Latar Belakang
• Pada K-13 terdapat KD sebagai 3.2 Memahami reproduksi pada tum
keturunan, serta kelangsungan keturunan, serta kelangsungan 4.2 Menyajikan karya hasil perkemb
• Kemampuan apa saja yang haru
• Materi apa saja yang harus dipe
• Bagaimana kegiatan belajar yang dan materi tersebut?
gai berikut :
tumbuhan dan hewan, sifat an makhluk hidup
an makhluk hidup
embangbiakan pada tumbuhan arus dilatihkan ke siswa?
ipelajari siswa?
"#"$ % &"!'() #(
& &
•
•
•
!
#( +"+( (!(, & % +(+-
&*
!
"
.(+ /"+ . "'( #
• "
"!' # ! 0
• $ % $ & '
•
•
(
# # "
( # !
1 • ) % * +
,
21 • , '
Connection
!') * "!3 * #
-./!
•
0
"
•
$
1
C
C
1
•
0
•
1
ion
11
Application
A
A
3.2 Memahami reproduksi pada
keturunan, serta kelangsungan m
" "
4.2 Menyajikan karya hasil perke
ation
– 80’
da tumbuhan dan hewan, sifat makhluk hidup
1 " 1
2 3
KD 3.3
*
Berbagi Gagasan
•
Sajikanlah hasil diskusi kelom
kepada kelompok lain
•
Kelompok lain: Berikan kom
terkait KETEPATAN jawaban a
tadi.
tadi.
kelompok Saudara
SISTEM REPRODUK
• Vegetatif (asexual) Lebih sering terjadi pada Tumbuhan.
Tidak melibatkan pertemuan gamet jantan dan gamet betina.
DUKSI TUMBUHAN
• Generatif (sexual) Terjadi baik pada Tumbuhan maupun Hewan
Hewan
Melibatkan pertemuan gamet jantan dan
BEBERAPA CONTOH REPRODUK DAN BUATAN PAD
• Alami
1. Tunas (pisang, tebuh, pohon pinang dan bambu).
2. Spora (Lumut dan tumbuhan paku)
3. Tunas adventif (cocor bebek)
3. Tunas adventif (cocor bebek)
4. Stolon / geragih (pegagan, strawberry, semanggi)
5. Rizoma / rimpang (Kunyit, jahe, Bangle, lengkuas dan tebuh.
6. Umbi batang (kentang, ubi jalar)
7. Umbi lapis (bawang-bawangan dan bunga tulip).
DUKSI SECARA VEGETATIF ALAMI PADA TUMBUHAN
• Buatan
Mencangkok
Menempel/Okulasi
Menyambung atau Enten Menyambung atau Enten Merunduk
Stek
Asexual Repr
•
Asexual reproduction
Parts of the plant, suc
produce roots and bec
plant.
plant.
Reproduction
tion is natural “cloning.”
such as leaves or stems,
Sexual Repr
•
Sexual reproduction re
cells in the pollen grai
the ovule.
eproduction
Pergiliran Ke
•
Plants have a double l
distinct forms:
– Sporophyte: produce d
– Gametophyte: produce
– Gametophyte: produce
n Keturunan
ble life cycle with two
ce diploid spores by mitosis. uce gametes by meiosis
Reproduksi Gen
Tumbu
Klasifikasi
•
Bunga lengkap dan bun
•
Bunga sempurna dan Bu
ikasi Bunga
bunga tak lengkap
MACAM MACAM
BERDASARKAN ASA
•
Penyerbukan sendiri (
aut
•
Penyerbukan tetangga(
ge
•
Penyerbukan silang(
allog
•
Penyerbukan silang(
allog
•
Penyerbukan bastar (
hyb
AM PENYERBUKAN
ASAL SERBUK SARI
autogami
)
geitonogami
)
llogami / xenogami
)
llogami / xenogami
)
MACAM MACAM
BERDASARKAN VEKT
Anemogami
(perantaraan
Hidrogami
(perantaraan
Antropogami
(perantaraa
Zoidiogami
(perantaraan
siput
: malakogami
serangga : entomogami
kelelawar : kiropterogam
burung
: ornitogami
Perkembangan Gener
• Konjugasi, yaitu reproduksi generatif kelaminnya. Contoh: Spyrogyra (gan benang.
