Term
| __________ size in different organisms range from a few thousand nucleotides in the smallest viruses to many billions of nucleotides in higher plants and animals. |
|
Definition
|
|
Term
| The units in which DNA size is expressed are __________ (thousands of bp) __________ (millions of base pairs) and __________ (billions of base pairs) |
|
Definition
1) Kilobase (kb)
2) Megabase (Mb)
3) Gigabase (Gb) |
|
|
Term
| The human genome is __________ __________ in size. |
|
Definition
|
|
Term
| The amount of DNA per haploid genome is called the __________-__________. |
|
Definition
|
|
Term
The __________-__________ __________ explains that even though there are large variations in the amount of DNA per genome, the number of genes does not vary much between related organisms.
Most of the increase in genome size comes from __________ or due to an increase in __________ __________-__________ DNA. |
|
Definition
1) C-Value paradox
2) Polyploidy
3) Non protein-coding |
|
|
Term
| What are the three methods that are used to resolve the packaging problem? |
|
Definition
1) Looping of DNA by attachment to a central protein scaffold
2) Supercoiling of loops using topiosomerase enzymes
3) Typing loops of DNA together using ring-shaped protein complexes (cohesins and condensins) |
|
|
Term
| The energy of __________ __________ is used by topoisomerase enzymes to introduce supercoils in DNA. |
|
Definition
|
|
Term
__________ __________ is a combination of an endonuclease and DNA ligase.
It cuts both strands of a DNA duplex, passing another duplex through the gap while still holding the two cut ends and then seals the cut. |
|
Definition
|
|
Term
Upon breaking open a __________ cell, the DNA becomes unfolded into a sticky mess.
This is because the tight compaction of DNA requires the neutralization of a large number of __________ charges on the surface of DNA molecules. This is done by complexing with positively charged __________.
Upon cell lysis, these basic proteins become dilute and the DNA (called a __________ since it is not a true stable chromosome) becomes unfolded.
Addition of positively charged molecules during __________ __________ allowed for the isolation of intact bacterial nucleoids. |
|
Definition
1) Bacterial
2) Negative
3) Proteins
4) Nucleoid
5) Cell lysis |
|
|
Term
| DNA in higher cells exist as a stable nucleo-protein filament called __________. |
|
Definition
|
|
Term
Upon gentle lysis of nuclei, all of the DNA is seen as a beaded string structure.
The beads are called __________. Each bead consists of eight molecules of highly basic (__________ and __________ rich) proteins called __________.
Each nucleosome has a core made of two copies each of histones __________, __________, __________, and __________. |
|
Definition
1) Nucleosomes
2) Arginine
3) Lysine
4) Histones
5) H2A
6) H2B
7) H3
8) H4 |
|
|
Term
In stained chromosomes, one can see a narrowing at one point - the __________.
With special staining techniques called __________ __________ more detail is visible.
In most cells in most organisms, the resolution of the light microscope is not sufficient to see a deletion of either single or even groups of genes; a special case occurs in the __________ __________ __________ of Drosophilia larvae. These are terminal tissues and are not passed onto the next developmental stage (the __________). In these specialized cells, the homologous chromosomes pair and undergo many rounds of __________ without strand separation or nuclear division. |
|
Definition
1) Centromere
2) Chromosome banding
3) Salivary gland chromosome
4) Pupa
5) Reolication |
|
|
Term
| Each __________-__________ in the human chromosome represents 10 million base pairs worth of DNA. |
|
Definition
|
|
Term
| The salivary gland chromosomes have proved very useful in localizing closed genes by a technique called __________ __________ __________, where a labeled piece of DNA is hybridized to salivary gland chromosomes and the labeled band is located under the light microscope. |
|
Definition
|
|
Term
| The rate of DNA renaturation depends on what three factors? |
|
Definition
1) Time
2) DNA concentration
3) Complexity of sequences in the DNA population |
|
|
Term
__________ __________ __________ (__________ __________) are several different kind of sequences ranging from dinucleotide repeats to repeats of somewhat longer sequences which are not transcribed into __________ and often stay condensed even in __________ (heterochromatin.
A large fraction of these sequences are found near the centromeres (__________ __________) or near the ends of chromosomes (__________ __________). |
|
Definition
1) Highly repeated sequences (satellite DNA)
2) mRNA
3) Interphase
4) Centromeric heterochromatin
5) Telomeric heterochromatin |
|
|
Term
| __________ __________ __________ are genes that are present in multiple copies (such as histones, tRNA and rRNA genes) as well as many functional complete transposons with intact transposase or reverse transcriptase genes. |
|
Definition
| 1) Middle repeated sequences |
|
|
Term
Most stained chromosomes show a lightly staining area that looks like a constriction; this is called the __________.
It has been known for a long time that when a chromosome breaks, only the part containing the __________ is partitioned properly at the cell division. The piece without a centromere (__________ __________) is usually lost within a few cell division cycles. |
|
Definition
1) Centromere
2) Centromere
3) Acentric fragments |
|
|
Term
The __________ is where the fibers of the spindle attach and pull the two daughter chromosomes to opposite spindle poles during the __________ stage of the cell division process.
Rarely, the centromere activity may diffuse and many spindle fibers may attach throughout the length of the chromosome - such chromosomes are called __________ and organisms with such are rare. |
|
Definition
1) Centromere
2) Anaphase
3) Holocentric |
|
|
Term
__________ centromeres are unusual in that they are quite small and have a well-conserved structure.
The three __________ __________ __________ within Yeast are usually followed by a 100-135 nucleotide variable sequence.
Attaching the centromere to any DNA sequence containing an origin of replication results in the creation of a stable __________. |
|
Definition
1) Yeast
2) Centromere determining elements (CDE)
3) Minichromosome |
|
|
Term
It has also been known for a long time that chromosomes, when broken by __________-__________, tend to have sticky ends that fuse with other broken chromosome ends.
The ends of chromosomes are unique in that they were named __________. |
|
Definition
|
|
Term
Since no known DNA polymerase can start a new chain, new DNA begins with __________ __________.
The two primers at the extreme __________-ends of linear chromosomes cannot be replaced by DNA.
If left un-repaired, the chromosomes would become progressively shorter as the cells replicate repeatedly, resulting in complete disappearance eventually.
Telomere repeats are generated by a special enzyme known as __________ that has an internal RNA template.
The shortening of telomeres is thought to be related to __________. |
|
Definition
1) RNA primers
2) 5'
3) Telomerase
4) Aging |
|
|
