Question

Genetics.

Answer 1

yes..

Answer 2

A woman with A blood group marries a man with B blood group.
Both have their mother with homozygous recessive blood groups.
What will be the expected blood groups and the genotypes of their children?
Show by making genetic cross.

Answer 3

ok...so do u know which is d homo recessive blood grup?

Answer 4

No, I think :I

Answer 5

ok...so here the recessive allele is O. So O blood grup is recessive.

Answer 6

Hmm...
Can I ask why is it recessive? O blood group

Answer 7

now both mother and father have 1 parent having blood grup O. so the genotype of that 1 parent is \[I^{O}I^{O}\]

Answer 8

u cannot decide that i want dis allele as recessive so it is recessive...when a particular allele is present against this O allele then O is not expressed. this has been observed so it can be termed as recessive

Answer 9

u getting it?

Answer 10

I don't know what that i represent :c

Answer 11

We use that as blood groups genotypes?

Answer 12

yes...like for sex linked genes u write \[X^{n}\]

Answer 13

its \[I^{A/B/O}\] HERE

Answer 14

So for blood groups we use i instead of x ?

Got it!

Okay, only O blood group is recessive? :I

Answer 15

yes...this is an eg of multiple alleles. earlier u studied dat der are 2 alleles 1 recessive and 1 dominant...but sometimes u hv more than 2 alleles. here a is dominant over o b is dominant over o but a is incompletely dominant over b. so v get ab blood group.

Answer 16

so now as i told u earlier each 1 of the parent has IOIO blood grup

Answer 17

Now I have to cross them?

Answer 18

not so early...now mother and father's parent has that genotype. so out of these one would be giveen to the child. so one of the allele of mother and father is \[I^{O}\]

Answer 19

Now mother's blood group is given as A so u the other allele must be \[I^{A}\]
And fathers is given as B so the other allele has to be\[I^{B}\]

Answer 20

So the genotype of mother is iaio and thaat of father is ibio.
remeber i told u...A is dominant over O and B is dominant over O

Answer 21

Oh no, I'm confused.

Answer 22

confused where?

Answer 23

wait ill try 2 draw a diag for u

Answer 24

Why A is dominant over O?
And B is dominant over O?

Answer 25

Because that is what has been observed.

Answer 26

Okay. It always remain the same?
I mean, A dominant over O and B dominant over O?
Or only in this problem..?

Answer 27

always...in case of blood groups.

Answer 28

Alright!

Answer 29

so u got how v get d genotype of mother and father?

Answer 30

mother-\[I ^{A}I ^{O}\]

Answer 31

IOIA mother's ?
IOIB father's ?

Answer 32

YES CORRECT

Answer 33

But while writing generally the dominant allele is written first. now u cross these genotypes.

Answer 34

so wat do u think would be the possible genotypes of children after a normal cross?

Answer 35

IAIB
IAIO
IBIB
IBIO

Answer 36

I did it right? :I

Answer 37

genotype-IAIO X IBIO
gametes-IA IO IB IO
children- IAIB IAIO IBIO IOIO

Answer 38

yes..but in place of IBIB it should be IOIO

Answer 39

so now IAIB would be AB
IAIO-A
IBIO-B
IOIO-O

Answer 40

GOT IT?

Answer 41

I crossed it wrong with B instead of O

Answer 42

YES...rest everything was perfect:)

Answer 43

u got it dude:)

Answer 44

So, IAIB means AB bloodgroup?

IBIO means B bloodgroup?

IOIO means O bloodgroup?

Answer 45

yes..because b is dominant over o so u get b
a dominant over o so u get a
and a and b are incompletely dominant so u get both ab.

Answer 46

I got it now.

Now I have to find children genotype?

Answer 47

see basically des blood grups depend on the antigen u have...B blood grup has antigen B A has antigen A O has no antigen and AB has both antigen A and B.

Answer 48

U just did...by crossing the parents..rite?

