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iGCSE Biology Animal Reproduction & Coordination - Coggle Diagram
iGCSE Biology
Animal Reproduction &
Coordination
REPRODUCTION
most animals:
sexual
gametes
produced
male
gametes
(
sperm
)
*haploid
cells*
produced by
meiosis
in male sex organs
testes
head
(sac of enzymes
to penetrate membrane
around egg) + nucleus
mid-piece
mitochondria = energy
for movement
tail
flagellum
for swimming
specialised
male gamete
travels to female
3 more items...
HORMONES
puberty
pituitary gland
pituitary hormones
girls -> ovaries secrete
eostrogen
sex hormone
female
secondary
sexual characteristics
menstruation
menstrual cycle
1 more item...
breasts
follicle stimulating
hormone
FSH
boys -> sperm production
luteinising
hormone
LH
boys -> testes secrete
testosterone
male
secondary sexual
characteristics
growth of penis & testes
facial & body hair, muscles
breaking of the voice
gametes start to
mature & be released
bodies adapt to
enable reproduction
sex organs =
primary
sex characteristics
Hydra
jellyfishlike
creature - 'buds'
asexually
clones
the same genes
COORDINATION
NERVOUS
SYSTEM
1. stimulus
aroma of food
2. receptor organ
nose
3. coordination
nervous system
4. effector organ
salivary glands
5. response
saliva secretion
end to end =
reflex arc
stimulus-receptor-sensory neurone
CNS-relay neurone-CNS
motor neurone-effector-response
eg. bright light, pain
reflex action
- rapid
automatic response
nerves: sensory and/or
motor neurones
thousands of
individual neurones
neurone
= nerve cell
sensory neurones
passing to CNS
1 more item...
motor neurones
passing to muscles & glands
2 more items...
impulses are ions
moving in and out
of the neurone
1 more item...
can be very
loooooooooong
CNS central nervous system
BRAIN
SPINAL CORD
sensory impulses
enter through
dorsal root
spinal nerve
connect by synapses to
relay neurones
bypasses the brain
although informs it
connect by synapses
to
motor neurones
exit spinal cord
through
ventral root
spinal nerve
middle of spinal cord
= nerve cell bodies
grey matter
reversed in brain
outer part of spinal cord
= axons with fatty myelin sheaths
white matter
reversed in brain
detects stimulus
converts energy into
electrical
nerve impulses
eye, ear, tongue, nose, skin, muscle
can be several components
EYE
sclera
white
cornea
window
iris
coloured ring
pupil
hole in iris
1 more item...
controls light
entering eye
2 more items...
Images focused by
refraction through
(1) cornea (2) lens
Images are upside
down on retina
ENDOCRINE
SYSTEM
Glands
secrete a substance
a cell in the gland
makes a chemical
which leaves through
the cell membrane
exocrine
glands
secrete through a
tube or
duct
endocrine
glands
produce
hormones
secreted in the blood
(ductless glands)
and travel through bloodstream
slower than nervous control
usually longer lasting than nervous
can have widespread effects
receptors
for hormones
are in target organs
eg. insulin receptors in liver cells
some in cell membrane
some in cytoplasm
some in nucleus
Main endocrine glands...
Pituitary gland
(base of brain), hormones =
FSH
(follicle stimulating hormone)
LH
(Luteinising hormone)
ADH
(anti-diuretic hormone)
some control by
hypothalamus
above
so a link between nervous & endocrine
regulates reproduction
control of water in blood via kidney
Testes
hormone=testosterone
male secondary
sexual characteristics
also a sex organ
Ovaries
hormones=oestrogen
& progesterone
regulates menstruation
female sexual characteristics
also a sex organ
Thyroid
(neck)
hormone =
thyroxine
controls metabolic rate
Pancreas
hormones =
insulin
& glucagon
INSULIN
a protein which lowers blood glucose
maintains at 1g per dm3 blood
made by special cells in pancreas
glucose comes to liver
from digested carbohydrate
via hepatic portal vein
insulin stimulates
liver to convert
glucose to glycogen
Diabetes
urine test for glucose
shows high levels
Type 1
- pancreas cannot
make enough insulin
Type 2
- body has
insulin resistance
2 more items...
constant thirst
1 more item...
Insulin injected into muscle
as would be digested in gut
1 more item...
ALSO an exocrine gland
secreting enzymes
Adrenal glands
'above kidney
ADRENALINE
Breathing rate increases
and deepens -> more oxygen
Heart beats faster -> more blood
to muscles, more glucose & oxygen
Blood diverted from intestine
into the muscles
In liver glycogen -> glucose
and released into blood
pupils dilate -> better visual sensitivity
Body hair stands upright ->
larger appearance
Mental awareness increased
-> faster reactions
Raises blood glucose
in an
EMERGENCY