CHAPTER 4

Evidence in support of the endosymbiotic theory...

-> Similarities between prokaryotes and eukaryotic organelles such as mitochondria and chloroplasts. All have 70S ribosomes -> Prokaryotic cells, mitochondria, and chloroplasts all multiply by binary fission. -> Fossil evidence shows that prokaryotes evolved first, approximately 3.5 billion years ago, whereas eukaryotic cells evolved only 1.4 billion years ago -> Modern-day examples of endosymbionts exist; the protozoan Myxotrichia paradoxa.

Choose the true statements that supports the endosymbiotic theory. *multiple answers* A- Mitochondria and chloroplasts both have their own circular DNA and 70S ribosomes that are similar to those found in bacteria. B- Endosymbiotic theory describes the evolution of prokaryotes as a series of sequential cell-merging events between a eukaryotic ancestor and certain prokaryotes. C- Mitochondria and chloroplasts replicate by a process similar to mitosis. D- Many mitochondrial genes resemble proteobacteria genes, while the genes in the chloroplast resemble genes found in some photosynthetic bacteria.

A & D -> Mitochondria and chloroplasts both have their own circular DNA and 70S ribosomes that are similar to those found in bacteria. -> Many mitochondrial genes resemble proteobacteria genes, while the genes in the chloroplast resemble genes found in some photosynthetic bacteria.

Choose the true statements about the structure and function of the endoplasmic reticulum (ER). A- Vesicles that bud off the ER are often shuttled to the Golgi apparatus. B- The endoplasmic reticulum modifies and packages cellular proteins. C- The ER is a key site of RNA production. D- The smooth ER is involved in lipid production and detoxification.

A, B & D -> Vesicles that bud off the ER are often shuttled to the Golgi apparatus. -> The endoplasmic reticulum modifies and packages cellular proteins. -> The smooth ER is involved in lipid production and detoxification.

Which of the following statements are true? *multiple answers* A- the four kingdoms of eukaryotes each include members that may conduct sexual and/or asexual reproduction. B- protists are strictly unicellular. C- the four kingdoms of eukaryotes include Animalia, Plantae, Fungi, and Protista. D- kingdom Fungi includes unicellular and multicellular organisms.

A, C & D -> the four kingdoms of eukaryotes each include members that may conduct sexual and/or asexual reproduction. -> the four kingdoms of eukaryotes include Animalia, Plantae, Fungi, and Protista. -> kingdom Fungi includes unicellular and multicellular organisms.

Which pairing of organism and the chemical component of its cell wall is matched *incorrectly*? A- Animals: cholesterol B- Bacteria: peptidoglycan C- Protista: cellulose, silica, or other components D- Plants: cellulose E- Fungi: chitin

A- Animals: cholesterol

Which fiber of the cytoskeleton is matched correctly with its function or structure? A- Microfilaments: Interact with the motor protein myosin B- Intermediate filament: Polymerize and depolymerize to facilitate cell movement C- Microtubule: Composed of the protein actin D- Microtubule: Contribute tensile strength to the cytoskeleton E- Microfilaments: Polymerize to form the spindle during mitosis

A- Microfilaments: Interact with the motor protein myosin

Which of the following processes is incorrectly matched to its description? A- Phagocytosis: Imports undissolved substances but not whole cells or viruses B- Receptor-mediated endocytosis: Uses specific binding between structures on the plasma membrane binding to ligands C- Exocytosis: Exports materials out of a cell D- Endocytosis: Imports materials into a cell E- Pinocytosis: Imports dissolved substance using small vesicles

A- Phagocytosis: Imports undissolved substances but not whole cells or viruses

Which of the following features is not found in protozoans? A- performs photosynthesis B- may reproduce sexually or asexually C- unicellular D- no cell walls E- usually heterotrophic

A- performs photosynthesis

Choose the true statements about mitochondria A- Photosynthetic cells lack mitochondria. B- Mitochondria make most of a cell's ATP. C- Mitochondria have 70S ribosomes. D- Mitochondria do not have their own DNA.

