Blueprint of Life
5a. DNA & RNA
DNA is a double helix made of a sugarphosphate backbone with complimentary
bases paired in middle
Nucleotide (sugar, phosphate, & base)
A pairs with T
C pairs with G
RNA vs. DNA
# of Strands
1. The monomers that are put together to make
nucleic acids are called:
2. DNA & RNA are made up of which type of macromolecule?
C) Nucleic Acids
C. Nucleic Acids
- ____________ (sugar)
- thymine (nitrogenous base)
- ______ stranded
- _______ (sugar)
- _____ (nitrogenous base
1. DNA or RNA?
2. Identify the bases in strand B
5b. DNA Replication
DNA Replication makes a copy
of DNA before cell division
(mitosis or meiosis)
DNA replication is semiconservative
parent strand is a template
for new daughter strand.
DNA has anti-parallel strands
run in opposite directions
Enzymes carry out replication
Helicase – unzips DNA
2) Primase – starts replication
3) Polymerase – matches A-T, C-G
to make new strands
4) Ligase – glues lagging strand
What does semi-conservative mean?
Strands are anti-parallel.
B) The old strands serve as templates for the new DNA.
C) The old strands are lost.
B. Old strand is conserved
What enzyme matches DNA base pairs (A-T, C-G)?
5c. Genetic Engineering
Recombinant DNA contains DNA from 2+
Restriction enzymes cut out gene from
Vectors (bacteria & viruses) can be used
to insert new gene into cell.
1) Make medicines
Ex: insulin, human growth hormone
2) Food Crops
Ex: pest-resistant, larger fruits/veggies
DNA > mRNA > ribosome > protein
Standard 4a & b
4a. Protein Synthesis
Protein Synthesis = making proteins
1. Transcription = DNA > mRNA
DNA is transcribed (copied) into
messenger RNA (mRNA) to leave
DNA is too big, it does not leave
mRNA carries the info in DNA out
of the nucleus to the ribosomes in
4a. Protein Synthesis
2. Translation = mRNA > protein
mRNA is translated into a protein by
Codon = 3 letter “words” on mRNA
Ex. U G G
Transfer RNA (tRNA) matches each
codon and transfers the correct
Amino acids add together to make
a polypeptide chain, which becomes
4b. Build a Protein
1. Transcription DNA > mRNA
Transcribe the DNA template strand into mRNA
C T G T A C G G A template strand
A base sequence of DNA is shown below.
How would the base sequence be coded on mRNA?
4b. Build a Protein
mRNA > protein
Use the codon
Changes in DNA
Mutation = permanent change in the DNA
Mutations can be good, neutral, or bad
base change – may or may not have an
effect (ex: A C)
What would happen if GGG changed to GGC?
Gly so nothing…
would happen if UAC changed to UAG?
protein production so effect could be major…
2. An insertion or deletion changes the reading “frame”
The fat cat ate the rat
The atc ata tet her at
Mutations occurs in sperm or egg – passed to offspring
Tay Sachs disease, sickle-cell anemia, muscular dystrophy
Mutations occurs in regular body cells they may cause
4d. Cell Specialization
All cells in your body have the SAME DNA
Only genes need by that cell are
Each cell only expresses the portion of the
DNA containing the genetic information
for the proteins required by that cell at
The remainder of the DNA is not
The cells of in your skin have the DNA that
codes for your eye color protein. They just
don’t use it
20 amino acids make up all proteins.
Your body creates many different proteins by changing
the number and sequence of amino acids
Proteins vary from about 50 to 3,000 amino acids in
The types, sequences, and numbers of amino acids used
determine the type of protein produced.
Hemoglobin – 574 aa
Insulin – 51aa
One human disease is caused by a change in one
codon in a gene from GAA to GUA. This disease
is the result of:
A a mutation.
B a meiosis error.
Although there are a limited number of amino acids, many different
types of proteins exist because the
A. size of a given amino acid can vary.
B. chemical composition of a given amino acid can vary.
C. sequence and number of amino acids is different.
D. same amino acid can have many different properties.
Mutations within a DNA sequence are:
A. natural processes that produce genetic diversity.
B. natural processes that always affect the
C. unnatural processes that always affect the
D. unnatural processes that are harmful to genetic
Wound up DNA
Write really small!!!
Chromosome - wound-up
DNA containing genes
Sister chromatids are
identical copies held
together by a centromere
Draw & label a chromosome
on the right margin.
