Genetics

Question 1

What is a Genotype?

Answer 1

All genes that make up an organism’s genetic composition.

Question 2

What is Helicase?

Answer 2

Enzyme that unwinds and unzips DNA during replication.

Question 3

What does DNA Polymerase III do?

Answer 3

Adds bases to a new DNA strand in the 5’ → 3’ direction.

Question 4

What is the function of Ligase?

Answer 4

Enzyme that seals nicks in DNA strands.

Question 5

What is Semiconservative Replication?

Answer 5

DNA replication where each new molecule has one old and one new strand.

Question 6

What is a Replication Fork?

Answer 6

The site where DNA strands are unwound and replication occurs.

Question 7

What is a Primer?

Answer 7

Short RNA sequence added to start DNA synthesis before being replaced by DNA.

Question 8

What is a Leading Strand?

Answer 8

Continuously synthesized DNA strand in the 5’ → 3’ direction.

Question 9

What is a Lagging Strand?

Answer 9

Discontinuously synthesized DNA strand, made in Okazaki fragments.

Question 10

What are Okazaki Fragments?

Answer 10

Short DNA segments synthesized on the lagging strand.

Question 11

What is the role of Topoisomerase?

Answer 11

Relieves tension in DNA strands during replication.

Question 12

What is the Central Dogma?

Answer 12

The flow of genetic information: DNA → transcription → mRNA → translation → protein.

Question 13

What is mRNA?

Answer 13

Carries genetic information from DNA to ribosomes for protein synthesis.

Question 14

What is tRNA?

Answer 14

Transfers amino acids to ribosomes during protein synthesis.

Question 15

What is rRNA?

Answer 15

Forms the major part of ribosomes and facilitates protein synthesis.

Question 16

What is Wobble?

Answer 16

Flexibility in base pairing at the third codon position, allowing redundancy in the genetic code.

Question 17

What is Translocation?

Answer 17

The movement of ribosomes along mRNA to read new codons.

Question 18

What is Eukaryotic Translation?

Answer 18

Occurs separately from transcription; AUG codes for methionine; one protein per mRNA.

Question 19

What is Prokaryotic Translation?

Answer 19

Occurs simultaneously with transcription; mRNA can code for multiple proteins.

Question 20

What is an Operon?

Answer 20

A cluster of genes controlled by a single promoter, common in prokaryotes.

Question 21

What is an Inducible Operon?

Answer 21

Turned on by a substrate (e.g., lactose operon).

Question 22

What is a Repressible Operon?

Answer 22

Turned off by excess product (e.g., tryptophan operon).

Question 23

What is Phase Variation?

Answer 23

Bacteria switching genes on/off to change phenotype.

Question 24

What is Horizontal Gene Transfer?

Answer 24

Transfer of DNA between bacteria, not parent to offspring.

Question 25

What is Conjugation?

Answer 25

DNA transfer between bacteria via a pilus.

Question 26

What is Transformation?

Answer 26

Bacteria take up foreign DNA from the environment.

Question 27

What is Transduction?

Answer 27

Bacteriophages transfer DNA from one bacterial cell to another.

Question 28

What is Generalized Transduction?

Answer 28

Random DNA fragments are incorporated into a phage and transferred.

Question 29

What is Specialized Transduction?

Answer 29

Specific bacterial genes are incorporated into a virus.

Question 30

What are Transposons?

Answer 30

Jumping genes that move within the genome.

Question 31

What is a Point Mutation?

Answer 31

A mutation affecting a single base in DNA.

Question 32

What is a Missense Mutation?

Answer 32

A mutation that results in a different amino acid in a protein.

Question 33

What is a Nonsense Mutation?

Answer 33

A mutation that converts a codon into a stop codon, halting translation.

Question 34

What is a Silent Mutation?

Answer 34

A mutation that changes the DNA sequence but not the amino acid sequence.

Question 35

What is a Frameshift Mutation?

Answer 35

Insertion or deletion of bases altering the reading frame.

Question 36

What is a Lethal Mutation?

Answer 36

A mutation that results in cell dysfunction or death.

Question 37

What is a Back Mutation?

Answer 37

A mutation that reverts a gene back to its original form.

Question 38

What is Photoreactivation?

Answer 38

Repairing DNA damage caused by UV light.

Question 39

What is Excision Repair?

Answer 39

Enzymes remove and replace incorrect DNA bases.

Question 40

What is the Ames Test?

Answer 40

A test that detects mutagenic and potentially carcinogenic substances.

Question 42

What is the basic unit of heredity?

Answer 42

Gene

Question 43

True or False: DNA stands for Deoxyribonucleic Acid.

Answer 43

True

Question 44

Fill in the blank: The process of copying DNA to RNA is called _____.

Answer 44

Transcription

Question 45

What are the four nucleotide bases in DNA?

Answer 45

Adenine, Thymine, Cytosine, Guanine

Question 46

Which base pairs with Adenine in DNA?

Answer 46

Thymine

Question 47

What is the function of ribosomes in protein synthesis?

Answer 47

To translate mRNA into protein.

Question 48

True or False: All mutations are harmful.

Answer 48

False

Question 49

What is the term for an organism's observable traits?

Answer 49

Phenotype

Question 50

What does the term 'homozygous' mean?

Answer 50

Having two identical alleles for a particular gene.

Question 51

In a Punnett square, what do the letters represent?

Answer 51

Alleles of the parents.

Question 52

What is the role of messenger RNA (mRNA)?

Answer 52

To carry genetic information from DNA to the ribosome.

Question 53

Fill in the blank: The physical location of a gene on a chromosome is called its _____.

Answer 53

Locus

Question 54

What is genetic variation?

Answer 54

Differences in DNA sequences among individuals.

Question 55

True or False: A phenotype can be influenced by environmental factors.

Answer 55

True

Question 56

What is the term for a segment of DNA that codes for a protein?

Answer 56

Gene

Question 57

Which process involves the splitting of a cell's nucleus?

Answer 57

Mitosis

Question 58

What is the difference between a dominant and a recessive allele?

Answer 58

A dominant allele expresses itself even in the presence of a different allele, while a recessive allele only expresses itself when two copies are present.

Question 59

Fill in the blank: The study of heredity is known as _____.

Answer 59

Genetics

Question 60

What is a genotype?

Answer 60

The genetic constitution of an organism.

Question 61

True or False: Chromosomes are made of DNA and proteins.

Answer 61

True

Question 62

What does the term 'allele' refer to?

Answer 62

Different forms of a gene.

Question 63

What is the purpose of genetic engineering?

Answer 63

To modify the genetic makeup of an organism.

Question 64

Fill in the blank: A trait controlled by multiple genes is called _____.

Answer 64

Polygenic trait

Question 65

What is the role of transfer RNA (tRNA) in protein synthesis?

Answer 65

To bring amino acids to the ribosome during translation.

Question 66

What are chromosomes made of?

Answer 66

DNA and proteins.

Question 67

True or False: All genes are expressed equally in all cells.

Answer 67

False

Question 68

What is the term for the observable characteristics of an organism?

Answer 68

Phenotype