Genetics Chapter 9.1. Genetics Genetics - the study of genes and heredity.
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Transcript of 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