Gene Action

Question 1

What does DNA stand for?

Answer 1

Deoxyribose nucleic acid

Question 2

Describe the shape of the DNA molecule. What is this called?

Answer 2

Ladder shape, two strands of nucleotides twisted around each other, double helix, discovered by Watson and Crick

Question 3

What are nucleotides?

Answer 3

Units that make up DNA: 3 parts- sugar group, phosphate group, nitrogen base

Question 4

What types of bonds are between the nucleotides?

Answer 4

Strong covalent bonds

Question 5

What types of bonds are between the two strands?

Answer 5

Weak hydrogen bonds

Question 6

Why can only certain bases bond? What is this called?

Answer 6

Depending on the number of hydrogen bonds, complementary base pairings

Question 7

Give the complementary base pairs of DNA

Answer 7

Guanine ; Cytosine

Adenine ; Thymine

Question 8

What is the function of DNA?

Answer 8

Carries the code (spelled out in the order of the bases) to make all the proteins that make up and control your body

Question 9

Give some examples of how DNA controls who/ what you are

Answer 9

DNA carries the genes that determine our genotype. The expression of your genotype is your phenotype - what you look like, etc..

Question 10

Where in the DNA is the code to form the proteins? What will result if this is mistaken?

Answer 10

The code is in the order of the bases on the DNA. If a base is wrong, this can result in an incorrect amino acid being added to the protein, which may or may not cause the protein to work correctly

Question 11

What is replication of DNA? What results?

Answer 11

Replication is copying DNA. The result is an exact copy of the original DNA

Question 12

What cell process is replication essential for? Why?

Answer 12

Cell division (mitosis and meiosis) because each resulting daughter cell needs its own copy of DNA

Question 13

Give a step by step explanation of the replication of DNA. What ensures that the copies will be exact?

Answer 13

DNA unzips down the middle between bases, new nucleotides come in and match the old bases by complementary base pairing, two exact duplicate strands of DNA form

Question 14

What is RNA used for? Compare and contrast RNA and DNA.

Answer 14

DNA- Shape=2 strands, Location= nucleus, Bases= thymine, Sugar= deoxyribose
RNA- Shape= 1 strand, Location= cytoplasm, Bases= uracil, Sugar= ribose

Question 15

List and give functions for the 3 types of RNA molecules

Answer 15

mRNA- cheap copy of DNA code that can come out of the nucleus
tRNA- brings in the amino acids in the correct order to make the protein
rRNA- on the ribosomes, manages the bonding of the amino acids together into proteins

Question 16

What is protein synthesis?

Answer 16

using coded information (bases) on DNA to make specific proteins

Question 17

What are the two steps of protein synthesis?

Answer 17

Transcription and translation

Question 18

Briefly describe what occurs in transcription. Where does this occur?

Answer 18

Code is copied from DNA to mRNA by complementary base pairing in the nucleus

Question 19

Briefly describe what occurs in translation

Answer 19

Amino acids are put together in the correct order as specified by the mRNA

Question 20

Where does translation occur?

Answer 20

On the ribosomes on the cytoplasm

Question 21

What molecule is the mRNA copied off of? How is this done?

Answer 21

DNA in the nucleus is the template mRNA formed with codons, mRNA moves to ribosomes in cytoplasm

Question 22

What molecule must the tRNA fit on to?

Answer 22

as tRNA leaves the polypeptide chain is transferred to the newly arrived tRNA

Question 23

What is a codon?

Answer 23

mRNA’s 3 bases

Question 24

What is an anti-codon?

Answer 24

tRNA’s 3 matching bases

Question 25

What must a codon and anti-codon be to each other?

Answer 25

They must match so the amino acid is correct

Question 26

How does the code ensure that each amino acid will be put in the correct spot in the protein?

Answer 26

Through complimentary base pairing; DNA is the template to make mRNA; tRNA must be complementary to mRNA

Question 27

Start fro the DNA and explain how a mistake in the code can get passed on to en up a mistake in the protein. What is this called?

Answer 27

A mistake in the DNA such as substitution (wrong base) or deletion/addition (base missing or extra one added) will cause the wrong amino acid to be bonded into a protein. The protein may still work, or it may not. A mistake in the genetic code is called a mutation

Question 28

How many differences in the code must you have to get sickle-cell disease? What protein is replaced and with what in the code?

Answer 28

Glutamine is replaced with valine

Question 29

What is gene therapy and how is it used?

Answer 29

Introducing genetically engineered human cells into a human body for the purpose of curing a genetic defect

Question 30

What is genetic engineering?

Answer 30

A process designed to artificially control the genetic makeup of an organism

Question 31

How are trans genetic bacteria made? What are they used for? What is the advantage?

Answer 31

DNA is taken out of one of the species and put into the bacteria to make them do something specific for us like make insulin

Question 32

Transcribe this sequence of DNA to mRNA:

AGTCACGTC

Answer 32

UCAGUGCAG