Chapter 4: Genes and Cellular Function

Question 1

This is a long threadlike molecule that is about 43 mm or 2 in long. Most human cells have 46 of these molecules.

Answer 1

Deoxyribonucleic acid (DNA)

Question 2

DNA is considered a polymer of nucleotides, what are the three components of these nucleotides?

Answer 2

Sugar-deoxyribose
Phosphate group
Nitrogenous base

Question 3

What are the 4 nitrogenous bases?

Answer 3

Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)

Question 4

Adenine and Guanine have a double-ringed structure and they considered what type?

Answer 4

Purines

Question 5

Cytosine and Thymine have a single-ringed structure and they are considered what type?

Answer 5

Pyrimidines

Question 6

Adenine pairs with _________ and forms ______ hydrogen bonds.

Answer 6

Thymine; 2

Question 7

Cytosine pairs with ________ and forms ______ hydrogen bonds.

Answer 7

Guanine; 3

Question 8

The fact that one strand governs the base sequence of the other is called ______________.

Answer 8

The law of complementary base pairing.

Question 9

Each sidepiece of double helix is a ________ alternating with a ________.

Answer 9

phosphate group; sugar deoxyribose

Question 10

What is the essential function of DNA?

Answer 10

To carry instructions (genes) for the synthesis of proteins.

Question 11

The fine filamentous DNA material complexed with proteins called histones, about 6 ft long packed in cell of 5 micrometer in diameter.

Answer 11

Chromatin

Question 12

When does looped chromatin form into thick chromatids only?

Answer 12

In dividing cells only

Question 13

Each chromosome is packed into its own region of nucleus called __________.

Answer 13

Chromosome territory

Question 14

When preparing to divide, cell makes copy of all nuclear DNA and each chromosome consists of 2 parallel filaments of identical DNA called ________.

Answer 14

Sister chromatids

Question 15

Chromatids are joined at the _________ where they contain ___________, which are protein plaques that play a role in cell division.

Answer 15

Centromere; kinetochores

Question 16

These acids are smaller cousins of DNA, essential functions are to interpret the code in DNA and use those instructions to synthesize proteins.

Answer 16

Ribonucleic acids (RNAs)

Question 17

What is the most significant difference between DNA and RNA?

Answer 17

RNA is much smaller- less amount of base pairs, one nucleotide chain instead of two, Uracil instead of Thymine, functions mainly in cytoplasm instead of nucleus.

Question 18

What are the three different types of RNA?

Answer 18

messenger RNA (mRNA)
ribosomal RNA (rRNA)
transfer RNA (tRNA)

Question 19

An information-containing segment of DNA that codes for the production of a molecule of RNA, which goes on to play a role in the synthesis of one or more proteins.

Answer 19

Gene

Question 20

46 human chromosomes come in two sets of _________, one set from each parent.

Answer 20

23 chromosomes

Question 21

All the DNA in one 23-chromosome set is called the __________.

Answer 21

Genome

Question 22

When it comes to genome, individual variation comes from what?

Answer 22

Single-nucleotide polymorphisms

Question 23

The study of the genome and how its genes and noncoding DNA affect the structure and function of the organism.

Answer 23

Genomics

Question 24

Application of knowledge of the genome to the prediction, diagnosis, and treatment of disease.

Answer 24

Genomic medicine

Question 25

The system that enables 4 nucleotides (A T C G) to code for the amino acid sequences of all proteins.

Answer 25

Genetic code

Question 26

Sequence of 3 DNA nucleotides that stands for one amino acid.

Answer 26

Base triplet

Question 27

A three-base sequence in mRNA

Answer 27

codon

Question 28

How many possible codons are available to represent 20 amino acids and how many are considered "stop codons?"

Answer 28

64; 3 considered STOP codons

Question 29

Give an example of the start codon that begins the amino acid sequence of the protein?

Answer 29

AUG; codes for methionine

Question 30

Give an example of the stop codons that signal "end of message"

Answer 30

UAG UGA UAA

Question 31

Any given cell uses how much of its genes?

Answer 31

1/3- 2/3 of its genes and the rest remain dormant

Question 32

DNA --->>> mRNA is called __________.

Answer 32

Transcription

Question 33

mRNA ---->>> protein is called ________.

Answer 33

Translation

Question 34

All body cells contain identical genes except ________ and some __________.