• Isogami, yaitu peleburan 2 sel game Contoh:Clamydomonas (ganggang b
• Anisogami, yaitu peleburan 2 sel gam
• Anisogami, yaitu peleburan 2 sel gam 1 lebih kecil (mikrogamet) dan game
Ulva (ganggang yang berbentuk lem
• Penyerbukan yang diikuti dengan pe
berbunga (Antophyta) atau tumbuha kelamin jantan berupa benang sari d putik.
neratif pada Tumbuhan
ratif pada tumbuhan yang belum jelas alat (ganggang hijau) yang koloninya berbentuk
amet atau kelamin yang sama besar. ng biru)
l gamet yang besarnya tidak sama. Gamet l gamet yang besarnya tidak sama. Gamet amet 2 lebih besar (makrogamet). Contoh: lembaran).
n pembuahan. Terjadi pada tumbuhan buhan berbiji (Spermatophyta). Alat
MACAM – MACAM
• GYMNOSPERMAE
terjadi pembuahan tunggal ( hanya
terbentuk biji) terbentuk biji)
CAM PEMBUAHAN
• ANGIOSPERMAE
terjadi pembuahan ganda ( terbentuk biji dan buah)
STROBI
• Strobilus yang telah pecah.
OBILUS
TUGAS KEL
•
Tiap kelompok
•
Umbi bawang merah meng
turunan asam amino yang
Sikloalliin 2%, propilalliin d
sel umbi pecah senyawa te
menjadi bentuk ester ( est
menjadi bentuk ester ( est
sulfinil disulfida (Kepaen),
begitu juga tiofen. Di samp
propantial-S-oksida (suatu
menyebabkan keluarnya a
Disamping turunan asam a
adenosine dan prostagland
engandung senyawa
ang mengandung sulfur yaitu
liin dan propenilalliin. Bila
sel-a tersebut sel-aksel-an berubsel-ah
( ester asam tiosulfinat),
( ester asam tiosulfinat),
en), disulfida dan polisulfida,
amping itu terbentuk pula
atu senyawa yang dapat
ya air mata).
am amino, ditemukan pula
•
www.wou.edu
Reproduct
• Reproduction is one of the life.
• Evolution is inextricably lin
• Two modes of reproductio
Asexual
– Asexual
– Sexual
duction
f the ubiquitous properties of
Asexual vs. Sexua
•
Asexual reproduction
offspring whose genes a
parent without the fusio
– Usually diploid eggs are
– Usually diploid eggs are which then develop dire
xual Reproduction
– the production of
es all come from one
fusion of egg and sperm.
Asexual vs. Sexual R
• Sexual reproduction – the production of offspring by the fusion of haploid
gametes (eggs & sperm) from two parents to form a diploid zygote (fertilized a diploid zygote (fertilized egg).
– Gametes arise by meiosis.
– Genetic variability is
increased by the random combinations of genes from the parents.
Asexual Repro
• Bacteria and many protozoa can
reproduce by
binary fission –
separating into two separating into two or more individuals approximately the same size.
Asexual Repro
• Budding is a form of asexual reproduction where new individuals form as offshoots of a parent.
parent.
• The offspring may separate or remain attached to form colonies.
Asexual Repr
•
Freshwater sponges rele
groups of cells called
ge
grow into new individua
Reproduction
release specialized
Asexual Repr
•
Fragmentation
results w
body is broken into sev
piece grows into a new
– Regeneration – the regr
– Regeneration – the regr
Reproduction
ults when an organism’s
several pieces and each
new organism.
Asexual Repro
• Fragmentation occurs in some sponges,
cnidarians, polychaete annelids, tunicates.
– Sea stars can
– Sea stars can
regenerate lost limbs, but only species in the genus Linckia can form new individuals from broken arms.
Asexual Reproduction
• Animals living far from memb of their own species can
reproduce without having to search for a mate.
• Numerous offspring quickly –
• Numerous offspring quickly – ideal for colonizing a new area
• Advantageous in a stable,
favorable environment because it reproduces a successful
genotype precisely.
ction - Advantages
Sexual Repr
• Generally involves two pare
• Special germ cells unite to f
•
S
exual reproduction recom– A richer, more diversified po
– A richer, more diversified po
• In haploid asexual organism expressed and selected qui
• In sexual reproduction a no homologous chromosome m mutation.
eproduction
parents.
to form a zygote.
combines parental characters.
d population results. d population results.
nisms mutations are quickly.
