Lab Quiz One

Question 0

Is interphase a time when the cell is resting? Why or why not?

Answer 0

No - during interphase the cell is growing, maturing and differentiating.

Question 1

What are the two major periods of the life cycle of the cell?

Answer 1

Interphase and mitotic phase

Question 2

What are the four stages of the mitotic phase?

Answer 2

Prophase, metaphase, anaphase and telophase.

Question 3

Why is it important for chromatin to coil and form discrete chromosomes before cell division?

Answer 3

Transcription and protein synthesis cannot occur whole DNA is tightly coiled.

Question 4

What are the primary four types of tissue?

Answer 4

Epithelial, connective, muscle and nervous

Question 5

Why do some epithelial cells have cilia? Where are these specialized surfaces found in the body?

Answer 5

To beat in rhythmic fashion and propel mucus and other materials across the cell’s apical border. Found in the urogenital and respiratory tracts.

Question 6

Why do some epithelial cells have microvilli? Where are cells with these specialized surfaces found?

Answer 6

Microvilli usually occur on cells that that are involved with absorption or secretion such as the epithelia in the intestinal and urinary tract. These “brush borders” greatly increase the surface area of the cell, thereby increasing it’s absorptive ability.

Question 7

What are the three basic shapes of epithelial cells?

Answer 7

Squamous, cuboidal and columnar.

Question 8

Where are goblet cells found. What type of secretion do they produce?

Answer 8

A unicellular goblet cell occurs among simple and pseudostratified epithelia that line the respiratory and digestive tracts. Goblet cell releases it’s stored mucus onto the tissue surface.

Question 9

What is the genetic basis of cellular differentiation?

Answer 9

The position of genes in chromosomes determines the genetic basis of cellular differentiation. Some genes may be located on a region of the chromosome that is available for transcription, whereas other genes may be located inside the molecule and cannot be reached by transcription molecules. We say that one gene is “turned on” while the other is “turned off”. Genes can be turned of permanently or temporarily. Chromosomes are dynamic in their ability to twist, so that a gene that was once inaccessible on the inside can be moved to the outside of the molecule for use. Differentiation involves the temporary or permanent inhibition of genes that may be active in other cells.

Question 10

Epithelial tissue is characterized as simple, stratified or pseudo stratified. What does this mean ?

Answer 10

Simple is single later of cells
Stratified is multiple layers on top of each other
Pseudo-stratified appears stratified, but each cell is actually rooted in basil layer

Question 11

What are the three basic constituents of connective tissue?

Answer 11

Extracellular fibers, ground substance and cells

Question 12

What are each of the shapes of epithelia and where in the body is each found?

Answer 12

Squamous

Question 13

List three types of muscle. How do they differ from one another? Be able to identify.

Answer 13

Skeletal, smooth and cardiac.

Skeletal is striated and voluntary
Smooth is involuntary and found in stomach and other organs
Cardiac is heart muscle

Question 14

Identify the anatomical layers of skin.

Answer 14

Epithelial

Question 15

Identify the common names of cells in skin and glandular structures

Answer 15

Goblet cells

Question 16

Why is skin important? Name 5 important functions of skin.

Answer 16

Sensory feedback
Prevent toxins from entering body
Prevent bacteria and viruses from entering body

Question 17

What happens in Prophase?

Answer 17

Prophase: Chromatin coils and condenses to form barlike chromosomes that are visible with light microscopy. These chromosomes are composed of two identical chromatids linked together at a constriction in their middle known as the centromere or kinetochore. The cytoplasm becomes more viscous as microtubules from the cytoskeleton are disassembled and the cell becomes round. Two pairs of centrioles form anchors on which new microtubules are constructed, and as the microtubules lengthen, they push the centrioles farther and farther apart. In this way a mitotic spindle is formed that provides the structure and machinery necessary to separate the chromosomes. Because transcription and protein synthesis cannot occur while the DNA is tightly coiled, the appearance of chromosomes marks the cessation of normal synthetic processes. Prophase is thought to conclude with the disintegration of the nuclear envelope.

Question 18

What happens in metaphase?

Answer 18

Metaphase: Chromosomes line up in the exact center of the spindle, known as the equator. The chromosomes are evenly spread apart and form what is called the metaphase plate midway between the poles of the cell. The centromere of each chromosome is attached to a single spindle fiber.

