5.2 Inheritance

(1)

5.2 INHERITANCE

Inheritance of Traits in Humans

(2)

•

• _{The ABO blood group system is based on}

_{The ABO blood group system is based on}

presence

or

absence

of

antigens A & B

•

• _{The antigens is}

_{The antigens is}

_{controlled by alleles A}

_{, B}

_&

O



_{Allele A:}

_{produce antigen A}



_{Allele B:}

_{Allele B: produce antigen B}

_{produce antigen B}



_{Allele O:}

_{Allele O: does not produce any antigens}

_{does not produce any antigens}

Determination of blood group

(3)

(4)

(5)

Eample !

(6)

Eample "

(7)

EXERCISE

(8)

•

• _A

_A

_{man #ith blo}

_{od grou}

_{p O marrie}

_s

a #oman #ith blood group B$

•

• _{Eplain #ith a genetic diagram, ho#}

_{Eplain #ith a genetic diagram, ho#}

is it possible for the couple to ha%e a

child #ith blood group O

•

• _{'hat is the percentage of their first}

_{'hat is the percentage of their first}

child ha%ing blood B

(9)

(HE

(10)

(hesus +actor -(h +actor.

•

• _{(eferring to the}

_{(eferring to the}

_antigen

_{found on the}

surface membrane of some

red bld cells

•

• _{R!es"s psiti#e $R!}

_{R!es"s psiti#e $R!}

%%

_

•

• _{/eople #ho ha%e (hesus factor}

_{/eople #ho ha%e (hesus factor}

•

• _{R!es"s negati#e $R! '}

_{R!es"s negati#e $R! '}

•

• _{/eople #ho do not ha%e}

_{/eople #ho do not ha%e}

•

(11)

+ather +ather (hesus positi%e (hesus positi%e (h (h 00_(h_(h 11 2other 2other (hesus negati%e (hesus negati%e (h (h 3 3_(h_(h 11 4 4 ( (hh 00 ((hh 11 (h 1(h 1 _{(h 1}_{(h 1} 2ale gamete 2ale gamete +emale gamete +emale gamete ( (hh 00 ((hh 11 ( (h h 11 ((h h 0 0 ((h h 11 ((hh1 1 ((hh11 ( (h h 11 ((hh0 0 ((hh11 ((hh1 1 ((hh11 (h0 (h0 (h1 (h1 5 5 (h1 (h1 (h1(h1 (h (hesesus us poposisititi%e %e 5 5 (h(hesesus us nenegagatiti%e%e ! ! 5 !5 !

(12)

(13)

(14)

(hesus factor & /regnancies

)t!er*s R! )t!er*s R! +actr +actr ,at!er*s R! ,at!er*s R! +actr +actr Ba Bab-b-**s Rs R! +! +aactctrr rreecaca"t"tiinsns ( (hh 00 ((hh 00 ((hh 00 66oonnee ( (hh 11 ((hh 11 ((hh 11 66oonnee ( (h h 00 ((h h 11 oouulld d bbe e ((h h 0 0 oorr (h 1 (h 1 6one 6one ( (h h 11 ((h h 00 oouulld d bbe e ((hh positi%e or (h positi%e or (h negati%e negati%e (h immune (h immune globulin in7ections globulin in7ections

(15)

(16)

*6DE()TA6DI68

I6HE(ITA6E

Determination of the se of a child

(17)

hromosomes

•

• _T#

_T#

_{o types}

_of

chromosomes5

•

• _Autosomes

_Autosomes

•

(18)

S SEEXX AA//TTOOSSOO))EESS SSEEXX CHRO)OSO)ES CHRO)OSO)ES SO)ATIC CE00 SO)ATIC CE00 2 2aalle e 999 9 : : """ " ppaaiirrss 44;; 999 9 0 0 44;; ,e(ale ,e(ale 999 9 : : """ " ppaaiirrss 4444 11 % XX11 % XX

(19)

DETE(2I6ATIO6 O+

THE

(20)

(21)

)E41<I6=ED

DI)O(DE()

(22)

)e <

in>ed A

lleles

•

• _{located on the}

_{located on the}

_X

c!r(s(es

•

• _{not in%ol%ed in}

_{not in%ol%ed in}

se

determination

(23)

