Evolution and Genetic Engineering - Inverness Royal Academy

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12 Δεκ 2012 (πριν από 4 χρόνια και 9 μήνες)

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Topic 4

Learning objectives:


By the end of the lesson you should be able to:


Explain the impact of the environment on the phenotype of
an organism.


Describe how identical twins or clones can be used to assess
the impact of the environment on a organisms phenotype.


State whether environmental impact on phenotype can be
passed on to the next generation.


1: Environmental effects on the
Environment


For most polygenic characteristics the phenotype is
determined by _______________


____________ which determines the ___________
development of the individual


_______________ which influences the _________
development

of the individual

two factors

genotype

potential

environment

actual

The combined effect of genotype and phenotype is often
shown as



e.g. over the last century the average height of humans
has increased as their diet has improved



e.g. For chlorophyll formation in tomatoes, a
mutant tomato plant which is white will turn green
if grown in temperatures above 26 oC

Genotype

Environment

Phenotype

2: Environmental effects and inheritance


Changes in phenotype are not inherited and so do
not affect evolution.


The ______________________ on the phenotype can be
dramatic e.g. a land mine may deprive a person of a leg.


_____________________________, so only changes to a
person’s genotype can affect ___________________, and
therefore _______________


e.g. The land mine victim with one leg can have healthy
children with 2 legs

effect of the environment

Only the genotype is inherited

future generations

evolution

3: Studying the effects of the environment
on the phenotype


Clones are genetically identical individuals


The effects of the ____________ on the _______________

_______________ is studied using _________

environment

development

of characteristics

clones


Cloned plants grown in ___________________ show effects
of that condition on the development.


Since the genotypes are the same, __________________________

e.g. Plants grown in light are green and healthy but clones
grown in the dark are yellow and sickly

different conditions

Any difference in the plant must
be due to the environment


Identical twins are _________ and are useful in
studying the effects of “nature” (genotype) and
“nurture” (environment on development


Differences between identical twins must be due to
the _____________________________

clones

effects of the environment

Learning objectives:


By the end of the lesson you should be able to:


Define the term Natural Selection.


Describe the mechanisms which drive natural selection


Explain how natural selection has acted on the peppered
moth




4: Evolution and natural selection


Evolution is the scientific explanation for the
____________________________________ over the 3.5
billion years since life first appeared on Earth.


The current theory of evolution was first proposed by
______________ in the 1850’s



It is based on simple observations

Changes seen in species and biodiversity

Charles Darwin



Organisms _____________________ than the
environment can support


This results in _____________ for limited resources


There is a __________________ the effects of



Lack of water / food


Lack of shelter


predation


disease

produce more offspring

competition

struggle to survive

Members of species show ___________________ due
to the expression of different alleles


Those individuals with ________________________
to the environment are more likely to _____________

____________________


Those individuals with ______________________ to
the environment are more likely to ____________

________________________

inherited variation

phenotypes better suited

survive and

breed and so pass on their genes


phenotypes less suited

Die so do
not

pass on their genes


This process is called __________________ and results
in ________________________


Over ______________________ the characteristics of
____________________ e.g. the peppered moth story

natural selection

survival of the fittest

many generations

species may change

5: The environment and evolution


If the environment __________________ there is no
pressure for a successful species to evolve


E.g. coelacanth is a deep sea fish which looks exactly
the same today as 80 million years ago

does not change


If the environment ________________________ then
species may become ____________


E.g. 65 million years ago many species including the
dinosaurs disappeared due perhaps to the impact of a
large asteroid

Changes too rapidly

extinct


________________ are causing __________________
and so many species which cannot adapt quickly
enough will become extinct.


Borneo

Human activities

rapid environmental change

Learning objectives:


By the end of the lesson you should be able to:


Explain the process of selective breeding.


Describe the advantages and disadvantages of selective
breeding.

6: Selective breeding


For thousands of years __________ have been
_______________________________________________
to produce the next generation.


This is in the hope of _____________ certain
characteristics

humans

selecting individuals with favourable characteristics

improving



This process is called artificial selection or _______________
________________________

selective

breeding



In this way most of the animals and plants used by humans
have been ___________________________________

modified from their ancestors

Some examples of characteristics which have been
____________ are


Size and taste of __________________


Beef and milk yield in _________________



Disease resistance in ___________________



Egg production and growth in ______________


Varieties of ________

improved

food plants

cattle

crops

poultry

dog

(note: fish and timber are still harvested from the wild, but the supplies are
running low due to poor management of these resources)

Learning objectives:


By the end of the lesson you should be able to:


Describe the process of genetic engineering from the
identification of a desired gene to the synthesis of the desired
product.


7: Genetic engineering


Genetic engineering involves altering the genetic
material of an organism.


This can be done in two ways



Altering or removing genes



Adding genetic material from another organism

Using Genetic Engineering to modify bacteria

Using Genetic engineering to modify plants


Using Genetic engineering to
modify animals

Result of genetic engineering


Produces individuals ________________________
called _________________________ (
GM
) or transgenic
organisms


Has led to _____________ and ___________________
of medicines

showing new characteristics

genetically modified

faster

larger scale production

Learning objectives:


By the end of the lesson you should be able to:


State some of the medicinal products produced by genetic
engineering.


Describe the advantages and disadvantages of genetic
engineering.





GM _______________ are used to produce the
proteins needed by humans


e.g. diabetics can now use human insulin
produced by bacteria which have had the human
insulin gene inserted into then.


In the past diabetics had to use animal insulin

bacteria

8: Genetic engineering compared
with selective breeding

Feature

Genetic engineering

Selective breeding

DNA can be introduced

from
___________________

DNA only comes from
______________________





Advantages

Genes

Time

Changes appear in the
_________ generation

Changes take _________
generations

Offspring

Will ________________ the
improvement

May or _____________
show the improvement

any species

one species

next

many

definitely show

may not


Disadvantages

Feature

Genetic Engineering

Selective Breeding

Public
Acceptance

Safety

People are
______________

of the new technology

____________________

of GM organisms

The _________________
of producing new
varieties

_______________________

seen as safe

suspicious

accepted way

concern over the release

natural process