IGCSE BIOLOGY
MADE BY RIANA CORDOVA
NITROGENOUS
°
broken down to form nitrogen
How
EX
o
C R E T O RY
Excretion
Removal from organisms
:
respiration )
(
Egestion :
*
toxic materials
,
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in
excess
as
it is
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arteriole
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and
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important for blood clotting
which is
acid molecules
amino
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.
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and the ammonia is
liver
kidney
contain
be excreted
to
Small amount excreted
.
away by the blood throughout the body
energy
,
it is
wasteful for it to be excreted
.
as
it is
structures called nephrons
loop down the medulla and
brought
There are thousands
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capsule
the renal capsule in the branch of
to
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kidneys
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Afferent arteriole
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blood
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of blood
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.
and
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get away easily
High pressure
.
blood in glomerulus pushes against
so
so
capillary walls
walls have holes in them to let molecules
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glucose and
t
Nephron
capillaries
urea
.
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ti on happens
cortex
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through :
big to go
water salts ,
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capsule and glomerulus is where filler a
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→
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nephron
has many mitochondria
-
salts
urea as well as excess
Urea
.
Not reabsorbed
cannot take place
-
°
After substances
have been absorbed
solution of salt and water
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Flows out
stored for
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a
while
Large quantities of
less
*
kidneys
urea
small
and
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more
along
urine
.
urea
as
else
TH E B LA D D E R
and into the bladder where it is
pale yellow
→
a
the urethra
lot
.
of water and
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Urine from all nephrons in the
Stores urine ; has
Leading
closed
→
anywhere
a
.
urine
and exercise
is
.
ureters
→
darker
concentration
water intake will affect
temp
product
being released through
before
concentration
quantities of
water
,
urine
:
the final
yellow / orange
-
little
.
the concentration of water in
water is lost in sweat
.
urine
.
duct
again
cortex
glomerulus
glomerulus
in
builds up
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A
.
of renal capsules in the cortex of each
Inside the renal capsule
.
ill aries called the
/
of
artery
renal
the
tubule
back up
goes down to the medulla
E⑧s÷÷÷
°
.
( Bowman's capsule)
renal
artery
.
→
.
( broken
deaminate d
are
split
in the liver
/ used
stored
are
stored
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.
blood and taken to
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broken down into
small intestine
for
vein
like fibrinogen
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blood is
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then
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are
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the amino acids
Because
Inside the nephron
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behind the intestines
,
:
tiny
million
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canal and protein molecules
Fi Iteration
renvadin
to the pelvis
in sweat
*
urea
Urea dissolves in
toxic substance
.
Start in the cortex
Carbs converted to glycogen
5)
in liver
.
absorbed into the blood inside the
are
Amino acids used to build protein
converted to
toxic waste products of metabolism and
the cortex again
'
urine
4)
are
.
Excess amino acids in the blood
.
( formed
and salts
alimentary
down ) into carbs and ammonia
.
kidney contains
(
,
urea
carried to the liver through the hepatic portal
.
acidic
an
activity
enzyme
producing
by
important functions
kidney tubules )
L
urea
water content in blood
in excess
(
)
,
in the back of the abdomen
Regulate
Each
form
K l D N EY
* Excrete
°
acids
amino
They have two
*
anus
product of aerobic respiration )
reducing
cells
excess water
high concentrations
Located
( waste
because it dissolves in water to
excrete
T HE
°
through
in faeces
containing product :
-
These
.
made in the Liver
As amino acids
3)
lowering pH of
Kidneys
from
2)
.
Excretion
during exhalation
°
food waste
amino acids
L
carbon dioxide
excrete
solution
excess substances
urea is
Protein in food taken into
of metabolism
kidney
t
Lungs
1)
products
of waste
and
undigested
of
Removal
Egestion
Lungs
o
PRODUCTS
amino acids
Animals produce nitrogenous waste formed from excess proteins and
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WASTE
.
kidney
stretchy walls to
out the bladder
take it to the ureter
hold
and then to the bladder
large quantities
is the urethra
with
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sphincter
muscle
at
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blood and
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dialysis fluid
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kidney Dialysis
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and water balance
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kidney
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kidney
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side of body
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membrane
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D l AL Y S IS
kidneys
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replace both kidneys
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fluid allowing exchange through concentration gradient
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concentration
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Anticoagulant
clotting
is
.ms/
gradients
added into blood before dialysis to prevent blood
.
