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All life has heredity in DNA
A always bonds with T, and
C always bonds with G.
Hydrogen bonds connect
the two strands of DNA.
DNA and Proteins
All life has heredity in DNA
1)DNA
replication – the process of making an
identical copy of DNA. Must occur before a cell
divides.
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All life has heredity in DNA
2)DNA
transcription: to rewrite the DNA code in
RNA as a messenger that will travel outside the
nucleus to begin protein
production.(Enzymes,hormones,tissue)
RNA
Single stranded;
sugar is ribose.
A—U
DNA T — A RNA
G—C
C—G
Messenger RNA
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All life has heredity in DNA
3)DNA
translation: the code in the messenger
RNA is translated into
protein within an
organelle called
a ribosome.
Cytoplasm
Nucleus
Ribosome
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Proteins
Proteins are polypeptides, which are long
chains of amino acids.
The sequence of nucleotides in each gene
contains information for assembling the
string of amino acids that make up
proteins.
During translation, proteins are created
from long chains of amino acids whose
structure depends on the order of amino
acid assembly. A mutation in DNA
changes the protein.
Biochemical Reactions
All organisms contain DNA.
DNA (deoxyribonucleic acid) carries the
genetic code for all organisms.
Four nucleotides: Nitrogenous bases
A - adenine
T – thymine
G – guanine
C - cytosine
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Cells can undergo chemical reactions that
release energy from carbon-containing
compounds (organic) as food.
There are 4 major classes of organic
molecules in organisms:
Carbohydrates
Proteins
Lipids
Nucleic Acids
Cells can undergo chemical reactions that
release energy from carbon-containing
compounds (organic) as food.
There are 4 major classes of organic
molecules in organisms:
Carbohydrates
Proteins
Lipids
Nucleic Acids
Carbohydrates
Include sugar – C6H12O6
Formed from photosynthesis
Broken down in cellular respiration
Equation: Photosynthesis
6CO2 + 6H2O → C6H12O6 + 6O2
Equation: Cellular Respiration
P + ADP + C6H12O6 + 6O2
→ 6CO2 + 6H2O + ATP
Carbohydrates
Needed
Deliver energy to the cell as glucose
Structural strength in plants as cellulose
Storage of energy in plants a starch
Short term storage of energy in animal as
glycogen
Needed:
Proteins
to access energy stored in cells
to build cell structures
to regulate rate of chemical
reactions as enzymes
Video
Lipids
Commonly known as fats and oils
Create membranes of cells that provide
sites for essential energy conversions.
Needed
As Long term energy storage in animal
As Insulating material in cold climate
As Shock absorber
Nucleic Acids
Commonly known DNA and RNA
Are made of nucleotides that contain,
carbon , nitrogen and phosphorus.
Needed
To contain and transmit genetic code
from generation to generation
Asexual and Sexual Reproduction
All organisms must reproduce
For sexual
reproduction
Gametes
For asexual
reproduction
video
Asexual Reproduction
One parent passes copies of all its
chromosomes to each of its offspring.
Organisms produce new cells by mitosis.
Mitosis is the process of nuclear division
in which 2 new daughter cells each
receive a complete set of chromosomes.
Offspring are genetically identical to
each other and the parent.
Examples: Refer to table 1 video
Sexual Reproduction
Involves two parents
The offspring receives half of its
chromosomes from the father and half
from the mother.
Gametes are sex cells (eggs – sperms)
Meiosis produces gametes (1/2 # chromosomes)
Upon fertilization, full number of
chromosomes is restored with the
formation of a zygote.
Sexual Reproduction
A zygote contains all the information
necessary for growth, development,
and reproduction.
The zygote will be similar but not
identical to its parents and different
also from its siblings. Increased genetic
variations and ,consequently, better
adaptations to environmental changes
Punnett Squares
Genotype – genetic characteristics
carried by an organism.
Phenotype – the way an organism looks
and behaves.
Alleles – genes that exists in alternative
forms. The allele combination
determines its genotype.
Dominant
Recessive
Punnet squares predict
probabilities of outcomes.
Gametes produced by
each parent pea plant
are shown along the
top and left side.
Remember: when the germ
cell that produces the
sperm or egg divides, the
2n (diploid) number of
chromosomes is split in
half: Tt becomes T and t.
T = dominant
t = recessive
All life has heredity in DNA
Punnet squares predict
probabilities of outcomes.
¼ of offspring are TT.
½ of offspring are Tt.
¼ of offspring are tt.
T = dominant
t = recessive
But ¾ of offspring
are tall, and only ¼
are short (3:1 ratio).
The dominant characteristic usually
overpowers the recessive one.
All life has heredity in DNA
Pedigree charts relate to
punnet squares
Square = man
Circle = woman
Filled = disease
Half filled = carrier
Open = healthy
An example of a sex-linked gene
All life has heredity in DNA
DNA
The code
of life
Mutation in the DNA code
in a sex cell chromosome
creates a new
inheritable alleles
Two pink-flowering plants are crossed. The offspring
flower are as follows: 25% red, 25% white; 50% pink.
What pattern of inheritance does flower color in
these flowers follow?
A. dominance
B. multiple alleles
C. incomplete dominance
D. recessiveness
E. polygenic trait