Answer 34

sex cells; immune cells

Question 35

The process of copying genetic instructions from DNA to mRNA because DNA is too large to leave the nucleus and participate in cytoplasmic protein synthesis. mRNA made to travel through nuclear pores into cytoplasm.

Answer 35

Transcription

Question 36

Which enzyme binds to DNA, opens up the helix 17 base pairs at a time, reads it, and makes RNA.

Answer 36

RNA polymerase

Question 37

Match the following for mRNA: C-->> A-->>

Answer 37

G U

Question 38

RNA produced by transcription is an "immature" version called _________ which contains segments called exons and introns

Answer 38

pre-mRNA

Question 39

Introns are removed while still in the ______ and exons are exported from the ________ to undergo translation in ___________.

Answer 39

nucleus; nucleus; cytoplasm

Question 40

Through mechanism called _________ one gene can code for more than one protein. Or exons can be spliced together into variety of mRNAs.

Answer 40

Alternative splicing

Question 41

This process converts the language of nucleotides into the language of amino acids.

Answer 41

Translation

Question 42

What are the three participants of the translation process?

Answer 42

1. messenger RNA mRNA 2. transfer RNA tRNA 3. Ribosomes

Question 43

mRNA acquires what which acts a passport to allows molecule to pass through nuclear pore to cytosol.

Answer 43

Protein cap

Question 44

tRNA is a single stranded molecule that includes an _____ which is a series of three nucleotides complementary to a specific codon of mRNA. it delivers a single amino acid to ribosome

Answer 44

anticodon ; is always UAC carries amino acid methionine

Question 45

which 2 subunits come together in ribosomes when translating mRNA? and what are ribosomes responsible for?

Answer 45

Small subunit and large subunit; read message and build peptide chain

Question 46

Ribosome has 3 pockets that bind tRNA. What are they?

Answer 46

A site - accepts new amino P site- carries protein E site- exit

Question 47

What are the three steps of translation?

Answer 47

initiation elongation termination

Question 48

All new proteins begin with amino acid _______ which is carried by initiator tRNA.

Answer 48

Methionine AUG

Question 49

If protein is going to be packaged into lysosome or secreted from the cell, the ribosome migrates to where? and then sent where for final modification?

Answer 49

Rough endoplasmic reticulum; Golgi complex

Question 50

Why is protein synthesis not complete after primary structure of amino acid has been completed? What protein helps?

Answer 50

To function, protein must fold into precise secondary and tertiary structures. Chaperone protein- older protein helps with this

Question 51

Enzymes in cisterns of endoplasmic reticulum modify new protein in variety of ways like: removing amino acid segments, folding protein, stabilizing with disulfide bridges, and adding carbohydrates. These changes are called _______

Answer 51

Posttranslational modification

Question 52

Gene regulation can be controlled by chemical messengers such as ___________.

Answer 52

hormones

Question 53

What is one example in which a hormone turns on a specific gene to produce a specific protein?

Answer 53

Woman who just gave birth, prolactin hormone stimulates cells of mammary gland to produce protein casein to synthesize breast milk for the baby.

Question 54

What type of proteins can activate gene transcription?

Answer 54

Regulatory proteins

Question 55

During DNA replication, which enzyme opens up a short segment of DNA helix at a time to expose nitrogenous bases?

Answer 55

DNA helicase

Question 56

During DNA replication, molecules of this enzyme move along each strand, read the exposed bases, and like a matchmaker arrange marriages with complementary free nucleotides.

Answer 56

DNA Polymerase

Question 57

During DNA replication which enzyme joins together the segments after they have been separated and copied.

Answer 57

DNA ligase

Question 58

process is DNA replication where each daughter DNA consists of one new helix synthesized from free nucleotides and one old helix conserved from parental DNA

Answer 58

Semiconservative replication

Question 59

There are multiples modes of correcting DNA replication errors and they are collectively called __________

Answer 59

DNA damage response (DDR)

Question 60

Which enzyme double-checks the new base pair and tends to replace incorrect, biochemically unstable pairs with more stable correct pairs.

Answer 60

DNA polymerase

Question 61

Changes in DNA structure called ________ can result from replication errors or environmental factors such as radiation, chemicals, and viruses.

