Download Semester 2 Exam Review

Semester 2 Exam Review
DNA, Genetics, Mitosis/Meiosis
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Chapter 11: DNA
Learning Target 1: Students will understand the make up and importance of DNA and RNA in all living things.
Learning Target 2: Students will understand the processes involved in DNA replication.
Learning Target 3: Students will understand the processes involved with Transcription and Translation and the relationship between the two.
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DNA
1. What do the letters DNA stand for?
Deoxribose Nucleic Acid
2. Describe the structure of DNA.
double helix ­ twisted ladder
3. Who are the individuals who first described the structure of DNA?
Watson & Crick
4. What are the components of a nucleotide?
nitrogen base, sugar, phosphate
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DNA
Fill in the Blank: Fill in the following flow chart to describe the process of DNA REPLICATION!!! Use each word only ONE time. ***Word Bank*** hydrogen bonds, DNA, nitrogen bases, helicase
DNA
__________________ replication begins with the enzyme ____________________. This enzyme is responsible for unzipping the double helicase
stranded DNA by breaking the _____________________ between the nitrogen bases
_____________________. hydrogen bonds
***Word Bank*** Deoxyribose sugar, DNA polymerase, nitrogen base, nucleotides, phosphate
DNA Polymerase
Then the enzyme _____________________ runs along the DNA strand and attaches the complimentary ______________________ (consisting of a _______________, nucleotides
nitrogen base
phosphate
deoxyribose sugar
_________________, and __________________________). ***Word Bank*** new, old, proof reading enzymes, two
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This results in _____________new strands of DNA consisting of one new
old
_____________________ strand and one _____________________ strand. Finally, _____________________ scan the new strands of DNA looking for and proofreading enzymes
fixing mistakes in the complimentary base pairing.
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DNA
Describe the differences between transcription and translation. (HINT: think about where they take place, what happens in each, do they use DNA or RNA as a template, what is the end product….LOTS to put here)
Transcription
DNA mRNA
Occurs in the nucleus
Translation
Occurs in the cytoplasm at the ribosome
mRNA carries the code to make a protein
DNA serves as the template for mRNA
mRNA is the end product
tRNA brings single amino acids to the ribosomes
Amino Acids bond together to form long chains (proteins)
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DNA
1. How do bases pair with each other in DNA? mRNA?
mRNA:
DNA: A ­ T
G ­ C
A ­ U
G ­ C
2. Be able to both replicate (complementary DNA) and transcribe (mRNA) a short DNA sequence.
Replication:
A­ T
C­ G
T­ A
C­ G
G­ C
A­ T
G­
C­
G­
T­
A­
T­
C
G
C
A
T
A
Transcription:
A­ U
G­ C
C­ G
C­ G
T­ A
G­ C
C­ G
T­ A
G­ C
A­ U
A­ U T­ A
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DNA
Compare and Contrast DNA & RNA
DNA
double strand
A (adenine) pairs with thymine Deoxyribose is the
sugar
RNA
Single Strand
A (adenine) pairs with U (Uracil)
Ribose sugar
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DNA
1.
Define mutation. any mistake in the DNA sequence
a. What does our body have to try to fix or “catch” mutations?
proof reading enzymes
2.
True or False: A codon is a three base­pair sequence of mRNA .
3.
True or False: A codon is what transfers the amino acid to the actual protein chain.
tRNA
4.
True or False: The anti­codon is the same sequence as tRNA.
5.
True or False: One codon codes for one amino acid.
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Genetics Learning Target #1: Understand and use scientific genetic vocabulary to determine the outcome of complete dominance monohybrid crosses.
Learning Target #2: Understand and use scientific genetic vocabulary to determine the outcome of complete dominance dihybrid crosses using both the punnett square and fork­line methods.
Learning Target #3: Understand and use scientific genetic vocabulary to determine the outcome of incomplete dominance, codominance, and sex­linked monohybrid crosses.
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Chapter 11: Genetics Genotype: "Code" of the trait, the genetic make­up your DNA says you will have.
Examples: AA, Aa, aa
Phenotype: Physical description of the trait.
Examples: Brown hair, blue eyes
Homozygous: Both alleles (letters) are the SAME.
Examples: AA or aa
Heterozygous: Both alleles (letters) are the DIFFERENT.
Examples: Aa
Allele: Genes on the chromosomes that are marked for certain traits (2 for each trait)
Gene: Part of chromosomal DNA that "codes" for a trait
Dominant: Version of the trait that is shown. It has the ability to cover up the recessive allele/trait
Example: Brown eyes Recessive: Version of the trait that is hidden or covered up by the dominant trait. Has the ability to disappear and reappear from generation to generation. Example: Blue eyes
Heredity: The passing on of traits from parents to offspring.
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Genetics 1.
What is a punnett square, how does it work and what can it tell you?
A punnet square is a tool that helps predict the traits of offspring by using genotypes of the parents bb­dad
Bb­mom
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Genetics Monohybrid Crosses: Predicts the genotypes and phenotypes of offspring for a single trait. Remember the terms homozygous, heterozygous, dominant and recessive!!!