2e. Homologous Chromosomes
Homologous chromosomes – have the SAME genes
at the SAME locations
came from mom, one from dad
Karyotype – chart shows all the homologous pairs
- pairs 1-22
Sex chromosomes - 23rd pair determines sex
XY = boy
True or False:
1) Humans have 46 chromosomes
2) Humans have 23 pairs of chromosomes
3) Pairs 1-23 are autosomes
4) XX is male
5) XY is male
6) Sister chromatids are copies of each other.
7) Homologous chromosomes are identical.
Making Sex Cells
std. 2a-d, 2g
2a. Chromosome Number
Divide Box 2a into 2 columns (5 concepts to write, 3 in left column, 2 in right)
1. Chromosome Number
Diploid (2n) – somatic (body) cells with
2 sets of homologous chromosomes
Humans = 46 chromosomes (23 pairs)
Haploid (n) – gamete sex cells that
have 1 set of chromosomes
Humans = 23 single chromosomes
1) A bug has a haploid number n=5. What is the
diploid number (2n)?
2) A crocodile has a diploid number 2n=50. What is
the haploid number (n)?
2a. Meiosis Overview
2. Meiosis vs. Mitosis
Meiosis – cell division specific to sexual reproduction
that results in 4, genetically different, haploid
gamete (sex) cells
First cell of a new
Mitosis – asexual cell division that results in 2,
genetically identical, diploid cells
A = Mitosis
B = Meiosis
C = Both
1) Type of cell division.
2) Produces 2 cells
3) Produces 4 cells
4) Sexual reproduction
5) Asexual reproduction
6) Resulting cells are genetically different
7) Diploid to haploid
8) Resulting cells are genetically identical
9) Diploid to Diploid
2a. Steps of Meiosis
3. Steps of Meiosis
Steps are mostly the same as Mitosis, but diploid cell
Meiosis I separates the homologous pairs
Meiosis II separates sister chromatids
Steps of Meiosis
2a. Crossing Over
4. Crossing Over
Homologous chromosomes pair up
and randomly trade piece of DNA
during Prophase I
This creates genetic variation (new
gene combinations that never
Draw Crossing Over (middle step
2a. Independent Assortment
5. Independent Assortment
Genes for different traits sort independently into
Genes on different chromosomes are not connected
Ex: The gene for eye
color is not connected
to the gene for hair
What accounts for so many possible combinations of
genes in gametes?
B) Independent Assortment
C) Both of these
True or False:
Meiosis 1 separates homologous pairs, while Meiosis
II separates sister chromatids.
2b. Meiosis in Humans
Only gonads undergo meiosis
= the testis produces 4 sperm (gametes)
FEMALES = the ovaries produces 1 large egg (gamete)
and 3 polar bodies
2c. Random Segregation
Law of Segregation
It is random whether the gamete gets the maternal
or paternal version of each trait
Each gamete only gets one allele
Draw the diagram:
Ex: If a pea plant is tall (Tt), half the gametes
will have T and the other half will have t.
After fertilization, the offspring will have 2
alleles, one from mom & one from dad
If a corn plant has a genotype of Ttyy, what are
the possible genetic combinations that could be
present in a single grain of pollen from this plant?
A. Ty, ty
B. TY, ty
C. TY, Ty, ty
D. Ty, ty, tY, TY
Sperm + egg = zygote
haploid + haploid = diploid
2g. Predicting Offspring
Alleles - different versions
of a trait
Blue or brown eyes
Knowing the alleles of the
parents allows you to
predict the possible traits of
Use a Punnett Square
True or False?
1) Segregation occurs when genes separate into
2) Females produce 4 eggs.
3) Males produce 4 sperm.
4) Fertilization occurs when diploid eggs and sperm
make a zygote.
5) Human zygotes have 23 chromosomes.
6) Alleles are different versions of a trait.
Standard 3a & b
3a. Punnett Squares
Vocabulary to know:
Genotype = genes (TT, Tt, tt)
Phenotype = appearance (Tall or short)
Homozygous/Purebred = 2 of the same allele (TT or tt)
Heterozygous/Hybrid = 2 different alleles (Tt)
Types of Inheritance
1. Autosomal – genes on regular
body chromosomes (#1-22)
Dominant covers up recessive
The protein created by the
dominant gene functions better
or is darker/stronger than the
2. Incomplete & Codominance
dominance = show
mix/blend between two alleles
Red + White = pink
Codominance = show both
traits at once
Red + White = red & white
3. Sex-linked – genes on
men have only 1
X (XY) they don’t have a
“backup” X like women
(XX) to hide the trait
If the X is bad, men have
3b. Mendel’s Laws (see 2a & c)
Mendel’s Law of Segregations – see 2c
Mendel’s Law of Independent Assortment – see 2a5