Module 10.1: Heredity

Question 1

What is a Genotype?

Answer 1

Your DNA resulting in your genetic makeup

Question 2

Genotypes are a combination of what?

Answer 2

Alleles possessed of a specific gene

Question 3

What is a phenotype?

Answer 3

Combination of observable characteristics or traits - what you look like

Question 4

What are included in phenotypes?

Answer 4

Only genes that are expressed

Question 5

_______ is directly inherited from parents. ________ is not, however is influenced by genotypes

Answer 5

1. Genotypes and phenotypes

Question 6

_______________ are variants of a particular gene due to changes in gene sequences

Answer 6

Alleles

Question 7

For each gene there can how many different alleles?

Answer 7

Many

Question 8

An ______ is one specific way a particular gene can be expressed

Answer 8

Allele

Question 9

What are two basic characteristics of an allele are?

Answer 9

1. Dominant
2. Recessive

Question 10

What does allele affect?

Answer 10

Affects the phenotype when present in one copy

Question 11

How many alleles must be present for a recessive allele to show up

Answer 11

Must be present in 2 copies to be expressed

Question 12

What is a punnet square?

Answer 12

Graphical representation of the possible genotypes two individuals can produce when combined

Question 13

What is the punnet square based on?

Answer 13

Alleles from both parents

Question 14

A punnet square is a map of what?

Answer 14

Statistical outcomes or risks of inheriting a disease or condition

Question 15

What is a dominant and recessive expressive in the punnet square

Answer 15

1. Dominant expressed as Big B
2. Recessive expressed as little b

Question 16

Humans have how many pairs of chromosomes? How many are sex chromosomes and how many are autonomies? 3

Answer 16

1. 23 pairs
2. 2 sex hormones
3. 44 autosomes

Question 17

What is meiosis?

Answer 17

Division of a cell that reduces the number of chromosomes to half

Question 18

What is an example of meiosis?

Answer 18

Diploid&raquo_space;> haploid

Question 19

What does meiosis entail?

Answer 19

Two divisions of the genetic material

Question 20

During meiosis if there is a production of four haploid cells, what assortment of genes and chromosomes does each carry?

Answer 20

New assortment of genes and chromosomes

Question 21

What does this image represent?

Answer 21

Meiosis

Question 22

What is the mode of inheritance depend on? 2

Answer 22

1. On whether an allele is dominant or recessive
2. Also whether the gene that determines that trait appears on a sex chromosome or an autosome

Question 23

One person carries more than how many possible combinations of a chromosome? How?

Answer 23

More than 8 million
1. +8 million combination of his or her partner
2. = A potential variability of 70 trillion genetic unique individuals

Question 24

What does homozygous mean?

Answer 24

An individual with 2 identical alleles for a gene

Question 25

What is heterozygous?

Answer 25

An individual with 2 different alleles for a gene

Question 26

__________disorders tend to be more severe and produce symptoms when?

Answer 26

1. Recessive disorders 2. Produce symptoms at a much earlier age

Question 27

_________disorders are not as common because these people are what?

Answer 27

1. Dominant disorders 2. These people are too sick to reproduce, thus the allele vanishes from the population

Question 28

Dominant disorders that do not present until adulthood remain in populations why?

Answer 28

These individuals can reproduce passing on the disorder

Question 29

Is it possible for alleles be co-dominant? If yes what is an example?

Answer 29

Yes, such as in AB blood type

Question 30

What is Tourette syndrome an example of?

Answer 30

Autosomal dominant, but has many different symptoms

Question 31

What is cystic fibrosis an example of?

Answer 31

Autosomal recessive

Question 32

What is Marfan syndrome an example of?

Answer 32

Autosomal dominant

Question 33

What is Marfan syndrome? What are signs and symptoms? 5

Answer 33

1. Connective tissue disorder caused by a defect in the gene that tells the body to make fibrillin 2. Long limbs 3. Pectus excavatum 4. Aortic aneurysm +/- dissection 5. Lens dislocation

Question 34

What is uniparental disomy?

Answer 34

Two copies of an allele from one parent

Question 35

What is an example of uniparental disomy? 2

Answer 35

1. It was discovered when a girl expressed cycstic fibrosis even though her mother was the only carrier of the recessive allele. 2. This child received both the genes from the Mother

Question 36

A Male inherits which chromosome from his father and which from his mother?

Answer 36

1. Y from father 2. X from mother

Question 37

Females inherit which chromosomes from each parent?

Answer 37

X chromosomes from each parent

Question 38

Are X linked traits passed from father to son?

Answer 38

Never

Question 39

Can a father pass a X chromosome to his male child?

Answer 39

No

Question 40

What is an example of an X linked trait? Who are carriers?

Answer 40

1. Hemophilia 2. Daughters are carriers, because her fathers X chromosome would make that mutant allele

Question 41

What is Klinefelter syndrome?

Answer 41

Males with an extra X chromosome passed on from mother

Question 42

What are some signs and symptoms of Klinefelter syndrome? 3

Answer 42

1. Underdeveloped sexually - rudimentary testes and prostate 2. Long arms and legs, large hands and feet. 3. No pubic or facial hair, may develop Brest tissue

Question 43

How common is Klinefelter’s syndrome? 3

Answer 43

1. Common 2. 1 in 500 Male births. 3. Most men do not know they have it until fertility becomes a problem

Question 44

What is Jacobs syndrome?

Answer 44

Males with an extra Y chromosomes passed on from their father

Question 45

What are some signs and symptoms of Jacob’s syndrome? How common is it? Who is affected? 3

Answer 45

1. Aggressive behaviour 2. Higher prevalence among inmates in jails however there are many men leading normal lives who are XYY 3. 1 in 1000 male births

Question 46

What may lead to variation of genes?

Answer 46

Exposure to viruses, drugs or radiation can cause these change to genes.

Question 47

What is deletion?

Answer 47

Part of the chromosome is missing

Question 48

What is duplication?

Answer 48

Extra genes

Question 49

What is translocation?

Answer 49

Gene has moved to another chromosome

Question 50

What is inversion?

Answer 50

Genes switched position on the chromosome arm

Question 51

Wha is the most common live born chromosomal abnormality?

Answer 51

1. Trisomy 21 2. 1 in 800 births

Question 52

______ is usually a random event and not inherited

Answer 52

T21

Question 53

Most cases of T21 are due to what?

Answer 53

Maternal Nondisjunction

Question 54

Nondisjunction occurs when? 2

Answer 54

1. The chromosomes do not separate in meiosis 2. Thus causing +1 or -1 chromosomes in gametes

Question 55

What increases the incidence of Nondisjunction?

Answer 55

Maternal age

Question 56

Some cases of T21 are due to what?

Answer 56

Genetic translocation- this can be inherited

Question 57

If an individual has a _________ they may not show any signs - normal, health individual. This individual has an increased chance having children with what?

Answer 57

1. Translocation 2. Down syndrome

Question 58

Do the two copies of the genes received from each parent have to be identical?

Answer 58

No

Question 59

What does this image demonstrate?

Answer 59

Autosomal Dominant gene inheritance

Question 60

What does this image demonstrate

Answer 60

Autosomal recessive gene inheritance

Question 61

What does this image demonstrate?

Answer 61

X linked recessive gene inheritance