study guide - unit two concept 3

Question 1

Differentiation

Answer 1

A process that creates special structures and functions

Question 2

Stem cells

Answer 2

Undifferentiated cells that can become differentiated into one or more types of specialized cells

Question 3

Gastrula

Answer 3

Embryo with 3 differentiated germ layers

Question 4

Organogenesis

Answer 4

The process of body organ and organ system formation

Question 5

Cell Cycle

Answer 5

A repeated pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells

Question 6

Chromosome

Answer 6

One long continuous thread of DNA that consists of thousands of genes and regulatory information.

Question 7

Gene

Answer 7

A section of DNA with instructions for making a protein

Question 8

Sister Chromatids

Answer 8

Two identical chromatids (halves of a duplicated chromosome)

Question 9

Centromere

Answer 9

Region of the condensed chromosomes that looks pinched

Question 10

Telomere

Answer 10

Ends of the DNA molecule

Question 11

Cancer

Answer 11

Uncontrolled cell division

Question 12

Metasize

Answer 12

Spreading of disease from one organ to others

Question 13

Carcinogens

Answer 13

Cancer causing agents

Question 14

Summarize the order of events from egg and sperm to embryo.

Answer 14

The male sperm travels to the female egg to fertilize it

The resulting zygote has all of its chromosomes for the first time.

It begins to go through mitosis, repeatedly making identical cells.

That clump of identical cells eventually starts to go through differentiation, and the resulting specialized cells organize into the tissues, organs, and organ systems that make up the embryo.

Question 15

Explain the difference between specialized cells and stem cells.

Answer 15

Stem cells are undifferentiated and can become any type of cell,
whereas specialized already have specific structures and thus functions.

Question 16

List the levels of organization from cell to organism that result from differentiation.

Answer 16

Cell 🡪 tissues 🡪 organs 🡪 organ systems 🡪 organism

Question 17

List the two main purposes for cell division.

Answer 17

Growth and repair.

Question 18

Sketch and label a homologous chromosome pair before and after S phase. Include a brief description of the importance of S phase.

Answer 18

During the S phase of Interphase DNA replication occurs, doubling the DNA. This is critical so that when the cell divides, each resulting daughter cell has a complete set of chromosomes.
Draw it too

Question 19

interphase

Answer 19

the growth phase of the cell

G1: Gap 1 Phase: cell grows and makes proteins

S: Synthesis Phase: DNA Replication occurs, doubling the number of chromosomes

G2: Gap 2 Phase: more cell growth and protein synthesis
draw

Question 20

Prophase

Answer 20

-chromosomes condense and become sister chromatids (in X’s)
-nuclear membrane disappears
-spindle fibers form out of centrioles
-know drawing

Question 21

Metaphase

Answer 21

-spindle fibers connect to the centromere of each sister chromatid
-chromosomes line up in the middle of the cell

Question 22

Anaphase

Answer 22

-sister chromatids separate, pulling away from each other and becoming individual chromosomes
-chromatids move to opposite ends of the cell

Question 23

Telophase

Answer 23

-chromosomes decondense and start to look like chromatin again
-nuclear membrane reforms around chromosomes at each pole
-spindle fibers break down
-cytokinesis begins at the end of telophase

Question 24

Cytokenesis

Answer 24

the division of the cytoplasm into 2 individual cells
END RESULT: 2 identical body cells

Question 25

Differentiate between cytokinesis in plant and animal cells

Answer 25

In plant cells- cell plate forms midway between divided nuclei and gradually develops into a cell wall.

In animal cells- forms cleavage furrows that pinches the cell into two equal parts

Question 26

Differentiate between cytokinesis in plant and animal cells

Answer 26

Plant cells form a cell plate, while animal cells form a cleavage furrow.

Question 27

Summarize how cells know when they need to divide. Include examples of the difference between internal and external regulation.

Answer 27

They utilize a chemical control system that responds to internal (from cell’s own DNA) signals and external (hormones, nutrients, etc.) signals.

Question 28

Explain the key roles of checkpoints and apoptosis in the regulation of the cell cycle.

Answer 28

Checkpoints are critical points were “stop” and “go” signals regulate if the cycle will proceed.
Apoptosis is programmed cell death that can be utilized to destroy damaged cells before they divide.

Question 29

Define tumor and differentiate between the two types.

Answer 29

Tumor = clump of cancerous cells that divides uncontrollably.
Benign tumors are clustered together, malignant tumors have metastasized and spread to other tissues and organs.

Question 30

List several potential causes of cancer.

Answer 30

Biological factors (like age and inherited mutations)
Lifestyle choices (like diet and physical activity)
Viruses (like HPV)
Carcinogens (like tobacco smoke)