Genetics

QOD

1. THE SHAPE OF DNA IS DESCRIBED AS A _____ _____.

2. A GENE IS A SEGMENT OF _____ THAT CORRESPONDS TO A PARTICULAR _____.

3. A CELL WITH ONLY 1 KIND OF EACH CHROMOSOME IS _____; A CELL WITH 2 KINDS OF EACH CHROMOSOME IS _____.

4. A PUNNETT SQUARE DETERMINES THE POSSIBLE COMBINATIONS OF _____.

5. _____ IS WHAT MENDEL CALLED HOMOZYGOUS.

6. CHROMOSOMES ARE MADE WHEN STRANDS OF _____ COIL AROUND _____.

Essential Question

How can I predict the genotype of an offspring?

In GlossaryHeredity The passing of traits from parent to

offspring.alleles

Dominant Traits

Recessive Traits

Genotype

Phenotype

Punnett Square

In GlossaryHeredity The passing of traits from parent to

offspring.alleles Different forms of a trait that make up a

gene pair.Dominant Traits

Recessive Traits

Genotype

Phenotype

Punnett Square

In GlossaryHeredity The passing of traits from parent to

offspring.alleles Different forms of a trait that make up a

gene pair.Dominant Traits A trait that covers over, or dominates,

another form of that trait.Recessive Traits

Genotype

Phenotype

Punnett Square

In GlossaryHeredity The passing of traits from parent to

offspring.alleles Different forms of a trait that make up a

gene pair.Dominant Traits A trait that covers over, or dominates,

another form of that trait.Recessive Traits The trait that is covered over of

dominated , by another trait and seems to disappear.

Genotype

Phenotype

Punnett Square

In GlossaryHeredity The passing of traits from parent to

offspring.alleles Different forms of a trait that make up a

gene pair.Dominant Traits A trait that covers over, or dominates,

another form of that trait.Recessive Traits The trait that is covered over of

dominated , by another trait and seems to disappear.

Genotype Genetic make up of an organism.

Phenotype

Punnett Square

In GlossaryHeredity The passing of traits from parent to

offspring.alleles Different forms of a trait that make up a

gene pair.Dominant Traits A trait that covers over, or dominates,

another form of that trait.Recessive Traits The trait that is covered over of

dominated , by another trait and seems to disappear.

Genotype Genetic make up of an organism.

Phenotype The way an organism looks and behaves. (blue eyes, brown hair)

Punnett Square

In GlossaryHeredity The passing of traits from parent to

offspring.alleles Different forms of a trait that make up a

gene pair.Dominant Traits A trait that covers over, or dominates,

another form of that trait.Recessive Traits The trait that is covered over of

dominated , by another trait and seems to disappear.

Genotype Genetic make up of an organism.

Phenotype The way an organism looks and behaves. (blue eyes, brown hair)

Punnett Square A tool used by Gregory Mendel to predict the genetic make up of an offspring.

Nucleotides

Adenine-Thymine Guanine-Cytosine

Chargaff's Ratios. Erwin Chargaff found that in DNA, the ratios of adenine (A) to thymine (T) and guanine (G) to cytosine (C) are equal. This parity is obvious in the final DNA structure.

Double Helix

DNA complementary ATCGAATTGA TAGCTTAACT

CGAATGGCCTGA GCTTACCGGACT

TTACCGGTCGAAATGGCCAGCT

Adenine

Guanine

Thymine

Cytocine

http://learn.genetics.utah.edu/units/basics/tour/

Tour of Basics

What is a genotype?

Heterozygous traits are the result of getting the different gene from each parent. (called HYBRIDS)◦ If the traits are different the dominant trait will always determine your looks.

Ex. Genotype = Bb or Tt etc…

Homozygous traits are the result of getting the same gene from each parent.◦ Looks are determined by the pair of alleles since they are equal. Ex. Genotype

= BB or bb or TT or tt etc…

What is a phenotype?

If T represents tall and t represents short.◦ Heterozygous genotype (called HYBRIDS) Tt = tall plant◦ Homozygous dominant genotype TT = tall plant◦ Homozygous recessive genotype tt = short plant

Phenotype are traits that can be detected with out extreme science. Ex. Ms. Johnson is tall.

Stop and Share

What is the difference between a genotype and a phenotype?

How is a Punnett Square interpreted?

Top = one parent’s genotype

Side = other parent’s genotype

Count how many boxes out of 4 have a phenotype to determine probability.

Let’s try some… If I cross a TT plant with a tt plant

___ # of tall

___ # of short

___ # of pure tall

___ # of pure short

___ # of hybrid tall

Sickle Cell Anemia A substitution in the order of bases

Sickle cells can not carry oxygen to the body

Sickle-cell disease occurs when a person inherits two abnormal copies of the hemoglobin gene, one from each parent.

Let’s try some…

If I cross a Tt plant with a tt plant

___ # of tall

___ # of short

___ # of pure tall

___ # of pure short

___ # of hybrid tall

Hemophilia Blood clotting disorder excessive bleeding, no clotting only in males females are carriers short life spand

Let’s try some… If I cross a TT plant with a Tt plant, what are the probably offspring?

___ # of tall

___ # of short

___ # of pure tall

___ # of pure short

___ # of hybrid tall

Cystic Fibrosis mutation in the gene heavy mucus in lungs difficulty breathing

Pedigree diagram that shows a history of a trait

Stop and DrawIn your spiral draw a Punnett square and describe how it is organized.Now, share this with your neighbor and compare your descriptions.

Exit Ticket If I cross a PP plant with a Pp plant

___ # of purple

___ # of white

___ # of pure purple

___ # of pure white

___ # of hybrid purple