Presentations for aspiring Biology students

1. STUDY
OF
ANIMAL TYPES

2. PHERETIMA --- EARTHWORM -- KINGBERG
 Classification
Kingdom – Animalia
(Heterotrophic, locomotory)
Phylum – Annelida
(round, cylindrical, elongated & segmented)
Class – Oligochaeta
(Presence of few setae/chetae)
Genus – Pheretima
(setae form complete ring)
Species – posthuma
(clitellum from 14th to 16th segment)

3. EXTERNAL FEATURES
 Long, narrow, cylindrical, with anterior
pointed & posterior blunt end. (100-120
segments)
 150-160 mm in length, 3-5 mm in width.
 Dark/glistening brown – porphyrin
pigment.
(Dorsal surface dark, ventral surface is light).
 Many small chambers are formed due to
septa.
 Such linear arrangement of body into
similar ring like segments is called
METAMERISM.

4. EXTERNAL FEATURES
 Body is divisible into
 Pre-Clitellar region (1st to 13th)
 Clitellar region (14th, 15th & 16th)
 Post-Clitellar region (from 17th onwards)
 Preclitellar region
 1st segment is called Peristomium (surrounds mouth), & its
extension on dorsal side is called prostomium (anterior
fleshy lobe).

5. EXTERNAL FEATURES
 Clitellar region (14th, 15th & 16thsegments)
 It is formed of thick circular band
called as clitellum/cingulum
(glandular cells secrete mucous & albumin for
coccon formation/egg case).
 Post-Clitellar region(from 17th onwards)
 Setae are absent in the 1st & last
segments.
 They are rod like with pointed “S”
shaped structures forming circular
ring in the middle of each segment.

6. EXTERNAL FEATURES
 There are 6 external
openings/apertures namely;
 Mouth, Anus, Genital openings,
Spermathecal pores, Dorsal pores
& Nephridiopores.
 MOUTH -- crescentic, ventral,
surrounded by peristomium.
 ANUS -- Slit like, last segment.

7. EXTERNAL FEATURES
 GENITAL OPENINGS
 Male – a pair ventro-laterally
on 18th segment.
 Female – single, medial, on
ventral side of 14th segment.
 SPERMATHECAL PORES
four pairs in grooves between
5/6, 6/7, 7/8, 8/9 segments.

8. DORSAL PORES – mid-dorsal
from 12th to last segment.
Coelom communicates with
these pores.
NEPHRIDIOPORES – many,
small, minute except first two,
clitellum and last segment.
EXTERNAL FEATURES

9. EXTERNAL FEATURES
 Body Wall
 It is thin, soft, shiny, elastic consists of Cuticle,
Epidermis, Muscles & Coelomic epithelium.
 Cuticle – thin, uppermost, non-cellular, protective.
 Epidermis – columnar cells, few glandular cells,
secretes mucous, antifungal & keeps surface moist.
 Muscles – two layered, outer circular & inner
longitudinal.
 Coelomic epithelium – cuboidal, lines coelom &
protects internal structures.

10. DIGESTIVE SYSTEM
 Alimentary canal is a long straight
tube from 1st to last segment.
 It consists of mouth, buccal cavity,
pharynx, oesophagus, gizzard,
stomach, intestine, and anus.
 MOUTH -- crescentic, ventral,
surrounded by peristomium, helps
in ingestion.
 BUCCAL CHAMBER – extends
from 1st to middle of 3rd segment,
protrusible.

11. DIGESTIVE SYSTEM
 PHARYNX – middle of 3rd segment
to 4th segment, pear shaped, broad,
muscular.
 OESOPHAGUS – short, narrow,
thin walled from 5th to 7th segment,
(conduction of food).
 GIZZARD – oval/round hard,
muscular, thick walled in 8th
segment, internally lined by cuticle
(grinding).
 STOMACH – thin, short, narrow up
to14th segment.(secretes proteolytic enzymes)

12. DIGESTIVE SYSTEM
 INTESTINE – longest part from
15th to anus, internally shows villi
(finger like projections).
 One of the dorsal villus becomes
large & forms typhlosole.
 Typhlosole is divided into
Pretyplosolar, Typhlosolar & Post
typhlosolar regions.
 Pretyphlosolar region – 15th to 26th
 Intestinal Caeca – 26th segment two
small projections extending till 24th
segment

13. DIGESTIVE SYSTEM
 Intestinal Caeca secretes Amylase.
 Typhlosolar region is longest from
26th segment and the last but 25
segments.
 Post typhlosolar region/rectum is
of last 25 segments, (no villi/typhlosole).
 ANUS -- Slit like, last segment,
useful in defaecation (casts/pellets).
 Food is soil containing organic
matter.

