Transcript All life has heredity in DNA - John A. Ferguson Senior High School

What is Biology?
What is Biology, you ask?
Biology is the study of life.
Living things are called organisms.
Organisms include bacteria, protists, fungi,
plants, and animals.
Viruses are not alive – they are not organisms.
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The seven characteristics of life
All life is made of cells.
All life must reproduce.
All life has heredity based on one universal
genetic code (DNA).
All life has metabolism.
All life must respond to environmental stimuli.
All life has homeostasis; it must maintain
a stable internal environment .
All life must evolve; that is, species
must change over time.
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All organisms are made of cells
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All organisms are made of cells
Cells are the building blocks of life.
All cells come from pre-existing cells.
Viruses (in red here) are not
made of cells; they are not alive.
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The cell theory states that
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all living things are made up of cells;
basic units of structure and function in
living things are cells
that new cells can only be produced
from living, existing cells.
Biochemical Reactions
Cells can undergo chemical reactions that
release energy from carbon-containing
compounds (organic) as food.
There are 3 major classes of organic
molecules:
Carbohydrates
Proteins
Lipids
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
Proteins
Needed:
to access energy stored in cells
to build cell structures
to regulate rate of chemical reactions
Lipids
Commonly known as fats and oils
Create membranes of cells that provide
sites for essential energy conversions.
Refer to figure 1 in the packet
Cell membrane
Separates the living from non-living environment.
Made of protein
and lipid
Cell membrane
A cell must be able to obtain food and get rid
of wastes through its cell membrane
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Diffusion
The movement of particles from a region of high
concentration to a region of low concentration.
Click here for video
Examples: perfume in air, smoke in air, sugar in water,
oxygen through cell membranes
Osmosis
Diffusion of water from an area of high
concentration of water molecules to
one of low concentration across a
partially permeable membrane.
Partially permeable means only some things can
pass, not everything: usually small molecules with
no charge, like H2O, CO2, & O2.
“High” water concentration means that there are a
lot of water molecules per some unit of volume.
“Low” water concentration means that
there is a lot of something dissolved in
the water, so fewer molecules of water.
video
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Comparison of
Photosynthesis and Cellular Respiration
Discuss Table 1
Photosynthesis video
6CO2 + 6H2O → C6H12O6 + 6O2
Cellular Respiration
P + ADP + C6H12O6 + 6O2
video
→ 6CO2 + 6H2O + ATP
All life has metabolism
Cellular Respiration (in Mitochondria)
Through respiration, cells release the chemical
energy stored in foods created by photosynthesis.
6O2 + C6H12O6
6CO2 + 6H2O + 36 ATP
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All life has metabolism
Sunlight is the ultimate energy for life on Earth.
Photo-synthesis is carried
out in the chloroplast of producers
such as algae, phytoplankton, plants.
Asexual and Sexual Reproduction
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.
A zygote contains all the information
necessary for growth, development, and
reproduction.
The zygote will be similar but not
identical to its parents.
All organisms must reproduce
For sexual
reproduction
Gametes
For asexual
reproduction
video
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.
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
All life has heredity in DNA
Pedigree charts relate to
punnet squares
Square = man
Circle = woman
Filled = disease
Half filled = carrier
Open = healthy
DNA and Proteins
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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All life has heredity in DNA
DNA
The code
of life