DNA and Chromosomes

Question 1

DNA

Answer 1

Is a long polymer made of 4 nucleotides

Question 2

A DNA molecule has two ________ strands of nucleotides

Answer 2

Compenmentary

Question 3

Nucleotides are made up of what?

Answer 3

A sugar attached to a phosphate group which makes the sugar -phosphate backbone & also the 4 different types of bases

Question 4

What are the 4 different types of bases?

Answer 4

1. Adenine (A)
2. Cytosine (C)
3. Guanine (G)
4. Thymine (T)

Question 5

Nucleotides are the sugar-phosphate & the different types of bases but since the sugar-phosphate backbone is the same & the only thing that changes is _______ we just refer to nucleotides to the _______

Answer 5

Bases

Question 6

Nucleotides(bases) are connected by ________ between the 5’ end of one sugar and the 3’ end of another

Answer 6

Phosphodiester Bonds

Question 7

The end with a hole on the DNA strand is the _________

Answer 7

3’ hydroxyl end

Question 8

The end with a knobe on the DNA strand is the ______

Answer 8

5’ phosphate end

Question 9

________ holds the nucleotides (base-pairs ) together

Answer 9

Hydrogen Bonds

Question 10

A pairs with what base?

Answer 10

T & U

Question 11

C pairs with what base

Answer 11

G

Question 12

The ______ of DNA provides a way for heredity

Answer 12

Structure

Question 13

_______ organize & carry the nucleotide sequences (genetic information)

Answer 13

Chromosomes (Main function is to carry genes)

Question 14

The _________ within a DNA strand encodes the genetic information in an organism (Like a 4 letter alphabet with different messages)

Answer 14

Nucleotide sequence

Question 15

Since genes contains instructions for producing protiens the _________ in DNA must be able to form the amino acid sequence in proteins (Central Dogma)

Answer 15

Nucleotide Sequence

Question 16

Genetic Code

Answer 16

The relationship between the nucleotide sequence & the amino acid sequence

Question 17

In eukaryotic cells DNA is packed into ________ which fits into the nucleus

Answer 17

Chromosomes

Question 18

Eukaryotic DNA is packed into _________

Answer 18

Multiple chromosomes (where DNA is disturbed into different chromomses; the human nucleus has 23 different chromomses & 46 all together)

Question 19

Chromatin

Answer 19

The DNA molecule that is folded by proteins in the chromosome

Question 20

Karyotype

Answer 20

An organize display of the full 46 chromosomes in humans

Question 21

Genes

Answer 21

A segment or piece of DNA molecule that contains nucleotide sequence(instructions) to produce certain types of RNA & proteins (Central Dogma)

Question 22

Genome

Answer 22

The total nucleotide sequence(DNA molecules) carried by a complete set of chromosmes in a cell

Question 23

Junk DNA

Answer 23

Additional specific nucleotide sequences required for normal gene expression (Non coding DNA)

Question 24

______________ are required for DNA replication & chromosome segration

Answer 24

Specialized DNA sequences

Question 25

What two stages occur in the cell cyle ?

Answer 25

1. Interphase 2. Mitosis

Question 26

Interphase

Answer 26

When chromosomes are duplicated

Question 27

Mitosis

Answer 27

The duplicated chromosomes are disturbed(segrgated) into the two daughter nuclei)

Question 28

DNA replication occurs in what phase of the cell cycle?

Answer 28

Interphase

Question 29

Centromere(Specialized DNA sequence)

Answer 29

Allows duplicated chromosomes to be seperated during mitosis phase

Question 30

\_\_\_\_\_\_\_\_\_\_\_ chromosomes are not randomly distrubted in the nucleus but rather they stay in certain regions in the nucleus

Answer 30

Interphase Chromosomes

Question 31

Nucleolus

Answer 31

Organization of the interphase chromosomes in the nucleus (Part of the chromosomes containing RNA genes)

Question 32

The DNA in chromosomes are always \_\_\_\_\_\_\_\_\_\_

Answer 32

Highly condense (packed tighly & very small)

Question 33

DNA is packed neatly into chromosomes by \_\_\_\_\_\_\_\_\_

Answer 33

Nucleosomes

Question 34

\_\_\_\_\_\_\_\_ are the basic units of eukaryotic chromosomes structure

Answer 34

Nucleosomes

Question 35

What are the two classes of the proteins that fold & bind DNA to form eukaroytic chromosomes?

