chapter 1 model organisms

Question 1

Model organisms are

Answer 1

experimental models

Question 2

The fundamental properties of all cells have been conserved during evolution.
Thus, basic cell biology principles learned from experiments on one type of cell are generally

Answer 2

applicable to other cells

Question 3

A ___ is a simplified system that is easy to use and work with, to study complex processes.

Answer 3

model

Question 4

3 things needed to be a model

Answer 4

Practical for growing in a lab, not hard to feed and care for
– Short reproduction time makes genetic studies feasible
– Easily manipulated

Question 5

One of the most well-studied organisms in all
biology is ___

Initial understanding of DNA replication, the
genetic code, gene expression, and protein
synthesis derive from studies of ___

Answer 5

E. Coli

Question 6

E. Coli’s Genome is small & easy to alter, contains

Answer 6

4.6 million

nucleotides containing ~4300 genes

Question 7

Routinely used for expressing genes and
producing proteins belonging to other
organisms …like Humulin (human insulin)

Answer 7

E. Coli

Question 8

yeast is a

Answer 8

unicellular eukaryote

Question 9

\_\_\_ are among the simplest
eukaryotic organisms. 
Highly valuable tool in cell &
molecular biology research.
• Easy to manipulate; grow quickly;
most are nonpathogenic.
• Unicellular; can reproduce by
dividing asexually, or by mating.

Answer 9

Yeasts

Question 10

Has contributed a lot to our
understanding of cancer & the
cell cycle

Answer 10

yeasts

Question 11

S. Cerevisiae (baker’s yeast):

Genome contains

Answer 11

12 million
nucleotides of DNA with ~6000
genes

Question 12

Invertebrates:

Answer 12

Nematodes (Roundworms,

C. elegans)

Question 13

_____one of the simplest multicellular organisms; widely used for studying the processes of animal development and cell specialization/differentiation.

Answer 13

Caenorhabditis elegans:

Question 14

• Genetic studies of ____have identified many mutations responsible for developmental abnormalities.
• This leads identification of genes that control development and differentiation in other animals and sometimes even plants.

Answer 14

C. elegans

Question 15

c. elegans genome contains

Answer 15

~100million nucleotides with 19,000 genes, which is

smaller and more manageable than most animals. They also have a set number of cells.

Question 16

\_\_\_\_\_\_is a species of fly that has been studied
extensively for years.
• Crucial model organism in
developmental biology and
neurobiology.
Short reproductive cycle (2 weeks)
makes it very useful for genetic
experiments.
• Many fundamental concepts in
genetics & development were
derived from studies of this

Answer 16

Drosophila melanogaster

Question 17

drophilia genome contains

Answer 17

Genome =180 million nucleotides,

with 14000 genes.

Question 18

Plant Model: 
• Small, easily cultivated member
of the mustard family.
Studies of \_\_\_\_have led
to the identification of genes
involved in plant development,
such as the development of
flowers.
• Has allowed us to see
similarities and differences in
the mechanisms controlling
plant vs. animal development.

Answer 18

Arabidopsis thaliana

Question 19

arabidopsis thaliana genome contains

Answer 19

Genome =125 million

nucleotides, with 26,000 genes.

Question 20

The African clawed frog ___ is an
important model for studies of early
vertebrate development and for the
events of the cell cycle.

Produces large(~1mm) eggs,
facilitating laboratory study and
biochemical analysis
– Led to insights into molecular
mechanisms controlling early
development, cell division, and
the cell cycle.

Answer 20

Xenopus

Question 21

Xenopus genone contains

Answer 21

– Genome =1.7 billion nucleotides,

with ~21,000 genes.

Question 22

Xenopus

Answer 22

X. laevis and X. tropicalis

Question 23

are used for developmental and genetic studies.
Embryos develop outside of the
mother and are transparent, so early
stages of development can be easily
observed.
– Have many of the same genes as
humans.
– Can be used to model human
medical conditions such as fetal
alcohol syndrome.

Answer 23

Zebrafish (D. rario

Question 24

zebrafish sci name

Answer 24

D. rario

Question 25

zebrafish genone contains

Answer 25

Genome is 1.7 billion nucleotides, | with ~24,000 genes.

Question 26

Mammals: • The mouse is the most common mammal model; they are the easiest to house and feed and genetically manipulate. • Almost every aspect of mouse biology mirrors that of other mammals, including humans. Genetically altered mice are regularly used to study the functions of a particular gene in the context of the whole mammalian organism.

Answer 26

Mouse (M. Musculus)

Question 27

``` ____are the most complex animals, and the most difficult to study in cell and molecular biology. • One approach is to use isolated cells from the organism of interest, grown in the lab in dishes or flasks. ```

Answer 27

Vertebrates

Question 28

``` allow us to study all sorts of cellular processes – membrane transport (ch12), gene expression (ch7-8), protein sorting/processing (ch15), cell signaling (ch16) cell division (ch18) & cell specialization (ch20). ```

Answer 28

Cultured cell lines

Question 29

``` HeLa cells – The HeLa cell line was established in 1951 from a biopsy of a cervical tumor taken from _____, who died from the cancer at age 31. • The cells were taken without the knowledge or permission of her or her family, and they became the first human cells to grow well in a lab. Hundreds of thousands of labs across the world use HeLa cells ```

Answer 29

Ms. Henrietta Lacks

Question 30

``` ______ cells have contributed to the development of a polio vaccine, development of cancer treatments & influenza vaccines, and countless other advances. ```

Answer 30

HeLa cells