Prokaryotes: Model Organisms and Diversity

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What is the most significant difference between eukaryotic and prokaryotic cells?

The presence of a membrane-bound nucleus in eukaryotic cells (correct)
The single, circular strand of DNA in prokaryotic cells
The presence of cell walls in prokaryotic cells
The ability of eukaryotic cells to perform carbon and nitrogen fixation

Which group among prokaryotes is best known for extremophiles such as halophiles and thermophiles?

Archaebacteria (correct)
Eubacteria
Cyanobacteria
Mycoplasma

What is the function of the rough endoplasmic reticulum (ER) in eukaryotic cells?

Generation of energy to power the cell
Synthesis of proteins for export and insertion into membranes (correct)
Conversion of carbon dioxide to carbohydrate using energy from sunlight
Regulation of cell shape and movements of materials within the cell

Which organelles in eukaryotic cells contain DNA that encodes some (but not all) of their own proteins?

Mitochondria and chloroplasts (D) Signup and view all the answers

What is the main function of lysosomes in eukaryotic cells?

Digesting worn-out organelles and material brought into the cell by phagocytosis (A) Signup and view all the answers

How did eukaryotic cells acquire mitochondria and chloroplasts?

Via an endosymbiotic relationship with prokaryotic cells (D) Signup and view all the answers

What characteristic of the ribosomes in mitochondria makes them more similar to prokaryotic cells than eukaryotic cells?

They are sensitive to antibiotics (C) Signup and view all the answers

How are the genomes of mitochondria organized, making them more similar to bacteria than eukaryotic cells?

They have a single, circular strand of DNA (B) Signup and view all the answers

What characteristic of the cytoskeleton makes it important in cell motility and the movement of organelles within a eukaryotic cell?

Microtubules (C) Signup and view all the answers

What distinguishes eukaryotic cells from prokaryotic cells in terms of genome size?

Eukaryotic cells have noncoding DNA sequences (C) Signup and view all the answers

What characteristic makes Saccharomyces cerevisiae (yeast) different from Homo sapiens (human) in terms of genome size?

It has fewer highly repeated noncoding DNA sequences (D) Signup and view all the answers

Which organism has a genome size most similar to Escherichia coli (bacterium)?

Caenorhabditis elegans (roundworm) (D) Signup and view all the answers

What distinguishes a theory from a hypothesis?

A theory has been tested critically under many different conditions, while a hypothesis has not. (C) Signup and view all the answers

What differentiates a scientific theory from a law?

A law is an explanation that has been thoroughly tested and confirmed, while a theory may eventually be regarded as a law. (D) Signup and view all the answers

What defines eukaryotes?

They contain a combination of genomes that originally derived from archaea and bacteria. (C) Signup and view all the answers

Which process is part of the central dogma?

Translation of DNA to RNA. (C) Signup and view all the answers

What is the most evident when control systems break down in cells?

Cells become incapable of self-regulation. (D) Signup and view all the answers

What defines prokaryotic cells?

They do not have genetic code or ATP synthesizing enzymes. (A) Signup and view all the answers