Answer 35

1. Histone chromosomal proteins 2. Nonhistones chromosomal proteins

Question 36

\_\_\_\_\_\_\_\_\_ are responsible for the formation of nucleosomes

Answer 36

Histones

Question 37

Nuclesomomes are the fundamental unit for _________ & convert DNA molecules in an interphase nucleus into a chromatin fiber (small length of DNA & contains clusters of closely packed nucleosomes)

Answer 37

Chromosome packagining

Question 38

Nucleosomes contains _____ wrapped around a protein core made up of eight histones

Answer 38

DNA

Question 39

Nucleases

Answer 39

An enzyme that cut the DNA by breaking the phospodiester bonds between nucleotides

Question 40

The ________ make up the core of the nuclesome

Answer 40

Histone protiens (4 of them)

Question 41

The 4 histone proteins that make up the core of the nucleosome have high proportions of ____________ & those positive charges bond tightly to the _______ of DNA

Answer 41

Positive charged amino acid, negative charged sugar-phosphate backbone of DNA

Question 42

In living cell _____ are stacked onto each other to make a compact structure

Answer 42

Chromatin

Question 43

\_\_\_\_\_\_\_\_\_\_ proteins fold the chromatin into a series of loops which allows chromosmes to become really condensed(tight like the mitotic chromosomes)

Answer 43

Nonhistone Chromosomal proteins

Question 44

H1 (type of histone)

Answer 44

Pulls adjacent nucleosomes together to stacking on top of each other (It allows it to form a more small condensed chromatin fiber)

Question 45

Changes in __________ structure allows acess in DNA

Answer 45

Nucleosomes

Question 46

What are the two ways that eukaryotic cells can change nucleosomes structure?

Answer 46

1. Chromatin -remodeling complexes(proteins) 2. Histone-modifying enzymes

Question 47

Chromatin-remodeling complexes

Answer 47

are proteins machines that use the energy of ATP hydroylsis to change the position of the DNA wrapped around the nuclesomome (They can alter the arragnment of the nucleosmes to allow DNA to be more or less accessible)

Question 48

Histone - modifying enzymes

Answer 48

Catalyze the reversible chemical modification of histones

Question 49

The tails of the histone are modified by either an ______ or ______ of acetyl, phosphate, or methyl group

Answer 49

Addtion or Removal

Question 50

Aceylation (process of adding an acetyl group)

Answer 50

Can loosen DNA & histone interactions

Question 51

Histone modifying enzymes ______ or ________ chromatins

Answer 51

Condense(shrink) or relax (expand)

Question 52

Interphase chromosomes contain both _______ & __ forms of chromatins

Answer 52

Highly condensed & extended forms

Question 53

The alteration made by _________ & _______ affect the structure of interphase chromsomes

Answer 53

Chromating packing remodeling complexes & histone modification

Question 54

Since interphase chromatin are packed into specific regions, regions of the chromsomes containing ______ that are actively expresses are more extended

Answer 54

Genes

Question 55

Regions of chromosomes that contain silent genes are \_\_\_\_\_\_

Answer 55

Condensed

Question 56

Heterochromatin

Answer 56

The most highly condensed form of interphase chromatin

Question 57

Euchromatin

Answer 57

The non-condensed part of the interphase chromatin

Question 58

Barrier DNA sequence

Answer 58

Stops the spread of the heterochromatin

Question 59

DNA that fold into heterochromatin dont contain genes because being packaged really tight into heterochromatin genes fail to be \_\_\_\_\_\_\_

Answer 59

Expressed

Question 60

\_\_\_\_\_\_\_\_ can silence genes in the X- chromosomes of female mammals (process called X-inactivation)

Answer 60

Heterochromatin