-
°
No
urea
in fluid
diffuses from blood to the dialysis fluid along
→
o
No concentration gradient
°
Movement of salts
across
for glucose
the membrane
TRANSPLANTS
VS
Patient
to
has
move
much
around
more
-
freedom
,
not connected
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procedure
°
Long
term solution
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only
work
-
for
dialysis
a
limited
occurs
if there is
an
are
similar in blood and fluid
imbalance in concentration
.
.
( low
This
prevents
salts in
net movement
blood
/
high
.
salts in blood )
-
D l A L Y S lS
.
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Risk of rejection
the donor
o
.
the concentration levels
large concentration gradient
Disadvantages of transplant
Advantages of Transplants
°
as
the
.
/
as a
'
as immune
foreign
'
system treats
substance
.
Not enough donors to cope with demand
.
Dialysis Procedure
#
/
Hypothalamus
A
°
Defined
L
as
the maintenance of
Internal conditions within
conc
to
.
,
glucose
body
ensure
L
If
conc
,
.
)
cells can
normal
asap
function
blood pressure
,
*
.
water
,
°
brought back
deviate and not
properly
to
°
o
.
°
They also
°
environment changes
have to
consume more
Ectothermic Animals
Unable to
:
due to
food
regulate
Take in temperature from surroundings
.
(
body temperature
Made up of two
dermis
layers
:
top layer epidermis
and bottom
o
-
layer
o
n
flat and trap
less
air
to parts of
body
.
it takes heat with it
as
lost from blood into air
body
distributed
hairs are
near surface dilate
.
More blood in
.
surface
.
upright which traps
contract and relax very
all over
vasoconstriction
so
the
body
a
layer
of warm air for insulation
to produce heat
quickly
This is shivering
.
.
Heat
.
generated
.
Arterioles that supply blood to surface of the skin
:
and no heat is lost
blood flows
through
Metabolism
may increase to produce
constricted so not much
are
.
heat
more
I:÷ :÷ :÷ ÷ ÷ f
NEGATIVE FEEDBACK
consists of Three layers
Epidermis
cornified
Layer
contains keratin
→
0
.
from UV radiation
conditions
iea
to normal
a
-
-
-
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.
:
0
.
Blood glucose levels
controlled
are
by negative feedback
involving production of
mechanism
-
and
Dermis
Blood Vessel
→
Temperature regulation
L
.
Gland
secretes sebum
→
acts as lubricant
-
glucagon hormones
by
Langerhans
the islets of
cells in
the pancreas with two glands in
one
.
Blood glucose falls
Blood glucose rises
.
insulin
.
Hormones are made
-
sebaceous
e-
mechanism
(
IGAINHEATN
change from the
Body too hot
conditions
.
erial
Occurs when
set point and returns back
effective waterproof
-
layer
→
,
Metabolism slows down
Muscles in the
.
.sn/ure'Functions-
→
nerves
.
I
→
hair lies
heat is easily
more
0
The Skin
o
along the
.
Arterioles supplying the the capillaries
Vasodilation :
Erector muscles contract
.
)
sends electrical impulses
Sweat in sweat glands evaporate to cool the skin
is
Cold blooded animals
hypothalamus
,
so
0
.
warm blooded animals)
37°C
is I
.
.
Cold Temperatures
constantly
energy from respiration
(
.
o
temperature
Maintain their body
Endothermic Animals :
even if their
CONTROL
.
temp
Erector muscles relax
means
B O D Y TEMP
.
temperature of blood running through it
Hot temperatures
certain limit
a
If
that controls body temp
.
body will not function
,
.
need to be kept within
of the conditions
one
body ( temp
your
etc
constant internal environment
a
the control mechanism that keeps internal temperature constant
at the centre of
Contains thermo receptors that sense
°
°
part of the brain
#
→
Sweat Gland
Produces sweat
→
-
cooling agent
1)
.
from pancreas
Insulin secreted
1) Glucagon
.
secreted
.
#
Hair
→
Heat control
→
2)
-
→
Erector Muscle
contracts
→
position
/ relaxes
Stimulates the liver and muscle
to control hair
glycogen
.
cells
glucose from respiration
the stored
2)
to convert
stored glycogen
into
glucose
.
-
→
Receptors
Detects
→
heat temp
.
and pressure
3)
.
stimulates liver and muscle cells to convert
concentration falls to normal
Blood glucose
.
( polysaccharide)
into
.
3)
Blood
be
regulated
concentration
rises to normal
.
