Chap. 10: Molecular Diagnostics

Question 1

Compacted into chromosomes and bound to basic proteins.

Answer 1

Helical human DNA

Question 2

Bound to basic proteins

Answer 2

histones

Question 3

DNA + histone complex is called?

Answer 3

chromatin

Question 4

The human nucleus contains ___ chromosomes.

Answer 4

46

Question 5

Humans have two copies of each chromosome, a condition called?

Answer 5

Diploid

Question 6

Two types of chromosomes are:

Answer 6

Somatic
Sex

Question 7

Somatic: ___ pairs
Sex: ___, ___

Answer 7

22 pairs
X or Y, XX (F), XY (Male)

Question 8

Coding parts of a gene.

Answer 8

Exons

Question 9

Exons are ________ sequences.

Answer 9

expressed

Question 10

Noncoding regions of a gene are called?

Answer 10

Introns

Question 11

Introns are _______ sequences.

Answer 11

intervening

Question 12

They can contain regulatory/transcriptional elements and have other functions.

Answer 12

Introns

Question 13

Approximately ___% of all human genes have multiple allelic forms called ___________?

Answer 13

25
polymorphisms

Question 14

Refers to a different version or form of a gene or noncoding region.

Answer 14

Allele

Question 15

Highly polymorphic which codes for peptides that establish self-identity of the immune system.

Answer 15

Human Leukocyte Antigen (HLA)

Question 16

Physical locations or positions of a gene or noncoding region on a chromosome.

Answer 16

Loci

Question 17

Lack a nucleus and nuclear membrane.

Answer 17

Procaryotes

Question 18

___% coding sequence.
___% noncoding sequence.

Answer 18

95
5

Question 19

Extrachromosomal DNA containing nonessential genetic information.

Answer 19

Plasmids

Question 20

Circular genome of approx. _______ base pairs, inherited _________.

Answer 20

16,600
maternally

Question 21

mtRNA contains:
___ tRNA
___ rRNA
___ genes coding for oxidation-phosphorylation components.

Answer 21

22
2
12

Question 22

Mutations in genes coding for oxidation-phosphorylation are responsible for ___________ and ___________.

Answer 22

neuropathies
myopathies

Question 23

noncoding regions: ___ bp
hypervariable I regions: ___ bp
hypervariable II regions: ___ bp

Answer 23

610
342
268

Question 24

Noncoding, hypervariable I, & hypervariable II are routinely sequenced for _________?

Answer 24

Forensics

Question 25

Normal conformation of DNA is _______ stranded.

Answer 25

double stranded (ds)

Question 26

Distrupted form of DNA is known as _________ (or ________) DNA, is ________ stranded.

Answer 26

denatured (melted) single stranded (ss)

Question 27

Denaturation can be accomplished through ___________ or ___________.

Answer 27

heating chemicals

Question 28

Assays requiring denaturation of human DNA are conducted at about ___ degrees celcius.

Answer 28

94

Question 29

Is the association of denatured DNA to native dsDNA.

Answer 29

Renaturation (annealing)

Question 30

Reassociation of complementary base sequences.

Answer 30

Hybridization

Question 31

Two requirements for annealing:

Answer 31

High salt concentration High temperature

Question 32

Why is high salt concentration a must for annealing?

Answer 32

To overcome electrostatic repulsion between negatively charged phosphate group in two strands.

Question 33

Why is high temperature is required for annealing?

Answer 33

To disrupt the random, nonspecific intrastrand hydrogen bonds.

Question 34

Annealing of human DNA will occur around what temperature?

Answer 34

52 degree celcius

Question 35

Is a process in which genetic information is transferred from parent to daughter cells. It requires energy to unwind the helix and distrupts H-bonds.

Answer 35

DNA Replication

Question 36

This exist to minimize the replication errors.

Answer 36

Proofreading, repair systems

Question 37

Base changes occur resulting in _________; sometimes it doesn't have an effect, producing polymorphisms.

Answer 37

mutations

Question 38

The synthesis of each nucleotide chain only occurs in the _______ direction.

Answer 38

5' --> 3'

Question 39

One strand is synthesized continuously, whereas the other strand is synthesized discontinuously, resulting in _____________ that must be ligated together by the enzyme _________.

Answer 39

Okazaki fragments ligase

Question 40

As replication proceeds, the parental double helix unwinds by the action of enzymes called __________ in procaryotes and ______________ in eucaryotes.

Answer 40

helicase topoisomerase

Question 41

Polymerization of DNA is catalyzed by enzymes called ____________.

Answer 41

DNA polymerases

Question 42

Most RNA molecules are __________ stranded.

Answer 42

single

Question 43

Environmentally labile and easily degraded.

Answer 43

RNA

Question 44

Ribosomal RNA (rRNA) makes up ___% to ___% of total RNA in a cell.

Answer 44

80-90

Question 45

It is part of ribosomes and involved in translation of mRNA into proteins.

Answer 45

Ribosomal RNA (rRNA)

Question 46

Messenger RNA (mRNA) makes up ___% to ___% of total RNA in the cell.

Answer 46

2.5-5

Question 47

It is an intermediate between the genetic code in DNA and the total protein product. It is read by ribosomes to produce proteins.

Answer 47

Messenger RNA (mRNA)

Question 48

In eucaryotes, transcription of DNA forms a pre-mRNA molecule with both introns and exon. This molecule is referred to as _____________.

Answer 48

heteronuclear RNA (hnRNA)

Question 49

In heteronuclear RNA (hnRNA), the introns are ________, and the exons are ______________.

Answer 49

removed joined together

Question 50

Further processing into mature mRNA inclues addition of ________________ cup and _____________ tail of up to ___ adenylate nucleotides at the _________ terminus.

Answer 50

5' methylguanine polyadenylate (poly A) 200 3'-OH

Question 51

Reads mRNA triplets and brings the appropriate amino acid to the ribosome for polypeptide synthesis.

Answer 51

Transfer RNA (tRNA)

Question 52

There are at least one ______ for each amino acid.

Answer 52

tRNA

Question 53

Involved in removal of introns.

Answer 53

Small nuclear RNA (snRNA)

Question 54

Other RNAs that involved in cellular processes.

Answer 54

Small and micro RNAs

Question 55

A variety of enzymes called _______ break phosphodiester bonds in nucleic acids.

Answer 55

nucleases

Question 56

Ubiquitous, very high concentrations on hands; thus it is necessary to wear gloves when working.

Answer 56

Ribonucleases (RNases)

Question 57

Cut only at the end of a nucleic acid, removing a single nucleotide at a time.

Answer 57

Exonucleases

Question 58

RNases act at a wide range of temperatures:

Answer 58

below -20 to >100 degree celcius

Question 59

Recognize a specific base sequence in a DNA molecule and cut near or within the sequence.

Answer 59

Restriction enzyme/endonucleases

Question 60

Endonucleases make two cuts, one in each strand, generating a ____ and ____ terminus.

Answer 60

3'-OH 5'-P