Transcript Core – Practice test 4

Core – Practice test 4
Genetics
Remember what an inference is?
• An explanation based on observations
Sexual VS Asexual Reproduction
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Sexual – two parents
Meisois
Testies and ovaries
Fusion of egg and sperm to
form a zygote
seeds, flowers
Increase variation
Evolution
Changing environments
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Asexual – one parent
Mitosis
Somatic, body cells
Cloning
Exact copy
No variation (unless
mutation)
• Produce many offspring
A normal human cell has 46
chromosomes. After a cell undergoes
meiosis, how many chromosomes
will the resulting cells have?
• 23
• In which organ of an animal's body would
meiosis occur?
• Testis and ovaries
• In a plant?
• flower
In changing environments, is
asexual or sexual better?
• Sexual. Why?
• The increase in genetic
variability.
• Why would some grasses be
able to grow on ground
polluted by an oil spill
• Genetic variation within the
grass species allows some to
survive and reproduce.
What do you know about the
Irish Potato Famine?
• 1845 A fungus like protist destroyed
the Irish potato crop which was the
main source of food for one third of
the population. This led to a 7 year
famine. Why did one little fungus
cause so much trouble?
• Potatoes grow by asexual
reproduction therefore the potatoes
lack variations that could have
withstood the infection.
When environmental conditions are bad or change, is
sexual or asexual reproduction better?
• Sexual reproduction
• Why?
• It increases genetic variation (like having more
choices).
How does asexual reproduction help
the survival of a species
• Asexual reproduction may result in many
offspring with the same strong useful
characteristics as the parent.
Forms of Asexual Reproduction
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Mushroom reproduce by producing–
spores
Bacteria reproduce by–
fission
Hydra –
budding
Tulips (and things with bulbs) –
vegetative
Reproduction/Plants
• Is it better to reproduce
with spores or seeds?
• Seeds
• Why?
• Seeds contain stored
nutrients for nourishment
and a hard protective coat.
Chromosome number
• In sexual reproduction (meiosis) what
happens to the chromosome number?
• It is cut in half (humans 46 to 23)
• In Asexual reproduction – chromosome
number?
• Stays the same.
From DNA to Protein
DNA vs. RNA
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DNA (where?)
Nucleus only
How many strands?
Double stranded
What type of sugar?
De oxy ribose
Bases are . . . . .
A-T and
G-C
• RNA (where)
• mRNA from nucleus to
cytoplasm
• tRNA and rRNA – cytoplasm
• How many strands?
• Single stranded
• What type of sugar?
• Ribose
• Bases?
• A-U
• G-C
What does DNA look like?
• A twisted latter.
How were discoveries of DNA
made?
• A lot of people involved.
• Watson, Crick, Wilkins,
Franklin and more
• What did they do?
• They did many experiments
and Watson and Crick made a
model.
Central Dogma
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What is Replication?
DNA to DNA
Where?
Nucleus
What is Transcription?
DNA to mRNA
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Where (transcrition)
Nucleus
What is Translation?
RNA to Protein
Where?
Cytoplasm on the
Ribosome
DNA to Protein
How does DNA get from the nucleus to the
ribosomes?
• It jumps
• Just kidding – mRNA (messanger RNA)
takes the message from the nucleus to the
ribosomes.
Patterns of inheritance
1. Which trait usually shows dominant or
recessive?
2. dominant
3. Wavy hair is where both are dominant or
_________ dominance.
4. codominance
5. If I cross a white and red flower and get
pink. What is this?
6. Incomplete dominance
inheritance
• Eye color, hair color, height is what type of
inheritance?
• Polygenic
• Blood type is what type of inheritance?
• Multiple allelic and codominance
Words to know
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Hetero zygote
Different - Rr
Homo zygote dominant
Same - RR
Homo zygote recessive
Same - rr
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Gene o type
Genes RR, RR, rr
Pheno type
Physical stuff – red,
white, tall, short
Punnet Squares
• If you cross a Green pea
with a yellow pea and
get all green peas, why
is this?
• Green is dominant over
yellow.
• Then, if I cross these
kids, what will happen?
G
G
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Gg
Gg
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Gg
Gg
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G
GG
Gg
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Gg
gg – some
yellow will
show up
Genetic Technologies
• And genetic engineering.
Selective breeding is also called
what?
• Artificial Selection.
• Why?
• Humans select for
certain traits instead
of nature (as in
natural selection)
• An orchard in California
makes really great
oranges. They want to
maintain this high
quality. How should
they do this?
• Clone the trees – Take
cuttings from the already
fabulous trees and make
trees.
What is the process called when an
egg is removed, fertilized outside of
the body, and then implanted in the
womb?
• in vitro fertilization
Selective breeding
• Also called
• Artificial selection
• Breeder/farmer chooses only the best animals or
crops
• Examples
• Corn Hybrid
• Race horses
• Shetland pony
• Siamese cat
Genetic technologies
• How do we do genetic testing on fetus?
• Amniotic fluid can be taken to diagnose
prior to birth (and possibly fix)
DNA profiling (CSI)
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Also called?
DNA fingerprinting and
Gel electrophoresis
Used for?
Identify the killer
Who’s the dad?
Gene Therapy
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Also called?
Recombinant DNA?
What is it?
Insert a foreign gene
into a host
• Being used for
• (cystic fibrosis)
• Use bacterial plasmids
to make?
• Insulin
• Human Growth
Hormone (HGH)
• Interferon
• Other stuff.
Other Genetic technologies
• Cloning
• Increase food supply, improve health, better
medicines, transplants etc.
• Stem cell research
On the board
• Punnet squares and pedigrees.