PP 8 (DNA)

Question 0

What are the nitrogenous bases of DNA? How do they bond?

Answer 0

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

– Guanine (G) binds with Cytosine (C)

– Adenine (A) binds with Thymine (T)

Question 1

What 4 things does DNA accomplish?

Answer 1

1) Stores info.
2) Directs the synthesis of proteins
3) Chemically change (mutate) genetic characteristics
4) Replicate

Question 2

What enzyme binds to DNA & separates the two strands?

Answer 2

Helicase

Question 3

3 letter word that specifies an amino acid is called a_____.

All the amino acids will make up a ___?

What is the bond called that holds the amino acids together?

Answer 3

– Codon

– Protein

– Polypeptide bond

Question 4

Name the 2 types of nucleic acids?

Answer 4

• RNA ( Ribonucleic Acid) = 1 strand

- DNA ( Deoxyribonucleic Acid) = 2 strands

Question 5

What are the 4 bases of Ribose?

Answer 5

1) Adenine (A)
2) Guanine (G)
3) Cytosine (C)
4) Uracil (U)

THERE IS NO THYMINE (T) IN RNA, ONLY DNA!!!!

Question 6

• Where is RNA made?

- What are the two types of RNA that participates in protein synthesis?

Answer 6

– made in nucleus, transported to cytoplasm

• • mRNA (messenger)
• • tRNA (transfer)

Question 7

DNA to RNA is called?

RNA to proteins is called?

Answer 7

–Transcription/portion of DNA is copied into a complimentary RNA strand

– Translation/ interpreting genetic message & building the proteins

Question 8

What is a mutation?
(Change)

What causes mutations?

Answer 8

– change in a DNA sequence of an organism, even if you don’t see it.

– mistakes in DNA replication (copies)
– external factors
Ex: radiation, drugs, viral infections

Question 9

What is a point mutation?

Name the 3 types of point mutations.

Answer 9

A change in a single nucleotide of the DNA sequence.

– nonsense mutation (stop)- stop translation prematurely

– missense mutation( change)- causes change in amino acid

– silent mutation- DOES NOT cause change in the amino acid sequence

Question 10

What is insertion & deflection mutation? What do they cause?

Answer 10

• -insertion/ nucleotides are added to a normal DNA sequence.
• • delection/ nucleotides are removed from normal DNA sequence

– Frameshift/ ribosomes read the wrong set of nucleotides, changes amino acid sequence & changes function of protein

Question 11

What is chromosomal aberration?

Answer 11

– any change in normal structure or # of chromosomes often results in physical or mental abnormalities

Question 12

Insertions & deflections cause what?

Answer 12

Frameshift/ when a nucleotide is added or deleted from a normal DNA sequence

Question 12

Define:

• mitosis
• meiosis
• haploid
• diploid
• zygote

Answer 12

• • cell division resulting into 2 cells, asexually
• • cell division resulting in 4 daughter cells, sexually
• • 1 set of chromosomes (N)
• • 2 sets of chromosome (2N)
• • cell formed when 2 gamete (egg & sperm) are joined by sexual reproduction

Question 12

Difference between DNA & RNA?

Answer 12

• • bases AT, GC
• • deoxyribose
• • double stranded
• • held by hydrogen bonds
• -bases AU, GC
• -Ribose
• -single stranded

Question 13

What mutation causes change?
What mutation cause to STOP?
What mutation has a change in letter but nothing else?

Answer 13

• • Missense
• • Nonsense
• • Silent

Question 14

Sickle cell anemia is an example of what mutation?, How do you know?

Answer 14

Missense mutation, one letter change in the codon

Question 15

Anticodon

Answer 15

Sequence of 3 nucleotides in tRNA

Question 16

Define:
Inversion (breaks,replaced wrong)
Translocation(breaks)
Duplication(copied)
Deletion(lost)

Answer 16

• • chromosome breaks & broken piece reattached in wrong place
• • broken part integrates into a diff. Chromosome
• • chromosome is copied & attached to original place
• • broken piece is lost or destroyed