Anatomy of the Cell + Tissues

Question 1

What are the three primary parts of an animal cell?

Answer 1

1) plasma membrane
2) nucleus
3) cytoplasm

Question 2

Describe the structure of the plasma membrane.

Answer 2

Plasma membrane is composed of a phospholipid bilayer, which is two layers of phospholipids back-to-back.

The phospholipids have one head and two tails. The head is polar and hydrophilic, and the tails are hydrophobic.

Question 3

Describe the structure of the nuclear membrane.

Answer 3

> double membrane (similar to plasma membrane)
outer membrane has embedded ribosomes
outer and inner membranes fuse in some areas to form nuclear pores
outer membrane is continuous with the ER
lumen (space between the 2 membranes), is continuous with the lumen of the ER

Question 4

Describe the structure of microvilli.

Answer 4

finger-like projections that contain cytoplasm and have a core of actin.

Question 5

Describe the structure of stereocilia.

Answer 5

composed of actin, are bound together by fimbrin. Longer than microvilli but not motile.

Question 6

Describe the structure of cilia.

Answer 6

hair-like motile cellular extensions that are composed of microtubules coated by the plasma membrane.

Question 7

What are the 3 structures that comprise the nucleus?

Answer 7

1) nuclear membrane
2) nucleoli
3) chromatin

Question 8

Which organelle is the principal site for energy production?

Answer 8

Mitochondria

Question 9

Which organelle is continuous with the nuclear membrane?

Answer 9

Endoplasmic reticulum (ER)

Question 10

What is the function of the nucleolus?

Answer 10

Site of assembly of ribosomal proteins, site of rRNA synthesis

Question 11

Which organelle is responsible for translation, storage, and transport of proteins?

Answer 11

Rough endoplasmic reticulum (ER)

Question 12

Which organelle is responsible for synthesizing lipids, and drug detoxification?

Answer 12

Smooth endoplasmic reticulum (ER)

Question 13

Which organelle is responsible for packing substances into vesicles and distributing them?

Answer 13

Golgi apparatus

Question 14

Describe an endosome.

Answer 14

pH is originally 6; as they mature, pH drops to 5.5. Have proton pumps on their membranes to acidify the contents.

Question 15

Describe a lysosome.

Answer 15

pH = 5.0, formed from late endosomes. Contain hydrolytic enzymes for intracellular digestion.

Question 16

Describe a peroxisome.

Answer 16

Oxidative enzymes that form free radicals to destroy certain substances. Detoxification, degrades hydrogen peroxide.

Question 17

Describe a proteasome.

Answer 17

Small, barrel shaped organelles that degrade cytosolic proteins.

Question 18

What are the three types of cytoskeletal elements?

Answer 18

1) microfilaments
2) intermediate filaments
3) microtubules

Question 19

What are histones?

Answer 19

a protein that provides structural support for a chromosome, associated strongly with DNA.

Question 20

What is chromatin?

Answer 20

complex of DNA and histones.

Question 21

What is a nuclear pore?

Answer 21

permit exchange (“communication”) between the nucleus and the cytoplasm, transfer of signals.

Question 22

What is an endothelium?

Answer 22

a thin membrane that lines the inside of the heart and blood vessels

Question 23

What is cristae?

Answer 23

a fold in the inner membrane of a mitochondrion

Question 24

What are the four basic tissues in the body?

Answer 24

1. Epithelium
2. Connective tissue
3. Muscle tissue
4. Nervous tissue

Question 25

What are the three basic components of connective tissue?

Answer 25

1. Fibers
2. Cells
3. Matrix (ground substance)

Question 26

What are the three types of connective tissue fibers?

Answer 26

1. Collagenous (most abundant)
2. Elastic
3. Reticular

Question 27

What is loose connective tissue?

Answer 27

low fiber density, contains spaces that can be filled with fat or fluid.

Question 28

What is dense irregular connective tissue?

Answer 28

high density of collagen fibers, oriented in different directions. Chief cells are fibroblasts.

Ex. adhesions. (found in dermis of skin, periosteum, etc.)

Question 29

What is dense regular connective tissue?

Answer 29

high density of collagen fibers arranged in parallel bundles, forming sheets, bands, or cords. (found in tendons and ligaments)

Question 30

What is the primary cell type?

Answer 30

Fibroblasts