNA sequences in fasta format & returns taxonomic assignment [if possible, upto species level]

- fasta: text representing either nucleic acid sequences/peptide sequences (b) Taxonomy is the science of classification. It’s trying to sort out, for the human mind, the array of diversity that we see out there in nature. Originally, we were reliant just on morphological characters, and that has given us a really good basis for classifying ferns, but then other technologies have come along, such as the scanning electron microscope that enabled us to look in detail at spore patterns and spore structures and other close-up features.

Most recently, it’s the DNA technology that has come along that enables us to sequence DNA and see the pattern of nucleotides in the DNA, and that gives us a much finer technique for determining how closely related different species are. And there is a whole lot of analysis that you can do around that that tells you a great deal about the evolution and the relationships of different species. It’s a very powerful technology.

With DNA work, we have been able to get a better idea of how things are related. We have learnt more about the evolutionary history of plants and animals. As we’ve updated our understanding of how plants and animals are related to one another, we’ve had to change the taxonomic classification in order to reflect that improved updated understanding of their evolutionary history.

A great example within the fern type of plants is that there are several small groups of plants which used to be regarded as fern allies. In particular, there is the Tmesipteris fork ferns. They were previously grouped with plants like Lycopodium and Selaginella in the fern allies, but with DNA analyses, people have worked out that Tmesipteris fork ferns they are actually more related, more closely related to ferns. So they are now regarded as ferns, rather than as fern allies.

(c) Application of DNA bar code technology is not complex molecular biology techniques, the main work processes, including sample collection, DNA extraction, design and synthesis of primers, primer selection, PCR amplification reaction conditions were optimized, PCR product purification, sequencing and analysis . Simply put, that is, through a group of individuals from different biological short homologous DNA sequences (about 800 bp) were PCR amplified and sequenced, and then measured the sequence of multiple sequence alignment and cluster analysis thus a precise positioning to a classification of the individual group.

DNA sequence data analysis is to explore the most important part of the bar code, the first sequence alignment and manual correction, calculated by MEGA or PAUP intraspecific and interspecific K2P distances (Kimura 2 parameter distance) [4] used to indicate the different taxa sequence variation between the extent of comparing species, genus and family level 3 sequence differences, and then to establish according to the results NJ tree (neighbour joining tree), the final genetic distance based on DNA bar codes can be on the classification and identification of unknown samples.

8. (ECO AND EVO/grp5) How is DNA technology used in the field of molecular paleontology? What is the value of recovering DNA from fossilized specimens?

(a) PCR can permit amplification of specific sequences from material in which the DNA is badly degraded or embedded in a medium from which conventional DNA isolation is problematic. As a result, it is again very suitable for molecular anthropology and paleontology studies, for example the analysis of DNA recovered from archaeological remains. It has also been used successfully to amplify DNA from formalin-fixed tissue samples, which has important applications in molecular pathology and, in some cases, genetic linkage studies.

9. (ECO AND EVO/grp5) How was DNA technology used to trace the movements of the human population from its African birthplace?

(a) Y-Chromosome Analysis

The Y chromosome is passed directly from father to son, so the analysis of genetic markers on the Y chromosome is especially useful for tracing relationships among males or for analyzing biological evidence involving multiple male contributors.

10. (MED AND HEALTH/grp3) How is gene therapy done? Enumerate the steps.

(a) PCR

(b) DNA Sequencing with the use of labeled nucleic acid probes (for tracking down pathogens) --> kasi known ang DNA sequence ng infectious diseases na ito. :> TAPOS dahil nga dun, PCR to amplify yung DNA

11. (MED AND HEALTH/grp3) What methods based on DNA technology are used for detecting infectious diseases?

1. Clone gene (normal gene, one that is absent in the patient's cells)

2. Insert normal gene into retrovirus

3. Retrovirus will infect (bone marrow) cells that have been removed from the patient

4. Viral DNA carrying the normal allele inserts into chromosome

5. Inject engineered cells into patient

//retrovirus: RNA virus that reproduces by transcribing its RNA into its DNA and then inserting the DNA into a cellular chromosome.

12. (MED AND HEALTH/grp3) Give at least two examples of human protein replacements and their effects.

(a) Human Insulin therapy -> for diabetics who cannot produce their own insulin

//insulin -> hormone that promotes the absorption of glucose into the body's cells para di mag-accumulate sa blood, therefore, di tataas ang blood sugar level :-bd

(b) Human Growth hormone -> for those with hypopituitarism, dwarfism caused by inadequate amounts of human growth hormone