Question 19

What happens in anaphase?

Answer 19

Anaphase: The centromeres of the chromosomes split apart and each chromatid becomes its own chromosome. The spindle fiber separates, each spindle segment shortens, and the twin chromosomes are pulled away from each another. The chromosomes take on a V shape as they are dragged at their midpoint toward the centrioles at opposite ends of the cell. The cell becomes elongated, and the cytoplasm begins to constrict along the plane of the metaphase plate. Although anaphase is the shortest phase of mitosis and usually lasts only a few minutes, its importance is clear in light of the devastating consequences if an error were to occur in chromosome separation. In anaphase the advantage of separating compact bodies of chromosomes, rather than long thin threads of chromatin, is particularly obvious.

Question 20

What happens in telophase?

Answer 20

Telophase: Begins when chromosomal movement stops. The chromosomes, having reached the poles, begin to unravel, elongate, and return to a diffuse threadlike form (chromatin). A nuclear envelope appears around each new set of chromosomes, and nucleoli appear in each nucleus. The microtubules that made up the spindle in the earlier phases of mitosis disassemble, and a ring of peripheral microfilaments begins to squeeze the cell into two parts. Ultimately, the cell pinches itself in half, dividing the cytoplasm and forming two completely separate daughter cells. The process of cytoplasmic division is called cytokinesis and marks the end of telophase.

Question 21

What are the parts of a microscope? How is a slide placed on a microscope stage? From what objective do you start to view?

Answer 21

Stage, diaphram

Question 22

What is keratinization and why is it an important process?

Answer 22

Because

Question 23

How are paw pads and the planum nasale different from other regions of skin?

Answer 23

Conical papillae covers entire pad

Question 24

Know the basic anatomical structure of the claw and the hoof.

Answer 24

Know the basic anatomical structure of the claw and the hoof.

Question 25

Name phases of the cell cycle

Answer 25

M phase - shortest phase (-1 hr)
G1 phase - first gap, longest phase
S phase - synthesis of DNA
G2 phase - second gap

Cells that are NOT growing or dividing at all are said to be at G0
Interphase. = G0 + G1+ S + G2 NOT mitosis!

Question 26

Describe activity during interphase

Answer 26

Intensive metabolic activity and cellular growth
Cell doubles in size and # of organelles doubles
Centrioles begin to replicate in prep for cell division

Question 27

Second part of interphase:

Answer 27

DNA replication

Question 28

Third part of interphase:

Answer 28

G2
Synthesis of enzymes and proteins necessary for cell division and continued growth of cell
Centrioles complete their replication

Question 29

What is cytokinesis?

Answer 29

Division of the cytoplasm

Question 30

What is the difference between somatic cells and gametes?

Answer 30

Somatic cells are diploid - two copies of every chromosome

Gametes are all haploid (one copy)

Fusion of two gametes (1n) results in 2N - zygote

Question 31

Karyotype

Answer 31

Arrangement by length of a persons chromosomes longest to shortest, sex chromo last

Question 32

Name three types of hairs

Answer 32

Primary or guard hairs - straight or arched; thicker and longer than secondary hairs
Secondary or wool hairs - softer and shorter than primary; wavy or bristles in the dog; predominant hair type in species with wool type coats
Tactile or sinus hairs-
Contain numerous sensory endings
Commonly known as whiskers
Large blood sinus located in connective tissue portion of folicle

Question 33

Growth cycle of hair:

Answer 33

Anlagen - cells added at base
Cartagena - period of transition btw Ana and telo
Telophase - max length of hair achieved - hair stops growing

Question 34

Parts of claw

Answer 34

Hard outer coating of distal digits

Question 35

How is planum nasale different?

Answer 35

Usually pigmented
Composed of only three epi layers
S. Germinativum
S lucidum
S granulosum

Question 36

Hood structure

Answer 36

Ungula
Rests on corium
Corium is attached to periosteum of distal phalanx
Outer hoof is mod epi layer
Corium is mod dermis
Bones include distal sesamoid (navicular) and third phalanx (coffin bone)
Central sulcus
Digital cushion lies below frog

Question 37

Claws

Answer 37

Attach to terminal p3 phalanx from st corneum