Question 1

The eukaryotic cell's glycocalyx is

Accepted Answer

The glycocalyx is primarily composed of polysaccharides, which act as a protective outer layer around the cell. It is involved in various functions such as cell-cell recognition, protection against pathogens, and cell signaling. Although some proteins may be present within the glycocalyx, they are not the primary component. The cell wall is a separate structure found in some organisms, such as plants and bacteria. The glycocalyx also does not typically serve as the site of metabolic reactions, as these occur within the cytoplasm or membrane-bound organelles. Finally, while the glycocalyx may contribute to protection against osmotic lysis, this is not its only function.

Question 2

The eukaryotic cell organelle that most resembles a bacterial cell is the

Accepted Answer

Mitochondria are believed to have originated from ancient bacterial cells through endosymbiosis. They have their own DNA and ribosomes, and can replicate independently of the nucleus. This similarity to bacterial cells is not found in other organelles like the nucleus, golgi apparatus, lysosome, or ribosome.

Question 3

Cilia are found in certain

Accepted Answer

A

Question 4

An organelle that is a stack of flattened, membranous sacs and functions to receive, modify, and package proteins for cell secretion is the

Accepted Answer

The Golgi apparatus is composed of flattened membranous sacs called cisternae and is responsible for modifying, sorting, and packaging proteins and lipids into vesicles for transport to other parts of the cell or for secretion outside of the cell. The other organelles listed (mitochondria, lysosomes, chloroplasts, endoplasmic reticulum) do not have this role in protein modification and secretion.

Question 5

Which organelle contains cristae where enzymes and electron carriers for aerobic respiration are found?

Accepted Answer

Mitochondria are the organelles that contain cristae where enzymes and electron carriers necessary for aerobic respiration are found. Lysosomes contain hydrolytic enzymes, the Golgi apparatus is involved in protein modification and sorting, chloroplasts carry out photosynthesis, and the endoplasmic reticulum is involved in protein synthesis and lipid metabolism.

Question 6

Protists include

Accepted Answer

Protists are a diverse group of eukaryotic organisms that include unicellular and multicellular organisms. The two main groups of protists are algae and protozoa. Yeasts and molds are types of fungi, not protists. Helminths are a separate group of parasitic worms. Therefore, option B is the best choice as it includes the correct types of organisms that are considered protists.

Question 7

Organelles found in algae but not found in protozoa or fungi are the

Accepted Answer

Chloroplasts are organelles found in algae that carry out photosynthesis, but they are not found in protozoa or fungi. Protozoa are single-celled organisms that lack organelles such as chloroplasts, while fungi obtain their nutrients through absorption and do not carry out photosynthesis.

Question 8

The cytoskeleton

Accepted Answer

All of the choices are correct. The cytoskeleton not only provides support and helps maintain cell shape, but also anchors organelles and functions in movements of the cytoplasm.

Question 9

Protists with contractile vacuoles

Accepted Answer

Protists with contractile vacuoles use them to expel excess water from the cell.

Question 10

The cell's series of tunnel-like membranes functioning in transport and storage are the

Accepted Answer

The endoplasmic reticulum (ER) contains a series of membranes that are involved in transport and storage of proteins and lipids within the cell. The rough ER is involved in protein synthesis and folding, while the smooth ER is involved in lipid metabolism and detoxification. The Golgi apparatus is responsible for modifying, sorting, and packaging proteins for transport to their final destinations. Lysosomes are membrane-bound organelles that contain enzymes for breaking down cellular waste and foreign substances. Mitochondria are responsible for generating energy through cellular respiration. Chloroplasts are found in plant cells and are responsible for photosynthesis.

Question 11

The endosymbiotic theory says that precursor eukaryotic cells acquired flagella by endosymbiosis with a _____ ancestor, and others gained photosynthetic ability from endosymbiosis with a _____ ancestor.

Accepted Answer

The endosymbiotic theory suggests that eukaryotic cells acquired flagella through endosymbiosis with a spirochete ancestor and gained photosynthetic ability from endosymbiosis with a cyanobacteria ancestor.

Question 12

Cell walls are not found on typical cells of

Accepted Answer

Protozoa are unicellular eukaryotes that lack cell walls and are surrounded by a flexible cell membrane. Therefore, cell walls are not found on typical cells of protozoa.

Question 13

Histones are

Accepted Answer

Histones are proteins that are closely associated with DNA in the nucleus of eukaryotic cells, and play a critical role in compacting DNA into a more condensed structure known as chromatin.

Question 14

When a eukaryotic cell is not undergoing mitosis, the DNA and its associated proteins appear as a visible thread-like mass called the

Accepted Answer

When a eukaryotic cell is not undergoing mitosis, the DNA and its associated proteins appear as a visible thread-like mass called chromatin. The chromatin is made up of DNA, histones, and other proteins that help package and organize the DNA within the nucleus. During mitosis, the chromatin condenses into visible chromosomes. The other choices are incorrect as the nuclear envelope is the membrane surrounding the nucleus, the nucleosome is the basic unit of DNA packaging, the nucleolus is the site of ribosome assembly, and the nucleoplasm is the fluid inside the nucleus.

Question 15

Chitin is a chemical component of the cell walls of

Accepted Answer

Chitin is a chemical component of the cell walls of fungi, specifically in the outermost layer of the cell wall. It is a tough and rigid polysaccharide that provides structural support to the cells of fungi. While chitin is also found in the exoskeletons of arthropods like insects and crustaceans, the question specifically asks about cell walls, ruling out those options.

Question 16

The size of a eukaryotic cell ribosome is

Accepted Answer

Eukaryotic ribosomes are composed of a 60S large subunit and a 40S small subunit, giving a total size of 80S. This is different than prokaryotic ribosomes, which have a size of 70S.

Question 17

Filamentous fungi are called

Accepted Answer

Filamentous fungi are commonly known as molds, due to their growth habit of forming visible, thread-like structures called hyphae.

Question 18

Eukaryotic flagella differ from prokaryotic flagella because only eukaryotic flagella

Accepted Answer

Eukaryotic flagella, unlike prokaryotic flagella, contain microtubules, which are protein structures that contribute to the flagellum's motility. Additionally, while both types of flagella can be used for cell motility, eukaryotic flagella are also involved in processes such as chemotaxis and phototaxis. Finally, while some eukaryotic flagella may be long and whip-like, this is not a characteristic that distinguishes them from prokaryotic flagella.

Question 19

Which of the following is found in eukaryotic cells but not in prokaryotic cells?

Accepted Answer

All of the choices are correct. These organelles are found in eukaryotic cells, but not in prokaryotic cells. The nucleus contains genetic material, mitochondria are responsible for energy production, the endoplasmic reticulum is involved in protein synthesis and transport, and lysosomes are responsible for cellular digestion.

Question 20

The site for ribosomal RNA synthesis in eukaryotes is the

Accepted Answer

The site for ribosomal RNA synthesis in eukaryotes is the nucleolus, which is a specialized region within the nucleus of a cell. The nucleolus is responsible for the transcription and processing of ribosomal RNA, which is then assembled into ribosomes in the cytoplasm. The other options listed (ribosome, nucleus, golgi apparatus, and lysosome) are not involved in ribosomal RNA synthesis.

Quiz 5: A Survey of Eukaryotic Cells and Microorganisms