Unit 2

Question 1

Zygote

Answer 1

Fertilized egg

Question 2

What happens when the sperm goes inside the egg?

Answer 2

the zygote (fertilized egg) goes through cell division repeatedly.

Question 3

Cell division through mitosis gives rise to what?

Answer 3

Many identical cells

Question 4

Differentiation

Answer 4

a process that creates special structures and functions

Question 5

Specialized cells become

Answer 5

tissues -> organs -> organ systems

Question 6

stem cells

Answer 6

undifferentiated cells that become differentiated into one or more types of specialized cells

Question 7

Embryonic Stem Cells

Answer 7

cells that haven never differentiated

Question 8

Adult stem cells

Answer 8

cells found in adult bone marrow that are partially differentiated and can become bone, blood, cartilage, fat, and connective tissue

Question 9

implanted blastocyst becomes gastrula:

Answer 9

embryo with three differentiated germ levels

Question 10

Organogenesis

Answer 10

the process of body organ and organ system formation that follows gastrulation (folding of the cell)

Question 11

organism

Answer 11

one individual member of a species: a living thing

Question 12

organ system

Answer 12

set of organs working together for a common function

Question 13

organ

Answer 13

set of tissues working together for a common function

Question 14

tissue

Answer 14

group of cells working together for a common function

Question 15

cell

Answer 15

most basic unit of life that has all the characteristic of life

Question 16

cell cycle

Answer 16

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

Question 17

2 purposes in cell division

Answer 17

growth and repair

Question 18

Interphase

Answer 18

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

Question 19

Chromosome

Answer 19

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

Question 20

Gene

Answer 20

a section of DNA that contains the instructions for making a protein

Question 21

In normal body cells, chromosomes always occur in in pair of _______ chromosomes

Answer 21

homologus

Question 22

Homologus Chromosome

Answer 22

———– |
| |
| ———– |
| |
| ———– |
(next to eachother)
| ———– |
| |
| ———– |
| |
| ———– |

Question 23

Chromatif

Answer 23

one half of a duplicated chromosome

Question 24

Sister Chromatids

Answer 24

two identical Chromatids

know drawing

Question 25

Centromere

Answer 25

region of the condensed chromosomes that look pinched

Question 26

telomere

Answer 26

ends of the DNA molecule's

Question 27

X crossed chromosomes

Answer 27

duplicated

Question 28

mitosis

Answer 28

the division phase of the cell cycle

Question 29

in mitosis 1 cell becomes ....

Answer 29

2 identical daughter cells

Question 30

Ptophase

Answer 30

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

Question 31

Metaphase

Answer 31

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

Question 32

Anaphase

Answer 32

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

Question 33

Telophase

Answer 33

-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 34

Cytokenesis

Answer 34

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

Question 35

Differentiate between cytokinesis in plant and animal cells

Answer 35

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 36

I-PMAT-C

Answer 36

interphase-prophase, metaphase, anaphase, telophase-cytokenesis

Question 37

how often do cells divide?

Answer 37

every cell divide at a different rate based on its need

Question 38

How do body cells divide?

Answer 38

they must stay small to maintain a high surface area to volume ratio smaller cells are more efficiant tgan larger cells

Question 39

How do body cells divide?

Answer 39

they must stay small to maintain a high surface area to volume ratio smaller cells are more efficient than larger cells

Question 40

What is the cell cycle controlled by?

Answer 40

Chemical reactions control system that starts & stops the cell cycle (proteins play a key role in this)

Question 41

External signals -

Answer 41

signals that come from outside of the cell Ex. Hormones, Nutrients, etc.

Question 42

Internal signals -

Answer 42

signals that come from the cell's own nucleus Ex. DNA inside the cell

Question 43

Checkpoints

Answer 43

critical points where "stop" and "go" signals regulate the cycle

Question 44

cell division is mostly in the ____ position in animal cells because there is no stimulus present

Answer 44

stop