ABO Blood Type Inheritance

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the cause of colour blindness?

mitochondrial inheritance

x-linked recessive (correct)

autosomal recessive

autosomal dominant

Which gender is more commonly affected by colour blindness?

Males (correct)

Both equally

Neither

Females

Individuals with colour blindness are unable to distinguish which shades?

Yellow-red

Red-green (correct)

Blue-green

Blue-yellow

Colour blindness is a genetic condition linked to which chromosome?

X chromosome Signup and view all the answers

Which genetic pattern of inheritance does colour blindness follow?

X-linked recessive Signup and view all the answers

Which alleles are codominant with each other?

IA and IB Signup and view all the answers

Which blood type is possible for an individual with IAi genotype?

Type A Signup and view all the answers

Which blood type results from the genotype ii?

Type O Signup and view all the answers

What is the relationship of the O allele in blood type inheritance?

Recessive Signup and view all the answers

Which genes are most commonly associated with sex-linked traits?

X and Y chromosomes Signup and view all the answers

What genotype corresponds to females?

XX Signup and view all the answers

Which condition is caused by a recessive gene on the X chromosome?

Hemophilia Signup and view all the answers

What is a common consequence of hemophilia?

Bleeding with small cuts Signup and view all the answers

What is the result of incomplete dominance in the F1 generation?

A blend of traits appears Signup and view all the answers

In codominance, what is the phenotypic expression of heterozygous alleles?

Both alleles are equally expressed Signup and view all the answers

Which of the following examples represents incomplete dominance?

Red and white flowered snapdragons producing pink flowers Signup and view all the answers

How are alleles typically represented in incomplete dominance?

Two capital letters with one having a prime symbol Signup and view all the answers

What does the 'R' and 'R'' notation represent in incomplete dominance?

Two alleles that blend phenotypically Signup and view all the answers

How many different alleles can exist for a gene showing multiple alleles?

Three or more Signup and view all the answers

Which blood type system is an example of multiple alleles in humans?

ABO blood type system Signup and view all the answers

Which of the following is represented by two capital letters indicating codominant alleles?

BW for both brown and white traits Signup and view all the answers

Study Notes

ABO Blood Type

ABO blood type follows both codominant and dominant inheritance patterns
The A and B alleles are codominant with each other, while both are dominant over the O allele
The O allele is recessive

ABO Blood Type Genes and Alleles

The blood type gene is represented by the letter I
The I gene has three alleles: IA, IB, and i
The alleles are expressed in heterozygous individuals, resulting in different blood types
The possible blood types are:
- A: IAIA or IAi
- B: IBIB or IBi
- AB: IAIB
- O: ii

Mendel's Luck

Mendel's experiments were successful because he studied traits in garden peas that behaved simply
These traits were not linked or lethal, had only two alleles, and displayed complete dominance
Other scientists, including Darwin, were conducting similar experiments, but they were using species with more complex patterns of heredity

Sex-linked Traits

Traits are located on the sex chromosomes, X and Y
Females have an XX genotype, while males have an XY genotype
Many sex-linked traits are carried on the X chromosome

Hemophilia

Hemophilia is a recessive gene on the X chromosome that causes a bleeding disorder
There are approximately 20,000 hemophilia patients in the United States
The severity of hemophilia is related to the amount of clotting factor in the blood
About 70% of hemophilia patients have severe hemophilia, with less than 1% of the normal amount of clotting factor

Color Blindness

Color blindness is a recessive sex-linked condition caused by a lack of color receptors in the eye
It results in an inability to see some colors correctly
Color blindness is more common in males
Individuals with color blindness are unable to distinguish between certain shades of red and green

Exceptions to Mendel's Laws

Incomplete dominance: alleles appear blended in the phenotype
Codominance: both alleles are expressed equally
Multiple alleles: some genes have more than two alleles

Incomplete Dominance

Incomplete dominance occurs when neither allele is fully dominant over the other
The two alleles are represented as two capital letters, one with an apostrophe to indicate the different allele
Example: snapdragons (flower)
F1 hybrids have an appearance that is a mixture of the two parental varieties

Codominance

Codominance occurs when both alleles of a gene are dominant and the heterozygous phenotype has both traits equally expressed
The two alleles are represented as two capital letters: the first letter of one trait and the first letter of the other trait
Example: ABO blood type

Multiple Alleles

Blood type is an example of multiple alleles, with three alleles: A, B, and O
Each person has two of these alleles in their DNA

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Learn about the inheritance patterns of ABO blood types, including codominant and dominant relationships between alleles and the resulting blood types.