Lect 5

Question 1

Chromosome painting

Answer 1

It is a technique that allows the visualization of chromosomes and the regions why hybridization with fluorescent DNA probes producing different colors at each side of hybridization

Question 2

Why chromosome painting

Answer 2

To detect numerical and chromosomal aberrations relationship with diseases

Question 3

Used on

Answer 3

Animal and human chromosomes for cancer
Recently on plants

Question 4

FISH provides intense and…fluorescent staining at …and…

Answer 4

Specific
Metaphase
Interphase

Question 5

First identified translocated chromosome in human neoplasia

Answer 5

Philadelphia chromosome
T(9:22)(q34:p11)

Question 6

Each homologous pair of chromosomes are
FISH depends on..

Answer 6

Similarly painted
Computer analysis softwares

Question 7

B chromosomes are…..
Due to….

Answer 7

Extra chromosomes to the standard complement and non essential
Inter and intraspecies crosses

Question 8

B chromosomes are……jumping genes
They display . Inheritance
They collect….and…

Answer 8

Transposons
Non mendelian
Transposons and repetitive DNA

Question 9

B chromosomes help scientists study…and in…

Answer 9

Centromeres
Genetic engineering

Question 10

B chromosomes are also called
…eukaryotes
…mammals

Answer 10

Supernumerary chromosomes
15%
1.2%

Question 11

The 3 main characteristics of B chromsomes

Answer 11

Non essential
Morphology distinct from As
Display non mendelian inheritance

Question 12

Are B chromosomes in all members of a species?
They vary in…and…
Example with grass

Answer 12

No
Copy number, in an individual, acc to tissue
No in roots but in aerial tissues and gametes

Question 13

B chromosomes are usually….
Size in plants
Size in mammals

Answer 13

Heterochromatinised
Smaller then smallest As
Similar to As

Question 14

Do As and Bs pair and combine during meiosis

Answer 14

No

Question 15

What is a meiotic drive

Answer 15

The bias in the transmission of certain alleles or chromosomes during meiosis

Question 16

Why Bs show non mendelian drive

Answer 16

To allow accumulation and inheritance at greater ratios

Question 17

Plants drive

Answer 17

Post meiotic nondisjunction in gametophytes, no proper separation of gametes after meiosis resulting in abnormal no of chromosomes.

Premeiosis, during meiosis
After fertilisation like oocytes of parasitic wasp

Question 18

Bs with drive in mammals usually have

Answer 18

Meiotic drive in females

Question 19

Bs freq is independent of…..
But larger….has…

Answer 19

Genome ploidy
Genomes more Bs

Question 20

…..Bs are…..with pollution and stress
More Bs=….=….

Answer 20

Vertebrates
Positively correlated
Larger cell size, more mass, longer mitosis, low RNA levels

Question 21

Bs applications

Answer 21

Amenability for research
Maize Bs
BA translocations and non disjunction
Mapping loci on maize As
Engineering minichromosomes

Question 22

Bs in maize

Answer 22

loci mapping, centromere biology, gene dosage, engineered minichromosomes

Question 23

Reciprocal translocations between As and Bs can lead to…..during…leading to

Answer 23

disjunction
Meiosis
Sperm with varying no. Of chromosomes

Question 24

BA translocations are in all maize As expect ….
Allows the ….of chromosome arm where….

Answer 24

8s
Identification
Gene of interest is present

Question 25

Do cells with damaged Bs suffer from aneuploidy

Answer 25

No

Question 26

Artificial chromosomes are

Answer 26

Synthetic chromosomes with DNA fragments integrated into a host chromosome. Non viral, non bacterial DNA into bacterial chromosome then expressed and continues with host

Question 27

Artificial chromosomes are used for

Answer 27

Transfection of cells

Question 28

Why use BAC not YAC

Answer 28

More stable No chimeric effect

Question 29

Plasmid vs BAC vs YAC

Answer 29

10k 300k 1 million

Question 30

What is the chimeric effect

Answer 30

For the gene to be expressed in some cells but not the others in the same organism

Question 31

Advantages of BAC

Answer 31

Larger genes Several genes at once entire viral genome

Question 32

The process of introducing BAC Results Media

Answer 32

Foreign DNA is ligated into lac z gene of bacterial F plasmid BAC is electroporated into E.coli Positive is white Negative is blue Media is x gal

Question 33

Prokaryotic chromosome structure

Answer 33

Folded genome 50-100 loops each -vely supercoiled

Question 34

DNases vs RNases

Answer 34

DNase cleaves a site to relax supercoiling at the site RNase destructs DNA connectors causing unfolding but no effect on supercoiling

Question 35

Eukaryotic chromosomes arrangement Digestion of DNA with an endonuclease

Answer 35

Multineme, multiple molecules per chromosomes Unineme, proved 1 DNA molecule per chromosome 200bp in length for nucleosomes

Question 36

Which plants were B chromosomes identified in Do all Bs exibit drive mechnisms

Answer 36

Rye Maize No

Question 37

Sometimes drive in one sex is balanced by...through the other in B chromosomes

Answer 37

Drag

Question 38

Researchers can cross recessive mutants ofB-A chromosmes if expressed...

Answer 38

Gene locus identified

Question 39

E.coli bp Human bp Each chromosome in human bp Largest human chromosome nm

Answer 39

4.7*10^6 3*10^9 50-250*10^6 8.5*10^7