)e <

in>ed A

lleles

•

• _{2ale only need to}

_{2ale only need to}

inherit only

ne cp-

ne

cp-+ t!e allele

+ t!e allele

to ehibit

the trait

•

• _{+emale must inherit}

_{+emale must inherit}

t cp- + t!e

allele

to ehibit the

trait

•

• _{Disorders 5}

_{Disorders 5}

•

• _{olor blindness}

_{olor blindness}

•

(24)

O<O( B<I6D6E))

(25)

(26)

(27)

(28)

(29)

olour Blindness

•

• _{The inability to differentiate bet#een}

_{The inability to differentiate bet#een}

_red

_&

green

color

•

• _{aused by a}

_{aused by a}

_{gene ("tatin}

_{that is located}

on the

X c!r(s(e

•

• _{)re (ale t!an +e(ales are clr blind}

_{)re (ale t!an +e(ales are clr blind}

because5

•

• _{Allele for colour blindn}

_{Allele for colour blindn}

_{ess -b. is recessi%e to the}

normal alelle B & is lin>ed to chromosome 4

(30)

/arents 5 /arents 5 8ametes5 8ametes5 +! 8eneration5 +! 8eneration5 4 4BB ₄₄BB Homo?ygous normal Homo?ygous normal female female 4 4bb_;_;

olour blind male

4

4BB 44bb ;;

4

4BB₄₄bb ₄₄BB_;_;

+emale carries the

color blindness color blindness gene gene 6ormal 2ale 6ormal 2ale

(31)

/arents 5 /arents 5 8ametes5 8ametes5 +! 8eneration5 +! 8eneration5 4 4bb ₄₄bb

olour blind female

olour blind female 44

B B_;_; 6ormalmale 6ormalmale 4 4bb 44BB ;; 4 4BB₄₄bb ₄₄bb_;_; +emale carries +emale carries the color the color blindness gene blindness gene +emale carrier +emale carrier 4 4bb 4 4bb_;_; olour1blind olour1blind male male 4 4BB₄₄bb olour1blind olour1blind male male

(32)

HAE2O/HI<IA

(33)

Haemophilia

•

• _{Blood disease caused by a lac> of}

_{Blood disease caused by a lac> of}

cltting +actrs

•

• _{aused by a}

_{aused by a}

_{recessi#e gene $!}

found on the

X c!r(s(e

of the

human

(34)

(35)

8enotype & phenotype of haemophilia

S See33 44eenntt--ppee !!eenntt--ppee + +eemmaallee 44HH₄₄HH _6ormal_6ormal + +eemmaallee 44HH₄₄hh _arrier_arrier + +eemmaallee 44hh₄₄hh _Haemophilia_Haemophilia 2 2aallee 44HH_;_; ₆₆_o_o_r_r_m_m_a_a_l_l 2 2aallee 44hh_;_; _H_H_a_a_e_e_m_m_o_o_p_p_h_h_i_i_l_l_i_i_a_a

(36)

(E@I)IO6

(37)

(38)

A ge

A gene carried at t!e ne carried at t!e X c!r(s(eX c!r(s(e

•

• *s (t!er is a carrier carr-ing ne recessi#e allele +r cl"r*s (t!er is a carrier carr-ing ne recessi#e allele +r cl"r

blindness and ne d(inant allele +r

blindness and ne d(inant allele +r nr(al #isin  *s (t!er : Xnr(al #isin  *s (t!er : XBB_X_Xbb

•

• *s +at!er is nr(al carr-*s +at!er is nr(al carr-ing ne d(inant allele ing ne d(inant allele +r nr(al #isin in+r nr(al #isin in

!is X c!r(s(e and nne in

!is X c!r(s(e and nne in !is 6 c!r(s(e  *s +at!e!is 6 c!r(s(e  *s +at!er : Xr : XBB₆₆

•

•  recei#e recei#ed t!e X d t!e X c!r(s(e carr-ing recessi#c!r(s(e carr-ing recessi#e allele +r( e allele +r( t!e (t!ert!e (t!er

and a 6 c!r(s(e +r( t!e +at!er $ca"sing !i( t be c"r blind

•

(39)

(40)

)t!er )t!er $X $XBB_X_XBB__ ,at!er ,at!er $X $Xbb_6_6 X X X XBB _X_XBB _X_Xbb ₆₆ $X $XBB_X_Xbb__ _$X_$X_B_B_X_X_b_b__ _$X_$X_B_B_6_6 $X $XBB_6_6 Carrier ,e(ale

Carrier ,e(ale _{Nr(al )ale}_{Nr(al )ale}

S

(41)

257

(42)

a"ts(e