Example: In humans having freckles is a recessive trait. Predict the offspring for two parents who are both heterozygous for freckles. F
KEY!!
F= no freckles
f= freckles
f
F
F F
F f
f
F f
f f
FF ­ no freckles 25%
Ff ­ no freckles 50%
f f ­ freckles 25%
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Genetics Codominance: Condition in which both alleles of a gene are expressed in heterozygous offspring.
Example: In cows black fur and white fur are codominant. If you cross a black cow and a white cow the offspring will be black with white spots. BB= Black
WW= White
BW= Black & White
100% BW ­ Black & White
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Genetics Incomplete dominance: The heterozygous genotype produces a phenoytype that falls in between the dominant trait and the recessive trait. (Blend)
Example: In flowers petal colors show incomplete dominance. Red petals are dominant to white petals. When you cross a red flowered plant with a white flowered plant you get pink plants.
RR= Red
RW= Pink
WW= white
R
R
W
RW
RW
W
RW
RW
100% RW ­ Pink
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Genetics Sex­linked traits: Traits that are located on the sex chromosomes. Males are XY and females are XX.
Example: Hemophilia is a blood disease located on the X chromosome. Cross a normal male with a carrier female
KEY:
XX = Normal female
XhX = Carrier female
XhXh = Hemophiliac female
XY = Normal Male
XhY = Hemophiliac Male
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Genetics Blood Typing: In humans blood typing shows codominance. Type A blood is codominant with Type B blood. Type O blood is recessive. Type O is a universal donor (can give blood to anyone)
Type AB is a universal receiver (can get blood from anyone).
Genotype:
AA or AO
BB or BO
AB
OO
Phenotype:
Type A
Type B
Type AB
Type O
Example: Cross a man who is heterozygous Type B with a women who is heterozygous Type A.
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Genetics Law of Independent Assortment:
Based on the idea that, in a dihybrid, the two traits sort independently of one another
* What happens with one trait is completely unrelated to what happens with the other trait.
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Genetics DiHybrid Crosses: Predicting offspring genotypes and phenotypes for two independent traits.
In mice, running (R) is dominant to waltzing (r), and black (B) coat color is dominant to white (b). Use a punnet square to predict the results of a cross between a heterozygous running, white mouse and Rrbb
a waltzing, heterozygous black mouse. _________ x _________
rrBb
Rb rb
Rb
rB rb
____ ____, ____ ____ X ____ ____, ____ ____
rb
rB
Rb
rb
Rb
rB
RrBb
rrBb
RrBb
rrBb
rb
Rrbb
rrbb
Rrbb
rrbb
rB
RrBb
rrBb
RrBb
rrBb
rb
Rrbb
rrbb
Rrbb
rrbb
rb
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Genetics Forkline Method: uses genotypic ratios to predict the outcomes of genetic crosses.
In mice, running (R) is dominant to waltzing (r), and black (B) coat color is dominant to white (b). Use a punnet square to predict the results of a cross between a heterozygous running, white mouse and a waltzing, rrBb
heterozygous black mouse. _________ x _________
Rrbb
R
r
r
Rr
rr
r
Rr
rr
1/2 Rr
1/2 rr
b
B
Bb
b
bb
b
Bb
bb
1/4 RrBb
1/2 Bb
1/2 bb
1/4 Rrbb
1/2 Bb
1/4 rrBb
1/2 bb
1/4 rrbb
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Genetics Pedigrees
= normal male
= affected male
= normal female
= affected female
I
= marriage
II
Children (oldest always on left)
III
1 2
Number of Generations
Person Number
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Genetics Pedigrees continued: Using the pedigree to the left: In humans, brown eyes (B) is dominant to blue eyes (b). 1.
What is the genotype AND phenotype of person 1 in the second generation?
2.
How many heterozygous females are there?
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Mitosis & Meiosis
Learning Target 1: Understand how cells replicate and the difference between cell division and the production of gametes. 22
Mitosis & Meiosis
1.What is the difference between haploid (n) and diploid (2n) cells?
haploid (n) ­ 1/2 chromosomes
sex cells ­ 23 chromosomes
diploid (2n) ­ total number of chromosomes
body cells ­ 46 chromosomes
2.What types of cells undergo mitosis? What types of cells undergo meiosis?
Meiosis = sex cells (sperm, eggs, gametes) (haploid n)
Mitosis = body cells (lung, skin, hair) (diploid 2n)
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Mitosis & Meiosis
1. Put the following phases of mitosis in order.
___ Anaphase
3
5
___ Interphase
Growth phase ___ Metaphase
2
1
___ Prophase
___ Telophase
4
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Mitosis & Meiosis
2.What is the differences (there are many) between mitosis and meiosis reaction? Mitosis
Meiosis
Complete set of Chromosomes
Half the amount of chromosomes
Body Cells
Sex Cells
2 daughter cells (diploid)
2 phases (prophase I, etc.)
4 daughter cells (haploid)
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