-
Diabetes
→
Has collagen
Elastic Fibre
→
elasticity of skin
#
-
.
Dermis
*
o
underneath the dermis is
L
Adipose Tissue :
Oil
a
layer of fat called adipose tissue
Made up of cells
.
large drops of
which contain
cells
L
0
.
body
*
Insulates
*
Energy
*
Provides protective
0
.
type
died
have
thought
1 Diabetes
padding
around organs
.
o
of the person's
to be result
Hyperglycemia
Hypoglycaemia :
o
symptoms
:
treatment
needed)
:
not able to
When blood
as
the islets of
Langerhans
are
too
system
high
glucose levels drop
.
because
low
no
insulin can be
because no
glucose
produced
has been made
.
due to
.
Monitor
As well
own immune
Blood glucose levels
extreme thirst
:
are
.
absence of insulin
reserve
glucose levels
blood
:
,
blood
weakness
/ tiredness
glucose levels
injecting insulin
,
,
weight
loss
physical activity
checking glucose
.
and diet
conc
( affects
in urine
amount of insulin
and
exercising (
glucose
)
.
can be
as
even
used for
respiration
.
,
.
,
Once pectin ase is broken down
*
juice squeezed
°
Biology
want
we
using living organisms to carry out processes to
involves
*
*
fungi
Ex : Bacteria and microscopic
fungi
Bacteria and
quickly
No
,
are
arise
can
plasmids
to remove
foods
and other useful substances
cloudy
seem
juice
clearer
a
down
regions
grow
,
do not take up much space
producing complex molecules
,
reproduce
Milk
*
down
.
L
.
manipulate
and
lactase
.
lactose
Many people
0
.
.
and easy to
very small
and are capable of
ethical issues
Easy
produce
larger poly
-
-
.
lactose is the sugar found in milk and lactase is
it
by humans to produce
can be used
Microorganisms
*
more
Lactase
.
USE OF MICROORGANISMS
L
to fruits also helps
saccharides like pectin makes juices
make substances
o
°
the cell walls break more easily and
.
Adding pectinase
*
,
lose the
They
.
can be
glucose
lactose intoler ht
become
made
-
lactose
galactose
t
ability to produce lactase
enzyme that breaks
an
older in certain
they get
as
.
free by adding lactase to it
allowing it
and
to break
.
Also
galactose for sweets
and
produces glucose
.
.
USE OF PENICILLIN
USE OF YEAST
0
Making Biofuels
°
*
Yeast is
single
a
sugar
uses
as
a
food
source
o
.
production of penicillin
Ethanol used
glucose
2) Yeast
as a
Ethanol
*
Alcohol
2C 5
Hs OH
and uses the
glucose for
use
of fossil
fuels
human cells
industrial fernenter
an
Ferment ers
-
.
.
containers used to grow
are
produce large
.
broken down to
so starch is
amylase
burns well
but does not contain
use
carefully controlled
quantities
.
to
of exactly the
right type of microorganism
.
respiration
.
.
as much
as
energy
fossil fuels
so
petrol
is
Industrial Fer mentor
.
sustainable resource
land used
anaerobic
by distillation
is extracted
produced
Disadvantage :
GENETIC ENGINEERING
reduce coz from air
,
for biofuels could
be
used for food instead
0
.
Making Bread
*
harming
.
Advantage :
present
even
if oxygen
transgenic organism
causes
an
organism by removing
organism relieving genetic material
L
.
Yeast is mixed with flour and water
CO2
changing of genetic material of
The
ting individual genes from another organism
Yeast will respire anaerobically if it has access to plenty of
sugar
L
without
Conditions can be
°
used and treated with
added for vehicle engine
is
.
culture microorganisms in large amounts
2 CO2
t
biofuel to reduce the
usually
is added
3)
*
using
ethanol t carbon dioxide
→
Maize crop is
o
scale
large
on a
o
→
CGH 1206
1)
that
Fermentation
glucose
°
fungus
by Alexander Fleming
are substances which kill bacteria
Antibiotics
L
celled
-
First anti Obi tic discovered in 1928
the bread to rise
Alcohol broken down and
,
respires anaerobically
producing CO2
L
.
DNA of the
bread bakes
Ex :
.
changing
inSer
or
-
.
said to be genetically modified
or
a
.
organism
recombinant DNA
.
is killed as
yeast
,
is
,
that now has the other organisms
'
DNA is known as
.
