BIO 25
To which of the superkingdoms do diatoms belong? Please choose the correct answer from the following choices, and then select the submit answer button. Amoebozoa Archaeplastida Stramenopila Opisthokonta Excavata
Stramenopila
Green algae are most closely related to...
land plants
The majority of prokaryotic DNA is arrayed in: Please choose the correct answer from the following choices, and then select the submit answer button. multiple linear chromosomes. multiple circular chromosomes. a single linear chromosome. a single circular chromosome.
a single circular chromosome.
Which of the statements is a hypothesis to explain the origin of the modern eukaryotic cell?
A cell evolved a nucleus first, then incorporated a proteobacterial cell that became a mitochondrion.
Which of the statements is a key advantage of eukaryotic cells over prokaryotic cells? Eukaryotic cells have a rigid cytoskeleton, which allows them to withstand greater stress. Eukaryotic cells have a flexible cytoskeleton, which allows them to change shape and gives them the ability to engulf other materials. None of the other answer options is correct. Eukaryotic cells have ribosomes, which allow them to make more complex proteins. Eukaryotic cells have a cell membrane, which allows them to ship materials into and out of the cell.
Eukaryotic cells have a flexible cytoskeleton, which allows them to change shape and gives them the ability to engulf other materials.
The current theory is that chloroplasts are descendants of symbiotic cyanobacteria that lived within eukaryotic cells. If we look at their respective genomes, however, we see that the cyanobacteria have many more genes than do chloroplasts. Where did cyanobacteria genes go? Nowhere; cyanobacteria and chloroplasts actually have the same number of genes. Restriction enzymes removed them. Many of the genes were transported to the nucleus, and others were lost. None of the answer options is correct. Endosymbiosis requires a reduction in genetic material in order to be successful.
Many of the genes were transported to the nucleus, and others were lost.
Why are some single-celled eukaryotes only found as haploid cells for the majority of their lifespan, whereas others are only found as diploid cells for the majority of their lifespan? Only the eukaryotes that reproduce sexually will occur as diploid cells. Only the eukaryotes that reproduce sexually will occur as haploid cells. Only the eukaryotes that reproduce asexually will occur as diploid cells. Only the eukaryotes that reproduce asexually will occur as haploid cells. None of the answer options is correct.
None of the answer options is correct.
You have learned that having linear DNA has consequences, the major one being that the DNA is shortened every time it replicates. This does not happen with the circular DNA found in prokaryotes. What, then, is the advantage of having linear DNA? Please choose the correct answer from the following choices, and then select the submit answer button. Linear DNA is less susceptible to viruses than circular DNA. All of these choices are correct. Replication can begin from multiple sites on linear DNA, allowing rapid replication and relieving the evolutionary pressure for a streamlined genome. Since mitochondria and chloroplasts have circular DNA, nuclear DNA had to be linear. Linear DNA is easier to package than circular DNA.
Replication can begin from multiple sites on linear DNA, allowing rapid replication and relieving the evolutionary pressure for a streamlined genome.
Which of the statements accounts for why eukaryotic cells are typically much larger than prokaryotic cells? Using molecular motors, eukaryotic cells can transport materials throughout their cytoplasm much faster than prokaryotic cells can; prokaryotic cells have to rely on simple diffusion. Reproducing sexually requires the cells to be larger so that everything in the cell can be evenly distributed to the daughter cells. A eukaryotic nucleus is so large that the cell has to be bigger to allow space for other organelles. Because eukaryotic cells have more DNA, their cell volume has to be larger. None of the answer options is correct.
Using molecular motors, eukaryotic cells can transport materials throughout their cytoplasm much faster than prokaryotic cells can; prokaryotic cells have to rely on simple diffusion.
How does current theory explain the origin of a nucleus in eukaryotic cells? Please choose the correct answer from the following choices, and then select the submit answer button. While there are some competing theories on the origin of the nucleus, neither theory discussed in the text really explains the origin of the nucleus. A prokaryotic cell was engulfed by another cell and became specialized in DNA replication. A prokaryotic cell was engulfed by another cell and became specialized in DNA transcription. None of the other answer options is correct. A prokaryotic cell was engulfed by another cell and became specialized in translation.
While there are some competing theories on the origin of the nucleus, neither theory discussed in the text really explains the origin of the nucleus.
Which superkingdom contains members that are responsible for forming red tides? Alveolata Archaeplastida Amoebozoa Stramenopila Excavata
a. alveolata
You are in a lab studying a newly discovered cell type. You observe a rigid cytoskeleton in this cell, along with a nucleus and a compartmentalized interior. How would you classify this cell? as an advanced prokaryotic cell, because it has a rigid cytoskeleton as a primitive prokaryotic cell None of the answer options is correct. as a possible transitional cell changing from prokaryotic to eukaryotic as a eukaryotic cell that has to be heterotrophic
as a possible transitional cell changing from prokaryotic to eukaryotic
In which group of Archaeplastids are the chloroplasts most similar to those of the ancestral cyanobacterial endosymbiont? a.green algae b.glaucocystophytes c.streptophyte algae d.viridoplantae e.red algae
b.glaucocystophytes
All of the membranes of the eukaryotic cell are in dynamic continuity except for membranes in the: a.nuclear membrane. b.endoplasmic reticulum. c.mitochondria and chloroplasts. d.Golgi apparatus.
c. mitochondria and chloroplasts
Sexual fusion brings two haploid cells together to produce a _____ cell. Please choose the correct answer from the following choices, and then select the submit answer button. polyploid None of the other answer options is correct. diploid haploid
c.diploid
You are in a lab studying a newly discovered cell type. You observe a rigid cytoskeleton in this cell, along with a nucleus and a compartmentalized interior. How would you classify this cell? a.as an advanced prokaryotic cell, because it has a rigid cytoskeleton b.as a primitive prokaryotic cell c.None of the answer options is correct. d.as a possible transitional cell changing from prokaryotic to eukaryotic e.as a eukaryotic cell that has to be heterotrophic
d.as a possible transitional cell changing from prokaryotic to eukaryotic
Organelles have their own genomes. When chloroplast DNA is sequenced and compared to genomes from members of the cyanobacteria, the chloroplast DNA sequence is nested within the genomes of cyanobacteria. This is strong evidence for the hypothesis that: a.cyanobacteria are so diverse that any organelle genome would nest within the group. b.cyanobacteria are descended from chloroplasts. c.photosynthesis evolved only once on the eukaryotic tree. d.the chloroplast originated as a symbiotic cyanobacterium that became permanently incorporated into its host.
d.the chloroplast originated as a symbiotic cyanobacterium that became permanently incorporated into its host.
In eukaryotes that lack mitochondria, what structures are present to generate ATP for cellular use? Please choose the correct answer from the following choices, and then select the submit answer button. There are no eukaryotes that lack mitochondria. There are no structures that generate ATP in eukaryotes that lack mitochondria. hydrogenosomes chloroplasts chloroplasts or hydrogenosomes
hydrogenosomes