Answer 49

i g2g now ryaan...hope ur doubts are cleared?

Answer 50

Oh right..lol

Question is asking to find possible bloodgroups and genotypes of children, so I got confuse.
I thought now I have to find genotypes.


Thank you for explaining me! :-)

Answer 51

nope...u got it all rite dude...bye for now...tag me if u hv ne genetics problems:)

Answer 52

happy 2 help:)

Answer 53

Sure I'll ask you, I still have some confusion with these genetics problems!

Thanks again:)

Answer 54

someday when v hv time...v will start from d basics of genetics:)

Answer 55

I have some confusion can I ask?

Answer 56

yes...go ahead

Answer 57

If parents blood groups are given to me as A both Mom and dad's. But not their mother's blood groups are given..
How do I find their genotypes and how do I cross them too see what will be their children bloodgroup and genotypes?

Answer 58

what would be the possible genotypes of mom and dad? wat do u think?

Answer 59

in earlier prob it was given 1 parent has O so 1 allele has 2 be IO. but in this thats not true. rite?

Answer 60

For blood group A, you told me A has antigen A only. So that would be AA?

Answer 61

yes...and?

Answer 62

So, for father..It'll be AA too?

Now how do I cross them? when I don't know what their other alleles are.
In that previous problem Mother and father's mother were given O..
But now I have another problem but parents mothers bloodgroup are not given...

So how do I make a cross?

Answer 63

ok wait...lets forget about this problem for now...

Answer 64

lets suppose i have a dominant allele A and a recessive allele O.
A gives me red colour and O gives me white colour ok?
what possible genotype combinations can u get from these 2 alleles?

Answer 65

it can be homo or hetero...give me all the possible combinations.

Answer 66

*Confused* :I

Answer 67

ok lets start from the start then...u know that every gene has 2 alleles?

Answer 68

*in normal cases

Answer 69

besides blood types?

Answer 70

i m talking about general genes...it can be anything...leave d blood groups aside for a while because bood groups are an exception. we will talk about the general statements first.

Answer 71

Okay!

Answer 72

Every gene has 2 alleles.

Answer 73

good..so out of these 1 is dominant and 1 is recessive.

Answer 74

2 alleles can't be dominant?

Answer 75

Means both?

Answer 76

so when we consider a genotype u can get 2 dominants together 2 recessive together or 1 dominant 1 recessive together.

Answer 77

its like a jigsaw puzzle...u hv only 2 places that are need 2 b filled and i give u a whole set of dominant and recessive alleles. at a time u can use only 2.

Answer 78

so lets consider A is dominant and a is recessive. it is generally abbreviated in this manner...dominant capital recessive small

Answer 79

now can u tell me d possible combinations?

Answer 80

Aa you mean?

Answer 81

yes...and what else? u can also have 2 dominant together and 2 recessive togder rite?

Answer 82

Right right!

Answer 83

so now tell me all d combinations.

Answer 84

AA, aa, Aa

Answer 85

exactly....:)
now AA and aa are called homozygous because they have same allele in a pair
while Aa is called heterozygous...ook?

Answer 86

Okaaaaay! :3

Answer 87

good...can i go ahead?

Answer 88

let us consider that A gives me red flowers and a gives me white flowers.
so when u have AA obviously u r going 2 get red flowers and in aa u get white flowers...ok?

Answer 89

Right.

Answer 90

I have a question.

Answer 91

ok...wat?

Answer 92

Alleles are when we make a pair? means AA they both are called alleles?

Answer 93

alleles when in a pair make a genotype....in a diploid person 2 alleles required.

Answer 94

u got it?

Answer 95

Here you said (AA and aa are called homozygous because they have same allele in a pair) How they have same allele in a pair? Here we call them as alleles?

Answer 96

aa has both alleles as a? while in AA both are A?

Answer 97

A- is an allele....AA-is a genotype.

Answer 98

Means together they are called genotype and if we separate them it will be called an allele?