Biology Ch. 2 Test Review

Front 1

Genes act in ___ that dictate ____

Back 1

Genes act in pairs that dictate traits.

Front 2

Genes control cellular chemical ____, by directing the formation of _____.

Back 2

Genes control cellular chemical reactions, by directing the formation of enzymes.

Front 3

___ are the units of inheritance that control particular characteristics or capabilities of an organism.

Back 3

Genes are the units of inheritance that control particular characteristics or capabilities of an organism.

Front 4

Genes are located on the ____ of the cell nucleus and consist of segments of DNA molecules.

Back 4

Genes are located on the chromosomes of the cell nucleus and consist of segments of DNA molecules.

Front 5

DNA & RNA are polymers of ____.

Back 5

DNA & RNA are polymers of nucleic acid.

Front 6

Each nucleotide is composed of:
1. A pentose (5 carbon) ____
2. A _____ group
3. A nitrogenous ____

Back 6

Each nucleotide is composed of:
1. A pentose (5 carbon) sugar
2. A phosphate group
3. A nitrogenous base

Front 7

Purines have a ____ ring structure and contain ___

Back 7

Purines have a double ring structure and contain adenine and guanine

Front 8

Pyrimidines have a ____ ring structure and contain ____

Back 8

Pyrimidines have a single ring structure and contain thymine, cytosine, uracil

Front 9

Each strand of DNA ladder is made of alternating molecules of ____ and ___ with a nitrogeneous base to each deoxyribose unit.

Back 9

Each strand of DNA ladder is made of alternating molecules of deoxyribose and phosphate with a nitrogeneous base to each deoxyribose unit.

Front 10

How many h-bonds in A and T?

Back 10

Two. A=T

Front 11

How many h-bonds in G and C?

Back 11

3 h-bonds.

Front 12

Sequence of bases code what?

Back 12

Heredity information.

Front 13

Before a cell can divide, all of the DNA must be?

Back 13

Duplicated.

Front 14

Each strand of DNA can produce a

Back 14

Reverse image of itself (complementary copy)

Front 15

Sequence of events in replication:

Back 15

1. Unzipping: DNA double helix unwinds and two strands of DNA separate: h bond between bases breaks (with helicase)
2. Complementary base pairing: new nucleotides in to pair up with bases of each template strand of DNA. these nucleotides are always floating around within the nucleoplasm.
3. Adjacent nucleotides bond: sugar phosphate covalent bonds form between adjacent nucleotides of the new strands to complete the molecule. New molecule winds into double helix.

Front 16

Each new strand of DNA contains one "old" ____ (the ____) and one new strand. You could say this is: ___

Back 16

Each new strand of DNA contains one "old" strand (the template) and one new strand. You could say this is: semi-conservative

Front 17

In replication, name enzymes:

Back 17

helicase and DNA polymerases

Front 18

RNA is the genetic materials of some viruses and is necessary in all organisms for___

Back 18

RNA is the genetic materials of some viruses and is necessary in all organisms for protein synthesis

Front 19

Like DNA, RNA have a similar chemical organization, consisting of ___

Back 19

Like DNA, RNA have a similar chemical organization, consisting of nucleotides

Front 20

each RNA molecule of is composed of 3 subunits, which are?

Back 20

1. 5 carbon sugar ribose
2. a phosphate group attached to one end of sugar molecule
3. one of several nitrogenous bases linked to the opposite end of the ribose

Front 21

RNA is ___ stranded

Back 21

single stranded

Front 22

mRNA is produced from DNA by a process called

Back 22

transcription

Front 23

name the steps of transcription

Back 23

1. specific section of DNA unwinds (template), exposing a set of bases
2. alone one strand of DNA (sense strand) complementary mRNA bases are brought in
3. adjacent mRNA nucleotides form covalent bonds
4. RNA strand is released from DNA
5. DNA molecule rewinds and returns to normal double helix form
6. RNA can leave nucleus and go into cytoplasm

Front 24

Where does transcription happen?

Back 24

in nucleus

Front 25

Enzyme involved in transcription is?

Back 25

RNA polymerase

Front 26

tRNA delivers amino acids from ___ to ___

Back 26

tRNA delivers amino acids from cytoplasm to ribosomes

Front 27

important: steps in translation!:

Back 27

1. initiation: the mRNA with its start codon attaches to the "R" site of the ribosome. tRNA bindes to start codon of mRNA. the tRNA has a binding site of 3 bases called an anticodon that is complementary to the mRNA codon.
2. elongation: more amino acids are added and connected together to form a polypeptide as specified by the mRNA sequence. a peptide bond is formed between the new aa and growing polypeptide. tRNA with aa can now move into available spot and bind with next codon on mRNA.
process repeats and the chain elongates as long as there are new codons to read on mRNA.
3. termination. stop codon binds to release factor in A site. the release factor causes water molecule to be added to the end of polypeptide chain and then separates from tRNA. after protein is complete, mRNA is broken down and ribosome splits into large and small subunits.
new protein is sent for final processing into endoplasmic reticulum and golgi apparatus.

Front 28

___ is needed by tRNA to pickup amino acid from cytoplasm

Back 28

ATP is needed by tRNA to pickup amino acid from cytoplasm

Front 29

Often many ribosomes will ___ translate the same mRNA. in this way ___ copies of the same protein can be made quickly. these clusters of ribosomes are called ___

Back 29

Often many ribosomes will simultaneously translate the same mRNA. in this way many copies of the same protein can be made quickly. these clusters of ribosomes are called polyribosomes

Front 30

A ___ is a change in an organisms DNA results from a _ change or one or more altered base in a structure of a gene.

Back 30

mutation, chemical change

Front 31

In a mutation, change will first be reflected in ___

Back 31

In a mutation, change will first be reflected in mRNA copy

Front 32

GENE mutations affect only _ gene(s)
Chromosomal mutations affect ___ gene(s)

Back 32

GENE mutations affect only 1 gene
Chromosomal mutations affect many gene(s) because they affect entire chromosomes or parts of chromosomes

Front 33

a mutation occur because of the alteration in one or more ___ of DNA

Back 33

base pairs

Front 34

if there is no stop codon, the protein will

Back 34

have no structure or function

Front 35

gene mutations may be caused by ___ in a single nucleotide. give an example a

Back 35

substitution, deletions, additions, sickle cell anemia

Front 36

chromosomal mutations occur after chromosomes are broken due to ___ and reform abnormally

Back 36

eg radiation, drugs, pesticides

Front 37

since changes in DNA directly affect protein synthesis, this can affect

Back 37

metabolism and body structure/function

Front 38

Recombinant DNA is what??

Back 38

where 1 species is inserted into DNA of a 2nd

Front 39

uses of recombinant dna?

Back 39

using viruses and bacteria to make copies of the genes of another species, production biotech products like genetically engineered proteins and hormones
making transgenic organisms (eg altering DNA of bacteria, plants and farm animals to m ake more healthy and less susceptible to disease)
gene therapy (replacing defective genes with healthy genes)

Front 40

where can gene therapy be done?

Back 40

ex vivo (removed from patient, treated and returned) or in vivo (introduced genes into bodies of patients)