interim 2 review. meiosis- forming sex cells process in which haploid cells are formed from diploid...
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Interim 2 review
Meiosis- forming sex cells
• Process in which haploid cells are formed from diploid cells• In humans:Parent 46 46 ParentDiploid (2N) Diploid
(2N)
Ovum 23 23 Sperm Haploid (N) Haploid (N)
Zygote 46 Diploid (2N)
Chromosome number cut in half
Fertilization
Mitosis vs Meiosis
Characteristic
Mitosis Meiosis
Cells produced
Body cells (somatic cells)
Sex cells (gametes)
Chromosome number
Same as parent cellDiploid 2N
Half number of parent cellHaploid N
Number of divisions
1 2
Number of cells produced
2 4
Meiosis
Meiosis I
Meiosis II
Meiosis
• During meiosis I, the ______________________ chromosomes separate.– What does this do to the chromosome number?
• During meiosis II, the sister ____________________ separate.
homologous
chromatids
Cut in ½
Meiosis I
Meiosis II
Prophase II Metaphase II Anaphase & Telophase II
Meiosis in Males and Females
• Males- results in 4 sperm cells• Females- results in one ovum (egg) and 3
polar bodies MALES FEMALES
4 Sperm cells 3 polar bodies 1 ovum
1st cell division
2nd cell division
• If three cells undergo meiosis in males, how many sperm cells will be produced? _____________
• If four cells undergo meiosis in females, how many ova (eggs) will be produced? _____________
• How many polar bodies would be produced for the same 4 cells? __________________
12
4
12
• If the 2N number of an organism is 32;• how many chromosomes are found in
a sperm cell? _______• how many chromosomes are found in
a diploid cell? _______• how many chromosomes are found in
an ovum? _______• how many chromosomes are found in
a haploid cell? _______• how many chromosomes are found in
a skin cell?________
16
32
16
16
32
• Sexual reproduction is important to the survival of the species because it adds genetic _________________________ to the population.
.
variation
Genetic variation
• Crossing Over- exchange of genetic information by non- sister chromatids during meiosis.
Mistakes in the Meiosis Nondisjunction- failure of chromosomes to
separate properly
Genetics Vocabulary
• ________________- the passing of traits from parents to offspring
• ________________- the study of heredity• _________________- rod-shaped structures
in the nucleus that transmits genetic information
• _________________- units of hereditary information found on the chromosomes
heredity
genetics
chromosomes
genes
Genetics Vocabulary• __________________- a gene that masks the
expression of another gene in a pair ( Symbol- capital letter)
• __________________- a gene in a pair that is hidden by the dominant gene (Symbol- lower case letter)
• ___________________- two genes in a pair that are identical. (RR or rr)
• _____________________- individual with one dominant and one recessive gene in a pair. (Rr)
dominant
recessive
homozygous
heterozygous
Genetics Vocabulary
• ______________________- either member of a pair of genes that determines a single trait.
• ____________________- the pair of alleles represented by the capital and lower case letters.
• ______________________- the trait that is actually expressed in an organism
allele
genotype
phenotype
• Immunity to poison ivy is a dominant trait while those people who get poison ivy show the recessive trait. Diagram a Punnett Square for a man who is heterozygous and a woman who get poison ivy.
1. What is the man’s genotype? ___________2. What is the woman’s genotype? ____________3. What is the probability of producing a child who gets poison ivy? __________4. What is the genotypic ratio?___________
Ii
ii
50%
1:1
I i
i
i
Ii
Ii
ii
ii
• Feather color in birds is an incomplete dominant trait. Genes for blue feathers and genes for white feathers combine to form birds with silver feathers. Diagram a cross for two silver feathered birds.
1. What is the parent’s genotype? ___________2. What is the phenotypic ratio? ____________3. What is the probability of producing bird with blue feathers? __________4. What is the probability of producing a bird with silver feathers?___________
BW
1:2:1
25%
50%
B W
B
W
BB
BW
BW
WW
• Blood type is a codominant trait. A man with blood type AO marries a female with blood type AB. 1. What are the genotypes
in the offspring? ___________________2. What is the genotypic ratio? ____________3. What is the phenotypic ratio? __________4. What is the probability of producing a child with blood type A? _______5. What is the probability of producing a child with blood type O? ______
AA, AO, AB, BO
1:1:1:1
2:1:1
50%
A O
A
B
AA
AB
AO
BO
0
• Eye color in canaries is a sex-linked trait. Black eyes are dominant and red eyes are recessive. A red-eyed female is crossed with a black-eyed male.
1. What is the male’s genotype? __________2. What is the female’s
genotype? _________What is the probability of
producing a 3. black-eyed female? _______4. black –eyed male? _______5. red-eyed female? ________6. red-eyed male? __________
XBY
Xb Xb
50%0
Xb Xb
XB
Y
XBXb
XbY
XBXb
XbY 050%
• Label the three parts of the nucleotide below.
A.______________
B.______________
C.______________
phosphate
sugar
base
In DNA, how do the bases bond?_____________ bonds with ____________
and_____________ bonds with ____________
Adenine Thymine
Cytosine Guanine
What is the name of the process in which DNA makes an exact copy of itself? __________________________Replication
Put the steps of DNA replication below in order.• 1. Free floating nucleotides attach to complementary
bases on both sides • 2. Sugars and phosphates join together on the new
strands• 3. DNA molecule unzips• 4. Two DNA molecules are produced each made of one
new strand and one template
________→ ________→ ________→ ________
3 1 2 4
Comparison of DNA and RNA
DNA RNA
Strands
Sugar
Base PairsLocation
2 1
deoxyribose ribose
A with T C with G
A with U C with G
nucleus Nucleus to cytoplasm
• Protein Synthesis is divided into two processes.
• Process 1- _____________________________-mRNA is made by copying the code from a DNA molecule.
This process occurs in the __________.
• Process 2-_____________________________- a protein is assembled from amino acids.
• This process occurs in the _______________ at a _____________________.
Transcription
nucleus
Translation
cytoplasmribosome
• Genetic information usually follows in one specific direction (Central dogma of biology). Which of the following BEST represents this flow?
• A.) DNA-->Protein-->RNA• B.) Protein-->RNA-->DNA• C.) RNA-->Protein-->DNA• D.) DNA-->RNA-->Protein
• Three bases on the mRNA molecule that code for one amino acid is a(n)
• A.) anti-codon.• B.) codon.• C.) tRNA.• D.) protein.
• Transcribe the section of DNA below.
G A C T T A C A G
C U G A A U G U C
• Label parts 1 through 5 in the diagram.
• 1. _______________ 4. _______________• 2. _______________ 5. _______________• 3. _______________
1
2
5
3
4
Amino acid
ribosome
tRNA
mRNA Protein
What is the name of the process in the picture?
_____________________
1
2
5
3
4
Translation
• A mistake in the genetic code is called a ____________________.
• Name the type of mutation in the DNA sequences below. Use these choices
Substitution Insertion Deletion• Original strand – CTGACT• New strand CTAGACT ___________________• New strand CTGCT ___________________• New strand CTGAGT ___________________
Mutation
Insertion
Deletion
Substitution
• ___________ ____________________ is a method used to separate and analyze DNA fragments.
• __________ ____________________ is the analysis of DNA fragments to identify an individual.
Gel Electrophoresis
DNA fingerprinting
s3cs s2s1 s5s4CS= crime scene DNAs1= suspect 1s2= suspect 2s3= suspect 3s4= suspect 4s5= suspect 5