Sexual Repr
• Why do so many animals re than asexually?
• The costs of sexual reprodu asexual methods:
– More complicated.
– More complicated.
– Requires more time.
– Uses more energy.
– The cost of meiosis to the fe her genes to offspring.
– Production of males reduce could produce eggs.
eproduction
ls reproduce sexually rather
roduction are greater than
e female is passage of only half of
Sexual Repr
• However:
– Sexual organisms produce m survive in times of environm
– In crowded habitats, selectio prevents extinction.
prevents extinction.
– On a geological time scale se variation are prone to extinc
– Many invertebrates with bo enjoy the advantages of bot
eproduction
ce more novel genotypes to onmental change.
ection is intense and diversity
le sexual lineages with less xtinction.
Parthenog
•
Parthenogenesis
involv
an embryo from an unfe
where sperm & egg nuc
– Ameiotic parthenogene
– Ameiotic parthenogene
formed by mitosis (diplo
– Meiotic parthenogenesi
by meiosis, it may be act
enogenesis
volves the development of
unfertilized egg or one
nuclei did not fuse.
enesis – no meiosis, egg is
enesis – no meiosis, egg is iploid)
Parthenog
•
In some animals (aphids
Daphnia (crustacea air t
can produce two types o
environment condition.
environment condition.
– One must be fertilized.
– One type will develop direct
parthenogenesis.
• Haploid females produce dewasa yang dihasilkan b tidak mengalami miosis d baru.
enogenesis
hids (kutu daun), rotifers,
air tawar)
) the females
pes of eggs depends on
ion.
ion.
irectly into haploid adults –
duce eggs by mitosis.(hewan
Parthenog
• Daphnia reproduce asexually (p conditions are favorable.
• pergantian reproduksi tergantu aseksual terjadi pada kondisi ya reproduksi seksual terjadi ketik reproduksi seksual terjadi ketik
• In times of environmental stress, reproduction.
– Increases variation!
enogenesis
lly (parthenogenesis) when
antung musim, reproduksi isi yang menguntungkan dan
Parthenog
•
In many social insects, l
(drones) (lebah madu ja
are produced by
parthe
females (workers & que
females (workers & que
fertilized eggs.
enogenesis
ts, like honeybees, males
du jantan) are haploid and
rthenogenesis
while
Parthenog
•
Parthenogenesis occurs
some fishes, amphibian
recently been discovere
– After meiosis, the chromoso
– After meiosis, the chromoso diploid “zygotes”.
– Often mating behavior is req development of offspring.
– Bereproduksi melalui parten melibatkan penggandaan kr kadal.
enogenesis
curs in vertebrates in
bians, lizards, and has
vered in
snakes
.
osomes are doubled, creating osomes are doubled, creating
s required to stimulate
Hermaphrod
• Hermaphroditism occurs when an organism has both male and female reproductive systems.
– Monoecious
– Monoecious
– Some can fertilize
themselves.
– Usually a mate is
required – they can fertilize each other.
Sequential Herma
• In sequential
hermaphroditism, an
individual reverses its sex during its lifetime.
– In wrasses, sex reversal is
associated with age, size associated with age, size and social conditions.
– Fish are female first.
– The largest female
becomes male if the previous male dies.
Sequential Herm
•
There are also sequenti
that are male first, later
•
This occurs in species th
at a bigger size – so it is
at a bigger size – so it is
larger females.
– Oysters
ermaphroditism
ential hermaphrodites
ater changing to female.
Perbalikan jenis kel
karang, w
•
Semua spesies pada ika
tetapi indvidu yang tert
mengalami perubahan k
menyelesaikan kehidup
menyelesaikan kehidup
•
Perubahan jenis kelamin
ukuran tubuh
is kelamin pada ikan
g, wrasse
ikan ini terlahir betina,
tertua dan terbesar
an kelamin menjadi dan
dupannya sebagai jantan
dupannya sebagai jantan
Fertilizati
• Fertilization – fusion of egg and sperm into a single diploid cell, the
zygote.
External
– External
– Internal
External Ferti
• External fertilization – fertilization takes place outside the female’s
body.
– A wet environment is
– A wet environment is
required so gametes don’t dry out and so sperm may swim to the eggs.
