Chapter 6:DNA structure and replication

Question 1

What does DNA stand for?

Answer 1

Deoxyribonucleic Acid

Question 2

What is a gene?

Answer 2

Genetic material is carried and stored in coded in genes, one section of DNA and can be switched off on and by other genes

Question 3

What does expressed mean?

Answer 3

A gene switched on

Question 4

Where is DNA found in Eukaryotes?

Answer 4

Nucleus, chloroplasts and mitochondria

Question 5

What is chromatin?

Answer 5

DNA in a non-dividing cell which only appears grainy and undefined under a microscope

Question 6

What happens to chromatin when a cell prepares to divide?

Answer 6

Condenses by coiling up and thickens allowing individual chromosomes to be seen

Question 7

What is a chromosome?

Answer 7

One molecule of DNA with its associated proteins

Question 8

How is DNA displayed?

Answer 8

Double stranded molecule

Question 9

What is an unduplicated chromosome?

Answer 9

A long double helix molecule coiled around a histone protein

Question 10

What is a histone?

Answer 10

A protein that DNA winds around in eukaryotic cells

Question 11

What are sister chromatids?

Answer 11

Two identical copies of a single chromosomes, formed by replication and connected by centromere

Question 12

What is a centromere?

Answer 12

A waist like construction in a chromosome required for the movement of chromosomes during cell division

Question 13

What shape do sister chromatids and centromeres form?

Answer 13

X shape

Question 14

When are chromosomes visible?

Answer 14

Prior to division stage and after replication has occurred

Question 15

What are homologous chromosomes?

Answer 15

pair of chromosomes that have the same size, shape and genes at the same location

Question 16

Where do the chromosomes come from in homologous chromosomes pairs?

Answer 16

One is inherited from each parent

Question 17

What is karyotype?

Answer 17

The display of the number and appearance of the chromosomes of organisms or observed in metaphase

Question 18

How many pairs of chromosomes do humans have?

Answer 18

23 pairs (46 chromosomes)

Question 19

What is the endosymbiotic theory?

Answer 19

A theory that suggests chloroplast and mitochondria arose from ancient prokaryote cells that were ingested by other prokaryote host cells

Question 20

What is maternal inheritance?

Answer 20

Inheritance only from mothers; any trait that is encoded by organelle DNA only from mother

Question 21

What is a nucleoid?

Answer 21

The region within a prokaryotic cell that contains the genetic material.

Question 22

Where are chromosomes join in prokaryotic cells?

Answer 22

A single circular chromosome which lies within the cytoplasm. Chromosomes often join to plasma membrane.

Question 23

What is plasmid?

Answer 23

A small circular piece of DNA found in bacteria which can replicate independently of the cell’s chromosomes

Question 24

What is a nucleotide?

Answer 24

The basic building block of nucleic acids linked by phosphodiester bonds

Question 25

What are nucleotides made of?

Answer 25

five-carbon sugar, a phosphate group and nitrogenous base.

Question 26

What are the 4 kinds of nitrogenous bases in DNA?

Answer 26

Adenine, thymine, guanine and cytosine

Question 27

What is complementary bases?

Answer 27

The nitrogenous bases on nucleotide that bind to each other

Question 28

What are complementary bases that bind?

Answer 28

A to T and C to G

Question 29

What holds the double helix together?

Answer 29

Hydrogen bonds

Question 30

What does antiparrell mean and do double helix have it?

Answer 30

Yes, it means they run the opposite ways

Question 31

How is RNA different to DNA?

Answer 31

RNA is a single strand chain of nucleotides, thymine is replaced by base uracil and ribs sugar replaces deoxyribose of DNA

Question 32

How is RNA useful?

Answer 32

It is useful in protein synthesis

Question 33

Why does DNA replicate?

Answer 33

Growth, repairs and reproduction

Question 34

What is a daughter cell?

Answer 34

Either of the two cells formed during cell division

Question 35

What is the start of cell division?

Answer 35

The enzyme helicase which helps the double helix unwind by breaking the hydrogen bonds and separate

Question 36

How does Helicase unwind and separate the strands?

Answer 36

By breaking the hydrogen bonds exposing the nucleotide bases

Question 37

What is parental DNA?

Answer 37

The DNA of the original cell

Question 38

What happens during interphase?

Answer 38

Active growth, synthesis of DNA and preparation of next division

Question 39

What is a replication fork?

Answer 39

The junction between unwound DNA and joined DNA

Question 40

What is DNA polymerase?

Answer 40

An enzyme capable of making exact copies of DNA fragments

Question 41

What happens after hydrogen bonds are broken?

Answer 41

DNA polymerase attaches the appropriate base pair to expose nucleotide running in a 3 prime to 5 prime

Question 42

What is semiconservative replication?

Answer 42

A double helix consisting of a parental strand and daughter stand. Is the outcome during cell division