lecture 1- human genetics

Question 1

what is the cleft lip and palate?

Answer 1

incomplete development of lip and palate.

Question 2

what is the lesch-nyhans syndrome?

Answer 2

a sex-linked genetic disorder with dementia and self-mutilation (chewed away fingers and lips)

Question 3

who is tay-sach’s disease most prominent in?

when does death occur?

characteristics of the eye?

Answer 3

jewish children

death usually within a year

cherry red spot at the macula

Question 4

what is the Beh’r syndrome?

Answer 4

degeneration of the optic disc

Question 5

what is the dominant optic atrophy?

Answer 5

degeneration of the optic disc leads to complete blindness.

Question 6

what is the Stargardt’s disease?

Answer 6

degeneration of retina affecting central region of retina affects central vision, can still see from sides of eye

Question 7

what is retinitis pigmentosa?

Answer 7

degeneration of retina affecting peripheral parts, as degeneration spreads towards macula and leads to tunnel vision

Question 8

what is Leber’s optic atrophy

Answer 8

degeneration of optic disc, has sudden onset and interesting genetics

Question 9

what is progressive ophthalmoplegia

Answer 9

eye movement Defect/ impaired

due to paralysis of muscles of eye due to defect in brain region that controls the eye muscles.

Question 10

brown’s syndrome

Answer 10

muscular paralysis

Question 11

congenital nystagmus

Answer 11

abnormal rhythmical movement of eye, eye flicks constantly back/forth/up and down , side to sided and rotatory

Question 12

Duane’s syndrome

Answer 12

horizontal limitation of eye movement, patient has difficulty moving eye from side to side, nerves to the eye muscles may be the problem.

Question 13

define genetics

Answer 13

the study of characteristics of individuals whether form, shape, function or disease that are inherited

Question 14

describe the Mendel’s experiment

Answer 14

pollen of one plant on ovary of other, fertilisation occurred to observe the characteristics produced as seed grew

round and wrinkled peas are crossed together and F1 (first batch) made round peas only.

he crossed both round peas and wrinkled and round peas produce as the F2 generation (2nd batch) although round peas were 75% and wrinkled peas are 25%.

hence some characteristics are more dominant than others

Question 15

describe the chromosome number?

Answer 15

it will always be even- half from mum and half from dad.

Question 16

define gene, genotype, allele?

Answer 16

gene= inherited factor
genotype= genetic constitution
allele= alternatives of gene