Ensuring Surviva
•
Species with external fe
huge quantities of game
of zygotes.
– Predation on young is hi
– Predation on young is hi
– Few will survive to repro
vival of Offspring
al fertilization produce
ametes that result in lots
is high. is high.
Ensuring Survival o
• Species with internal
fertilization produce fewer zygotes, but protect them more from predation.
– Tough eggshells
– Tough eggshells
– Embryo may develop in
reproductive tract of female
– Parental care of eggs &
offspring
(Kutu air raksasa)
Perlindungan telu
raksa
• Kutu air raksasa menghasilk jumlah relatif sedikit tetapi meningkatkan kelangsunga tersebut
Fertilisasi internal dan betin
• Fertilisasi internal dan betin yang sudah dibuahi ke bagi
• Kutu air jantan membawa t supaya tetap lembab dan te
telur pada Kutu air
aksasa
asilkan keturunan dalam
tapi perlindungan dari induk ngan hidup keturunan
etina menempelkan telur etina menempelkan telur bagian belakang jantan
Advantages of Sexu
•
Sexual reproduction has
finding mates, greater e
proportion of genes pas
and slower population g
and slower population g
•
However, sexual reprod
variability
in the popula
during times of environ
Sexual Reproduction
has costs including
ter energy cost, reduced
passed on to offspring,
ion growth.
ion growth.
roduction
increases
TUGAS kel
•
TIAP KELOMPOK MEMB
•
1. PARTHENOGENESIS
•
2. BUDDING
3.FRAGMENTATION
•
3.FRAGMENTATION
•
4. BINER FUSION
•
5.EXTERNAL FERTILIZAT
•
6. Hermafrodit
S kelompok
EMBAHAS
Gamete Producti
•
Gametes
(eggs & sperm
sexual reproduction.
•
Usually, gametes are pro
(ovaries & testes).
(ovaries & testes).
•
Germ cells
are set aside
development. They will
gametes.
uction & Delivery
erm) are required for
e produced in
gonads
side early in
Migration of Ger
• Germ cells arise in the yolk-sac endoderm of vertebrates – not in the gonads.
They migrate to the
• They migrate to the gonads using
amoeboid movement.
Gametog
•
Gametogenesis
– the pr
– Spermatogenesis – each divides to form 4 sperm.
– Oogenesis – each primar ovum and 2-3 polar bodi ovum and 2-3 polar bodi
• In oogenesis, cytokinesis cytoplasm goes to one d the ovum. The other cell
etogenesis
e production of gametes.
each primary spermatocyte rm.
imary oocyte divides to form 1 bodies.
bodies.
esis is unequal, most of the
Spermatog
•
Outermost layer of the
contain
spermatogonia
grow to become
primar
•
After the first meiotic di
•
After the first meiotic di
secondary spermatocyt
•
When meiosis is comple
are
spermatids
.
atogenesis
the
seminiferous tubules
nia
, diploid cells that
imary spermatocytes
.
tic division, they are called
tic division, they are called
ocytes
.
Spermatogen
• Spermatids mature
into motile sperm with a tail for locomotion, and a head containing an acrosome as well as an acrosome as well as the nucleus.
Oogen
• In the ovary, early germ cel diploid.
• Oogonia grow to become
• After the first meiotic divisi
• After the first meiotic divisi unequally and only one sec polar body result.
• Following the second meiot another polar body result.
• The ootid develops into a fu
genesis
cells called oogonia are
e primary oocytes.
ivision, the cytoplasm divides ivision, the cytoplasm divides
secondary oocyte and one
eiotic division, one ootid and ult.
Oogen
•
Meiosis is usually arrest
meiosis and is not comp
or fertilization.
genesis
Reproductive
• Oviparous – animals that la
– Most invertebrates, many ve
• Ovoviviparous – animals th their bodies. Nourishment c their bodies. Nourishment c
– Some annelids, insects, som
• Viviparous – eggs develop i nourishment from mother.
– Mammals, some sharks, sco
ctive Patterns
at lay eggs.
ny vertebrates
ls that retain the eggs within ent comes from the egg.
ent comes from the egg.
some fishes, reptiles.
lop in oviduct or uterus, her.
Invertebrate Reprodu
• Many insects have separate sexes,
internal fertilization and have complex
reproductive systems. reproductive systems.
– Female crickets use
long ovipositors to deposit eggs.