Human insulin into bacteria
GM crop plants
,
Process
USE OF ENZYMES
1)
Biological washing Powders
°
Many
°
Contain
in
stains on clothes are organic molecules
to break down
enzymes
2)
.
large food
molecules
Quickly breaking
that will dissolve
L
L
down large
,
insoluble molecules into smaller
soluble ones
,
Be used to clean delicate
→
fabrics
less energy and money
which
aren't suitable for high temp
*
Fruit juices
extracted using
Pectinase is added
plant cell walls
.
plasmid from bacteria cell
gene
.
and
an
breaks
enzyme called
down
a
pectinase
.
chemical called pectin that is found inside
will
want to put
(
.
Transformation : Recombinant DNA plasmid is inserted into
If successful
they
of the DNA strand and to cut
4)
6)
are
with the trait
Gene splicing takes place
5)
.
A
used to cut the gene out
are
organism getting the
Effective at lower temperatures
organism
.
Restriction enzymes
a
the gene in
3)
.
Pectinas e
°
identify
organism B
Open
.
Advantages
L
Scientists
,
new
trait
begin making
when cell divides
,
protein
it copies the
develops from original
an
.
embryonic
cell
of
an
.
cell will make the DNA
it 's
to plasmid )
cut out gene inserted
and causes
foreign
cell has a
plasmid
a
part of
a new
it's
trait
new
gene
DNA and the
foreign
.
gene along with it's
copy of the
own
in
own
DNA
so
organism that
all it's cells
.
INHERITANCE
What is inheritance ?
inheritance
-
What is
genotype ?
a
Genotypes
-
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to
form
EX :
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colour
What is
a
An organisms
factors
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gametes
alleles
called
are
-
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a
letter
gene that
) usually
be dominant
can
the most
seen
dominant
it is
as
recessive
or
father
.
( XY )
.
Y
(
:
letter
lowercase
)
:
( Having
:
( Having different )
the
when there
Only
same
)
is
dominant allele present
no
Heterozygous
alleles
two identical
→
Pure
skin
'
What is
a
Offspring
Ratio
sex-linked
carrier
Organism
sex
recessive allele for
not show
a
trait but
the trait
Only able to pass
What is
inherited
Not
→
Pure
breeding
f)
chromosomes
-
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Females
*
-
If
linked characteristic
a
male has
have two
Females
X
an
-
..
me
determining
the gene responsible is located
:
condition
linked
X chromosomes
on a sex
gender
chromosome
pass the gene to the
→
likely to inherit
→
came ,
.
gene shows
→
daughter
in
chromosome
X
÷
"""
Gitmo
more
likely
""
other
one sex than the
effect of recessive allele
dominant allele that masks
one
similarity
of the single
b/c
XX
→
.
to show sex-linked
recessive conditions
.
does
If the recessive allele is
at au
masked
they
,
become
the
carrier
one dominant
→
.
.
allele that
allele
the
( XY )
boy
PV NN ET SQUARE
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that
500/0 of
:
500/0 of girl ( XX )
Two different alleles
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breeding
,
XX and XY
nutrition
X
.
.
.
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X
Y
X
-
-
mother ( XX )
→
H
.
environmental
and
,
(capital
:
Homozygous
genotype
the
another
-
Recessive
phenotype ?
genetic modification
to
- -
height
physical properties
Determined by
-
generation
one
.
with two letters that
shown
Dominant
,
phenotypes
and
Alleles : two alternative forms of
gene
a
Eye
consists of genotypes
information from
of genetic
transmission
:
.
?
w dominance
if offspring is male
codominance when genes have
:
expressed
*
equally
the disease
he will inherit
→
alleles
that
equally
are
recessive
.
dominant
both
→
→
in
a
phenotype
masks
allele
.
Inherits the disease
ble inherited recessive allele
Codominant alleles shown with uppercase
using different
in genetic diagrams
letters
letters
.
EX
:
AB is
Blood group
co dominance
.
-
What is Putten
*
synthesis ?
*
pro tiers
are
polymers of
amino acids
to translation
Transcription
is
DNA to RNA
there
in humans
→
are
::4" I
twenty amino acids
Genotype
-
IA IA
.
'
'
::: : :::
RNA
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ribonucleic acid
→
Lt
In
what is DNA ?
