Sunday 4 February 2018

FROG

Common name- Rana tigrina
Class- amphibia
Phylum-chordata
They can live on land and fresh water both.
They do not have constant body temperature, i.e. it varies with temperature of surrounding.
They are cold blooded or poilkilothermic.
They have ability to change their body temperature according to surrounding.

MORPHOLOGY
-Skin of frog is smooth because of presence of mucus.
-Frog never drink water but absorb it through skin.
-Body is divided into head and trunk.
-A pair of nostril present above mouth.
-Eyes are bulged and covered by membrane.
-Tympanum receive sound.
-Fore limb and hind limb helps in swimming, walking and other movement.
-Hind limb has 5 digits and it is larger than fore limbs.
-Fore limb has 4 digits.
-Both sexes can be distinguished easily by the presence of vocal sac and copulatory pad on first digit of fore limbs on male frog and absent in female frog.

ANATOMY
-The body of frog consist of organ system level.

DIGESTIVE SYSTEM
-D.S. consist of alimentary canal and digestive glands.
-Mouth opens into buccal cavity,which opens into oesophagus opens into pharynx.
-Oesophagus opens into stomach which in turn continues as  intestine, rectum and finally opens outside by cloaca.
-Liver secretes bile which are stored in gall blader.
-Pancreas produces digestive enzymes.
-Food is captured by bilobed tongue.
-Digestion takes place in stomach by the help of HCL and gastric juice, secreted from the wall of stomach.
-Chyme is further passed to duodenum,where fat is emulsify by bile and protein & carbohydrate is digested by pancreatic juice.
-Final absorption of food is in intestine by the help of villi & microvilli.
-Undigested solid moves to rectum & passes through cloaca.

RESPIRATORY SYSTEM
-In frog both cutaneous respiration and pulmonary respiration can be observed.
-In water, skin acts as respiratory organ and this is called cutaneous respiration.
-On land skin, buccal cavity & lungs act as respiratory organ called pulmonary respiration.

CIRCULATORY SYSTEM
-C.S. is closed type. It has a lymphatic system also.
-Heart has 3 chambers i.e. two artria and one ventrical.
-Sinus venous attached to artrium which receives blood through major vein called vena cava.
-Ventrical opens into conus arteriosus which carries blood from heart to body part.
-Hepatic portal system( connection between liver and kidney) & reanl portal system(connection between kidney and lower part) are found in frog.
-RBC, WBC and platelets are found in blood.

EXCRETORY SYSTEM
-Frog is ureotelic animal(excretes urea)
-It has well developed excretory system consists of kidney, uterus,cloca and urinary bladder.

CONTROL &COORDINATION
-Frog has highly evolved  neural & endocrine neural system.
-Prominent endocrine glands are pituitary, thyroid, parathyroid, thymus,pineal body, pancreatic islets,adrenal and gonads.
-The nervous system consists of CNS(brain and spinal cord), PNS(cranial and spinal) and ANS(sympathetic and parasympathetic)
-10 pairs of cranial nerves arising from brain.
-Brain is inclosed in cranium.
-Brain-Fore brain- olfactory lobe,paired cerebral hemisphere & single diencephalone.
           Mid brain-optic lobes
           Hind brain-cerebellum & medulla oblongata.

SENSE ORGAN
-Frog has different types of sense organ- touch organ, taste bud, smell epithelium, eyes and hearing organ.
-Eye and internal ear are well developed rest are cellular aggregation

REPRODUCTIVE SYSTEM
-Well organised reproductive system can be seen in male and female frog.
-A pair of testes  is found in male frog and sperm, urine and faecal matter are communicated through urinogenital tract.
-Female reproductive organ includes a pair of ovaries.
-A pair of oviduct arise from ovary and open separately in cloaca.
a mature female can lay 2500 -3000 ova at a time.
-Fertilization is external and takes place in water.
development involves larval stage called tadpole.
-Tadpole undergoes metamorphosis to form the adult.






Thursday 1 February 2018

COCKROACH

Class- insecta
Phylum- arthropoda
Cockroaches are brown or black bodied 1/4 inches to 3 inches long animal and have antennae, head and legs.
They are nocturnal.
They are omnivorous.
They are vector of several disease.

MORPHOLOGY

-Body is divided into head, thorax and abdomen.
-Entire body is covered by hard chitinous exoskeleton.
-Exoskeleton has hardened plates called sclerits.
-Head is triangular in shape.
-Head is formed by fusion of 6 segments, hence it has great mobility in all direction.
-Head bears a pair of compound eye.
-A pair of antennae arise from membranous shockets lying in front of eyes.
-Antennae has sensory receptors.
-The mouth part consists of labrum(upper lip), a pair of mandibles,a pair of maxillae and a labium(lower lip)
-Hypopharynx acts as tongue.
-Thorax-protothorax-known as neck,connect head and thorax.
             mesothorax-first pair of wings arises.
             metathorax-second pair of wings arises.
       each segment of thorax bear a pair of walking legs.
-The abdomen of both male and feamle consist of 10 segments.

