Chapter 22/23 - Cellular Development

Question 1

What are the 4 steps of cellular development?

Answer 1

Cell division

Differentiation

Pattern formation

Morphogenesis

Question 2

Describe cell division?

Answer 2

production of new individual cells

Meiosis: forms gametes, which will fuse to form a zygote

Mitosis: division of previously existing diploid cells

Begins post-fertilization

Question 3

Describe Diferentiation.

Answer 3

As cells divide, changes in gene expression result in differences between cells which results in cell specialization.

In differentiated cells, certain genes are expressed at particular times, but other genes may not be expressed at all.

Question 4

Cells change their gene expression to become specialized for specific functions

What am I?

Answer 4

Differentiation

Question 5

Describe Pattern Formation.

Answer 5

Cells in a developing embryo must become oriented to the body plan of the organism the embryo will become

Involves cells’ abilities to detect positional information that guides their ultimate fate.

Question 6

Describe Morphogenesis.

Answer 6

Involves: cell death, cell division, cell migration, changes in cell shape and differentiation.

organs and anatomical features will develop from dividing cells

Body is generated

Question 7

Process of Development - Cell Division

In animal embryos, the period of rapid cell division following fertilization is called

Answer 7

cleavage

Question 8

Process of Development - Cell Division

What happens to a zygote during cleavage?

Answer 8

1. the enormous mass of the zygote is subdivided into a larger and larger number of smaller and smaller cells, called blastomeres
2. The zygote maintains its size

• G1 and G2 phase during which a cell increases its mass and size, are shortened or eliminated

Question 9

Process of Development - Cell Division

Question 10

Process of Development - Cell Division

During cleavage, cells have extremely short G1 and G2 phases of the cell cycle due to ____________ ?

Answer 10

Rapid Cell Division

Question 11

Process of Development - Cell Division

How many Somatic Cells does a C. Elegans, or nematode contain?

Answer 11

959

Question 12

How are C. elegans useful in research?

Answer 12

1. Can use them to follow or observe how each cell is derived from the fertilized egg and or the first division (of zygote) to the last cell division (full development of all structures)

Question 13

Plant growth occurs in specific areas called __________?

Answer 13

Meristems

Question 14

Process of Development - Cell Division

Undifferentiated plant tissue from which new cells arise is called ___________?

Answer 14

meristems

Question 15

Process of Development - Cell Division

As _____________ cells continually divide, they produce cells that can differentiate into the tissues of the plant.

Answer 15

meristematic stem

Question 16

Process of Development - Cell Differentiation

Cells become determined prior to differentiation (T/F)

Answer 16

true

Question 17

Process of Development - Cell Differentiation

Cells must ____________ to accommodate their specialization of function

Answer 17

differentiate

Question 18

Process of Development - Cell Differentiation

A human body contains more than ______ types of differentiated cells.

Answer 18

210

Question 19

Process of Development - Cell Differentiation

Differentiated cells are distinguishable from one another by

Answer 19

particular proteins that they synthesize, their morphologies, and their specific functions.

Question 20

Process of Development - Cell Differentiation

The molecular “decision” process by which a cell becomes destined for a particular developmental pathway. This occurs before overt differentiation and can be a stepwise process.

Answer 20

Cell Determination

Question 21

Process of Development - Cell Differentiation

Molecular process to determine specialization of a cell is called:

Answer 21

cell determination

Question 22

Process of Development - Cell Differentiation

Used to understand determination and timing of determination

Answer 22

Transplanting studies, or Tracking determination

Question 23

Process of Development - Cell Differentiation

Describe Tracking determination.

Answer 23

Move the donor cell(s) to a different location in a host (recipient) embryo. If the cells of the transplant develop into the same type of cell as they would have if left undisturbed, then they are judged to be already determined

Question 24

Process of Development - Cell Differentiation

What are the requirements of cell determination?

