Ch12 - Genetics

Where is the SR-Y gene and what is its function?

On the Y chromosome and is responsible for development of the testes

What is the cause of too many or too few chromosomes?

Nondisjunction?

What chromosome makes a male?

Y chromosome

What is the genotype of a normal male and a normal female?

Normal males are 46XY and normal females are 46 XX

What is an autosome?

Autosomes are all chromosomes that are not the sex chromosomes

What is a karyotype?

A diagram of chromosomes in metaphase

What happens if non-disjunction occurs during meiosis 1? What is aneuploidy?

Aneuploidy, the wrong number of chromosomes

What happens to chromosome numbers if non-disjunction occurs?

They become 22 or 24

What is non-disjunction and how many chromosomes can you have when it occurs?

22, 23, or 24

If a child has a trisomy 21, down’s syndrome, will her heart cells also have 47 chromosomes?

Yes, they would

How many chromosomes are there on the 21st chromosome when someone has down’s syndrome?

3

When does nondisjunction occur in meiosis? What cells are involved?

Meiosis 1 or meiosis 2 of sperm and egg

What does multifactorial mean with inheritance?

When more than one factor causes a trait or health problem

When a chicken has an equal number of black and white feathers, that is what type of inheritance?

Codominance

Human disorders such as depression can be linked to stressful events like a death of a loved one or a biology test. Depression can also run in families. What is this called?

Multifactorial inheritance

If two twins were separated at birth and one is raised in a loving family and the other is raised in abusive, an abusive home with food insecurity, when they are reunited, one has a lower IQ than the other. Why?

The twin in the abusive home has multifactorial inheritance

What type of inheritance is skin color?

Polygenic

Can a Punnet square predict multifactorial inheritance?

No

Give several examples of multifactorial inheritance.

Diet, environment (Physical and environment), amount of exercise, etc.

List 2 polygenic human traits.

Skin color and human hair

Who is a universal blood recipient?

AB

Find the father if the male child based on STR’s on the Y chromosome.

Dad 4

Compare and contrast codominance and incomplete dominance.

Incomplete dominance is the blending of two traits and codominance is when both traits show up equally

You are a live-saving heath care worker and a patient just arrived who needs a lot of blood.  Below is the following you have in the hospital bank.  How many liters can you give to this patient before you have to find other sources of blood donation? The patient is B+. (for this question you need to know universal recipients, universal donors and compatible blood types) 

45 liters of blood

There are three genes that will affect the melanin pigment of skin tone. However, when you go in the sun, as a defense mechanism against sunburn, and DNA damage, your skin produces more melanin. Of what is this an example of?

Both an example of polygenic and multifactorial

Why do more males express sex-linked traits?

Because they have only one x chromosome

List several sex-linked (X-linked) traits.

DMO, color blindness, and hemophilia

What is a pedigree chart?

A family tree, used to examine inheritance over several generations

When you see a pedigree chart that only shows males shaded in for expressing a trait, what type of inheritance is this?

A sex linked trait

What can Y chromosome analysis be used for?

The Y chromosome has been used to study human evolution, genealogy, proving Jefferson’s kids, and even tracing decedents of Genghis Khan, and the 12 tribes of Israel.

Does the Y chromosome have homologous pairs?

No, because there is only one Y chromosome

Does the Y chromosome every undergo recombination during meiosis?

No

Is wavy hair incomplete dominance?

Yes

When there is a catastrophic event, what blood type is most needed?

O

1\.    Is blood type ABO blood types an example of codominance?

A and B

1\.    You have a trait that has 4 alleles that are codominant.  AA, BB, CC, DD.  If mom has AA and Dad has BB, what will the offspring be?

AB

If the genotype of hair is HH for curly hair and hh for straight hair, what will the genotype be for a wavy haired person?  Check you BSU pedigree problems in the worksheet to answer this question.

Hh

Based on curly, wavy, straight hair, What percentage of offspring will be curly haired if you have 2 wavy haired people mate? What about  someone straight and curly?

25% curly, 50% wavy, 25% straight

What percentage will have straight hair when you cross HH and hh?

All children will be Hh, so they all should have curly or wavy hair

What is the predicted outcome of crossing wavy and straight hair?

Wavy or straight hair

Just because a disease runs in your family, does that mean you will also get that genetic disease? Explain?

No, because if the trait is recessive, then chances differ. Sometimes environment plays a role too.

Draw the shape of a population graph of polygenic inheritance.

Bell shaped curve

If you have A+ blood, who can you donate to? A-?

A+ and AB+, not A-

How do you get a O blood baby when parents are A and B?

AO and BO

A blood can receive from?

A+ can receive from A+, O+, O- and A- can receive from A-, O-

O blood can receive from?

O blood

What blood type would an AB person reject?

None

Draw what the cell surface markers would be on an AB blood person.

A circle with circles and triangles sticking out of it

Repeat question 24 but now your patient is B-.

16 liters of blood

Who can O- people donate to?

Everyone

Who can AB+ people receive blood from and donate to?

Can receive from any blood type but can only donate to AB

If you have a horse and a brown horse, the colts have black and brown patches, what is this an example of?

Codominance

Hardy Weinberg equation estimates in a population the number of people that are homozygous dominant for a trait and heterozygous for a trait, if you know the population number that is homozygous recessive for the trait. P2 + 2PQ + Q2 = 1 or 100% of the population.   Q +P = 1 If you have 200 students in a population.  Of those 200, 180 can taste, and 20 cannot taste.  

Find the decimal of the non tasters  20/200. This will give you Q2. (aa non tasters)  20/200 = .1

Find Q  (not Q-anon)     .1 square root = .316

Find P 1-Q = P  1-.316 = .684

Find P2 (AA tasters)    .684 square it  = .468

Find 2PQ (Aa tasters)   2 x.684 x .316 =  .432

Calculate how many students are AA of the 200.      .468 x 200 = 94 people

Calculate how many students are Aa of the 200.    .432 x 200 = 86 people

Based on the sickle cell lab, if Malaria were eliminated in the a village, what would happen to the sickle cell allele?

Sickle cell would slowly start to dissipate through each new generation

How is the DNA sequence in cystic fibrosis different from normal gene?

Cystic fibrosis has a deletion of a codon which codes for an Animo acid

Look at the pictures of the horses at the end of this study guide? What does this show?

Incomplete dominance

Know what a karyotype of each of the following looks like. One of them will be on your test. Trisomy 21, Turner’s syndrome, Klinefelter’s syndrome.

47XX+21, 45XO, 47XXY

What are all these genotypes? 46XX, 46XY, 45XO, 47XXY

Normal female, normal male, Turner’s syndrome, and Klinefelter’s syndrome

When looking at infographic 12.6 on blood slides, What is the blood type of slides 1-4?

1) A

2) B

3) AB

4) O

The genotypes of blood are listed as  IAIA    IAi     IBIB    IBi  IAIB, ii.  

 

The I stands for isoagglutinogen.  Which genotype is for A? Which is for B? which is for O?

AA, AO, BB, BO, AB, OO