I bob. Molekulyar biologiyaga oid masalalari va ularning yechimlari

2017_DTM


Yechimi
1) 80 • 8 =640 2) 640 • 0,75=480 ta qatnashmagan spermiylar soni
3) 640-480=160 ta qatnashgani 4) 480-160=320
5) 7680:320=24 Spermiyda xromasoma n. 6) 24 • 2 = 48 2n=48 Javob: C) 2n=48


11.Bugʼdoy donining rangi polimer tipda irsiylanadi. Pushti rang tetraploid navli bugʼdoy oʼzaro chatishtirilishidan olingan donning endosperimidagi polimerlar sonini toping. A) 12B) 24C) 32D) 8
DTM_2017
Yechimi
Pushti = A¹a¹A²a² bundan gameta olinsa...
holati n = A¹A² , A¹a² , a¹A² , a¹a²

1) Diploid navidagi (2n) polimer genlar soni... n = holatida 2 ta polimer gen tutsa...

Mikrosporasida(n) = 2 ta Somatik hujayrasida(2n) = 4 ta Endospermasida(3n) = 6 ta

2) Tetraploid navidagi (4n) polimer genlar soni...

Mikrosporasida(n) = 4 ta Somatik hujayrasida(2n) = 8 ta Endospermasida(3n) = 12 ta

Javob: A) 12 ta


12.Shimpanzening embrionidagi blastomerlar soni ularning tarkibidagi xromosomalar sonidan 6016 taga kam bo'lsa, zigota necha marta meridian va va ekvatorial bo'linganini aniqlang?
A) 3 ; 2 B) 4 ; 3 C) 4 ; 2 D) 5 ; 2
Yechimi
Shimpanzeda xromasoma 2n=48

1) 48-1=47 farq

2) 47 ----------- 1 ta blastomer

6016 ----- x =128 ta blastomer

Meridian = M

Ekvatorial = E

M - M - E - M - E - M - E

2 - 4 - 8 - 16 - 32 - 64 - 128


Javob: B) 4 : 3

13. Qora kalamushning zigotasi 4 marta meridianal bo'lingandan so'ng uning blastulasidagi blastomerlarida jami xromosomalar soni 2688 taga yetgan bo'lsa uning tuxum hujayrasidagi xromosomalar sonini aniqlang.
A) 19 B) 20 C) 18 D) 21
Yechimi

Meridian = M
Ekvatorial = E

M - M - E - M - E - M

2 - 4 - 8 - 16 - 32 - 64

1) 2688/64=42

2) 42/2=21