Gamete Producti
•
In vertebrates, reprodu
similar with a few impo
– Nonmammalian verteb combined opening, the combined opening, the excretory, and reproduc
– The uterus is partly or c two chambers in most v
• Humans & other mamm snakes have a single str
uction & Delivery
roductive systems are
important variations.
rtebrates usually have one
the cloaca, for the digestive, the cloaca, for the digestive, oductive systems.
or completely divided into ost vertebrates.
Female Reproduc
• Ovaries are where female gam produced.
– A follicle contains one egg cel
nurture the developing egg.
– Most/all of the follicles a wom
before birth.
ductive System
gametes, egg cells, are
Female Reprodu
•
Each month from puber
menopause one follicle
its egg cell –
ovulation
– The corpus luteum form
– The corpus luteum form follicle and secretes estr
help maintain the uterin If the egg is not fertilized
roductive System
uberty through
licle ruptures and releases
tion
.
orms from the ruptured orms from the ruptured
Female Reproduc
• After ovulation, the egg le enters the oviduct, which
ductive System
g leaves the ovary and
Male Reproduc
•
Testes
are where male g
are produced.
– Testes contain the semin
sperm are formed.
Leydig cells scattered be
– Leydig cells scattered be produce testosterone &
– Sperm production can’t temperature in mammal outside the body abdom
oductive System
ale gametes, sperm cells,
miniferous tubules where
d between the tubules d between the tubules
& other androgens.
Male Reproducti
• After leaving the testes, sperm pass through the
epididymis where they become motile and
become motile and gain the ability to fertilize an egg.
• Sperm leave the body through the vas
deferens and urethra.
Reproductiv
•
Males produce sperm c
females only release on
certain intervals.
uctive Cycles
Reproductive Cycles in
•
Humans & some other p
menstrual
cycle while o
an
estrous
cycle.
– In both, ovulation occurs
– In both, ovulation occurs endometrial lining of the embryo to implant.
– If no egg is fertilized, the (menstruation) in human reabsorbed in other mam
es in Female Mammals
her primates have a
ile other mammals have
curs at a time when the curs at a time when the f the uterus is ready for an
, the lining is shed
Reproductive Cycles in
•
Female mammals that h
may have more behavio
•
Estrous cycles may be m
season and climate.
season and climate.
•
Females will usually onl
– the time surrounding
es in Female Mammals
at have estrous cycles
avioral changes.
be more closely tied to
only mate when in
estrus
Female Reprod
•
The female reproductive
contains two parts:
– Uterine (menstrual) cycle
– Ovarian cycle
– Ovarian cycle
•
One integrated cycle inv
ovaries.
roductive Cycle
ctive cycle in humans
cycle
Female Reproductive
• The ovarian and uterine cycles are
regulated by changing hormone levels in the blood.
blood.
The Ovaria
•
GnRH
(gonadotropin-re
released from the hypo
stimulates the release o
hormone) and
FSH
(folli
hormone) from the pitu
hormone) from the pitu
•
FSH stimulates follicle g
•
The follicle cells start pr
– Rise in estrogen during t
varian Cycle
releasing hormone) is
ypothalamus which
se of
LH
(luteinizing
(follicle stimulating
pituitary gland.
pituitary gland.
le growth, aided by LH.
rt producing estrogen.
The Ovaria
•
When the secretion of e
steeply, the release of F
as well.
– Low levels of estrogen in
– Low levels of estrogen in production.
– High levels of estrogen s production. (Positive fee
varian Cycle
of estrogen begins to rise
of FSH and LH rise rapidly
n inhibit FSH & LH n inhibit FSH & LH
The Ovaria
•
The maturing follicle de
fluid filled cavity and gro
– The follicular phase ends follicle ruptures releasing follicle ruptures releasing
varian Cycle
e develops an internal
d grows very large.
ends with ovulation. The
asing the secondary oocyte.
The Ovaria
•
Following ovulation, du
LH stimulates transform
into the
corpus luteum
– The corpus luteum secre
– The corpus luteum secre progesterone.
– As the combination of th GnRH production in the (Negative feedback)
varian Cycle
, during the
luteal phase
,
formation of the follicle
um
.
ecretes estrogen and ecretes estrogen and
of these hormones rises,
The Ovaria
•
At the end of the luteal
luteum disintegrates an
estrogen and progestero
•
Now, the hypothalamus
•
Now, the hypothalamus
GnRH and the cycle star
varian Cycle
teal phase, the corpus
s and production of
sterone drops.
