Do you look exactly like either one of
- Slides: 11
Do you look exactly like either one of your parents? What about your siblings? Why is this & how do you explain it? ? ?
Summing up Mendel’s Laws The Key Terms!!
What is Genetics? • Study of heredity from generation to generation AND variation of organisms – Heredity – passing of characteristics: parents → offspring – Traits – characteristics received by offspring (Ex: color, size)
A quick review of cells… Somatic Cells vs. Gametes
A quick review of reproduction • Sexual reproduction – Sex cells (gametes) from male & female come together Sperm Egg • Fertilization – fusion of gametes; individual traits passed to fertilized cell (zygote)
• DNA in sperm & egg cells carry genes on chromosomes – Genes – sections of DNA that code for traits (proteins); come in different forms called alleles – Allele – located on 2 different copies of a chromosome, 1 inherited from mother, 1 from father Examples: Plant Height – Tall/Short Plant Color - Purple/White
Law of Dominance – Dominant allele – masks recessive trait – Recessive allele – trait that can be masked Example: Can you roll your tongue? Tongue rollers are dominant. Let’s symbolize the tongue rolling trait using a letter code – let’s use “T. ” If dominant is T Then recessive must be t
Genotypes and Phenotypes • Letter codes can be joined together in various combinations…what are they? Genotype: gene combos TT – tongue rollers Tt – tongue rollers tt – non-tongue rollers Phenotype: observable characterisitics
How do we categorize these combinations? ? ? • Homozygous – same 2 alleles → recessive alleles are ALWAYS homozygous TT, tt • Heterozygous – different alleles Tt
Mendel’s Laws 1. Law of Segregation – – Because each organism has 2 alleles → TWO different types gametes can be produced – During fertilization, gametes randomly pair → produce combinations of alleles
Mendel’s Laws cont… 2. Law of Independent Assortment – Genes for different traits inherited independently of each other – Genes separate and recombine – This accounts for variation in genotypes/phenotypes!
Look to the right look to the left
Which features of the sun look like huge cloudlike arches
Why does ethanol look like water but behave more like wood?
If bcde is a kite
Quadrilateral that has 2 pairs of parallel sides
Everyone has exactly one best friend
1 oz of food
How does a trillion dollars look like
You look like your sister
Why do you look somewhat like your parents
How will you look like in the future
What do you look like?