14. MERE BARE ME PADHOGE ??? TO CHALO

15. COCKROACH
Kingdom – Animalia
(Heterotrophic, locomotory)
Phylum – Arthropoda
(jointed appendages,
chitinous & segmented body)
Class – Insecta
(3 pairs of walking legs,
2 pairs of wings)
Genus – Periplaneta
(straight wings, nocturnal,
chewing type of mouthparts)
Species – americana (origin in Mexico, USA)

16. EXTERNAL FEATURES
 Elongated, dorso-ventrally flattened.
 3-5 cm in length, 1.5-2 cm in breadth.
 Reddish brown, bilaterally
symmetrical, triploblastic, &
coelomates .
[Body cavity is called HAEMOCOEL (haemolymph)].
 Exoskeleton is hard, waxy, waterproof
made up of chitin (polysaccharide)
 Provides surface area for attachment
of muscles apart from protection.
 Made up of Tergum (dorsal), Sternum
(ventral), 2 - Pleurons (lateral).

17. EXTERNAL FEATURES -- HEAD
 Body is divisible into Head,
Thorax & Abdomen.
 Head is ovate/pear shaped at
right angles to the body.
 Attached to thorax by thin
narrow, movable neck /
cervicum
 Six sclerites, fuse in adults &
forms head capsule.
 Head bears Compound eyes,
Antennae, Fenestrae &
Mouthparts.

18. EXTERNAL FEATURES – HEAD CONTD….
 Compound eyes are paired, dark,
kidney shaped, lateral structures
made up of ommatidia (hexagonal
facets).
 Each ommatidium acts as a
single, simple eye & forms an
image.
 All such images combine in the
brain & form a single blur
mosaic image.

19.  Antennae are paired, long,
slender, filamentous jointed
structures lodged in
membranous pits named
antennal sockets.
 They are tacto-receptors/organs
of olfaction (smell).
 Fenestrae are white oscillar
spots situated at the base of
antennae.
EXTERNAL FEATURES – HEAD CONTD….

20. EXTERNAL FEATURES – MOUTHPARTS CONTD…
 Chewing & biting type --
Made up of movable,
segmented appendages;
Labrum, Mandibles,
Maxillae, Labium,
Hypopharynx.
 Labrum/Upper lip -- flap like/shield like, covers from
upper side(anterior wall mouth cavity). Holds food during
feeding.
 Mandibles – true jaws are dark, hard, chitinous
structures with serrated margins & teeth below the
labium on either side. Useful in cutting & crushing food.

21. EXTERNAL FEATURES – MOUTHPARTS CONTD…
 Maxilla /Accessory jaws
Paired appendages, on either
sides behind mandibles.
 Show maxillary palp/1st pair
of maxillae (many jointed structure)
 Labium / Lower lip / 2nd
maxillae covers mouth
ventrally has 3 jointed labial
palps.
 Pushes the food in pre-oral
cavity, also sensory in
function.

22. EXTERNAL FEATURES – MOUTHPARTS CONTD…
 Tongue/Hypopharynx – long
prominent medially placed
appendage.
 CERVIX/NECK
 Membranous structure between
head & thorax

23. EXTERNAL FEATURES – THORAX
 Divisible into prothorax,
mesothorax & metathorax.
 Dorsally covered by meso &
metathoracic wings. (Fore & Hind).
WINGS
 Fore wings – dark, opague,
thick & protective.
 Hind wings – thin, broad,
delicate & transparent, useful
in flight (true wings).

24. EXTERNAL FEATURES – THORAX CONTD…
 Ventrally thorax shows 3 pairs of
legs.
 Each leg is 5 jointed structure
covered with sensory bristles &
spines.
 The 5 podomeres are Coxa,
Trochanter, Femur, Tibia &
Tarsus
 Tarsus is made up of 5 movable
segments called as tarsomeres.
 Last segment bears pair of claw &
arolium (helps in clinging).

