AP biology unit 2 test

Which would you not find in a prokaryotic cell?

A.Cytosol

B.Dna

C.Nucleus

D.Ribosome

Which would you not find in a prokaryotic cell?

A.Cytosol

B.Dna

C.Nucleus

D.Ribosome

C.nucleus

Where do prokaryotic cells store their DNA since they have no nucleus?

The nucleoid. This is a region in the cytosol where the DNA is located. The nucleus provides a membrane to surround the DNA, so in a prokaryote the DNA will just freely float in the cytosol.

Which is smaller?

A.Prokaryote

B.Eukaryote

A.Prokaryote

What organelle is believed to be a prokaryote?

The mitochondria (a chemotrophic prokaryotic cell) or the chloroplast (a phototrophic prokaryotic cell).

The endosymbiotic theory states that an ancestral cell engulfed a prokaryotic cell and they had a symbiotic relationship.

Which was likely engulfed first?

A.Chloroplast

B.Mitochondria

A.Mitochondria

All eukaryotic cells have a mitochondria, but not all have a chloroplast. This means that the mitochondria was engulfed first then a later eukaryotic cell engulfed the chloroplast on a different lineage.

What is the structure of DNA in a prokaryote?

Circular

How does a prokaryotic cell divide?

Binary fission

Which is not a way for a cell to contain a new gene?

A.Conjugation

B.Crossing over (Prophase 1)

C.Transduction

Transformation

A.Conjugation

B.Crossing over (Prophase 1)

C.Transduction

D.Transformation

What type of cell is the most efficient?

A.Large surface area to volume ratio

B.Small surface area to volume ratio

A.Large surface area to volume ratio

B.Small surface area to volume ratio

Calculate the surface area to volume ratio of a cube with side length 2.

SA = 6s² 
SA = 6(2)²  SA/V = 24/8
SA = 24  SA/V = 3:1

V = s³
V = (2)³
V = 8

How can you increase surface area without increasing volume?

Adaptations like villi/microvilli in the intestines or root hairs in plant root are extensions of the plasma membrane that will increase the surface area without increasing the volume.  

Which organelle is responsible for detoxification?

A.Smooth ER

Structurally, what is the difference between the rough ER and the smooth ER?

The Rough ER is studded with ribosomes, the Smooth ER has no ribosomes.

Technically, the rough ER membrane originates from the nuclear membrane while the smooth ER membrane originates from the rough ER. Also, rough ER is made of cisternae, whie smooth is made of tubules.

Which organelle stores the genetic information for the cell?

Nucleus

Where is the rRNA synthesized?

The nucleolus

Which is responsible for making polypeptides?

Rough ER

What is the difference in function between bound and free ribosomes?

Free ribosomes are in the cytosol. This means they make cytosolic proteins (proteins the function in the cytosol).

Bound ribosomes are attached to the membrane. This means they make membrane proteins or proteins to be secreted.

Describe the structure of the ribosomes and what these do?

The ribosome is made up for a small and
large subunit. The small subunit binds to
mRNA at the 5’ cap and then finds the
start codon. The large subunit has sites
for the tRNA to bind to bring amino acids
to translation.

Ribosome is composed of rRNA and proteins.

How do the three organelles from this section work together?

The nucleus is the site of transcription. The DNA housed in the nucleus is used as a template to make mRNA.

The ribosome is attached to the membrane of the rough ER. It uses mRNA (and tRNA) to synthesize membrane proteins.

Note: ribosomes are free until they get a signal to bind to the ER membrane. 

Which organelle is responsible for digestion?

Lysosome

How are more lysosomes synthesized?

Lysosomes are just sacs of hydrolytic enzymes, so the enzymes are made by the rough ER and then packaged by the Golgi Apparatus.