Deck 1: The Genetics Revolution

Question 1

Arabidopsis thaliana is a diploid plant model organism with 2n = 10.
a)How many copies of each gene does each Arabidopsis thaliana cell have?
b)How many sets of chromosomes does the nucleus of an Arabidopsis thaliana leaf cell contain?
c)How many pairs of homologous chromosomes does the nucleus of an Arabidopsis thaliana leaf cell contain?

Answer 1

a)2 b)2 c)5

Question 2

Which of the following is/are FALSE about genes?

A)Genes are located on chromosomes.
B)Genes come in variants known as alleles.
C)Genes always encode protein products.
D)All of the answer options are correct.
E)None of the answer options are correct.

Answer 2

C

Question 3

Which of the following is/are TRUE of the DNA structure solved by Watson and Crick?

A)It is a double-helical structure.
B)Sugar-phosphate backbone is always toward the outside of the DNA.
C)There are three hydrogen bonds between A and T and two hydrogen bonds between C and G.
D)All of the answer options are correct.
E)It is a double-helical structure with the sugar-phosphate backbone always toward the outside of the DNA.

Answer 3

E

Question 4

Wild cats (Felis silvestris)and common mice (Mus musculus)are diploid.In wild cats 2n = 38,while in common mice 2n = 40.Based on this information,we can conclude that wild cat cells have:

A)less DNA than common mouse cells.
B)smaller genomes than common mouse cells.
C)fewer DNA molecules than common mouse cells.
D)fewer genes than common mouse cells.
E)fewer sets of chromosomes than common mouse cells.

Question 5

Adenine and thymine are held together by two hydrogen bonds,while guanine and cytosine are held together by three hydrogen bonds.If you were to slowly heat a piece of DNA rich in GC base pairs-in order to denature it-would you expect the melting temperature to be higher or lower than a piece of DNA rich in AT base pairs?

Question 6

Using a concept map,indicate all the relationships that exist among the following: chromosomes,DNA,genes,genomes,proteins,histones,chromatin,nucleus,and mitochondria.

Question 7

In one strand of DNA the nucleotide sequence is 5'-ATGC-3'.The complementary sequence in the other strand must be:

A)3'-ATGC-5'.
B)3'-TACG-5'.
C)5'-ATCG-3'.
D)5'-CGTA-3'.
E)5'-TACG-3'.

Question 8

A sample of normal double-stranded DNA was found to have a guanine content of 18%.What is the expected proportion of adenine?

A)9%
B)32%
C)36%
D)68%
E)82%

Question 9

A gene is transcribed into an mRNA,and this mRNA is 110 nucleotides long.Which of the following proteins could it encode?

A)an enzyme that is 330 amino acids long
B)a ribosomal protein that is 360 amino acids long
C)a regulatory protein that is 36 amino acids long
D)a signaling protein that is 10 amino acids long
E)a structural protein that is 110 amino acids long

Question 10

Mutations are often viewed as negative events,and they are nearly always bad for an organism.Paradoxically,without mutations there would be no evolution,and so they are essential.Explain how this is so.

Question 11

Explain what it means to say that the genetic code is redundant.How does this redundancy help protect against mutations?

Question 12

Using molecular techniques,researchers have knocked out both copies of gene "G" in a series of genetically identical mouse embryos.These mice develop normally,except for their forelimbs,which are missing several small bones.What can be concluded from the results of this experiment?

A)Gene "G" encodes a protein that is a crucial component of the forelimbs' small bones in mice.
B)Gene "G" encodes a protein that is normally only present in the forelimb cells of developing mice.
C)Gene "G" is necessary for proper development of the forelimbs' small bones in mice.
D)Gene "G" is normally only present in the forelimb cells of developing mice.
E)Gene "G" is normally only transcribed in the forelimb cells of developing mice.

Question 13

You have come across a dog (named Cindy)that does not have a tail.Interestingly,all the puppies produced by this dog don't have a tail.If the lack of tail is caused by a genetic mutation,where has this mutation most likely taken place?

A)in Cindy's gametes
B)in the cells that should normally have given rise to Cindy's tail
C)in the cells that should normally have given rise to Cindy's and her puppies' tails
D)in all of Cindy's cells (including her gametes)
E)in a gamete of one of Cindy's parents

Question 14

Which of the following is a component of DNA?

A)alanine
B)arginine
C)cysteine
D)guanidine
E)tyrosine

Question 15

Which of the following features make a species suitable as a model organism?

A)small organism
B)short generation time
C)small genome
D)produce large number of offspring
E)All of the answer options are correct.

Question 16

Choose the best answer from the list below.Not all of the answers will be used.
a.alleles
b.de novo mutations
c.point mutations
d.nucleases
e.DNA polymerase
f.Tatum and Beadle
g.Gregor Mendel
1.___one-gene-one-enzyme hypothesis
2.___gene variants
3.___cut DNA at specific location
4.___unique DNA variants that exist in a child but neither of its parents.
5.___DNA replication

Question 17

Which of the following is a correct representation of the central dogma?

A)RNA → DNA → protein
B)protein → DNA → RNA
C)DNA → RNA → protein
D)DNA → protein → DNA
E)None of the answer options are correct.

Question 18

The nuclear genome of a mouse nerve cell is compared to that of a mouse skin cell.What differences can we expect to see between these two cells' nuclear genomes?

A)The two cells have almost identical genomes,but the nerve cell has more nerve-specific genes.
B)The two cells have almost identical genomes,but the skin cell has more skin-specific genes.
C)The two cells have different genomes: the nerve cell has nerve-specific genes but not skin-specific genes,and the skin cell has skin-specific genes but no nerve-specific genes.
D)The two cells have similar genomes,but the nerve cell has more nerve-specific genes and the skin cell has more skin-specific genes.
E)The two cells have the same genome;there will be no differences.

Question 19

How many different DNA molecules that are eight-nucleotide pairs long are theoretically possible?

A)24
B)32
C)64
D)256
E)65,536