Transport in and out of the nucleus of molecues larger

QUESTION 4

Choose all that apply. Transport in and out of the nucleus of molecues larger than 9 nm:

1. must have a nuclear localization sequence (NLS) for entry into the nucleus, that is NOT removed after entry.
2. requires a nuclear import receptor protein in the cytoplasm to recognize the NLS and bring it to the nuclear pore for entry into the nucleus.
3. must have a nuclear localization sequence (NLS) for entry into the nucleus, that is removed (cleaved) after entry.
4. requires energy in the form of GTP.
5. is by passive diffusion through the nuclear pores.
6. is an active transport process.
7. requires a nuclear import receptor protein in the nucleoplasm to recognize the NLS and bring it to the nuclear pore for entry into the nucleus.

1 points

QUESTION 5Choose all that apply. The NLS (Nuclear Localization Signal/Sequence)

1. is a short stretch of amino acyl residues in the protein destined to the nucleus.
2. has a consensus basic amino acid residue sequence, KKKRK.
3. is a GFP tag on the protein being imported into the nucleus.
4. is not the signal sequence for transport out of the nucleus.
5. has a consensus acidic amino acid residue sequence, KKKRK.
6. is recognized by a soluble nuclear import receptor protein in the cytoplasm and taken to the nuclear pore complexes, for entry into the nucleus.
7. is recognized by a nuclear import receptor protein that is a nuclear membrane protein close to the nuclear pore complexes.

1 points

QUESTION 6

Choose all that apply: The nuclear lamina

1. breakdown is caused by the phosphorylation of lamin proteins.
2. has an enzymatic role which facilitates nuclear transport.
3. is similar to the ER.
4. has a structural role in providing support to the nuclear envelope.
5. is a meshwork of intermediate filament proteins called the lamins.
6. breakdown is caused by the dephosphorylation of lamin proteins.
7. makes direct contact with the outer membrane of the nuclear envelope.
8. breakdown can cause the breakdown of the nuclear envelope during mitosis.
9. 
   

1 points

QUESTION 7

Choose all that apply: The nucleolus

1. is an area of intense translation activity.
2. is a single membrane-bound entity inside the nucleus.
3. is an area of intense mRNA transcription activity.
4. is an area in the nucleus containing expanded chromosomal loops of rDNA from different chromosomes.
5. is an area of intense rRNA transcription activity.

1 points

QUESTION 8

Histones are said to belong to a family of basic proteins, because they are rich in:

1. basic amino acyl residues carrying an overall positive charge.
2. aminoacyl residues that interact with DNA.
3. really simple (i.e. basic) amino acids
4. basic amino acyl residues carrying an overall negative charge.

1 points

QUESTION 9

Interphase cells contain chromosomes that are less densely packed and __________________________.

1. share the same nuclear territory as their homolog.
2. occupy discrete territories in the nucleus.
3. are restricted to the nucleolus.
4. are completely tangled with other chromosomes.

1 points

QUESTION 10

Choose all that apply. A 30 nm chromatin fibre is made of:

1. non-histone proteins.
2. nuclease.
3. DNA
4. H1 histone proteins.
5. Core histone proteins.

1 points

QUESTION 11

The classic "beads-on-a-string" structure is the most decondensed chromatin structure possible and can only be produced experimentally. Which chromatin components are not retained when this structure is generated?

1. H1 histone
2. linker DNA
3. nucleosome core particles
4. core histones