This in-depth IEB Grade 12 Life Sciences guide explains molecular biology concepts, focusing on DNA structure, protein synthesis, gene mutations, and advanced biotechnology topics such as genetic engineering, CRISPR, and GMOs. Covering the Human Genome Project, polygenetic inheritance, and various ...
cellular and
,
11 9
.
PIMS P
""" y
tissue
level
EL1I WWII 114 11 NESQUI
A genome complete set of to create
what is a
is a
genetic instructions
(genes) necessary
an organism
human genome ?
>
Nearly every somatic cell body has a complete copy of a genome
in the
< Each species has a
unique genome although the genome of individuals
-
the same due to mutation
Within species may vary slightly
What was the
The Human Genome Project CHGP) is an international scientific research project
set
up in 1990
human genome
project ? hat was Its primary
~ goal ?
determine the of chemical base pairs which make-up human
sequence
·
DNA (DNA sequencing)
Identify and map all
genes of the human genome from both a
physical
·
and a functional point of view
#T: Humans only have 1 % of
unique genes (genes we don't share with other
species)
the function of and proteins
now is/was the
As more is learned about genes ,
this knowledge will
have a
major impact in the folds of medicine biotechnology and life sciences .
information ,
More than 1800
used ? genes causing diseases have already been discovered
A2 gene associated with increased risk of breast cancer a
·
Apo-E gene linked to Alzheimers disease
gene linked to bad
· LDL receptor cholestrol and heart disease
: Many ethical , legal and social issues have arisen since the human
genome was sequenced
, DALL WO PINTIS
Nine
life at a molecular ,
cellular and
level
tissue
↑ En
and
SUN
what is meant
Polygentic Inheritance refers to when more than one pair of alleles is responsible
for trait/characteristic
by polygenetic
a
single
Inheritance ? -
these more complex traits determined by interactions of many
are
alleles each
having small individual effects on the
,
offspring
resulting in ,
a
(continuous characteristic
range of
phenotypes
-
As the number of loci affecting the trait increases , the number of
phenotypic
classes increase
What is meantThe more pairs of alleles that controls a characteristic
,
the greater the
by continuous number of possible combinations and greater the variety of phenotypes Each
variation ? phenotype differs slightly from the next ,
forming a
graduated series known
as continuous variation
examples :
height ,
skin colour ,
weight
how does nature
Sometimes environmental factors such as , exercise and disease can
diet play a
role in variation
vs nuture
play a
role ?
examples :
·
average height in
many europeans has increased over the past century
as nutrion has improve
If mulnurished child intended
·
as a to reach the
a person is
unlikey
height that was coded for
by genes
, M
life at a molecular ,
cellular and tissue N
level
What is a
A sudden
change in the
genetic make-up of an
organism
gene mutation ? es
a
gene mutation arise
A gene mutation results from
· a
change in the sequence of neucleotides
a DNA molecule
causing change in the information the gene
In ,
a
gives
to the cell
factors that increase the rate of mutation
What are
mutagens ? knising radiation :
ultraviolet light and X-rays
-
have a
now de
mutation can variety of effects on
organisms depending on the type
of mutation
mutations
affect
-somatic mutations : occur in
body cells and are not transmitted to
organisms ?
the next generation , These cells to become
can cause malignant which
will result in cancer
-gametic mutations reproductive organs (plants + animals)
:
occur in
and produce change to the genesIn the gametes . These mutations
(germ-line mutations) may lead to variation in offspring. An accumulation
of these changes can result in speciation or lead to hereditary disease
Neutral mutations do not affect the life of an organism .
NEUTRAL
MUTATIONS · Every individual has some mutation but most of them will not be visible in
the phenotype
· Some gene mutations , change the physical features of the body .
however , do
but do not seriously affect body functioning ite tongue rollers and non-tongue rollers
* small
percentage of mutations result in a
change In the phenotypes.
BENEFICIAL
If the change results in
organisms adapting better to new or unfavourable
MUTATIONS conditions , they will survive and breed more succesfully than the rest of the
Population . This Is natural selections as nature has selected the better to
survive and breed . In time the whole population will have a new genotype (speciation)
-mostly occur In viruses and bacteria due to their rapid reproduction rate
in the color of the
eppered moth
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