25. EXTERNAL FEATURES – ABDOMEN
 11 segmented, largest, 11th segment is fused hence only
10 segments are distinct.
 Presence of anal styles in 9th in males is a sexual
dimorphic feature.
 10th segment bears Anal cerci (common to males & females).
 Sensitive to air movements & ground vibrations.
 Abdomen shows 8 pairs of spiracles.

26. EXTERNAL FEATURES – ABDOMEN CONTD…
 Genital openings are present on different segments.
 Surrounded by chitinous plates collectively called
gonapophyses.

27. DIGESTIVE SYSTEM
 It consists of Alimentary ( 6-7cm)
canal & salivary glands.
 Alimentary canal is made up
of Foregut/Stomodaeum,
Midgut/Mesentron & Hindgut/
Proctodaeum.
 Mouthparts cover mouth
cavity.
 Tongue/Hypopharynx lies in
the cavity.

28. DIGESTIVE SYSTEM CONTD…
 Foregut is made up of Pharynx,
Oesophagus, Crop,
Gizzard/Proventriculus.
 Pharynx – short, dialated,
muscular tube, has tactile
sensillae. (conducts food)
 Oesophagus – narrow, tubular
passage, runs through neck &
opens into crop.
 Crop–large, highly distensible,
pear shaped sac, stored food.
 Gizzard– circlet of 6
chitninpous teeth

29. DIGESTIVE SYSTEM CONTD…
 Gizzard– circlet of 6 chitinous
teeth, crushing, behind teeth are
backwardly pointed bristles.
 Bristles are in grooves &
interconnected forming filter.
 Gizzard is hence efficient
grinding & straining apparatus.
 MIDGUT
 Ventriculus/Stomach – short,
narrow tube (uniform diameter).
 Hepatic caeca (8) – thin,
transperant, blind tubules (whorl)

30. DIGESTIVE SYSTEM CONTD…
 Midgut is major organ of
absorption.
 HIND GUT
 Made up of Ileum, Colon,
Rectum.
 Broader than midgut, at the
junction are 150 yellow thread
like malphighian tubules.
 Excretory product from
malphighian tubules is poured
in ileum.

31. DIGESTIVE SYSTEM CONTD…
 Ileum is short & narrow, colon
is coiled & wide tube.
 Rectum – terminal part, opens
by anus.
 SALIVARY GLANDS
 Two, one on either side of crop.
 Each gland has a glandular lobe
& receptacle/reservior.
 Glandular lobe has irregular,
white lobules with collecting
ducts.

32. DIGESTIVE SYSTEM CONTD…
 Secretes saliva CT unite &
forms common salivary duct.
 Thin bag like structures called
salivary receptacles store saliva.
 Common salivary receptacular
duct runs below oesophagus &
opens at the base of tongue.
 Cockroaches have tendency of
cannibalism.

33. CIRCULATORY
SYSTEM

34. CIRCULATORY SYSTEM
 Open / Lacunar type of circulatory system.
 Blood is Haemolymph, flows through sinuses & lacunae.
 Body cavity – Haemocoel, divided into 3 compartments
namely; Dorsal sinus, Middle sinus & Ventral sinus.
 Compartments are formed by muscular perforated septa
viz; Dorsal & Ventral diaphragms.

35. CIRCULATORY SYSTEM CONTD…
 Dorsal sinus – pericardial sinus presence of tubular heart.
 Middle sinus – perivisceral sinus contains visceral organs.
 Ventral sinus – perinueral sinus contains ventral nerve
cord.

36. CIRCULATORY SYSTEM CONTD…
 Heart – 13 chambered,
elongated, muscular, open in
front, closed behind.
 3 thoracic & 10 abdominal
chambers, posterio-laterally
a pair of openings ostia are
seen.
 Movement of blood is from
posterior to anterior direction
peristalitically.
 heart extends into head as
anterior aorta.

