Unit 4 Pt 2

Question 1

A ______ is a segment of DNA that codes for a protein, serving as the basis for gene expression.

Answer 1

Gene

Question 2

Gene expression converts DNA’s genetic information into functional proteins, involving _____ (DNA to mRNA) and _____ (mRNA to protein).

Answer 2

Gene expression converts DNA’s genetic information into functional proteins, involving transcription (DNA to mRNA) and translation (mRNA to protein).

Question 3

_____ is the process of using DNA’s code to synthesize proteins via transcription and translation.

Answer 3

Gene expression

Question 4

Proteins are macromolecules made of ______, linked by peptide bonds to form polypeptides.

Answer 4

amino acids

Question 5

Amino acids are the building blocks of proteins, joined via _____ bonds to create a _____ chain, which folds into a functional protein.

Answer 5

Amino acids are the building blocks of proteins, joined via peptide bonds to create a polypeptide chain, which folds into a functional protein.

Question 6

The ______ group on an amino acid determines its unique properties, influencing protein shape and function.

Answer 6

R

Question 7

The _ group (side chain) varies among amino acids, driving interactions that cause protein folding (e.g., alpha helices, beta sheets).

Answer 7

R

Question 8

The ______ structure of a protein is its linear sequence of amino acids, held by peptide bonds.

Answer 8

primary

Question 9

______ structure is the order of amino acids, which dictates higher levels of protein organization (secondary, tertiary, quaternary).

Answer 9

Primary

Question 10

Protein ______ structure involves folding into alpha helices or beta pleated sheets due to R group interactions.

Answer 10

secondary

Question 11

_____ structure forms coils (helices) or folds (sheets) via hydrogen bonds, driven by R group properties.

Answer 11

secondary

Question 12

RNA contains the base ______ instead of thymine, distinguishing it from DNA.

Answer 12

uracil

Question 13

______ RNA carries the genetic code from the nucleus to ribosomes for protein synthesis.

Answer 13

Messenger (mRNA)

Question 14

___ is a single-stranded RNA with codons (three-nucleotide groups) that encode amino acid sequences.

Answer 14

mRNA

Question 15

______ RNA pairs with mRNA codons and delivers specific amino acids during translation.

Answer 15

Transfer (tRNA)

Question 16

tRNA has an _____ (three nucleotides) that matches mRNA codons and carries one of 20 amino acids to the ribosome.

Answer 16

tRNA has an anticodon (three nucleotides) that matches mRNA codons and carries one of 20 amino acids to the ribosome.

Question 17

______ RNA is a component of ribosomes, the organelles where protein synthesis occurs.

Answer 17

Ribosomal (rRNA)

Question 18

_____, combined with _____, forms ribosomes (large and small subunits), the sites of translation.

Answer 18

rRNA, combined with proteins, forms ribosomes (large and small subunits), the sites of translation.

Question 19

A ______ is a group of three nucleotides in mRNA that codes for a specific amino acid or signal.

Answer 19

codon

Question 20

____ (e.g., AUG for methionine) specify amino acids or signals (start/stop) during translation.

Answer 20

Codons

Question 21

The ______ on tRNA complements an mRNA codon, ensuring the correct amino acid is added.

Answer 21

Anticodon

Question 22

The anticodon (e.g., UAC for AUG) pairs with the____ codon, delivering the corresponding amino acid.

Answer 22

mRNA

Question 23

The ______ is the organelle where mRNA and tRNA interact to synthesize proteins, with A, P, and E sites.

Answer 23

Ribosome

Question 24

____ facilitate translation by matching codons to anticodons and linking amino acids via peptide bonds.

Answer 24

ribosomes

Question 25

The codon ______ codes for methionine and signals the start of translation in most proteins.

Answer 25

AUG

Question 26

____ is the start codon, recognized by the initiator tRNA carrying methionine, beginning protein synthesis.

Answer 26

AUG

Question 27

The enzyme ______ synthesizes mRNA by copying DNA during transcription.

Answer 27

RNA polymerase

Question 28

___ _____ reads the DNA template strand and builds pre-mRNA in the nucleus.

Answer 28

RNA polymerase

Question 29

Transcription begins at the ______ region of DNA, which contains a TATA box.

Answer 29

promoter

Question 30

The ____, with its ____ box (thymine-adenine-rich), signals where RNA polymerase binds to start transcription.

Answer 30

The promoter, with its TATA box (thymine-adenine-rich), signals where RNA polymerase binds to start transcription.

Question 31

______ help RNA polymerase bind the promoter to initiate transcription.

Answer 31

Transcription factors

Question 32

Transcription ends when RNA polymerase reaches the ______ signal, forming AAUAAA in mRNA.

Answer 32

Polyadenylation

Question 33

The _____ signal (adenine-rich) triggers mRNA release, marking the gene’s end.

Answer 33

The polyadenylation signal (adenine-rich) triggers mRNA release, marking the gene’s end.

Question 34

In transcription, ______ is the stage where RNA polymerase copies DNA into pre-mRNA.

Answer 34

elongation

Question 35

During _____, RNA polymerase moves along DNA, synthesizing pre-mRNA, while DNA reanneals behind it.

