“Bell Ringer” for 4/6 What are the 2 types of mutations that you see

below? Which is more detrimental and why?

Correct sequence: A T T C G T G A A Mutation A: A T T T G C G A A Mutation B: A T T G T G A A

Your Monster Lab and your index card (make sure your name is on it!) will be collected in 10 min. Make sure you are ready when time is called!

Study Guide DNA and RNA:

Know the base-pairing rules Who discovered them? How?

Transcription and Translation What happens and where they occur

Mutations Identify types, what causes them

Kayrotypes What are they used for, autosomes vs. sex chromosomes

Pedigrees Demonstrate knowledge of the symbols used Be able to construct one based on descriptions of individual

phenotypes Analyze for inheritance pattern

Inheritance Patterns Understand sex-linked, incomplete, and codominant traits Construct Punnett squares to show patterns of inheritance

MUTATIONMUTATION defined as:

can be caused by errors in _________, _____________,

____________, or by _________________

change in the DNA sequence

replication

Transcription

External agents, or mutagens

Cell division

Mutations Review Reproductive cells

(eggs/sperm) Will be passed down to

offspring

Body (somatic) cells Will NOT be passed

down to offspring

Base-pair mutations A change caused by one

to few bases on a DNA or RNA strand

Chromosomal mutations A change caused by

larger scale chromosomal changes (involving alteration of several hundred-several thousand base-pairs)

What kind of mutation?

What do you see happening?

Point Mutation

What type of mutation?

How is this different than a point mutation? How is it similar?

Chromosomal mutations When there are changes that affect the

chromosome, it is considered a chromosomal mutation. Part of a chromosome is broken off and lost Break and rejoin incorrectly

Nondisjunction

Nondisjunction

What do you notice about the daughter cells that are produced?

Pedigree basics

Rewiew What is genotype? How about phenotype? What is an allele?

Autosomal Dominant Inheritance Alleles:

Dominate traits are represented by ____________ letters. Affected individuals have to carry at least ___ dominant

gene (heterozygous or homozygous) Chance of Inheritance:

Passed onto __________________________ Parents:

Every person affected must have at least 1 parent with the trait

Generations: Does not skip generations

oneCAPITAL

Males and females EQUALLY

Autosomal Recessive Inheritance Alleles:

Represented by _______________ letters Unaffected parents (heterozygous) can produce

affected offspring (if they get both recessive genes: homozygous)

Chance of inheritance: Inherited by both males and females

Parents: If _____ parents have the trait then all offspring will also

have the trait. The parents are both homozygous. Generations:

__________________________

Lower case

both

Can skip generations

Review Homozygous Heterozygous Genotype Phenotype

Incomplete dominanceAlleles (See page 322 in text)

Use ___________ capital letter for both alleles, but one is distinguished by __________

_______________ individuals will have a phenotype that is an intermediate between both alleles for a trait.

Black + white = grey

The same

Adding ‘

heterozygous

Incomplete dominance

Co- dominance Alleles:

Use the SAME capital letter to represent the trait, distinguish the alleles by:

________________________________ Heterozygous individuals will have a phenotype

that distinctly shows ________ alleles. Think “dairy cow”

See page 331 in your books.

Using different capital letters, superscript to the one for the trait

both

Co- dominance

Genotype Phenotype (blood group)

IA IA or IAi A

IB IB, or IBi B

IAIB AB

ii O

How many alleles do you see for determining blood type?

Sex linked inheritance Genes are carried on the sex chromosomes

(X or Y) Sex-linked notation

XBXB normal female XBXb carrier female XbXb affected female XBY normal male XbY affected male

Sex linked inheritance Dominant Dominant gene on X chromosome Affected males pass to all daughters and none of

their sons Genotype= XAY

If the mother = X- linked dominant trait & is homozygous (XAXA) all children will be affected

If Mother heterozygous (XAXa) 50% chance of each child being affected

Sex linked Inheritance Recessive Gene located on the X chromosome More males than females affected (males inherit X from

mother) Females can only inherit if the father is affected and

mother is a carrier (hetero) or affected (homo) An affected female will pass the trait to all her sons

Daughters will be carriers if father is not affected Males cannot be carriers Can skip generations E.g. colour blindness, haemophilia, Duchene muscular

dystrophy

Autosomal Dominant PedigreeLook for: Trait in every generation

Once leaves the pedigree does not return

Every person with the trait must have a parent with the trait

Males and females equally affected

Autosomal Recessive PedigreeLook for: Skips in generation Unaffected parents can

have affected children Affected person must be

homozygous Males and females

affected equally

Sex linked Dominant pedigreesLook for: More males being affected Affected males passing onto all daughter

(dominant) and none of his sons Every affected person must have an

affected parent

Sex linked recessive pedigrees More males being affected Affected female will pass onto all her sons Affected male will pass to daughters who

will be a carrier (unless mother also affected)

Unaffected father and carrier mother can produce affected sons

What kind of inheritance pattern?

What kind of inheritance pattern?