Answer 61

Mutations

Question 62

Genetic mosaicism

Answer 62

genetic variations within one's body due to mutations and replication errors

Question 63

The cell cycle is divided into what 4 main phases?

Answer 63

First gap phase G1 Synthesis phase S Second gap phase G2 Mitosis m

Question 64

Phase in cell cycle where a cell synthesizes proteins, grows, carries out its preordained tasks for the body, and accumulates materials needed for DNA replication

Answer 64

First gap phase G1

Question 65

Phase in cell cycle where cell makes duplicate copy of centrioles and nuclear DNA. Semiconservative replication

Answer 65

Synthesis phase S

Question 66

Phase in which cell exhibits further growth, makes more organelles, finishes replicating centrioles, synthesis enzymes that control cell division, checks for errors.

Answer 66

Second gap phase G2

Question 67

Phases G1, S, and G2 are collectively called _________

Answer 67

Interphase

Question 68

Phase in which a cell replicates its nucleus and pinches off in two to form 2 daughter cells.

Answer 68

Mitotic phase M

Question 69

This is usually the phase in which no cell division is happening for a cell, taking a "rest," usually seen in cancer cells.

Answer 69

G0 G-zero phase

Question 70

What are the 4 phases of mitosis?

Answer 70

Prophase Metaphase Anaphase Telophase

Question 71

Phase in mitosis where genetic material condenses into compact chromosomes, nuclear envelope disintegrates, and centrioles sprout spindle fibers,

Answer 71

Prophase

Question 72

Phase in mitosis where chromosomes align at cell's equator, and spindle fibers form lemon-shaped array called the mitotic spindle.

Answer 72

Metaphase

Question 73

Phase in mitosis in which enzyme cleaves two sister chromatids apart at centromere, single stranded daughter chromosomes migrate to each pole of the cell.

Answer 73

Anaphase

Question 74

Phase in mitosis where chromosomes cluster on each side of the cell, rough ER makes new nuclear envelope around each cluster, chromosomes uncoil to chromatin, each nucleus forms nucleoli.

Answer 74

Telophase

Question 75

Telophase is the end of cell division but it overlaps with _________ which involves the division of the cytoplasm into two cells. Creates cleavage furrow around equator of cell

Answer 75

Cytokinesis

Question 76

Cells divide when. CRNGN

Answer 76

They have enough Cytoplasm They Replicated DNA They have enough Nutrients They are stimulated by Growth Factors Neighboring cells die opening up space

Question 77

What will cells stop doing if they are: snugly contacting neighboring cells, don't have enough nutrients or any, experience contact inhibition.

Answer 77

They stop dividing

Question 78

Cell cycle is regulated by which molecular timers? Protein and enzyme

Answer 78

Cyclins and cyclin-dependent kinases.

Question 79

When we lay out the 46 chromosomes out in order by size and other physical features we get a chart called _________.

Answer 79

Karyotype

Question 80

GG would describe someone as what?

Answer 80

Homozygous dominant

Question 81

Copying genetic information from DNA to RNA is called _______, using the information contained in mRNA to make a polypeptide is called ________.

Answer 81

Transcription; Translation

Question 82

Gg would be considered what?

Answer 82

Heterozygous

Question 83

gg would be considered what ?

Answer 83

Homozygous recessive

Question 84

Two chromosomes that share the same genes are called a _________ pair.

Answer 84

Homologous

Question 85

Chromosomes x and y determine individuals gender and therefore are called _______ chromosomes.

Answer 85

sex

Question 86

Since sperm and egg cells combine their chromosomes, each has an unpaired set of 23 and is said to be _________.

Answer 86

haploid

Question 87

All of the body's nonreproductive cells called _________ usually have 23 pairs of chromosomes and are thus called __________.

Answer 87

somatic cells; diploid

Question 88

when both alleles are equally dominant, present, and phenotypically expressed.

Answer 88

Codominance

Question 89

When 2 different alleles are present, the phenotype is intermediate between the traits that each allele would produce alone.

Answer 89

Incomplete dominance

Question 90

DNA replication is called _________ because each daughter DNA consists of one new helix and one old helix.

Answer 90

semiconservative

Question 91

The different forms of a particular gene expressed

Answer 91

Allele

Question 92

These traits are carried on the x or Y chromosome and therefore tend to be inherited by one sex more than the other.

Answer 92

Sex-linked traits