TRANS LECTURE 3

Question 1

What are alleles?

Answer 1

Alleles are different forms of genes found at each locus on the chromosomes.

Question 2

What is the definition of a gene?

Answer 2

A gene is a basic unit of inheritance on a chromosome.

Question 3

Define locus.

Answer 3

A locus is the site at which a gene is located on a chromosome.

Question 4

What does it mean if allelic genes are identical?

Answer 4

When allelic genes are identical, they are said to be homozygous for that characteristic or factor.

Question 5

Give an example of homozygous genes.

Answer 5

KK, CC, and EE are examples of homozygous genes.

Question 6

Define heterozygous genes.

Answer 6

Heterozygous genes are allelic genes that differ from each other.

Question 7

Provide an example of heterozygous genes.

Answer 7

Kk, Cc, and Ee are examples of heterozygous genes.

Question 8

What is the definition of a genome?

Answer 8

A genome refers to the full complement of genes.

Question 9

What does polymorphic mean in the context of genes?

Answer 9

Polymorphic refers to having two or more alleles at a given locus.

Question 10

Which blood group system is more polymorphic?

Answer 10

The Rh system has more possibility to be polymorphic.

Question 11

What are antithetical partners in the context of alleles?

Answer 11

Antithetical partners are opposite antigens encoded at the same locus.

Question 12

Give an example of antithetical partners.

Answer 12

Fya and Fyb antigens, as well as K and k antigens, are examples of antithetical partners.

Question 13

What is the definition of homozygous?

Answer 13

Homozygous refers to having identical alleles at a given locus on a pair of chromosomes.

Question 14

Define heterozygous.

Answer 14

Heterozygous refers to having different alleles at a given locus on a pair of chromosomes.

Question 15

How are most blood group antigens inherited?

Answer 15

Most blood group antigens are inherited co-dominantly, resulting in equal expression of both inherited alleles.

Question 16

Are recessive or dominant inheritance patterns common in blood group system genetics?

Answer 16

No, recessive or dominant inheritance patterns are not common in blood group system genetics.

Question 17

What is the concept of independent segregation?

Answer 17

Independent segregation refers to the passing of one gene from each parent to the offspring.

Question 18

Explain the concept of independent assortment.

Answer 18

Independent assortment refers to the random behavior of genes on separate chromosomes during meiosis, resulting in a mixture of genetic material in the offspring.

Question 19

Define homozygosity.

Answer 19

Homozygosity refers to a genotype made up of identical genes at a given locus, such as AA, BB, or OO.

Question 20

What is heterozygosity?

Answer 20

Heterozygosity refers to the inheritance of different alleles from each parent, such as AO, BO, or AB.

Question 21

What is dosage effect?

Answer 21

Dosage effect refers to the stronger agglutination demonstrated by certain antigens when expressed homozygously.

Question 22

Give an example of antigens that demonstrate dosage effect.

Answer 22

Duffy (Fya, Fyb), Rh (except D), MNSs, and Kidd (Jka, Jkb) antigens demonstrate dosage effect.

Question 23

What is meant by linkage in genetics?

Answer 23

Linkage refers to genes being inherited together because they are very close on a chromosome.

Question 24

What is crossing over?

Answer 24

Crossing over is the exchange of genetic material during meiosis between paired chromosomes.

Question 25

When does crossing over occur?

Answer 25

Crossing over is seen with genes on the same chromosome, but it does not occur when genes are linked.

Question 26

How is the phenotype frequency determined?

Answer 26

Phenotype frequency is determined by testing red cells from a large random sample of individuals of the same race.

Question 27

How are the positive and negative percentages calculated for a given blood group system?

Answer 27

The positive and negative percentages are calculated by testing a large random sample of individuals and determining the percentage of positive and negative reactions.

Question 28

What should be the sum of all possible frequencies for any given blood group system?

Answer 28

The sum of all possible frequencies for any given blood group system should be 100.

Question 29

What is the frequency for the Kell positive phenotype in the example given?

Answer 29

The frequency for the Kell positive phenotype is 9%.

Question 30

What is the frequency for the Kell negative phenotype in the example given?

Answer 30

The frequency for the Kell negative phenotype is 91%.

Question 31

If 10,000 Caucasians are tested for the Kell antigen and 900 produce a positive reaction, how many samples are negative?

