Biolab midterm

In the result of a Nucleotide BLAST search, a bit score tells you how well the sequence is aligned with the query sequence and a small E-value means the chance that thee similarity b/t the hit and the query is due to coincidence is very small. If a shorter length of query sequence is used in Nucleotide BLAST search A. the E-value is expected to increase B . The E-value is expected to decrease

A

Large DNA fragments (e.g.>10kb) willl be better separated in which % of agarose gel? A. 0.8 % B. 1.8 % C. The percentage of the gel does not affect the how well DNAs are separated

A

Which of the following is a correct description of restriction enzymes? A. They are DNA endonucleases B. They cut DNA randomly or nonspecifically C. They are DNA molecules themselves D. They are DNA exonucleases

A

Which of the following is true about restriction digest of DNAs? A.. the buffer used in the restriction enzyme digest provides both the necessary cations and also the optimal pH for the enzyme to function properly. B. After restriction enzyme digestion, DNA molecules become single stranded. C. if a plasmid DNA has two EcoRi sites, three linear fragments will be produced after this l=plasmid is completely digested by EcoRI.

A

Which of the following methods is NOT a proper way to. Sterilize ? A. Clean the bench surface by wiping with 70% alcohol B. Autoclave get the media C. Flaming the inoculating instrument.

A

CLUSTALW (omega)

A bioinformatics tool that compares multiple amino acid sequences and aligns them to hi=ghlight their similaries

Nucleotide Blast

A computer program that search for sequence similarities. It can be sued to identify homologous genes in different organisms

A diploid cell contains a total of 20 chromosomes. At the end of mitosis, there will be ______ chromosome in eaddch of the daughter cells, and at the end of meiosis, there will be _______ chromosome in each gamete. A. 20-20 B. 20-10 C. 10-20

B

A student is trying to make a 1:20 dilution of an overnight yeast culture wth sterile . The final volume of the diluted culture needs to be 50ml. He should______. A. Mix 5ml of the overnight culture with 95ml of water. B. Mix 2.5 of overnight culture with 47.5ml of water C. Mix 5 ml of overnight culture with 45ml of water.

B

As you increase the total magnification of a ligh microscope, which of the following is true? A. Field of view increases B. Depth of field decreases C. Resolution does not change D. Working distance increases

B

Choose thee correct answer A. Protein BLAST is a computer program that search for DNA sequence similarities, IT can be used to identify homologous genes in different organisms B. Clusters is a bioinformatics tool that compares multiple amino acids sequences ( multiple SE sequence alignment) and aligns them to highlight their similarities. C. Nucleotide BLAST is a computer program lethal search for sequence similarities , it can only be used to identify homologous gens within a single organism.

B

During which of the following would you expect to observe crossing-over A. Mitosis B. Meiosis C. Both D. Neither

B

Which method counts only live cells? A. Spectrophotometer you B. Standard pate count C. Neither of the above

B

Which of the folllowing descriptions about bacteria population growth is TRUE? A. During LAG phase, the cells are not increasing in cell numbers and the cells are not Active engaged in metabolism B, during the LOG phase, the cells are actively dividing ad experiencing exponential growth C. During the DEATH phase, all cells are dead D. During the LAG phase, some cells are dividing and equal number of cells are dying and therefore is no net increase in cell number.

B

Which of the following can not be seen clearly or appear the smallest at 400x total magnification? A. Yeast cells B. Bacteria C. Spinach leaf cells. D. Human cheek cells..

B

Which of the following is TRUE? A. There are total of 3 possible open reading frames within a segment of double stranded DNA sequence. B. there is no intron sequence in DNA C. All 64 possible codons can be translated into amigo acids. D. Translation of the codons occurs from 3' to 5' end of the mRNAs.

B

Which of the following statements about DNA agarose gel is true? A. The DNAs are positively charged and migrate toward cathode. B. The DNAs can be stained by ethidium bromide and visualized under U-VERSE. C. The samples DNAs migrate the slowest D. The bromophenol blue and Selene cyanogen dyes directly stain in DNAs blue so that one can visualize where the DNAs are in the gel without UV.

B

During which phase of meiosis would expect to see crossing over b/t two non-sister chromatids? A. Metaphase I B. Telophase I C. Prophase I D. Prophase II E. None of the above

C

Which of the following is not a function of mitosis? A.Tissue repair B. Growth from a zygote to an adult orgaism C. Reproduction in unicellular organisms D. Generating genetic variation in offspring

C

Which of the following statements is true? A. In the process of cytokinesis in plant cells, a cleavage furrow willl form to separate two daughter cell B. There is an interphase with DNA replication b/t meiosis I and meiosis II C. Mitosis can be used for reproduction in certain organisms. D. Meiosis can be used for growth and repair in certain oganisms

C

Which of thee following is a palindromic sequence? A. 5' GTTTTC 3' B. 5' CTTAAC 3' C. 5' AATT 3' D. 5' GAATTAAG 3'

C

If you want to make 50 ml of 0.8 agarose gel, how many grams of agarose powder should you weight? A. 6 grams B. 0.8 grams C.0.6 grams D.0.4 grams

D

Which of the following is NOT a way of increasing the contrast in light microscopy ? A. Staining the specimen B. Using dark-field microscopy C. Using phase-contrast D. Using oils immersion with the 100X objective lens.

D

Which of the following phases take the longest tie to complete? A. Anaphase B. Prophase C. Cytokinesis D. Interphase

D

A which of the following phases is the longest in a typical eukaryotic cell cycle? A.Telophase B. Metaphase C. Prophase E. Interphase

E

What can affect the migration rate of DNA molecules in an agarose gel electrophoresis? A. Size of the DNA B. Conformation of DNA( circular, linear nicked circle, etc) C. Percentage of agarose gel D. Electrophoresis buffer used E. All of the above

E

Protein Blast

Is use to compare a amino acid query sequence against a protein sequence database

Cleavage furrow formation is observed in _________ cells during cytokinesis

Plant

Explain the distinction in ingredients b/t solid media and liquid media

Solid media have the same chemical ingredients as the liquid media EXCEPT that they contain an additional solidifying agent , typically agar.

Single colony represent

The progeny of a single cell

streaking plates

To Dilute the cells on the surface of the agar

Spreading plates

To evenly distribute a consistent number of cells so the individual colonies can be count

Why do we incubate inoculated plates upside down?

To prevent condensation from dripping onto the colonies and disrupting the growth pattern

The equipment used to sterilize liquid media in this topic is ?

autoclave