108

Question 1

108

what is accretion

Answer 1

increase in size by gradual addition of smaller parts

Question 2

108

what is apoptosis

Answer 2

programmed cell death

Question 3

108

what is differentiation

Answer 3

the process by which cells aquire a cell type

Question 4

108

what is ectoderm

Answer 4

the outermost of the three germ layers giving rise to skin and other tissue

Question 5

108

what is an embryo

Answer 5

the organism between the first division of the zygote until it becomes a foetus at 8 weeks

Question 6

108

what is gastrulation

Answer 6

the stage of development when the embryo is restructured by cell migration ( giving rise to the 3 germ layers)

Question 7

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what is induction

Answer 7

the action of inducing cells to change, usually in response to signalling molecules

Question 8

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what is mesoderm

Answer 8

the middle of the three germ layers that gives rise to connective tissue, muscles and the circulatory system.

Question 9

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what is a morphogen

Answer 9

a substance that governs morphogenesis by eminating from a localized source to form a concentration gradient during embryonic development.

Question 10

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what is the neural crest

Answer 10

cells from the ectoderm migrate and generate many differentiated cell types

Question 11

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what is the neural plate

Answer 11

a thick flat bundle of ectoderm which develops in the empbyo into the neural tubeand subsequently the nervous system.

Question 12

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whats an alantois

Answer 12

extension of the primitive gut or yolk sacinto the umbilical cord

Question 13

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what are amnioblasts

Answer 13

calls of the amniotic membrane from the epiblast

Question 14

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what is an amnion

Answer 14

a thin tought membraneous sac that encloses the embryo or fetus. Filled with serous fluidin which the embryo is suspended

Question 15

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what is a blastocyst

Answer 15

the early embryoas a sphere of cells with a fluid filled central cavity

Question 16

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what are blastomeres

Answer 16

any cell resulting from cleavage of a fertilised egg early in embryo development

Question 17

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what is chorionic

Answer 17

the outermembrane enclosing the embryo

Question 18

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what is a coelom

Answer 18

fluid filed body cavity lined by cells derived from mesoderm

Question 19

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what is a cytotrophoblast

Answer 19

the innder layer of the trophoblast

Question 20

108

what is the ectoderm

Answer 20

the outermost germ layer from which the epidermis, nervous tissue and sense organs develop

Question 21

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what is an embryoblast

Answer 21

any of the germinal disk cells of the inner mass in the blastocystthat form the embryo

Question 22

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what is the notocord

Answer 22

a rod of cells constituting the foundation of the axial skeleton

Question 23

108

what is an oocyte

Answer 23

a cell from which an eggor ovum develops by meiosis.

Question 24

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what is the syncytiotrophoblast

Answer 24

the syncytical outer layer of trophoblast

Question 25

108

what is the trophoblast

Answer 25

the outermost layer of cells on the blastocyst that attaches the fertilised ovum to the uterine walland serves a nutritive pathway for he embryo.

Question 26

108

autosomal recessive condition

Answer 26

cystic fibrosis, sickle cell, tay sachs, spinal muscular atrophy

Question 27

108

x linked recessive diseases

Answer 27

duchenne muscular dystrophy, haemophilia A, red-green colour blindness

Question 28

108

autosomal dominant diseases

Answer 28

huntingtons, marfan, familial hypercholesterolaemia, spinocerebellar ataxia, long QT syndrome

Question 29

108

% risk of offspring getting an autosomal dominant disease

Answer 29

50%

Question 30

108

% risk of offspring getting an autosomal recessive disease

Answer 30

25%

Question 31

108

carriers and affected in x linked recessive disorders

Answer 31

50% of sons affected, 50% daughters are carriers