Answer 31

The remaining 9100 samples are negative.

Question 32

If a patient has anti-K antibody, how many samples out of ten would be compatible?

Answer 32

Out of ten samples, 9 or 91% would be compatible.

Question 33

What does the Antigen Frequency Chart indicate?

Answer 33

The Antigen Frequency Chart indicates the frequency of the population that is positive for specific antigens.

Question 34

What does a low frequency antigen indicated on the Antigen Frequency Chart?

Answer 34

A low frequency antigen, indicated as '5-', means that 9 out of 10 individuals should be negative for that antigen.

Question 35

What percentage of the population is the silano (k) antigen present in?

Answer 35

The silano (k) antigen is present in 99% of the population.

Question 36

How can you calculate the likelihood of finding a combination of antigen negative blood?

Answer 36

By multiplying the frequencies of antigen negative blood together, you can calculate the likelihood of finding that combination.

Question 37

What is the recommended control for positive control in antigen testing?

Answer 37

The recommended positive control is a heterozygous cell (single dose) for the appropriate antigen, such as E+ e+, C+ c+, Fya + Fyb +.

Question 38

What is the recommended control for negative control in antigen testing?

Answer 38

The recommended negative control is a cell negative for the appropriate antigen, such as E neg, c neg, Fya neg.

Question 39

What is a super important point to remember about positive control in antigen testing?

Answer 39

The positive control must always be a heterozygous cell.

Question 40

What is the first step to calculate the frequency of units that are negative?

Answer 40

The first step is to subtract each frequency from 100 to get the percent of blood negative for each antigen in the population.

Question 41

What should you do if you are looking for the frequency of units that are negative?

Answer 41

If you are looking for the frequency of units that are negative, you need to take the reciprocal of the frequency.

Question 42

What is the reciprocal of a frequency of 70%?

Answer 42

The reciprocal of a frequency of 70% is 30% or 0.30.

Question 43

What might you need to know everything about for the national exam?

Answer 43

You may need to know everything about blood group system frequencies for the national exam.

Question 44

What is the definition of linkage?

Answer 44

When genes are very close together and inherited as a unit.

Question 45

What are haplotypes?

Answer 45

Gene units inherited together when genes are close.

Question 46

Give an example of genes that are closely linked.

Answer 46

The D gene is closely linked to the Cc and Ee genes.

Question 47

What is the most frequently inherited Rh Positive set of genes?

Answer 47

CDe.

Question 48

What is the most frequent Rh Negative gene?

Answer 48

cde or ce since d is an amorph.

Question 49

What are silent genes called?

Answer 49

Amorphs.

Question 50

What happens if silent genes are passed on by both parents?

Answer 50

They can result in an unusual phenotype called "NULL" types.

Question 51

Give an example of an Rh null individual phenotype.

Answer 51

Lacking the presence of all Rh system antigens, no Rh antigens at all.

Question 52

What do suppressor genes do?

Answer 52

Suppress the expression of another gene to produce a NULL expression.

Question 53

Give an example of a suppressor gene.

Answer 53

In(Jk) results in the Jk(a – b –) phenotype.

Question 54

What is CIS in genetic interaction?

Answer 54

Genes on the same chromosome.

Question 55

What is TRANS in genetic interaction?

Answer 55

Genes on opposite chromosomes that may weaken the expression of one antigen.

Question 56

Give an example of trans inheritance in the Rh system.

Answer 56

When the C gene weakens the D antigen expression on RBC's.

Question 57

What is obligatory gene?

Answer 57

A gene that should be passed on by the alleged father to prove/disprove paternity.

Question 58

How can paternity be excluded?

Answer 58

Through direct exclusion or indirect exclusion.

Question 59

What is direct exclusion in paternity testing?

Answer 59

A genetic marker inherited by the child but not found in the mother or alleged father.

Question 60

What is indirect exclusion in paternity testing?

Answer 60

When the child lacks a genetic marker that should have been inherited.

Question 61

What does an indirect exclusion result from?

Answer 61

It may result from the presence of a silent gene.

Question 62

Can indirect exclusion be the only marker used to exclude paternity?

Answer 62

No, it cannot be the only exclusion gene.

Question 63

Why can't indirect exclusion be the only marker used to exclude paternity?

Answer 63

You would need to test multiple sites to ensure accuracy in the example of silent or suppressor genes.