Download DNA RNA

Interim 2 review
Meiosis- forming sex cells
• Process in which haploid cells (gametes) are formed from
diploid cells
• In humans:
(F) Parent 46
46 (M)Parent
Diploid (2N)
Diploid (2N)
Chromosome number cut in half
Ovum 23
Haploid (N)
23 Sperm
Haploid (N)
Fertilization
Zygote 46
Diploid (2N)
Mitosis vs Meiosis
Characteristic
Mitosis
Cells produced Body cells
(somatic cells)
Chromosome
Same as
number
parent cell
Diploid 2N
Number of
1
divisions
Number of
2
cells produced
Meiosis
Sex cells
(gametes)
Half number of
parent cell
Haploid N
2
4
Meiosis
Meiosis I
Meiosis II
Meiosis
• During meiosis I, the
______________________
chromosomes
homologous
separate.
– What does this do to the chromosome number?
Cut in ½
• During meiosis II, the sister
chromatids
____________________
separate.
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
1st cell division
2nd cell division
4 Sperm cells
3 polar bodies
1 ovum
• If three cells undergo meiosis in males, how
many sperm cells will be produced?
_____________
12
• If four cells undergo meiosis in females, how
many ova (eggs) will be produced?
4
_____________
• How many polar bodies would be produced
12
for the same 4 cells? __________________
• If the 2N number of an organism is 32;
•
how many chromosomes are found in
16
a sperm cell? _______
•
how many chromosomes are found in
32
a diploid cell? _______
•
how many chromosomes are found in
an ovum? _______
16
•
how many chromosomes are found in
16
a haploid cell? _______
•
how many chromosomes are found in
32
a skin cell?________
.
• Sexual reproduction is important to the
survival of the species because it adds genetic
variation
_________________________
to the
population.
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 during meiosis. Ex: Down
Syndrome. Extra 21st chromosome
Genetics Vocabulary
• ________________the passing of traits from
heredity
parents to offspring
genetics
• ________________the study of heredity
chromosomes
• _________________rod-shaped structures
in the nucleus that transmits genetic
information
genes
• _________________units of hereditary
information found on the chromosomes
Genetics Vocabulary
• __________________a gene that masks the
dominant
expression of another gene in a pair ( Symbolcapital letter)
recessive
• __________________a gene in a pair that is
hidden by the dominant gene (Symbol- lower
case letter)
homozygous
• ___________________two genes in a pair
that are identical. (RR or rr)
heterozygous
• _____________________individual with
one dominant and one recessive gene in a
pair. (Rr)
Genetics Vocabulary
• ______________________either member of
allele
a pair of genes that determines a single trait.
genotype
• ____________________the pair of alleles
represented by the capital and lower case
letters.
phenotype
• ______________________the trait that is
actually expressed in an organism
• 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.
i
i
I
i
Ii
ii
Ii
ii
1. What is the man’s
Ii
genotype? ___________
2. What is the woman’s
ii
genotype? ____________
3. What is the probability of
producing a child who gets
poison ivy? __________
50%
4. What is the genotypic
1:1
ratio?___________
• 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.
B
W
B
BB
BW
W
BW
WW
1. What is the parent’s
BW
genotype? ___________
2. What is the phenotypic
1:2:1
ratio? ____________
3. What is the probability of
producing bird with blue
25%
feathers? __________
4. What is the probability of
producing a bird with silver
feathers?___________
50%
• Blood type is a codominant trait. A man with
blood type AO marries a female with blood
1. What are the genotypes
type AB.
A
B
A
O
AA
AO
AB
BO
in the offspring?
___________________
AA, AO, AB, BO
2. What is the genotypic
1:1:1:1
ratio? ____________
3. What is the phenotypic
2:1:1
ratio? __________
4. What is the probability of
producing a child with
50%
blood type A? _______
5. What is the probability of
producing a child with
blood type O? ______
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
1. What is the male’s
male.
Xb
Xb
XB XBXb
XBXb
bY
X
Y
XbY
XBY
genotype? __________
2. What is the female’s
b Xb
X
genotype? _________
What is the probability of
producing a
3. black-eyed female? _______
50%
4. black –eyed male? _______
0
5. red-eyed female? ________
0
50%
6. red-eyed male? __________
• Label the three parts of the nucleotide below.
phosphate
A.______________
sugar
B.______________
base
C.______________
In DNA, how do the bases bond?
_____________
bonds with ____________
Adenine
Thymine
and
_____________
bonds with ____________
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
Strands
Sugar
DNA
RNA
2
1
deoxyribose
ribose
Base
A with T
A with U
Pairs
C with G
C with G
Location nucleus
Nucleus to
cytoplasm
• Protein Synthesis is divided into two processes.
Transcription
• Process 1- _____________________________mRNA is made by copying the code from a DNA
molecule.
This process occurs in the nucleus
__________.
Translation
• Process 2-_____________________________a
protein is assembled from amino acids.
cytoplasm
•
This process occurs in the _______________
at a _____________________.
ribosome
• 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 UG U C
• Label parts 1 through 5 in the diagram.
5
1
4
3
2
tRNA
Amino acid
• 1. _______________
4. _______________
mRNA
Protein
• 2. _______________
5. _______________
ribosome
• 3. _______________
5
1
4
3
2
What is the name of the process in the picture?
_____________________
Translation
• A mistake in the genetic code is called a
Mutation
____________________.
• Name the type of mutation in the DNA sequences
below. Use these choices
Substitution
•
•
•
•
Insertion
Deletion
Original strand – CTGACT
New strand
CTAGACT ___________________
Insertion
New strand
CTGCT ___________________
Deletion
New strand
CTGAGT ___________________
Substitution
Gel
Electrophoresis is a
• ___________
____________________
method used to separate and analyze DNA
fragments.
DNA
fingerprinting
• __________
____________________
is the
analysis of DNA fragments to identify an
individual.
CS= crime scene DNA
s1= suspect 1
s2= suspect 2
s3= suspect 3
s4= suspect 4
s5= suspect 5
cs s1 s2 s3 s4 s5
Recombinant DNA or Cloning?
Where is genetic engineering used
in?
Recombinant DNA Technology
• Medicine: gene therapy
• Agriculture: genetically
modified foods
Cloning
• Medicine: therapeutic
cloning of stem cells