Answer 24

Positional details from surrounding cells

Timing and number of cells

Need commitment from cells for a specific fate

Transcription factor changes to induce cells to a specific fate

Question 25

Process of Development - Cell Differentiation Cells are committed via one of two pathways called :

Answer 25

Inheritance of cytoplasmic determinants Cell-cell interactions

Question 26

Process of Development - Cell Differentiation Which _pathway_ is **maternally produced** and **deposited into the egg during oogenesis**? **A)** Inheritance of cytoplasmic determinants **B)** Cell-cell interactions

Answer 26

**A)** Inheritance of cytoplasmic determinants

Question 27

Process of Development - Cell Differentiation **Determination** can be due to **cytoplasmic determinants** (T/F)

Answer 27

True

Question 28

Describe **Tunicates.**

Answer 28

Tunicates are marine invertebrates Adults are attached to substratum (rock, ocean floor, etc) larvae are mobile

Question 29

Process of Development - Cell Differentiation 1. _Yellow pigment_ molecules in **tunicates** determines \_\_\_\_\_\_\_\_\_\_\_\_\_ 2. **Transplanting** these _yellow pigment molecules_ to other areas of the developing embryo causes: Expression of __________ **(a transcription factor)** within the egg post-fertilization _allows some of the dividing cells to express yellow pigment_, thus _sealing its fate to become the tail muscle_

Answer 29

1. which dividing cells becomes the tail muscle 2. those regions to turn to muscle cells 3. macho-1 gene

Question 30

Process of Development - Cell Differentiation The elimination of **macho-1** function leads to a

Answer 30

loss of tail muscle in the tadpole

Question 31

Process of Development - Cell Differentiation A **transcription factor** that can **activate** the expression of several **muscle-specific genes.**

Answer 31

macho-1 gene

Question 32

Process of Development - Cell Differentiation **_leads to the formation of additional (ectopic) muscle cells_** from nonmuscle lineage cells.

Answer 32

misexpression of macho-1

Question 34

Process of Development - Cell Differentiation **Induction** can lead to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 34

cell differentiation

Question 35

Process of Development - Cell Differentiation Cell-cell interactions results in changing of cell fates **What am I?**

Answer 35

induction

Question 36

Process of Development - Cell Differentiation _Signaling molecules_ **released** from one cell can **change** _gene expression_ in adjacent cells, altering their fates **What am i?**

Answer 36

induction

Question 37

Process of Development - Cell Differentiation 1. Embryos have **three germ layers** which are : 2. **(the “animal pole”)** develop features of : 3. Blastomeres from the opposite pole of the embryo **(the “vegetal pole”)** develop features: 4. If animal-pole cells and vegetal-pole cells are placed next to each other, he animal-pole cells develop as :

Answer 37

1. Ectoderm, Endoderm, Mesoderm 2. ectoderm 3. endoderm 4. mesoderm

Question 38

Process of Development - Cell Differentiation 1. Gives rise to muscle, notochord, and mesenchyme: 2. releases FGF to mesoderm cells 3. Induces formation of notochord and mesenchyme

Answer 38

1. Mesoderm 2. Endoderm cells 3. fibroblast growth factor (FGF) +**mesodermal cells** _receive signals_ from the underlying **endodermal precursor cells** that _lead to the formation_ of **notochord and mesenchyme**

Question 39

Process of Development - Cell Differentiation **Induces** the o_verlying marginal zone cells to **differentiate**_ into either **notochord** (anterior) or **mesenchyme** (posterior)

Answer 39

fibroblast growth factor (FGF)

Question 40

Process of Development - Cell Differentiation Depending on the signal and combination of signals will determine

Answer 40

cell fate

Question 41

Process of Development - Pattern Formation 1. Multicellular organisms have **body plans**, with the basic body plan laid out during ____________ of the embryo, in early stages. 2. May involve **morphogenesis of organs in later stages** 3. Axial differences between **dorsal-ventral** and **anterior-posterior structures** 4. The _positional axis_ of **dorsal-ventral** and **anterior-posterior** structures determines :

Answer 41

1. pattern formation 2. pattern formation 3. Polarity **(Describes patteren formation)** 4. the location of each body part​

Question 42

Process of Development - Pattern Formation Studies to determine **pattern formation** uses:

Answer 42

Drosophila embryos