*
deoxy ribonucleic
*
acid
*
*
grab
will they
on
to
a
ribosome
to
make
protien
a
'
Nuclear division
genetically
identical cells
88%-1%8
⑧⑧
*
←
*
since DNA is too big to travel out of the nucleus
mRNA
moves
out nucleus
Ribosome translates
I
used for
base code
,
and attaches to ribosome
from ribosome
to
fold
and
of
reads
→
gene is transcribed
each
code
acids
on
→
the mRNA
makes
to mRNA
three
in groups of
protein
growth
different
four
chromosomes
of each chromosome
*
cells
*
Used for
,
bases codes
specific
amino acid
)
.
form final protein structure
→
g
replacement of cells
,
offspring
identical
produces
genetically
parent
µ
asexual reproduction
.
→
Mitosis occurs
,
each chromosome
splits
and each
goes
to
daughter
cell
→
During growth
,
exact
copy is
.
production of gametes
Reduction division
Reduction Division
:
number is halved from
chromosome
diploid
genetically
.
occurs
during
to increase
meiosis
→
variation
.
that
to ensure
gametes
are
haploid
Starts with chromosomes doubling in mitosis and lining up in the centre of the cell
cells
→
cells divide twice
.
passes to each
different cells
,
dqmeeeaged
tissues
( triplet
Meiosis
Nuclear division that produces
→
p
repair damaged
.
.
replace
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Parent cell contains
made
What is meiosis ?
haploid
O
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sequence of bases into sequence of amino
Amino acid chain released
f
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genetically
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ii :
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depth detail
Mitosis
producing
IA lo
or
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cell division
what is mitosis ?
Phenotypes
.
to
*
Gametes
as
gamete
.
haploid cells
→
b/c of
double division
,
meiosis produces
four haploid
cells
.
so
only
one
copy of each chromosome
.
VARIATION AND NATURAL SELECTION
¥on?
Continuous variation
Variation
has
:
charts
*
graphs
( Bell shaped )
.
continuous variation
a
normal distribution in
differences between individuals of the
:
situation in which there
:
Genes
ment
are
can
inherited
change
it
There
environ
-
Discontinuous Variation
are
several numbers
Depend entirely
:
charts show
a
:
the
there
random
usually caused
genes and environmental factors
by both
→
are
genetically
in
arranged
can be
,
controlled
an
order
can be measured on
,
and cannot be
a
(EX
scale
environmentally altered
:
.
height
,
mass
)
.
colour blindness
albinism )
,
discontinuous variations
are
( Ex
:
.
gender
,
blood group )
.
are
intermediate
no
States
.
-
Mutations
bird develops mutation to
give colorful feathers
N
d
breeding and the
of the mutation
No
* on
passing
*
→
when the nucleotide sequence in the DNA changes randomly
:
effect
on the
phenotype
rare occas sirens
protein that mutated gene
→
mutations lead to the
,
can lead to harmful
*
greater advantage of mating
increased
are
( step shaped )
.
*
:
and
graph
WYNTON ?
Example
involved
of genes
genes
on
Genetic defects (
distribution
are many intermediates
.
Discontinuous variation
and
.
and
-
→
species
same
changes
spontaneously
Mutations happen
development
sickle cell anaemia
→
and
continuously
works the
produces
of
new
alleles
→
random
genetic changes
phenotypes
new
's
gene
un mutated
same as
.
protein
.
small effect on
→
organism
→
gives them
survival adv
.
.
due to the
factors
following
:
.
-
Ionising
radiation
bonds and
damage
:
change in
base
sequence
-
-
*
increased
rates of mutation
-
mutagens
( Mercury
chemicals
types of
certain
:
lead )
and
.
sickle cell Anaemia
causes
to
strokes
:
lungs
,
blindness
,
kidneys
,
heart
Risk for life
acute chest syndrome
,
damage
*
Mutation changes the molecule
*
sickle cell tends to
haemoglobin
→
RBC 's to become sickle
causes
-
shaped when releasing oxygen
.
.
threatening
.
Two alleles
*
(
get stuck in
A and
)
s
are
co
narrow
blood vessels
dominant
blocks flow of blood
→
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→
.
S is sickle cell anaemia
and
.
Carrier Mother
→
normal Hb
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develop
→
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WhH-aM ?
Adaptive Features
Fitness
Hydrophytes
-
plants adapted to extremely wet
conditions
-
probability
:
small roots
Thin cuticle
-
Xerophytes
to
-
extremely dry
conditions
-
.
-
-
-
-
WW
Increased variation
&
Overproduction of
offsprings
need to
no
:
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closing
waxy
Hairy leaves
stomata
on
to
offspring
&
Greater chance of survival
process
reproducing in its environment
.
