Week 1: Model Organisms

Question 1

model organisms

Answer 1

studied to give insight into particular biological phenomenon, systems of other organisms, explore causes and treatments for human diseases, and evolution

Question 2

fundamental mechanism of life; what organism did we learn this from?

Answer 2

DNA replication, transcription; E-coli

Question 3

properties of budding yeast (S cerevesiae)

Answer 3

rapid growth, easy mutant isolation, DNA transformation, complete genome sequencing

Question 4

cell division cycle genes (CDC)

Answer 4

identified in yeast and yeast cdc genes are interchangeable with humans because of conservation

Question 5

limitation of yeast

Answer 5

we cannot learn multicellular information

Question 6

C. elegans properties

Answer 6

small, harmless, genome sequenced, mutants, simply body with 959 somatic cells

Question 7

how do we use single cell lineage?

Answer 7

experts can determine which cells express and determine mutations => mutations where programmed cell death should happen

Question 8

drosophila melanogaster properties

Answer 8

broad knowledge, easy/cheap, large mutant numbrs, genetic tools (transgenics, conditional expression systems, clonal analysis), entire genome sequenced, cell/organ culture, developed informatics, evolutionarily conserved mechanisms

Question 9

homeotic mutations

Answer 9

transform parts of the body structures appropriate for other positions

Question 10

Hox genes

Answer 10

homeotic genes that encode regulatory proteins in almost every animal species to establish the identity of body parts

Question 11

eyeless gene

Answer 11

pax 6 is mice/human homolog => master control gene for eye developement

Question 12

what happens if you lose the eyeless gene or move it transgenically?

Answer 12

you cannot produce an eye because it is required and sufficient or you may initiate ectopic eye structures in other body segments

Question 13

required definition

Answer 13

you need it for something to occur and if you remove it you lose it

Question 14

sufficient definition

Answer 14

adding the gene means you get the whole thing and allows for a structure to be created

Question 15

master control gene

Answer 15

when turned on you can achieve eye morphogenesis
- all genes may be required but only the master control initiated eye development by coding a TF regulating all genes

Question 16

Xenopus laevis

Answer 16

African clawed frog => high tolerance for physical and pharmacological manipulation, microsurgery, and experimental embryology

Question 17

organizer is a small piece of tissue that?

Answer 17

can reorganize the structure of a developing body by secreting molecules when transplanted in a host cell

Question 18

is an organizer or a host responsible providing cells for a second embryonic primordia

Answer 18

the organizer secretes molecules that have activities to organize host cells to develop body structures

Question 19

which model organism is good for cell division studies or microsurgery for nervous system development

Answer 19

Xenopus laevis because of its large egg size

Question 20

genetic redundancy

Answer 20

2 genes serve the same function so one can be knocked out and the genetic product will remain the same

Question 21

advantages and disadvantages of whole genome duplication

Answer 21

ADV: development of more complex life forms
DIS: separate gene copies can mutate and serve divergent purposes => also makes it more difficult to figure out if a gene code performs certain functions

Question 22

mus musculus

Answer 22

close genetic/physiological similarities to humans, genetic manipulation, low cost, multiply fast, human-mouse gene counterparts, same complex physiological systems, naturally develop diseases

Question 23

what physiological systems and diseases do mice share with humans

Answer 23

immune, endo, nervous, cardiovascular, skeletal; cancer, atherosclerosis, hypertension, diabetes, down syndrome, epilepsy, heart disease, and muscular dystrophy

Question 24

how do we alter mouse embryos?

Answer 24

we use a blastocyst and a clump of ES cells are injected into the blastocyst with a micropipette. Then they are incorporated in the mass of the host blastocyst which develops in a foster mother so the ES can contribute to any tissue