Chapter 9: Genes and Replication

Question 1

What is DNA?

Answer 1

A nucleic acid found in nearly all cells of every living organism on Earth

Question 2

Unique blueprint to individual, except what?

Answer 2

Clones (identical, not fraternal twins)

Question 3

DNA is increasingly used in modern society

Answer 3

Paternity tests, criminal investigations, genetic testing and behavior

Question 4

DNA played a role in

Answer 4

Inheritance, growth, and development raised more questions than answer

Question 5

DNA structures are a

Answer 5

Double helix, two strands, connected in a twisting ladder structure

Question 6

The ladder is composed of

Answer 6

Nucleotide units, each containing a sugar molecule, phosphate group, and nitrogen-containing base

Question 7

Hydrogen bonds form between bases on either side of the ladder in specific pairs

Answer 7

1) A (Adenine) and T (Thymine)
2) G (Guanine) and C (Cytosine)
3) Means DNA always has the same number of C’s and G’s, and A’s and T’s
4) Because of this, we only have to know the sequence of 1 side to translate the other
5) One human DNA molecule can have 200 million base pair (double helix allows it to fit in a cell)

Question 8

DNA does the blueprint for

Answer 8

How to build and maintain an organism, kept in a code (sequence) of bases

Question 9

The entire set of DNA is a

Answer 9

Genome

Question 10

Prokaryotes have

Answer 10

Small, circular DNA

Question 11

Eukaryotes have

Answer 11

Longer, linear DNA

Question 12

Broken into short segments called

Answer 12

Chromosomes

Question 13

The number of chromosomes varies between

Answer 13

Species

Question 14

Humans have 46 chromosomes (23 pairs), and the percentage of shared.

Answer 14

Genes

Question 15

Inside a chromosome: Length varies depending upon

Answer 15

Species and particular chromosome

Question 16

Large chunks are

Answer 16

Non-coding, with interspersed genes: sequence of bases that code for a product (proteins and RNA)

Question 17

Inside a chromosome not necessarily one version of a gene variation are called, what?

Answer 17

Alleles

Question 18

Non-coding portion of DNA is called

Answer 18

Junk DNA

Question 19

Junk DNA can be

Answer 19

Small (10% bacteria) or large (98% human) proportion of DNA

Question 20

Junk DNA purpose is unclear

Answer 20

1) Found between as well as within genes (introns)
2) Long repeating sequences (nonsense sequences), fragments/duplicates of working genes, non-functional variations

Question 21

Not all genes are expressed equally in

Answer 21

Cells DNA in each cell codes for everything (in multicellular organism this could be a problem)

Question 22

Each tissue group only expresses genes necessary for

Answer 22

Its functioning (why we don’t have hair on our stomachs, or acid on our scalps)

Question 23

Outward expression of trait is

Answer 23

Phenotype

Question 24

Genetic material present is

Answer 24

Genotype

Question 25

DNA is copied through

Answer 25

DNA replication such as:
1) Semi-conservative process
2) DNA replication
3) Real time replication

Question 26

How do we get from DNA to protein?

Answer 26

Transcription and translation

Question 27

Transcription copying the gene sequence to

Answer 27

Be exported as mRNA (real time)

Question 28

RNA polymerase (an enzyme) pulls apart a piece of DNA at a

Answer 28

Promoter site and untwists a short segment

Question 29

RNA polymerase makes an RNA copy of

Answer 29

One strand of DNA putting appropriate base pairs on (no T, instead U (uracil))

Question 30

Terminate RNA polymerase hits a termination sequence stops

Answer 30

Building RNA, and drops off

Question 31

In eukaryotes add cap and tail to protect

Answer 31

RNA ends and for recognition; remove introns; export mRNA to cytoplasm

Question 32

Translation reading of mRNA to

Answer 32

Build proteins

Question 33

Translation occurs in the cytoplasm and requires:

Answer 33

1) Free amino acids (AA’s) building blocks
2) Ribosomal subunits (builders)
3) Transfer RNA (translator between mRNA and protein languages)

Question 34

Translation initialize

Answer 34

Ribosome recognizes start codon (sequence of 3 AA’s - AUG) on mRNA and attaches (small and large subunits)

Question 35

Translation elongate

Answer 35

Find appropriate tRNA to translate; attach AA’s to create a protein

Question 36

Translation terminate

Answer 36

Ribosome recognizes stop codon, release protein and detach; mRNA can be reused

Question 37

Mutations are errors or alterations in DNA by

Answer 37

Deleterious, neutral and beneficial

Question 38

Two classes of mutations

Answer 38

Point and chromosomal mutations

Question 39

Mutation point

Answer 39

Changing one base pair by replacement, deletions, or insertions, and can cause major downstream problems

Question 40

Chromosomal mutations

Answer 40

Change to the sequence of genes on a chromosome by deletions, duplications, and inversions

Question 41

Causes of Mutations

Answer 41

1) Spontaneous
2) Radiation-induced
3) Chemical-induced

Question 42

Spontaneous

Answer 42

Translation mistake (DNA has a spellcheck function that fixes most of these)

Question 43

Radiation-induced

Answer 43

High energy can break apart DNA, increasing errors

Question 44

Chemical-induced

Answer 44

Mutagens: react with DNA to increase the rates of mutation

Question 45

Results of Mutations: Wrong genetic code =

Answer 45

Bad protein equals to problem

Question 46

Misspelled gene leads to

Answer 46

Malfunctioning enzyme (can’t do its job)

Question 47

Mutations often will have

Answer 47

One good copy and one bad copy and still function