'
and
.
water loss
on
:
traps
Individuals show
*
Overproduction
of adaptation
of offsprings
Stabilizing
variations
.
→
lowers
temperature
fittest
→
→
less water
evaporates
evaporates
deep down /
theory
across
wide
of survival of the
competition for
characteristic
→
area
.
fittest
.
in genes
by differences
food and
more
resources
reproduction
.
→
allele is passed down to
offspring
→
greater
number
:
overtime as
a
result of natural selection
when natural selection tends to keep populations
the
same
.
from generation to generation
→
change
will
Antibiotic resistance to Bacteria
*
*
Baden as reproduce
-
Variation will
of individuals with better
.
change in adaptive features
selection
plant float for photosynthesis
water loss
→
reflects heat
range of variation caused
Individuals with the
Evolution :
:
's
Charles Darwin
a
and
surface is cooler
less water
seeks water
*
*
lower
:
spread
:
transpiration
evaporation
for
area
:
the
in moisture
underside
out roots
help
air to
quicker gas exchange from atmosphere
:
Cuts down surface
-
filled w/
:
slows down
:
barrier
:
spaces
both sides
of stomata
cuticle
adapted
Fittest characteristic gets
The
prevent
hollow
stem and leaves
Natural selection
&
on
organism surviving
an
to reproduce and survive in their environment
extract nutrients easily
:
.
passed
of
organisms
that helps
.
-
plants adapted
inherited feature
:
occur
quickly
caused
→
greater
by mutation
chance
→
of evolution in
might
cause
some
a
short amount
of time
.
bacteria to be resistant to antibiotics
→
they
do not die
.
occur
it environment changes
.
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Selection
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Genes of antibiotic resistance will
Breeding
passed
select individuals with the
:
process has to be
be
repealed for
many successive
to next
on
generations
-
-
-
increased crop
yield
-
Hardiness to weather
Better tasting fruits
Large 1
Domestic
-
.
breed
new
a
and
breeding
organism
them together
.
.
with the desirable traits
.
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lay large eggs
dogs
gentle
with
sheep w/ good
-
flowers
unusual
chicken that
-
to ensure
.. ..
.
whole population will inherit the gene
→
characteristic
most desirable
.
-
offspring
quality
nature
wool
Horses with fine features and
are
fast
-
AND RESPONSE
COORDINATION
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System
consists of
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central nervous
system ( cws )
system
Nervous
all of the nerves in the
impulses
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signals
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from
sense
carry impulses
:
to
organs
Voluntary Response
CNS
*
Neurons
have
and
surroundings
our
the nervous
through
long fibre (
a
Axon insulated
cell
by
a
axon
)
peripheral
and
to
system
nerve
as
which enables
fatty sheath w/
bodies have dendrites
nervous
respond
system
to them
.
and coordinate and
regulate body functions
impulses
.
.
less time to be wasted
in
transferring impulses
.
small uninsulated sections along it
connects to
→
many
other neurons
( nodes )
( forms
→
a network
electrical
jumped
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of connection )
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sensory
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body
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to make sense of
system
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electrical
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that pass
us
central nervous
:
:
the brain and the spinal chord
peripheral
Allows
the
.
SENSORYNEVRONETTRELAYNEVRON.LI
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MOTORNEVRONETAyhraiandt.im
decision is made
carry out
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pain I pressure
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the brain
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RESPONDED
→
impulses
to
→
carries impulse to effector
connects to motor neurone
spinal chord
receptor cells
and passes impulses
REFLEX
PATHWAY
effector will react
where the stimulus
essential to basic survival
sends electrical
detected by
touch
involuntary
→
accordingly
touched
to stimulus
The synapse
synapse junction
:
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between two
minimum
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gap between
is the
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Hormones
ystem
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that
glands
:
produce hormones
*
*
cells
or
w/ receptors found inside
cells
cell membrane
on
Endocrine Glands
*
once
good
a
to
blood
shape of
the
hormone
to another
organism
get
to the
to
plasma in
bring
about
a
change
.
quickly
the blood stream
travel around the
→
.
in the
target receptors
an
need to
hormones
response
destroyed
→
only bind to cells with
a
part of
one
→
supply
bring about
hormone has been used
a
Hormones can
the
have
target organs
to
body
transmit information from
chemicals which
:
that
liver
are
Pancreas produces hormones to
regulate
.
as
to
complimentary
well as
such
as
lipase
ru
blood glucose levels
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digestive enzymes
pancreatic
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Adrenaline
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f
t
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get
muscles to react
our
g
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pupils
dilate to allow
also
much light
as
information
possible for
.
