ch 17

Question 2

Steps from DNA to protein

Answer 2

step 1: transcription, step 2: translation

Question 3

Transcription

Answer 3

DNA sequence of a gene is copied into a messenger RNA (mRNA) molecule in the nucleus

Question 4

Translation

Answer 4

the (mRNA) molecule moves to the cytoplasm, where it is read by a ribosome to assemble a specific sequence of amino acids, which then fold into a functional protein

Question 5

Three classes of RNA

Answer 5

messenger RNA (mRNA) which carries genetic code, transfer RNA (tRNA) which brings amino acids, and ribosomal RNA (rRNA) a key part of the ribosome where proteins are made

Question 6

Structural differences of DNA and RNA

Answer 6

DNA is double helix while RNA is single stranded

Question 7

Base paring during DNA replication

Answer 7

A-T, G-C in DNA

Question 8

Base pairing during RNA

Answer 8

A-U, T-A, G-C going from DNA to RNA

Question 9

tRNA structure

Answer 9

a distinctive L-shaped 3D structure, folded from a single strand, featuring an anticodon loop to match mRNA codons and a CCA-acceptor stem where the correct amino acid attaches

Question 10

Three stages of translation

Answer 10

initiation, elongation, and termination

Question 11

Initiation

Answer 11

where the ribosome, mRNA, and tRNA assemble

Question 12

Elongation

Answer 12

where amino acids are added one by one to form a polypeptide chain

Question 13

Termination

Answer 13

when a stop codon is reached, releasing the completed protein and disassembling the complex

Question 14

Three gene mutation

Answer 14

substitution (swapping one base with another), insertion (adding extra bases), deletion (removing bases)

Question 15

Mutation rate

Answer 15

the frequency of DNA changes, influenced by spontaneous errors and external agents called mutagens

Question 16

Mutagens

Answer 16

physical, chemical, or biological agents that cause changes (mutations) in an organism’s DNA

Question 17

Chromosome

Answer 17

thread-like structures in the nucleus of cells that carry genetic information (DNA) organized into genes

Question 18

Template

Answer 18

a pattern or guide, often a strand of DNA or RNA, that directs the synthesis of a new, complementary molecule

Question 19

Replication

Answer 19

the biological process where a cell makes an identical copy of its DNA

Question 20

Anticodons

Answer 20

three-nucleotide sequence on a transfer RNA (tRNA) molecule that pairs with a complementary three-nucleotide codon on messenger RNA (mRNA) during protein synthesis (translation), ensuring the correct amino acid is added to the growing protein chain

Question 21

Transcription

Answer 21

when a cell creates mRNA copy from a specific segment of DNA, acting as genetic blueprint to build proteins

Question 22

Semiconservative

Answer 22

a process where each new DNA molecule contains one original (‘parental’) strand and one newly synthesized strand, effectively ‘conserving’ half of the original DNA in each new copy, ensuring accurate genetic inheritance

Question 23

Promoter

Answer 23

a specific DNA sequence located near a gene that acts as the starting point for transcription

Question 24

Exon

Answer 24

a segment of a gene’s DNA that contains the instructions building a protein, which gets kept and joined together in the final mRNA molecule

Question 25

Intron

Answer 25

a non-coding segment of DNA within a gene that is transcribed into RNA but then removed through a process called splicing before the mature mRNA is translated into a protein

Question 26

Codon

Answer 26

a simple three letter code in DNA or RNA that tells the cell which specific amino acid to add to a growing protein, or when to start/stop making the protein, acting as the fundamental unit of the genetic code that translates genetic instructions into functional proteins

Question 27

Binding site (P and A)

Answer 27

in site A, tRNA carries an amino acid and enters the ribosome, while the P site holds the tRNA attached to the growing polypeptide chain

Question 28

Transposon

Answer 28

class of genetic elements that can “jump” to different locations within a genome

Question 29

Translation

Answer 29

the process where a cell creates protein from the genetic information in mRNA