Animal Physiology - Lecture 6

Question 1

DNA doesn’t control … cell division, instead all enzymes, proteins and instructions are provided by the ..

Answer 1

early, cytoplasm

Question 2

the change from maternal to embryo control is called … activation

where the DNA of the young embryo starts … and takes control of .. ..

Answer 2

genomic
transcription, cell division
-at genomic activation cell division slows down

Question 3

pigs/rats switch to genomic activation at ..-.. cell embryo
humans/cattle .. cell
and frogs …-… cell stages

Answer 3

4-8
8
3000-4000
-so frog cytoplasm in control for longer than humans, pigs etc.

Question 4

if a cell is fated to become a nerve cell, all genes in a cell switch off bar the ones for .., .. .. and .. impulse generatic cells

Answer 4

axons, axon terminals, electrical

Question 5

take out the nucelus of a somatic cell in an egg and trasnfer an epidermal cell in from an adult frog and a normal embryo will .. develop

Answer 5

still
-shows differentiated cells still have the information to produce normal cells, just inactive

-this shows cytoplasm around nucleus controls a cells fate - different cytoplasm different fate?

Question 6

genomic equivilence refers to .. information being lost in earely stages of embryonic development

Answer 6

no

Question 7

Spemann bisected an egg which produced normal complete embryos, he concluded .. factors from the grey crescent are needed for development

Answer 7

cytoplasmic

Question 8

cytoplasmic segregation refers to unequal .. distribution in a zygote/embryo

Answer 8

chemical

-for example, most nutrients at vegetal pole, so after rounds of clevage divided cells have different amounts

Question 9

induction refers to factors being secreted by some celsl, inducing others to ..

Answer 9

differentiate

Question 10

the dorsal lip of the blastopore is called the … organiser

cells move other this to form .. .. (in birds, cells moving over … node form the CNS)

Answer 10

Spemann
neural tissue
Hensen’s

Question 11

The first state in eye formation starts when the .. buldges to form .. vesicles

these vesicles induce surface tissue to form lens .. tissue, from which a .. organ can develop

Answer 11

forebrain, optic
placode, sensory
-lens placode differentiates into lens, which influences optic cup size
-also induces surface tissue of eye to form cornea

Question 12

morphogens in varied concentrations allow cells to .. where they are

Answer 12

know

-effectively interpreting positional information

Question 13

vertebrate limbs develop from round bud of tissue, cells within the bud become .., .. of hand and via morphogenic information can organise themselves

Answer 13

bones, muscles

Question 14

BMP2 is a morphogen made at the base of the bud, a high dose of BMP2 forms the .. while a smaller dose the .. ..

Answer 14

thumb

little finger

Question 15

some genes are only active if from a particular gamete this is known as ..

Answer 15

genomic imprinting

• male/male zygotes no egg
• female/female zygotes no placenta

Question 16

if paternal chromosome 15 is deleted ..-… syndrome is caused

if maternal chromosome 15 is deleted … syndrome is caused

Answer 16

Prader-Willi
Angelman
-both deletions on same section of chromosome

Question 17

segmentation genes influence body …

gap genes organise large areas along ..-.. axis

pair rule genes .. the embryo into units of two segment

segment .. genes determine segment ..

homeotic genes are expressed along the length of the body, the determine .. segments will become

Answer 17

segments
anterior-posterior
divide
polarity, boudaries
what

Question 18

mice have .. families of Hox gene

Answer 18

4

Question 19

Hoxb1 is expressed on the .. part of hte hindbrain, the rest are expressed further back
B9 is expressed at the ..

Answer 19

anterior
tail
-referring to mice

Question 20

mutations in homeotic genes can change a segments ..

Answer 20

identity

Question 21

Aptosis is programmed cell ..

C.elegans has .. somatic cells, with .. programmed to die

Answer 21

death
1090, 131
-useful in humans for removing webbed hands etc.

Question 22

environmental factors may be needed for normal developement, house mice need … to colonise their gut, as they induce gene expression in the .. for normal .. development

Answer 22

bacteria

intestine, capillary

Question 23

anencephaly is caused by the failure of the .. tube to close at the .. ends

.. acid is vital for neural development

Answer 23

neural, anterior

folic

Question 24

Cretinism and goitre are caused by .. deficiencies

Answer 24

iodine

Question 25

Cyclopamine inhabits the .. .. protein, which is involved in formation of the .. ..

Answer 25

Sonic Hedgehog

neural system