Genetics

Flower dissection

1. What is the name of the male reproductive part of a flower 1. What is the name of the male reproductive part of a flower? (Name ALL if there are more than one) 2. What is the name of the female reproductive part of a flower? (name ALL if there are more than one) 3. WHERE on the flower is the pollen? 4. How is a new flower produced? (meaning how does pollination happen?) 5. Identify structure A, B, C and D and write their FUNCTION. Quiz B A C D

Mendel Brainpop Video -Blending Theory of Inheritance -Why he chose Pea Plants -Controlling pollination (Anther produces pollen = sperm, stigma leads to ovary) -Had to prevent self-pollination by removing anthers Brainpop Video

F1 and F2 Generation Practice: Dominant Recessive Round seed Wrinkled seed Purple color White color Tall stem Short stem Practice: #1: What would the F1 generation look like if a plant with round seeds was cross pollinated with a plant with wrinkled seeds? #2: What would the F2 generation look like if the results form above were self pollinated? #3: What would the F1 generation look like if a plant with tall stems was cross pollinated with a plant with short stems? #4: What would the F2 generation look like if the results form above were self pollinated?

Mendel’s Two Laws: Independent assortment - factors controlling different characteristics are inherited independently of each other. Allele for Purple flowers Allele for White flowers -Every organism has 2 copies of the same gene -The gene may have different versions: usually 2. -Different alleles (versions) account for most of the variation among organisms law of segregation - there are two factors controlling a given characteristic, one of which dominates the other, and these factors separate and go to different gametes when a parent reproduces.

Homo = same Hetero = different Mini Lesson Genotype Phenotype Explanation The ALLELES the individual inherits from parents The EXPRESSIN of the genotype (what it looks like) Example 1 PP Purple Flowers Example 2 Pp Example 3 ll Short stems Example 4 Ll Long stems Example 5 Rr Round seeds Fertilization = resulting gamete gets one allele from each parent. Homo = same Hetero = different Which of the examples above are homozygous? Which are heterozygous?

Probability Sperms Eggs

Punnett Squares Practice: #1. Homozygote dominant crossed with a heterozygote #2. Homozygous recessive crossed with a homozygous dominant #3. Heterozygote crossed with a heterozygote 929 plants 705 purple (76%) 224 white (24 %)

Incomplete dominance

Codominance

Polygenic inheritance Skin color Eye color Height

Pleiotropy

Pleiotropic versus polygenic

Autosomal traits Autosomal traits are controlled by genes on one of the 22 human autosomes  Examples: The allele for free-hanging earlobes (F) is dominant to the allele for attached earlobes (f). widow’s peak is dominant over no widows peak Rolling your tongue is dominant over not being able to.

Sex Linked Traits Traits controlled by genes on the sex chromosomes  X-linked traits in the case of the X chromosome. X-linked traits have a different pattern of inheritance than autosomal traits because: males have just one X chromosome. always inherit their X chromosome from their mother they pass it on to all their daughters but none of their sons

Autosomal Genetic Disorders caused by mutations in one or a few genes on an autosome (chromosome #s 1-22) If it is on an autosome, it can either be a “dominant disorder” or a “recessive disorder” If it is a dominant disorder you will express the disorder if you are heterozygous for the trait or homozygous dominant. If it is a recessive disorder you will only express the disorder if you are homozygous recessive for the trait. AA/Aa aa

Sex-Linked Genetic disorders Disorders that are a result of 1 or more genes on a sex chromosomes (usually the x) X LINKED RECESSIVE DISORDERS (most common): If a male carries 1 mutated copy of the gene he will have the disorder. A female needs 2 mutated copies of the disorder to have the disorder. If a female has 1 mutated copy she is called a “carrier”, meaning she does not have the disorder but can pass it on to her offspring.

Chromosomal Genetic Disorders Caused by an abnormal number of chromosomes Mistakes may occur during meiosis that result in nondisjunction. This is the failure of replicated chromosomes to separate during meiosis. Some of the resulting gametes will be missing a chromosome, while others will have an extra copy of the chromosome

Examples of chromosomal disorders

Autosomal Genetic Disorders

Sex Linked Genetic Disorders

Pedigrees A pedigree is a representation that shows the blood relationships of family members It shows individuals expressing the trait or disorder under study. The chart describes relationship to various members of the family It can also show the origin of a particular trait or disorder.

Inheritance patterns

Treating genetic diseases Genetic counseling Just treat symptoms (PKU, cystic fibrosis, insulin for symptom prevention) Gene therapy: replacing the defective gene Somatic cell gene therapy Germ cell gene therapy (controversial)

Pedigree Rules

Pedigrees

Layer B 1. Mendel Photobook/scrapbook 3. Blood Typing Webquest: http://www.nobelprize.org/educational/medicine/bloodtypinggame/game /index.html 2. Blood Type Mystery 4. Punnett Square practice packet Extra Credit: Biotechnology brochure (processes, uses) As a class: Baby lab Article jigsaw Gattaca

Layer A Genetic Counselor Project