TOPIC: Genetics Aim: Describe how to use punnett squares. Do Now: next slide HW: Study for...
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Transcript of TOPIC: Genetics Aim: Describe how to use punnett squares. Do Now: next slide HW: Study for...
TOPIC: GeneticsAim: Describe how to use punnett squares.
Do Now: next slide
HW: Study for tomorrow’s Reproduction test!
BRING YOUR TEXTBOOK TO CLASS!Pedigree Chart Reading notes due Wednesday!Genetic Engineering Reading notes due
Thursday!
Identify each structure described.1.Where pollen tube forms2.Produces pollen3.Where pollination occurs4.Will turn into fruit5.Where fertilization occurs6.Will turn into seeds
B - Style
F - Anther
A - Stigma
D - Ovary
C - Ovule
C - Ovule
Seed coat
Cotyledon
Embryo
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?
Homozygous
dominant
Tall
Homozygous
recessive
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
Probability•The possibility that an event may or may not happen
Punnett Square
•Shows possible gene combinations of offspring bw 2 organisms
Example:1. T = tall t = short TT x tt
T T
t
t
T
T
T
T
t t
t t
T T
t
t
T
T
T
T
t t
t t
Phenotype=
100% heterozygous
100% tall
Genotype=
Example #2: B = Black fur b = white furBb x Bb
B b
B
b
B
B
B
b
B b
b b
B b
B
b
B
B
B
b
B b
b b
Phenotype=Genotype=25% homozygous
dominant25% 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 x RRR r
R
R
R
R
R
R
R r
R r
Phenotype=
100% red
Genotype = 50%
homozygous dominant50%
heterozygous
TOPIC: GeneticsAim: Practice using punnett squares.
Do Now: next slide
HW: Pedigree Chart Reading notes due
Monday.Study for Tuesday’s Reproduction test.
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 x bb
B b
b
b
B
B
b
b
b b
b b Answer: 50% chance of having a puppy with black fur
The phenotype of an organism1. represents its genetic
composition2. reflects all the traits that are
actually expressed3. 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
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?1. 8 2. 2 3. 16 4. 4
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 tissue2.making new sex cells3.meiosis4.sexual reproduction
The pistil of the flower includes the1.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 to1.transport gametes 2.produce mature gametes3.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 formed1.cell 1, only2.cells 1 and 23.cell 3, only4.cells 2 and 3