Genetics Part 1

Question 1

What do DNA polymerases III do?

Answer 1

• Adds new bases to the new DNA chain
• Proofreads the chain for mistakes

Question 2

Define mutation.

Answer 2

A permanent, inheritable change in genetic information

Question 3

What is a gene?

Answer 3

A specific segment of DNA that codes for one functional product

Question 4

What is genetics?

Answer 4

Study of inheritance (heredity) in living organisms

Question 5

What does genetics cover?

Answer 5

• Transmission of biological traits
• Expression of traits in organisms
• Structure & function of genetic material
• Changes in genetic material

Question 6

What is a genome?

Answer 6

Sum total genetic material of an organism

Question 7

How is genetic material primarily organized in cells?

Answer 7

In the form of chromosomes; also as plasmids or in organelles

Question 8

What is a eukaryotic chromosome composed of?

Answer 8

DNA wrapped around histone proteins

Question 9

Where are eukaryotic chromosomes found?

Answer 9

In the nucleus

Question 10

How do eukaryotic chromosomes appear?

Answer 10

diploid, haploid (linear appearance)

Question 11

How are bacterial chromosomes organized?

Answer 11

• DNA condensed with histone-like proteins
• usually one or a few circular chromosomes

Question 12

What is the difference between diploid and haploid chromosomes?

Answer 12

Diploid contains two sets of chromosomes; haploid contains one set

Question 13

What are structural genes?

Answer 13

Genes that code for proteins

Question 14

Genes for RNA machinery

Answer 14

help in protein production

Question 15

Regulatory genes

Answer 15

control gene expression

Question 16

What is the genotype?

Answer 16

Sum of all gene types; organism’s complete genetic makeup

Question 17

What is the phenotype?

Answer 17

Expressed traits resulting from the genotype

Question 18

What are the components of a nucleotide?

Answer 18

• Phosphate
• Deoxyribose sugar
• Nitrogenous base

Question 19

Fill in the blank: The sugar-phosphate backbone attaches in a repetitive pattern of two phosphates in the _______ direction.

Answer 19

5′ to 3′

Question 20

What are the base pairs in DNA?

Answer 20

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

Question 21

What is semiconservative replication?

Answer 21

• 30+ enzymes involved
• Two daughter molecules are identical to the parent strand
• Each daughter molecule has one original and one new strand

Question 22

What is the role of helicase in DNA replication?

Answer 22

Unzipping the DNA helix

Question 23

What does DNA polymerase I do?

Answer 23

• removing primer
• closing gaps
• repairing mistakes

Question 24

What is the function of ligase in DNA replication?

Answer 24

• Final binding of nicks in DNA during synthesis and repair
• links Okazaki fragments on the lagging strand

Question 25

Gyrase/ Topoisomerase I and II

Answer 25

helps untangle DNA supercoils

Question 26

Primase

Answer 26

synthesizing RNA primer

Question 27

True or False: DNA replication involves two daughter molecules that are identical to the parent strand.

Answer 27

True

Question 28

What is transcription?

Answer 28

Master code of DNA that is first used to synthesize an RNA molecule

Question 29

What is the process of translation?

Answer 29

Transcribed RNA is used to produce protein

Question 30

Where does translation occur?

Answer 30

in ribosomes

Question 31

70S ribosomes are found in

Answer 31

* bacteria * mitochondria * chloroplasts

Question 32

80S ribosome are found in:

Answer 32

eukaryotes

Question 33

Function of small ribosomal subunit?

Answer 33

binds to the 5' end of mRNA

Question 34

Function of the large ribosomal subunit?

Answer 34

supplies enzymes for making peptide bonds

Question 35

What are the exceptions of the transcription and translation pattern?

Answer 35

* RNA viruses convert RNA to other RNA * Retroviruses convert RNA to DNA

Question 36

How does RNA differ from DNA?

Answer 36

* RNA is single-stranded * Contains ribose (not deoxyribose) * Uses Uracil (U) instead of Thymine (T) * RNA can form secondary and tertiary levels of complexity (tRNA, rRNA)

Question 37

What is the function of messenger RNA (mRNA)?

Answer 37

Carries genetic instructions

Question 38

What is the role of transfer RNA (tRNA)?

Answer 38

Brings amino acids to ribosome

Question 39

What does ribosomal RNA (rRNA) do?

Answer 39

Component of ribosomes

Question 40

Regulatory RNAs includes:

Answer 40

* Micro RNAs * Anti-sense RNAs * Riboswitches * Small interfering RNAs

Question 41

Primer RNAs

Answer 41

operative in both bacterial and eukaryotic cells

Question 42

What is a codon?

Answer 42

Triplet of bases that determines amino acid sequence

Question 43

What is the start codon?

Answer 43

AUG (Methionine)

Question 44

List the stop codons.

Answer 44

* UAA * UAG * UGA

Question 45

What is the wobble effect?

Answer 45

* Some mutations do not change amino acid sequence * Only the first two nucleotides are required to encode the correct amino acid

Question 46

How does bacterial translation differ from eukaryotic translation?

Answer 46

Bacterial translation can begin before transcription ends

Question 47

What are introns?

Answer 47

Non-coding sequences that are removed before translation in eukaryotic mRNA

Question 48

True or False: Eukaryotic mRNA can code for several genes in a series.

Answer 48

False

Question 49

What is the characteristic of eukaryotic genes?

Answer 49

Contain introns that do not code for proteins and exons that do

Question 50

What is the role of regulatory RNAs?

Answer 50

Regulate gene function

Question 51

What are ribozymes?

Answer 51

Made of RNA; remove unneeded sequences from other RNAs