:
Paper 1:
,Topic 3:
Reproduction in vertebrates:
EXTERNAL FERTILIZATION :
-
occur outside females body
egg 31 sperm cells are released simultaneously
-
to
according certain signals .
released
large no of gametes
-
.
-
small no ,
of fertilization
-
No parental care
-
low survival rate
INTERNAL FERTILIZATION :
-
eggs fertilized in females -
sperm deposited into females
-
common in terrestrial animals
fewer eggs produced
-
-
higher chance of survival
-
sperm released in a medium : A fertilization
-
co-operative behaviour between sexes
EMBRYO DEVELOPMENT :
OVIPARY :
-
females lay eggs that natch outside her body
Animal lays eggs
.
-
-
little to no embryonic development .
eg .
fish birds ,
reptiles
,
↳ jelly like protection
, OVOVIVIPARY :
inside
-
eggs kept animals body until they catch
snakes
eg sharks
-
.
,
VIVIDARY :
give birth to
young
-
-
close contact between mother $ child
no shell
egg
-
nourished through placenta
-
gestation period (
pregnancy >
-
, in the development of
Important factor
M reptiles on land .
AMNIOTIC EGG :
which can survive & develop on land
↳ an
eggshell
structure :
POROUS SHELL
}
ALLANTOIS :
grows out
of the
embryo $
collects waste ALBUMEN
products
Embryo
a%11.IE?::ianto .is
allows gaseous exchange
AMNION : YOLK SAC
around the embryo
grows ,
contains amniotic fluid
which protects the
embryo
BLOOD VESSELS
UMBILICAL CHORD
Role ↳ embryo with
: connects yolk
31 allantois
-
important step in revolution
,
reptiles
evolved from amphibians
-
enabled them to breed on land 31 complete their life cycle
independently of water .
Paper 1:
,Topic 3:
Reproduction in vertebrates:
EXTERNAL FERTILIZATION :
-
occur outside females body
egg 31 sperm cells are released simultaneously
-
to
according certain signals .
released
large no of gametes
-
.
-
small no ,
of fertilization
-
No parental care
-
low survival rate
INTERNAL FERTILIZATION :
-
eggs fertilized in females -
sperm deposited into females
-
common in terrestrial animals
fewer eggs produced
-
-
higher chance of survival
-
sperm released in a medium : A fertilization
-
co-operative behaviour between sexes
EMBRYO DEVELOPMENT :
OVIPARY :
-
females lay eggs that natch outside her body
Animal lays eggs
.
-
-
little to no embryonic development .
eg .
fish birds ,
reptiles
,
↳ jelly like protection
, OVOVIVIPARY :
inside
-
eggs kept animals body until they catch
snakes
eg sharks
-
.
,
VIVIDARY :
give birth to
young
-
-
close contact between mother $ child
no shell
egg
-
nourished through placenta
-
gestation period (
pregnancy >
-
, in the development of
Important factor
M reptiles on land .
AMNIOTIC EGG :
which can survive & develop on land
↳ an
eggshell
structure :
POROUS SHELL
}
ALLANTOIS :
grows out
of the
embryo $
collects waste ALBUMEN
products
Embryo
a%11.IE?::ianto .is
allows gaseous exchange
AMNION : YOLK SAC
around the embryo
grows ,
contains amniotic fluid
which protects the
embryo
BLOOD VESSELS
UMBILICAL CHORD
Role ↳ embryo with
: connects yolk
31 allantois
-
important step in revolution
,
reptiles
evolved from amphibians
-
enabled them to breed on land 31 complete their life cycle
independently of water .