-
-
,
Produced in situations where the
causes a
range of
different things
in the
increasing blood glucose concentration
Increasing pulse rate
t
breathing
gum , you aimed towards
be in
body may
rate
or
flight
:
increase respiration in muscle cells
glucose
→
mu, yes
.
fight
to prepare for
body
→
danger
t
oxygen delivered
oxygen is
,
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to muscle cells
quickly
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COORDINATION
THE EYE
:
-
Whory Erg and?
Receptors
detect
:
a
Sensory organs
specialized cells that
change in the environment
and stimulate impulses in
-
-
response
.
-
Structure
t
function of
-
Eye
-
skin
:
:
group of receptors that respond to specific stimuli
a
sensitive to pressure
Tongue
Ear
contains
:
:
,
temperature and pain
chemicals in food
t
sound and movement
cornea
:
transparent
drink
→
touch and temperature
→
Iris
:
taste
→
hearing
lens that retracts
controls how much
t
light entering eye
light enters pupil
.
Accommodation
bring
hens :
fine
the
elastic
can
,
on
change shape
-
ligament
-
Muscles
cause the
-
suspensory
:
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circular muscles relax
is
attached
area
More
light
enters the
eye
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light
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ciliary
muscles relax
suspensory ligaments
pulled
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less
sight
retina
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circular muscles contract
-
smell
→
£
enters the
eye
-
Rods and
-
-
-
ciliary
muscles contract
slack
suspensory ligament
lens are
fat
lens are thin
cones
receptor
:
cells sensitive to
dim
light
→
found all
over retina
where the retina
to the
and there are
.
radial muscles relax
-
eight
→
muscles that
change
:
-
Pupil dilates
Rods
Blind spot
.
lens
focusing
depending
ciliary
way
:
:
chemicals in air
.
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brain
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.
optic
no rod
nerve
cells found
cones :
fovea
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receptor cells that
area on
retina
→
distinguish
color in
almost where all
bright light
cone
cells
are
→
found
3
types
that
are
colour sensitive
( red
,
blue
and green
)
HUMAN REPRODUCTION
Fertilisation
Whwin ?
Gametes
:
sex cells
adaptations
( have
the
male
development of embryo)
ammonium
immature em released each
egiau.msg.im
takes
nuclei to create
gamete
a
Egg
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enzymes to digest jelly
zygote
.
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cells
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.
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fertilisation to prevent other sperm cells )
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chances of fertilisation and
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Embryo
:
unborn
fetus form ?
*
After fertilisation
offspring
Gestation time : period of
remaining gestation
*
Amniotic
embryo
in the
*
Embryo
*
First
development
abdomen
time
travels to the uterus
zygote
→
three
a
day
period
which the
in
zygote
will divide several times
to
form
an
implants
then
12 weeks
itself in the thick
*
lining
for the major development of organs
embryo gets nutrients
→
of the uterus then grows and develop es →
→
gestation period
nutrients taken from
the
is nine months
mother
.
by diffusion through
uterus
.
organs
all in peace
are
placenta formed
→
embryo
→
fetus
is now
.
fetus to mother
's
protects fetus
→
the
.
fetus
→
.
cushions
sac
,
.
lining
*
bigger
in the oviduct
#
process of development
grows
c
egg )
to
,
* Telus surrounded
by
.
*
amniotic
's
join
Umbilical chord
sac
's blood plasma
filled with amniotic fluid made from mother
→
fetus 's blood
supply
to
placenta
exchange of
→
nutrients
t
.
removal of waste products
.
The placenta
*
worth
→
→
*
remembering
waste
Nutrients
:
fats
:
,
→
substances
urea
water
Movement of molecules
diffusion
gradients
*
two
substance
difference
Oz
t
by
occurs
in cone
.
After birth
:
uterus wall
on
molecule sire )
gaining
develops by
glucose
amino acids
,
vessels connects to and from the
* fetus 's blood
*
Mother's blood absorbs
waste
*
Placenta is
diffusion by having
from fetus 's blood
,
fats
,
's blood
water and oxygen from mother
placenta via umbilical chord
that
in the placenta
so
large surface
area
.
.
don't accumulate in high concentrations
they
.
adapted
to
*
Acts
*
umbilical
*
Placenta is removed
to
a barrier
as
prevent toxins
and
a
thin wall
t
pathogens entering fetus 's blood
.
.