B & C -> Mitochondria make most of a cell's ATP. -> Mitochondria have 70S ribosomes.

Which statement is NOT true about eukaryotic ribosomes? A- Both bound and free ribosomes consist of a 40S and a 60S subunit. B- Bound ribosomes are attached to the endoplasmic reticulum (ER).Bound ribosomes produce proteins that are destined for secretion from the cell. C- Bound ribosomes are always bound while free ribosomes are always free. D- Ribosomes found in mitochondria are 70S rather than the 80S type found in the cytoplasm.

C- Bound ribosomes are always bound while free ribosomes are always free.

Choose the correct pairing. A- Eukaryotic flagella: rotary motion B- Eukaryotic flagella: only one per cell C- Eukaryotic flagella: 9 + 2 microtubule arrangement D- Eukaryotic flagella: made up of flagellin protein

C- Eukaryotic flagella: 9 + 2 microtubule arrangement

Which of the following is a FALSE statement about fungal infections. A- tinea pedis is caused by Trichophyton species and affects the foot. B- Coccidioidomycosis is a respiratory disease also known as Valley Fever. C- tinea infections, or ringworm infections, are due to a pathogenic worm. D- vaginal yeast infections are caused by Candida species.

C- tinea infections, or ringworm infections, are due to a pathogenic worm.

Which of the following is mismatched? A- Mitochondria: site of ATP production in a cell B- Nucleus: houses the cell's DNA C- Cytoskeleton: maintains the cell's shape D- Ribosomes: central to RNA production in a cell

D- Ribosomes: central to RNA production in a cell

Choose the FALSE statement about the cell's nucleus. A- The nucleus is typically visible with a light microscope. B- Unless the cell is dividing, the DNA of the nucleus is loosely organized as chromatin. C- The nucleus has a membrane that gives rise to the endoplasmic reticulum. D- The nucleus contains a region called the nucleolus, where DNA is copied.

D- The nucleus contains a region called the nucleolus, where DNA is copied.

Mitochondria do NOT participate in which function? A- programmed cell death B- production of ATP C- production of amino acids and vitamins D- regulation of cell division E- motility

E- motility

Which of the following phagocytic processes occurs last in the sequence?

Exocytosis Submit

What does the plasma membrane of a phagocyte attach to on a microorganism?

Glycoproteins

Vesicles that bud off the ER are typically shuttled to the ________ where their contents can be modified, sorted, and distributed.

Golgi apparatus

_____________ is a type of sexual reproduction that occurs in eukaryotes and results in four genetically unique haploid daughter cells.

Meiosis

How is phagocytosis in the immune system different from protozoan phagocytosis?

Protozoan phagocytosis is used for feeding; phagocytosis by immune cells is used to fight infection.

TRUE or FALSE Animal cells are unique among all other eukaryotic groups in that they universally lack a cell wall.

TRUE

TRUE or FALSE Cells which are active and have high energy demand will have more mitochondria than cell that are less active and have lower energy demand.

TRUE

What is a phagolysosome?

The structure that results from the fusion of a phagosome and a lysosome.

What is the role of opsonins?

They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.

You have discovered a compound that inhibits the placement of sterols in the plasma membrane. What can you deduce about the efficacy of this drug?

This drug may be broadly effective against eukaryotic cells but may be toxic in human patients.

What are Hyphae?

a collection of tubular structures that result from fungal growth.

The process by which a phagocyte moves toward a chemical signal at the site of an infection is called...?

chemotaxis

A similarity between mitosis and meiosis is...?

copying DNA before the cell divides.

What is the primary function of the nucleus?

housing the cell's DNA

_________ are a collection of tubular structures, either septate or aseptate, which allow for growth in most fungi.

hyphae

Protozoans are mainly grouped by their __________

means of motility Submit

What are Fungal infections called?

mycoses.

Phagocytosis is defined as

the ingestion of solid material by a eukaryotic cell. Submit

Where are cilia found in the human body?

upper respiratory tract