part one

Question 1

do single celled organisms have a nervous system?

Answer 1

no, they’re single celled

Question 2

what are single celled organisms receptive and responsive to?

Answer 2

external stimuli

Question 3

why do single celled organisms have spontaneous activity?

Answer 3

it’s in response to their internal environment

Question 4

what properties to single celled organisms share with a nervous system?

Answer 4

receptive, responsive and also spontaneous activity.

Question 5

when does a nervous system appear?

Answer 5

in multicellular organisms

Question 6

what comes with multicellularity?

Answer 6

specialisation

Question 7

in marine sponges what does water flow through? flow out of? and what causes this flow?

Answer 7

flows through the cell wall, flows out of the osculum and flagella cause this flow

Question 8

what is water flow in marine sponges regulated by?

Answer 8

it is regulated by myocytes.

Question 9

what are myocytes? where are they found?

Answer 9

they are primitive muscle like cells, found in the channels

Question 10

what does it mean when something is an independant effector?

Answer 10

that they can act without the nervous system

Question 11

what does autoregulative refer to?

Answer 11

refers to independant effectors

Question 12

what do myocytes respond to?

Answer 12

they respond to stretch when water moves through or to signals such as chemical signals.

Question 13

what kind of cells are the first neurons? where do these span from?

Answer 13

probably sensorimotor cells. span from the exterior to effector cells

Question 14

why are neurons important in hydra?

Answer 14

they help the hydras tenticles trap particles

Question 15

where do motor neurons receive input from?

Answer 15

from true sensory neurons

Question 16

where do motor neurons have output to? (2)

Answer 16

effector cells and other motorneurons

Question 17

what are amacrine processes?

Answer 17

they conduct action potentials both ways

Question 18

what is a nerve net?

Answer 18

the nerves are scattered eveny around organs

Question 19

what are interneurons and why do they allow more complex interactions?

Answer 19

they are between sensory and motor neurons. because they allow inhibition or excitation

Question 20

what does spontaneity in all classes refer to?

Answer 20

it means all neurons are capable pf spontaneity

Question 21

in higher organisms what may spontaneous activity regulate?

Answer 21

the development of connectivity

Question 22

what may the modulation of spontaneous activity do?

Answer 22

it may underly learning

Question 23

if something can move what does this mean?

Answer 23

it has a front and a back

Question 24

what do flatworms have a clustering of?

Answer 24

neurons

Question 25

what do clustered neurons in flatworms show? (5)

Answer 25

``` gangliation cephalization bilateral symmetry fasciculation commisures ```

Question 26

what is cephalization

Answer 26

it's the development of a head

Question 27

what is fasiculation

Answer 27

axonal bundles

Question 28

what are commissures

Answer 28

clustering of processes running from one side to another

Question 29

in annelids what fuses?

Answer 29

the longitudinal nerve cords

Question 30

how many neurons and glia does the c. elegans have?

Answer 30

302 neurons and 56 glia

Question 31

what nerve cords does the c.elegans have?

Answer 31

ventral, dorsal and lateral

Question 32

what lineage does the c. elegans NS have? what are most neurons derived from?

Answer 32

ectodermal, most neurons derived from AB cells

Question 33

where are the precursor neuronal cells found first, then what happens?

Answer 33

found on the surface of the embryo and then migrate in

Question 34

what's different about the drosphilla embryo development

Answer 34

it forms a syncytial blastoderm due to nuclear division occuring interiorily without any cytokinesis

Question 35

in drosophilla embryo development what happens once the nucleii are generated? what does this form

Answer 35

nuclear migration and cellularization occurs, forms a cellular blastoderm

Question 36

what is cellularization?

Answer 36

the cell wall forms

Question 37

what two processes occur after the cellular blastoderm is formed?

Answer 37

gastrulation and then neurogenesis

Question 38

what does delamination lead to?

Answer 38

the formation of neuroblasts

Question 39

what is delamination?

Answer 39

when cells pull away from the surface and migrate

Question 40

what do neuroblasts form?

Answer 40

ganglion mother cells

Question 41

what do ganglion mother cells form?

Answer 41

neurons and glia

Question 42

what does the vertebrate nervous system form from?

Answer 42

ectoderm

Question 43

what is different about the nervous system in vertebrates to that of insects?

Answer 43

it is dorsal unlike in insects where it's ventral

Question 44

what's the common feature of the NS across organisms?

Answer 44

we all have a phase where surface cells involute under other surface cells

Question 45

what does a variety in neurons give?

Answer 45

flexibility and co-ordination

Question 46

what happens when organisms become polarised?

Answer 46

neurons and axons become aggregated