The Uterin
•
Estrogen and progestero
ovary affect the uterus.
•
Increasing amounts of e
the growing follicles cau
the growing follicles cau
uterus (
endometrium
) t
– The follicular phase of th with the proliferative ph
terine Cycle
sterone secreted in the
rus.
of estrogen released by
s causes the lining of the
s causes the lining of the
) to thicken.
of the ovarian is coordinated
The Uterin
•
After ovulation, estroge
stimulate the maintenan
growth of endometrial g
nutrient fluid to sustain
nutrient fluid to sustain
implantation.
– The luteal phase of the o
secretory phase of the u coordinated.
terine Cycle
rogen & progesterone
enance of the lining and
rial glands that secrete
tain an embryo before
tain an embryo before
The Uterin
•
If the egg is not fertilize
disintegrates, and produ
progesterone drops sha
breakdown of the endo
breakdown of the endo
menstruation.
terine Cycle
ilized, the corpus luteum
roduction of estrogen and
sharply. This triggers
Male Reproduc
•
In males, the principle s
androgens
, including
te
– Produced mainly by Ley
– Responsible for seconda Important determinants
– Important determinants vertebrates.
• Sex drive
• Aggression
• Calling in birds & frogs
oductive System
ple sex hormones are
testosterone
.
Leydig cells in the testes.
ndary sexual characteristics. ants of behavior in
Male Reproducti
• As in females, GnRH from the
hypothalamus
stimulates release of FSH and LH from the FSH and LH from the pituitary.
– FSH promotes
spermatogenesis.
– LH stimulates Leydig
cells to make testosterone.
Pregnan
• Conception,
fertilization of the egg, occurs in the oviduct.
Results in zygote.
– Results in zygote.
• Cleavage, rapid mitotic divisions, starts after 24 hrs.
Pregna
•
After about a week, the
during cleavage develop
called a
blastocyst
.
•
It then implants into the
•
It then implants into the
egnancy
, the ball of cells produced
elops a cavity and is now
Pregna
•
The embryo secretes ho
human chorionic gonad
like LH to maintain secre
and estrogen to maintai
and estrogen to maintai
uterus.
egnancy
s hormones including
nadotropin (
hCG
) that act
secretion of progesterone
First Trim
•
For the first few weeks t
nutrients from the endo
•
The outer layer of the b
trophoblast
grows into
trophoblast
grows into
forms the
placenta
.
Trimester
eks the embryo gets
ndometrium.
he blastocyst – the
Placental Circ
• The placenta contains clos & maternal blood vessels f nutrients and wastes.
Circulation
Hormone L
• hCG is produced by the placenta.
• Estrogen and
progesterone are produced by the progesterone are produced by the
corpus luteum, then by the placenta.
First Trim
•
Organogenesis
is occurr
trimester.
– The heart starts beating
– At 8 weeks, all major org
– At 8 weeks, all major org rudimentary form.
• Now called a fetus.
Trimester
curring during the first
ting about the fourth week. r organs are present in
Second Trim
• The fetus grows to about 3
• Hormone levels stabilize, h luteum disintegrates and t production of progesteron
Trimester
ut 30 cm and is very active. ize, hCG declines, the corpus
Third Trim
•
Fetal activity may decre
limited.
– Fetus grows to about 50
•
Development of organs
•
Development of organs
•
Neural development co
birth.
Trimester
ecrease as space becomes
t 50 cm and 3-4 kg.
ans is completed.
ans is completed.
Labor & Del
• Birth, parturition,
occurs through strong rhythmic contractions of the uterus.
Dilation
– Dilation
– Expulsion
– Delivery of placenta
Lactat
•
One defining characteri
that we have mammary
•
After birth, progesteron
stimulating the product
stimulating the product
stimulates milk product
– The release of milk is con
ctation
teristic of mammals is
ary glands.
erone levels fall
duction of
prolactin
which
duction of
prolactin
which
duction.
Multiple B
• Humans are usually
uniparous – one offspring at a time.
– Multiparous animals
have several. have several.
• Fraternal twins result from ovulation &
fertilization of two eggs.
• Identical twins result
from the splitting of one zygote.
