Lecture 7: Y chromosome Flashcards Preview

2nd year sem 1: Forensic Genetics > Lecture 7: Y chromosome > Flashcards

Flashcards in Lecture 7: Y chromosome Deck (77)
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1

Lineage markers are ___ as discriminative as autosomal markers

not

2

Are lineage markers useful as forensic markers?

possess some features which make them useful

3

whats the difference between autosomal DNA markers and Lineage markers?

Autosomal DNA markers are shuffled with each
generation
Lineage markers passed down generations

4

when do lineage markers change?

if theres a mutational event

5

whats the lineage marker for the Y chromosome called?

patrilineage

6

lineage markers are passed down from?

generation to generation

7

can you use the product rule when calculating random match probability ?

no

8

when do mutations arise?

during the DNA copying process

9

are mutations random?

yes

10

mutation rates for a Y-STR are between ?

10^-3 and 10^-4 per locus per generation.

11

How many Y chromosomes do males have?

1

12

How much of the human genome is contained in the Y chromosome ?

2%

13

how long is the Y chromosome?

50-60 Mb

14

what male specific functions odes the Y chromosome code for?

sex determination and spermatogenesis

15

what are the 2 main regions for the Y chromosome ?

1. pseudo- autosomal regions (PAR 1 and PAR 2)
2. Male specific Y region (NRY)

16

whats the euchromatic region?

chromatin that exists in an extended state containing genes that may or may not be expressed

17

what's more constant in size the euchromatic region or heterochromatic region?

euchromatic regin - 23 Mb

18

in meiosis when does the genetic crossing over occur and what doe sit lead too?

prophase 1, leads to new gene combinations.

19

The Y chromosome does not have _____ chromosome.

homologous

20

Does a large region of the Y chromosome recombine with the X chromosome ?

only a very small region

21

what's located on the tip of the short arm?

pseudo-autosomal region one (PAR 1)

22

where is PAR 2 located?

distal end of the long arm.

23

whats avoided when looking for suitable forensic markers, for Y chromosome ?

regions of the Y-chromosome that share homology with the X chromosome

24

on the Y chromosome what is diversity due to?

due to mutation alone due to the lack of recombination

25

diversity on the Y chrosome terms?

haplotype (STRs) or haplogroups (SNP or Alu element insertion)

26

whats a haplotype/group?

collection of alleles that are linked (inherited together)

27

Name 3 Y polymorphisms?

• Y-VNTRs • Y-STRs • Y-SNPs

28

what do VNTRs consist of?

MSY1 consists of a repeat unit of 25 bp. Polymorphism of 48-118 repeats.

29

Autosomal VNTRs contain a lot of what?

GC

30

MSY1 is __ AT

75%