.
placenta detaches from
→
pushed out due to
contractions
Fetus
.
Not all toxin molecules are stopped
( depends
*
CO2
t
.
chord is out
→
after baby
afterbirth
is born
( does
not hurt →
no
)
nerves
→
tied
to
prevent bleeding
.
Breastfeeding
*
*
During pregnancy
After birth
→
mammary glands enlarged
mother will
→
be
become prepared to secrete milk
t
stimulated to release milk due to
sucking
action of the
-
right nutrients in right
amounts
-
the
-
baby
-
-
-
mother
t
bond
at breast
.
Disadvantages
easily to the
-
meows father
t
postnatal
→
to bond
-
Risk of infection increased
bottles
Allows mother
-
Responsibility
baby
more
freedom
-
t
equipment not
→
it
sterilized
expensive
with the mother
the
Antenatal
*
baby
not come
depression
→
infection
prevents
Does
mother
contains antibodies
baby
Advantages
Disadvantages
Advantages
.
Bottle feeding
Breastfeeding
Whwe?
.
Diet
:
:
( before birth )
take
*
Exercise
*
Health
:
to
name is
given
to the
care and
advice given to expectant mothers
folic acid to prevent development issues with the fetus
stay fit
precautions
:
t
importance
of balanced diet
.
avoiding infections
,
tobacco
,
alcohol
,
nicotine
,
drugs
along
.
with checks
.
on
fetal
growth
and
development
.
HUMAN SEX HORMONES
Whdary Sexual
oestrogen
sex
:
hormone in
* Emotional
changes also
changes that
:
controlled by release of hormones
*
girls
characteristics
sexual
secondary
M¥4.4 ?
occur
occur
during puberty
.
temall
mood
→
swings
t
more
interest
Breasts develop
-
sex
:
hormone in
in
boys
opposite gender
menstrual
.
-
Hips get
-
cycle begins
muscles develop
-
voice
-
I
*
*
t
natural change that occurs in the female
g-
-
*
Starts in
*
Ovulation occurs
early
adolescence
y
.
days
* Failure
*
→
halfway
by rise
and fall of
oestrogen
that
makes pregnancy possible
.
.
After menstruation
lining
→
CONNING thlmenstmal
② Egg
cycle ?
of
-
stimulating
③
Hormone
develops inside
FSH
then egg travels down oviduct to uterus
cycle
causes menstruation
fertilize egg
to
① Pituitary gland produces
follicle
controlled
through
Whatarethehormonls
:
reproductive system
sperm
.
Menstruation lasts around
f- SH
regular
:
produce
#
Average menstrual cycle is 28
days long
cycle
Menstrual
cycle ?
breaks
Testes start to
-
what is the Menstrual
t testes
facial hair and body hair
of
Growth
-
wider
penis
Growth of
-
Body hair grows
-
testosterone
Male
.
FSH
to occur
of uterus starts
stimulates
→
follicle
produces
→
to
the breakdown
caused by
→
thicken
again
development of
oestrogen
→
a
in
.
preparation
in the
follicle
growth
causes
for
the thick
of
implantation
ovary
and
lining
uterus
in the
next
.
cycle
.
.
repair of the lining of the uterus wall
t
inhibits
production
.
Oestrogen
rises
to
high enough
level
→
stimulates release of
LH from
pituitary
gland
→
causes
ovulation
.
A
released by
pituitary gland
&
causes
egg to start maturing and
ovaries to start
LH
:
releasing
Luteinising
Follicle become the corpus luteum
⑤
Ovum not
⑥
If pregnancy
Oestrogen
Hormone
levels reach
fertilized
→
occurs
→
starts producing progesterone
→
corpus luteum breaks down
maintains
→
progesterone levels drop
t
→
uterus
causes
lining
peak
:
corpus luteum continues to produce progesterone
levels rise from
day
* causes uterine wall to start
I
to peak before
thickening
t
day
14
preventing
→
.
menstruation
oestrogen
A
oestrogen
④
uterus
.
lining from breaking
down
.
.
egg to mature
.
N
pituitary gland stimulated
to release
LH
µ
Causes
ovulation to
occur
stimulates ovary to produce
progesterone
Progesterone
:
stays
low from
day
I
-
14
and starts to rise once
ovulation
occurs
.
.
*
Increasing levels
*
Decreasing
cause
uterine
lining
to thicken further
→
continues
through pregnancy until placenta
has developed
.
t
levels
causes
uterine lining to break down
→
causing menstruation
.
.
#