37.  Haemolymph is composed of
Plasma & Haemocytes.
 It has no respiratory pigment
hence no respiratory role.
 Plasma constitutes absorbed
food & nitrogenous wastes.
 30000 Haemocytes per cubic
millimeter are seen in the blood.
 12 pairs of alary muscles are
attached to dorsal diaphragm
 Pointed ends are connected to
terga
CIRCULATORY SYSTEM CONTD…

38.  Pulsation of heart is due to muscular
walls assisted by Alary muscles.
 During Diastole, heamolymph from
pericardial sinus enters heart
through ostia.
 During Systole ostia gets closed &
Haemoplymph gets propelled.
 Heart chambers & anterior aorta
contract from behind forwards
driving the blood to head sinus.
 From head it is transferred to
perivisceral & perinueral sinus
BLOOD CIRCULATION

39.  Nervous system is divided into
Central Nervous system
Peripheral Nervous system
Autonomic Nervous system
 Central Nervous System
consists of ;
Pair of Supra oesophageal
ganglia, Sub oesophageal
ganglia, Circum oesophageal
connectives.
NERVOUS SYSTEM

40.  Supra Oesophageal ganglion
It is bilobed situated in the head
above oesophagus between the
antennae & is called as brain.
 Formed by fusion of 3 pairs of
ganglia; Protocerebrum,
Dueterocerebrum &
Tritocerebrum.
 Sub Oesophageal ganglion is
also bilobed, below oesophagus
in head formed by fusion of 3
pairs of ganglia.
CENTRAL NERVOUS SYSTEM

41.  Circum oesophageal connectives
 A pair of nerves arising from supra
oesophageal ganglion & connected
to the sub oesophageal ganglion
encircling the Oesophagus. (nerve
ring)
 Nerve cord is double, ventral, solid
& ganglionated.
 It has paired ganglia, 3 in thorax &
6 in the abdomen (1st 5 in 5 abdominal segments).
 6th is largest & lies in the 7th
segment. (formed due to fusion of last few ganglia)
CENTRAL NERVOUS SYSTEM

42.  It comprises of nerves, arising
from supra oesophageal
ganglion (6 pairs supplied to eyes,
antennae, labrum).
 From sub oesophageal ganglion
are the nerves for mandibles,
maxillae & labium.
 From thoracic ganglia the
nerves are for thoracic muscles,
wings, legs & other organs.
PERIPHERAL NERVOUS SYSTEM

43.  Abdominal ganglia supply
nerves which controls the
organs in the abdomen & their
processes like respiration,
circulation, movements of
alimentary canal.
PERIPHERAL NERVOUS SYSTEM

44. RESPIRATORY SYSTEM
 It is made up of Spiracles
(openings on the surface), Trachea
& Tracheoles.
 Trachea are larger tubes which
branches into smaller tubes
called tracheoles, they surround
the organs.
 Air enters through spiracles &
reaches the tissues (cells) through
trachea & tracheoles.
 O2 diffuses into cells & Co2 in
the air which leaves the body.

45. REPRODUCTIVE SYSTEM - FEMALE
 Female reproductive system is
made up of pair of ovaries,
oviducts, common oviduct (vagina)
& Spermatheca.
 Each ovary contains 8 ovarioles,
they unite to form oviduct on
either side which further unites to
form common oviduct.
 Common oviduct opens into
genital chamber.
 The 6th abdominal segment has
spermatheca, recieves sperms.

46. REPRODUCTIVE SYSTEM - FEMALE
 Collateral glands (female
accessory glands) secrete
leathery dark reddish/blackish
brown egg case/ootheca.
 It contains 14-16 eggs, protects
the developing fertilized eggs.

47. REPRODUCTIVE SYSTEM - MALE
 It includes pair of testes, vasa
deferentia & an ejaculatory duct.
 Testes is lateral on either side in
4th to 6th segment.
 A thin vas deferens carries
sperms to ejaculatory duct
through seminal vesicle.
 It opens into gonopore below
anus.
 Sperms are stored in the seminal
vesicle in the form of bundles
called spermatophores.

48.  Accessory male reproductive
glands are mushroom shaped
glands present in the 6th & 7th
segment.
 Phallic gland, other glands with
ejaculatory duct secrete
substances which help in
fertilisation.
REPRODUCTIVE SYSTEM - MALE