Answer 35

elongation

Question 36

In RNA processing, a ______ cap is added to the 5’ end of pre-mRNA to aid ribosome binding.

Answer 36

guanine

Question 37

The _____ cap stabilizes mRNA and helps ribosomes recognize it during translation.

Answer 37

guanine

Question 38

The ______ tail, a string of adenine nucleotides, is added to the 3’ end of pre-mRNA during processing.

Answer 38

poly-A tail

Question 39

The ____ protects mRNA from degradation and aids its export to the cytoplasm.

Answer 39

The poly-A tail protects mRNA from degradation and aids its export to the cytoplasm.

Question 40

In eukaryotes, ______ are non-coding gene regions removed from pre-mRNA during splicing.

Answer 40

Introns

Question 41

____ are cut out, as they don’t code for amino acids, leaving only coding regions in mature mRNA.

Answer 41

Introns

Question 42

______ are coding gene regions spliced together to form mature mRNA in eukaryotes.

Answer 42

Exons

Question 43

____contain the protein-coding sequences, joined after intron removal for translation.

Answer 43

Exons

Question 44

Translation occurs in the ______, primarily at the rough endoplasmic reticulum where ribosomes are located.

Answer 44

cytoplasm

Question 45

Mature mRNA travels to the ____ for translation, targeting ribosome-rich areas like the rough ER.

Answer 45

Mature mRNA travels to the cytoplasm for translation, targeting ribosome-rich areas like the rough ER.

Question 46

The ______ tRNA, carrying methionine, binds the ribosome to start translation at the AUG codon.

Answer 46

initiator

Question 47

The ____ tRNA recognizes the start codon (AUG), beginning protein synthesis with methionine.

Answer 47

The initiator tRNA recognizes the start codon (AUG), beginning protein synthesis with methionine.

Question 48

During translation’s ______ stage, peptide bonds form between amino acids to build a polypeptide.

Answer 48

elongation

Question 49

In _____, tRNAs deliver amino acids, and ribosomes link them via peptide bonds in the A, P, E sites.

Answer 49

elongation

Question 50

Translation ends when a ______ codon (UAG, UAA, or UGA) is reached, halting amino acid addition.

Answer 50

stop

Question 51

____ codons have no matching tRNA; a release factor binds, freeing the polypeptide.

Answer 51

stop

Question 52

A ______ factor adds water to release the polypeptide from the ribosome during translation termination.

Answer 52

release

Question 53

The release factor binds at a stop codon, triggering polypeptide release for folding into a protein.

Answer 53

The release factor binds at a ___ codon, triggering polypeptide release for folding into a protein.

Question 54

______ are changes in DNA nucleotide sequences that may alter protein structure and function.

Answer 54

mutations

Question 55

_____ disrupt the DNA → mRNA → protein pathway, potentially changing traits or functions

Answer 55

Mutations

Question 56

A ______ mutation changes one nucleotide, creating a stop codon and halting protein synthesis early.

Answer 56

nonsense

Question 57

_____ mutations (e.g., AAG → UAG) produce a stop codon, resulting in a truncated protein.

Answer 57

nonsense

Question 58

A ______ mutation substitutes one amino acid for another, potentially altering protein function.

Answer 58

missense

Question 59

____ mutations (e.g., AAG → AGG, lysine → arginine) change one amino acid, which may affect protein activity.

Answer 59

Missense

Question 60

A ______ mutation changes a nucleotide but does not alter the amino acid due to codon redundancy.

Answer 60

Silent

Question 61

____ mutations (e.g., AAG → AAA, still lysine) have no effect on the protein because multiple codons code for the same amino acid.

Answer 61

silent

Question 62

A ______ mutation shifts the codon reading frame by inserting or deleting nucleotides, altering all downstream amino acids.

Answer 62

Frameshift

Question 63

____mutations (e.g., inserting G in ACA-AAG) disrupt codon triplets, changing the protein sequence significantly.

Answer 63

frameshift

Question 64

A ______ mutation enhances an organism’s survival or reproduction, like a dark body in fruit flies evading predators.

Answer 64

positive

Question 65

______ mutations improve fitness, increasing survival or reproductive success (e.g., camouflage).

Answer 65

positive

Question 66

A ______ mutation has no effect on survival or reproduction, like a fruit fly’s eye color change.

Answer 66

Neutral

Question 67

_____ mutations (e.g., brown vs. reddish eyes) don’t impact fitness, maintaining function unchanged.

Answer 67

Neutral

Question 68

A ______ mutation harms survival or reproduction, like an eyeless fruit fly struggling to find food.

Answer 68

Negative

Question 69

____ mutations reduce fitness, impairing survival or reproduction (e.g., loss of functional eyes).

Answer 69

negative

Question 70

RNA types: “____ = message, ____ = transfer, _____ = ribosome.”

Answer 70

RNA types: “mRNA = message, tRNA = transfer, rRNA = ribosome.”

Question 71

Transcription stages: “____(TATA), _____ (copy), _____ (poly-A).”

Answer 71

Transcription stages: “Initiation (TATA), Elongation (copy), Termination (poly-A).”

Question 72

Mutations: ____ = one change (nonsense, missense, silent), ____= shift everything.”

Answer 72

Mutations: Point = one change (nonsense, missense, silent) Frameshift = shift everything.”