Ch 5 Eukaryotic Cells & Microorganisms

Question 1

What are some organelles that eukaryotic cells have?

Answer 1

Golgi apparatus, lysosomes, endoplasmic reticulum, etc

Question 2

What are the external structures of a eukaryotic cell?

Answer 2

Appendages, Cilia, Glycocalyx, Capsule, Slime, Flagella

Question 3

What does the cell boundary consist of?

Answer 3

Cell membrane or cell wall

Question 4

What does the nucleus consist of?

Answer 4

Nuclear envelope, Nucleolus, Chromosomes

Question 5

Describe a flagella in a eukaryotic cell

Answer 5

• 10x thicker than prokaryotic flagella
• long & cylindrical containing microtubules
• moves in a snake-like pattern or the tip squiggles and whips forward

Question 6

Describe Cilia

Answer 6

• similar to flagella but is shorter and higher in quantity
• used for feeding, filtering, and motility
• found only on a single group of protozoa and certain animal cells

Question 7

Describe Glycocalyx

Answer 7

• outermost boundary
• appears as a network of fibers, a slime layer or a capsule
• functions in adherence (sticking), protection, and signal reception

Question 8

Cell wall

Answer 8

Rigid, provides structural support and shape

Question 9

How does the cell wall differ in fungi & algae?

Answer 9

• Fungi have thick inner layer of polysaccharide fibers composed of chitin or cellulose and a thin layer of mixed glycans
• Algae – varies in chemical composition; substances commonly found include cellulose, pectin, mannans, silicon dioxide, and calcium carbonate

Question 10

Cytoplasmic (cell) membrane

Answer 10

• typical bilayer of phospholipids and proteins
• regulates the transport of materials entering and exiting the cell.

Question 11

Nucleus

Answer 11

• Sphere-shaped
• Contains chromosomes
• Nucleolus – dark area for rRNA synthesis and ribosome assembly

Question 12

Endoplasmic reticulum (ER)

Answer 12

• Smooth: closed tubular network without ribosomes; functions in nutrient processing, synthesis, and storage of lipids
• Rough: rough due to ribosomes; proteins synthesized and shoved into the ER for packaging and transport

Question 13

Golgi apparatus

Answer 13

• Modifies, stores, and packages proteins
• Consists of a stack of flattened sacs called cisternae

Question 14

Transport Processes

Answer 14

• Transitional vesicles from the ER containing proteins go to the Golgi apparatus for modification and maturation
• Condensing vesicles transport proteins to organelles or secretory (secreted by a cell) proteins to the outside

Question 15

Lysosomes

Answer 15

Involved in intracellular digestion of food particles and in protection against invading microbes

Question 16

Vacuoles

Answer 16

Membrane-bound sacs containing particles to be digested, excreted, or stored

Question 17

Mitochondria

Answer 17

• Function in energy production
• Consist of an outer membrane and an inner membrane with folds called cristae
• Divide independently of cell
• Contain DNA and prokaryotic ribosomes

Question 18

Chloroplast

Answer 18

• Convert the energy of sunlight into chemical energy through photosynthesis
• Found in algae and plant cells
• Primary producers of organic nutrients for other organisms

Question 19

Ribosomes

Answer 19

Composed of rRNA (ribosomal RNA) and proteins

Scattered in cytoplasm or associated with RER (rough endoplasmic reticulum)

Larger than prokaryotic ribosomes

Function in protein synthesis

Question 20

Cytoskeleton

Answer 20

Flexible framework of proteins

Microfilaments & microtubules form network throughout cytoplasm

Involved in movement of cytoplasm, amoeboid movement, transport, and structural support

Question 21

Concept Check: The Eukaryotic organelle that is responsible for transporting vesicles inside the cells is the______________.

Answer 21

Rough Endoplasmic Reticulum (RER)

Question 22

Name some eukaryotic microbes

Answer 22

Fungi, Algae, Protozoa, Parasitic worms

Question 23

Characteristics of Fungi

Answer 23

Macroscopic (mushrooms) or Microscopic (yeast & mold)

Can be uni, multicellular, or colonial

Morphology:
- Yeast: round ovoid shape, soft, asexual reproduction (budding)
- Hyphae – long filamentous fungi or molds
** can be dimorphic (both yeast & hyphae)

Question 24

Filamentous fungi

Answer 24

Definition: mass of hyphae called mycelium; cottony, hairy, or velvety texture

Hyphae may be divided by cross walls (septate)

Vegetative hyphae – digest and absorb nutrients

Reproductive hyphae – produce spores for reproduction

Question 25

Fungi are generally classified according to their_________________.

Answer 25

Sexual Reproduction

Question 26

Protists: Algae & Protozoa characteristics

Answer 26

Algae - eukaryotic organisms, usually unicellular and colonial, that photosynthesize with chlorophyll a Protozoa - unicellular eukaryotes that lack tissues and share similarities in cell structure, nutrition, life cycle, and biochemistry

Question 27

Algae

Answer 27

Photosynthetic organisms Microscopic forms are unicellular, colonial, filamentous Macroscopic forms are colonial and multicellular Contain chloroplasts with chlorophyll and other pigments Cell wall May or may not have flagella

Question 28

Protozoa

Answer 28

Vary in shape, lack a cell wall Most are unicellular; colonies are rare Most are harmless, free-living in a moist habitat Some are animal parasites and can be spread by insect vectors All are heterotrophic – lack chloroplasts Cytoplasm divided into ectoplasm and endoplasm Feed by engulfing other microbes and organic matter

Question 29

Protozoa Pt 2

Answer 29

Most have locomotor structures – flagella, cilia, or pseudopods Exist as trophozoite (absorbs nutrient from host) – motile feeding stage Can enter into a dormant stage when conditions are unfavorable for growth and feeding – cyst All reproduce asexually, mitosis or multiple fission; many also reproduce sexually – conjugation

Question 30

Example of Pathogenic flagellates

Answer 30

African Trypanosomiasis aka “sleeping sickness” - caused by microscopic parasites of the species Trypanosoma brucei. - transmitted by the tsetse fly (Glossina species), which is found only in sub-Saharan Africa.

Question 31

Parasitic Helminths

Answer 31

Multicellular animals, organs for reproduction, digestion, movement, protection Parasitize host tissues Have mouthparts for attachment to or digestion of host tissues Most have well-developed sex organs that produce eggs and sperm Fertilized eggs go through larval period in or out of host body

Question 32

Major Groups of Parasitic Helminths

Answer 32

Flatworms – flat, no definite body cavity; digestive tract a blind pouch; simple excretory and nervous systems Roundworms (nematodes) – round, a complete digestive tract, a protective surface cuticle, spines and hooks on mouth; excretory and nervous systems poorly developed

Question 33

How are helminths spread?

Answer 33

Through the ingestion of larvae or eggs through food, soil, or water