biology test 4

1.

1 point

which occurs first?

5' capping

translation

splicing

polyadenylation

2.

1 point

snRNAs are...

part of the proteasome complex

Part of the spliceosome complex

part of ribosomes

3.

1 point

Phenotype refers to:

the organism being diploid or haploid

the way an individual looks

Which alleles are at a given locus

how many chromosomes are in one organism

4.

1 point

Which sugar is found in RNA

Ribose

glucose

Deoxyribose

5.

1 point

You are a loaded tRNA involved in translation. which ribosome sites will you visit, in order?

E P A

A P E

E P A

P A E

6.

1 point

The elongating polypeptide chain will never reach which ribosome site?

E

It can be in all three, although briefly in some

P

A

7.

1 point

during splicing:

Some regions called introns are removed from the gene

Some regions called introns are removed from the pre mRNA

Some regions called exons are removed from the pre mRNA

Some regions called exons are removed from the gene

8.

1 point

What is not observed during replication

A transcription initiation complex

a replication bubble

a replication fork

all of the above will be observed

9.

1 point

one aminoacyl-tRNA synthetase might load more than one tRNA type...

this phenomenon is known as 'degeneration of the genetic code'

this statement is false

this phenomenon is called wobbling

10.

1 point

Which of the following is part of RNA processing in prokaryotic cells?

5' capping

polyadenylation

splicing

none of the above occur in prokaryotes

11.

1 point

Which of the following includes one promoter and many genes transcribed in the same conditions?

operon

repressor

activator

operator

12.

1 point

What's a Barr Body?

inactivated y-chromosome

genetic disorder

inactivated x-chromosome

13.

1 point

which of the following is present only in some viruses?

genome

capsid

envelope

14.

1 point

The frequency of recombinant gametes after meiosis is always...

four times the frequency of crossing over between the two loci

equal to the frequency of crossing over between the two loci

half the frequency of crossing over between the two loci

double the frequency of crossing over between the two loci

15.

1 point

DNA replication is semi-conservative because:

mutations can be introduced

only one of the two strands is in each daughter cell

it changes in different cell types but the principle is the same

16.

1 point

A silent mutation

never changes DNA

never changes the protein

can cause disease

never changes RNA

17.

1 point

Consider a case of incomplete dominance. You cross a homozygous red flower with homozygous white flower. The progeny will be...

pink

White

White or red, depending on which is dominant.

red

18.

1 point

Virulent phages:

can only perform the lysogenic cycle

can only perform the lytic cycle

can alternate between lytic and lysogenic

19.

1 point

Which is not located on tRNA

A site

anticodon

amino acid attachment site

all of the above are found on tRNA

20.

1 point

Consider a double stranded molecule of DNA. Its two strands, typically, will not...

contain uracil

be antiparallel

contain phosphate

21.

1 point

Transcription of one operon involves an activator. The operon...

is always negatively regulated

is always positively regulated

is always repressible

is always inducible

22.

1 point

at which of the following levels is eukaryotic gene expression never regulated?

chromatin level

transcription level

RNA processing level

translation level

All of the above can regulate gene expression

23.

1 point

DNA methylation...

is a histone tail modification

is not an epigenetic modification

is an epigenetic modification that affects transcription

24.

1 point

An individual has a dominant phenotype. Which genotype could it have according to Mendelian genetics?

homozygous dominant

homozygous recessive

heterozygous

A&C

25.

1 point

Two genes are 'linked'. The frequency of recombinant gametes will be...

less than it would have been if the genes were assorting independently

more than what it would have been if the genes were assorting independently

proportional to the distance between two genes

A & C

26.

1 point

What phenotypic ratio could you expect from a monohybrid cross?

3:1

1:1:1:1

1:2:1

9:3:3:1

27.

1 point

Which is a natural defense of bacteria against viruses?

endogenous capsids

ligase

retro-transcriptase

restriction enzymes

28.

1 point

Which is the correct order for the following enzymes to intervene during DNA replication?

Topoisomerase, ligase, helicase, primase, DNA polymerase

Primase, helicase, topoisomerase, DNA polymerase, ligase

Helicase, topoisomerase, primase, DNA polymerase, ligase

29.

1 point

Genes A and B are linked. An individual AaBb generates 24% of recombinant gametes. You conclude that:

Genes A and B are 24 mu apart

Genes A and B are 48 mu apart

crossing over between A and B occurs 48% of the time

A & C

30.

1 point

The % of A in an organism is 30. the % of G will be:

There is no way to know.

20

40

30

31.

1 point

An enzyme represses gene transcription by modifying the histones' tails. It will more likely...

Acetylate them

deacetylate them

histone tail modification is not relevant for gene expression

it will depend on the gene

32.

1 point

Which of the following does not belong in a transcription initiation complex?

RNA polymerase

promoter

transcription factors

ribosome

33.

1 point

A woman could never show a phenotype for:

An autosomal linked disorder

a y-linked disorder

an x-linked disorder

34.

1 point

The trp operon is...

negative repressible

negative inducible

positive inducible

positive repressible

35.

1 point

You want to find the genotype of a dominant individual. You use...

a backcross

a dihybrid cross

a testcross

a monohybrid cross

36.

1 point

Retro-transciptase is typical of...

DNA viruses

Retro-viruses

dsRNA viruses

37.

1 point

DNA replication occurs during

G2

S

G1

M

38.

1 point

A protein needs to be secreted outside the cell. Which will NOT be involved in making sure it is synthesized in the correct intracellular location?

SRP (signal recognition particle)

tRNAs

SRP receptor

signal peptide

39.

1 point

polyribosomes...

consist of one mRNA scanned by multiple ribosomes at once

slow down translation

form only on the SER membrane

40.

1 point

The norm of reaction is...

the array of possible phenotypes in multifactorial characters

the time it takes to get offspring from a cross

the ratio of normal progeny from a meiotic non-disjunction

none of the above

41.

1 point

The genome of HIV is...

ssRNA

dsRNA

dsDNA

ssDNA

42.

1 point

Codons are found

on the mRNA

on the tRNA

on the protein

on the template strand

43.

1 point

True breeding plants are:

Heterozygous

Sterile

always homozygous recessive

Homozygous

44.

1 point

Which of the options below results in some normal gametes?

Meiotic non-disjunction

meiotic non-disjunction at meiosis I

meiotic non-disjunction at meiosis II

none of the above result in normal gametes

45.

1 point

An insertion of one base within the sequence of one exon will cause

A frameshift mutation

a silent mutation

a missense mutation

a nonsense mutation

A or D

46.

1 point

Which of the following could result in multiple copies of the same gene?

duplication

translocation

inversion

deletion

47.

1 point

Choose the correct statement:

one amino acid always corresponds to one codon

One codon might encode for more than one amino acid

one amino acid might be encoded by more than one codon

48.

1 point

Two alleles of a same locus, within one cell, are always:

only on sister chromatids

separated during meiosis

different

identical

49.

1 point

Mutated ras causes uncontrolled cell proliferation. Mutated ras is...

a tumor suppressor gene

a proto-oncogene

an oncogene