ANATOMY

-The alimentary canal is divided into foregut, midgut and hindgut.
-Mouth opens into pharynx, opens into oesophagus, opens into crop which finally opens into gizzard.
-Ring of 6-8 blind tubule called hepatic caecae secretes digestive juice.
-At the junction of midgut and hindgut 100-150 ring of malphigian tubules are present which help in excreation.
-Cockroach is uricotelic animal.
-Hindgut is differentiated into ileum, colon and rectum.
-Rectum opens into anus.
-Blood vascular system is of open type,vessels are poorly developed.
-Haemolymph is composed of colourless plasma and haemocytes.
-Heart is differentiated into funnel shaped chambers and ostia on either side.
-Respiratory system consist of network of trachea.
-Trachea opens through 10 pairs of holes called spiracles, which helps in diffusion of gas for respiration.

NERVOUS SYSTEM-
-Nervous system consist of fused segmentally arranged ganglia.
-3 ganglia lie in thorax and six in abdomen.
-Nervous system of cockroach spread throughout body a bit of  N.S. is in head and rest is situated along belly side(ventral part) of its body.
      Hence, it is easy to understand that  if it's head is cut off, it will still alive for a week.
-Sense organ are antennae,compound eye, maxillarypalps,labial palps and cerci.
-Compound eye are situated at dorsal surface of head.
-Each eye consists of 2000 hexagonal ommatidia.
-Ommatidia helps in receiving several images of same object having less resolution. It gives mosaic vision.

REPRODUCTION-
-Male and female body are separate.
-In male 4th- 6th segment of abdomen consists of a pair of a testes.
-Vas deferens attached to testes opens into ejaculatory duct through seminal vesical, which opens into gonopore.
-External genitalia of male is represented by gonapophysis.
-In female 2nd-6th segment of abdomen consists two large ovaries.
-Each ovary forms of 8 ovarioles(chain of developing ova)
-Ootheca-fertilized eggs are stored here.
-Female cockroach  produces 9-10 ootheca, each ootheca contains 14-16 eggs.
-Development is paurometabolous, means development through nymphal stage.

EARTHWORM

*Zoological name- Pheretima posthuma
*Habitat- burrows and moist soil.
*Nocturnal habit.
*Species- more than thousand.
*Phylum- Annelida.
*life span-  3&1/2 to 10 yrs.
*Cold blooded animal.


Morphology 

- Bilaterally symmetrical, cylinde body.
- Length- ~150mm
- Colour-dark brown due to presence of  PORPHYRIN pigment.
- Body consist of 100-120 metameres or small ring like segments.
- Inner body is divided by septa,but septal wall is absent in first four segment and between 9th and 10 segment.
- All body segment are alike except first and last segment.
- First body segment consist of  prostomium and mouth.
- First body segment is called peristomium.
- Clitellum is a band of glandular tissue which cover 14-16th segment of mature worm.
- 5th-9th segment- spermathecal aperture.
- 14th segment- single female  genital pore is present.
- 18th segment- a pair of male genital pores.
- Nephridiopores are present on body surface.
- Setae are present on middle of each segment except first, last and clitellum. it helps in locomotion.


Anatomy

- Epidermis is made up of columnar epithelial cell which contain secretary glands and epidermis is covered by non cellular cutical.
- Alimentary canal runs between first to last segment.
- 1-3 segment- mouth opens into buccal cavity
- 5-7 segment- oesophagus
- 8-9 segment-musculas gizzard( helping in grinding food)
- 9-14 segment- stomach, here calciferous glands present.
- 15th-last  segment- intestine.
- 26th segment- intestinal caecae.
- 26-35 segment- typhlosole is an internal median fold.
- closed boold vascular system consist of vesssel, capillary and heart.
- 4th-6th segment- blood glands produces haemoglobin and blood cell.
- Blood cells are phagocytic in nature.
- Respiratory exchange occurs through moist body surface.
- Nepheridia is an excretory organ.
- NEPHERIDIA-Septal nepheridia...15th to last segment,that open into intestine
                         Integumentary nepheridia...3rd to last,attached to lining of the body.
                         Pharyngeal nepheridia...present in 4th,5th and 6th segment in pairs.(3pairs)
- Nervous system is represented by ganglia.
- Sensory system doesn't have eyes but posses light and touch sensitive organ.
- Earthworm is a hermaphrodite.
- 10th-11th segment-two pairs of testes and vasa deferentia run upto 18th segment.
- 17th &19th segment- two pairs of accessory gland.
- 18th segment-male genital pore.
- 6-9th segment- four pairs spermathecae, which receive and stores spermatozoa.
- 12&13 segment- 1 pair of ovary.
- 14th segment- female genital pore.
- After mating mature sperm,egg and nutritive fluid are deposited into cocoons, produced by gland cells of clitellum.
- Fertilization and development occurs inside cocoons.
-These cocoons holds worm embryo for 3 weeks and then each cocoons produces 2-12 baby worm.
-No larval stage in earthworm. Development is direct.