TOPIC: Genetics Aim: Describe how to use punnett squares. Do Now: Take out your genetics reading notes. HW: Earth Day poster due tomorrow!

AB Mitosis Meiosis 2 daughter cells 4 daughter cells Asexual repro Sexual repro Daughter cells have same # of chromosomes Daughter cells have half the # of chromosomes Used to reprilcate somatic cells Used to make gametes

2 alleles or genes that are the same Ex: BB or bb 14. Describe what a homozygous pair of alleles consists of.

Homozygous dominant Ex: BB 15. Identify the pair of alleles that consist of two dominant genes.

Homozygous recessive Ex: bb 16. Identify the pair of alleles that consist of two recessive genes.

One dominant and one recessive gene Ex: Bb 17. Identify what a heterozygous pair of alleles consists of.

Hybrid 18. Identify another term with the same meaning as heterozygous.

It is always expressed unless there are two recessive genes. Ex: –BB –Bb 19. When will a dominant gene be expressed?

When there are two recessive genes. Ex: bb 20. When will a recessive gene be expressed?

The trait for height in pea plants can be represented by using the letter “T.” T represents the allele for tall and t represents the allele for short. a.What do we call the genotype for TT? b. What is the phenotype for TT? c. What do we call the genotype for tt? d. What is the phenotype for tt? e. What do we call the genotype for Tt? f. What is the phenotype for Tt? Homozygousdominant Tall Homozygousrecessive short Heterozygous tall

The trait for seed color in pea plants can be represented by using the letter “G.” G represents the allele for green seeds and g represents the allele for yellow seeds. a.What do we call the genotype for gg? b. What is the phenotype for gg? c. What do we call the genotype for Gg? d. What is the phenotype for Gg? e. What do we call the genotype for GG? f. What is the phenotype for GG? Homozygous dominant yellow Homozygous recessive green Heterozygous green

Genetics The study of how traits are inherited.

Probability The possibility that an event may or may not happen

Punnett Square Shows possible gene combinations of offspring bw 2 organisms

1. T = tall t = short TT x tt T T t t T T T T t t t t

TT t t T T T T t t tt Phenotype= 100% heterozygous 100% tall Genotype=

Example #2: B = Black fur b = white fur Bb x Bb Bb B b B B B b B b bb

Bb B b B B B b B b bb Phenotype = Genotype= 25% homozygous dominant 25% homozygous recessive 75% black, 25 % white 50% heterozygous

Example #3: Red is dominant in flowers & white is recessive. Cross a heterozygous flower with a homozygous dominant flower. R = red r = white Rr x RR

Rr R R R R R R R r Rr Phenotype= 100% red Genotype = 50% homozygous dominant 50% heterozygous

One dog carries the heterozygous, black fur trait and the other carries homozygous recessive white traits. What are the chances of having a puppy with black fur? B = black, b = white Bb x bb

Bb b b B B b b b b bb Answer: 50% chance of having a puppy with black fur

The phenotype of an organism 1.represents its genetic composition 2.reflects all the traits that are actually expressed 3.occurs only in dominant pure organisms 4.cannot be seen

If an individual possesses two recessive alleles for the same trait, the individual is said to be 1.homozygous for the trait 2.haploid for the trait 3.heterozygous for the trait 4.mutated

Identify each structure described. 1.Where pollen tube forms 2.Produces pollen 3.Where pollination occurs 4.Will turn into fruit 5.Where fertilization occurs 6.Will turn into seeds B - Style F - Anther A - Stigma D - Ovary C - Ovule

The cell in Diagram 1 contains 4 chromosomes and is undergoing the process of mitosis. What is the total number of chromosomes in each individual cell in Diagram 3?

In humans, which cell is produced by mitosis (mitotic cell division)? 1.sperm cell 2.skin cell 3.egg cell 4.zygote cell

What would result if mitosis was not followed by division of the cytoplasm? 1.two cells, each with one nucleus 2.two cells, each without a nucleus 3.one cell with two identical nuclei 4.one cell without a nucleus

The diagram can be used to show a process of: 1.making new body cells for repair of tissue 2.making new sex cells 3.meiosis 4.sexual reproduction

The pistil of the flower includes the 1.stigma, anther, and filament 2.stamen, stigma and anther 3.stigma, style, and ovary 4.petals, sepals and pollen grains

1.Identify the process represented in the diagram. 2.Where does this occur? 3.Describe what happens to the chromosome number. 4.Compare the daughter cells to each other. Meiosis Gonads Splits in half Not genetically similar to each other

The blockages shown at A and B would most likely interfere with the ability to 1.transport gametes 2.produce mature gametes 3.eliminate waste products through the urethra 4.express secondary sex characteristics

Which statement is true of both mitosis and meiosis? 1.Both are involved in asexual reproduction. 2.Both occur only in reproductive cells. 3.The number of chromosomes is reduced by half. 4.DNA replication occurs before the division of the nucleus.

Which statement about the gametes represented in the diagram below is correct? 1.They are produced by females. 2.They are fertilized in an ovary. 3.They transport genetic material. 4.They are produced by mitosis.

The process of meiosis formed 1.cell 1, only 2.cells 1 and 2 3.cell 3, only 4.cells 2 and 3