Thursday, February 23, 2012

Skin and Hair facts

Skin
  • A lifespan of an eyelash is approximately 150 days.
  • A Russian man who wore a beard during the time of Peter the Great had to pay a special tax.
  • A survey done by Clairol 10 years ago came up with 46% of men stating that it was okay to color their hair. Now 66% of men admit to coloring their hair. 
  • After you die, your body starts to dry out creating the illusion that your hair and nails are still growing after death. 
  • An average human scalp has 100,000 hairs. 
  • An average woman has 17 square feet of skin. When a woman is in her ninth month of pregnancy she has 18.5 square feet of skin.
  • Ancient Egyptians used to think having facial hair was an indication of personal neglect.
  • Approximately 25% of all scald burns to children are from hot tap water and is associated with more deaths than with any other liquid.
  • Blondes have more hair than dark-haired people do.
  • Brylcreem, which was created in 1929, was the first man's hair product.
  • During a 24-hour period, the average human will breathe 23,040 times.
  • Each square inch (2.5 cm) of human skin consists of 20 feet (6 m) of blood vessels. 
  • Every human spent about half an hour as a single cell. 
  • Every square inch of the human body has about 19,000,000 skin cells.
  • Every year about 98% of the atoms in your body are replaced. 
  • Everyday approximately 35 meters of hair fiber is produced on the scalp of an adult.
  • Eyebrow hair lasts between 3-5 months before it sheds.
  • Forty-one percent of women apply body and hand moisturizer at least three times a day.
  • Hair and fingernails are made from the same substance, keratin.
  • Hair is made from the same substance as fingernails.
  • Hair will fall out faster on a person that is on a crash diet.
  • Humans have about the same number of hair follicles as a chimpanzee has.
  • In a lifetime, an average man will shave 20,000 times.
  • In one day, a human sheds 10 billion skin flakes. This amounts to approximately two kilograms in a year.
  • In the average lifetime, a person will walk the equivalent of 5 times around the equator. 
  • It’s impossible to sneeze with your eyes open.
  • Next to bone marrow, hair is the fastest growing tissue in the human body.
  • On average redheads have 90,000 hairs. People with black hair have about 110,000 hairs.
  • On average, a hair strand's life span is five and a half years.
  • On average, a man spends about five months of his life shaving.
  • Our eyes are always the same size from birth, but our nose and ears never stop growing. 
  • The average human brain has about 100 billion nerve cells.
  • The average human scalp has 100,000 hairs.
  • The average human will shed 40 pounds of skin in a lifetime. 
  • The entire length of all the eyelashes shed by a human in their life is over 98 feet (30 m).
  • The fastest growing tissue in the human body is hair.
  • The first hair dryer was a vacuum cleaner that was used for drying hair.
  • The length of the finger dictates how fast the fingernail grows. Therefore, the nail on your middle finger grows the fastest, and on average, your toenails grow twice as slow as your fingernails.
  • The longest human beard on record is 17.5 feet, held by Hans N. Langseth who was born in Norway in 1846.
  • The loss of eyelashes is referred to as madarosis.
  • The reason why hair turns gray as we age is because the pigment cells in the hair follicle start to die, which is responsible for producing "melanin" which gives the hair colour.
  • The reason why some people get a cowlick is because the growth of their hair is in a spiral pattern, which causes the hair to either stand straight up, or goes to a certain angle.
  • The surface of the human skin is 6.5 square feet (2m). 
  • There are as many hairs per square inch on your body as a chimpanzee. You don't see all of them because most are too fine and light to be noticed.

Eye facts

Eye

Heart, Blood & Blood vessels- Facts

Wednesday, February 22, 2012

Excretory Organs of animals


Phylum
Excretory organ
Porifera
No. Diffusion through body surface
Cnidaria
No. Diffusion through body surface
Ctenophora
No. Diffusion through body surface
Platyhelminthes
Protonephredia (Flame cells)
Nemathelminthes
Renette cells
Annelida
Oligochaetes
Nephredia (Metanephredia)
Polychaetes
Protonephredia and metanephredia
Arthropoda
Crustaceans
Antennary (Green) glands
Arachnids (spiders, scorpions etc), Limulus
Coxal glands
Insecta, chilopods, diplopods
Malpighian tubules
Mollusca
General
Metanephredia
Fresh water mussel
Organs of Bojanus, Keber’s organs
Echinodermata
Dermal branchiae
Hemichordata
Proboscis gland
Chordata
Urochordata
Neural glands
Cephalochordate
Protonephredia with solenocytes
Vertebrata
Kidney
Amphioxus
Hatschek’s nephredium, paired nephredia and Brown funnels

RESPIRATORY ORGANS OF ANIMALS


Phylum
Respiratory organ
Porifera
Body surface
Cnidaria
Body surface
Ctenophora
Body surface
Platyhelminthes
Body surface
Nemathelminthes
Body surface
Annelida
Skin (integument)
Arthropoda
Aquatic insects (mayflies, nymphs etc)
Tracheal gills
Damselfly nymphs
Caudal gills
Limulus
Gill books
Scorpion, some spiders, Scutigera and chilopods
Book lungs (Diffusion lungs)
Insects, some spiders
Trachea
Some crabs (e.g. coconut crabs)
Branchiostegal lung (gill-like lung)
Mollusca

Skin (Cutaneous)
Aquatic forms
Ctenidia (gills)
Terrestrial forms
Pulmonary sacs (lungs)
Echinodermata

Dermal branchiae (skin gills)
Holothurians
Water lungs
Hemichordata
Gills
Chordata
Lungfishes
Ventilation lungs
Fishes
Internal gills, lungs (for lung fishes)
Some teleost fishes
Swim bladder (air bladder)
Fishes such as Misgurnus, Ancistrus and Plecostomus
Alimentary mucosa
Labyrinth fish
Labyrinth organ – A secondary breathing organ
Amphibians
Skin, lungs, external gills (for tadpoles)
Reptiles
Ventilation Lungs
Birds
Ventilation Lungs
Mammals
Ventilation Lungs

Monday, February 20, 2012

Download Free Biology Books

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'via Blog this'

Animal Kingdom- Notes


  
 Phylum
Name given by
No. of species
Levels of organization
Germ layers
Symmetry
Coelom
Porifera
Robert Grant
5000
Cellular
Diploblastic
Asymmetrical/ radial
Acoelomate
Cnidaria
Leuckart (1847)
9000
Tissue
-do-
Radial
-do-
Ctenophora
Escholtz (1829)
<100
-do-
-do-
-do-
-do-
Platyhelminthes
Gegenbaur (1859)
13000
Organ/Organ system
Triploblastic
Bilateral
-do-
Aschelminthes
Gegenbaur (1859)
15000
-do-
-do-
-do-
Pseudocoelomate
Annelida
Lamarck (1809)
9000
-do-
-do-
-do-
Coelomate
Arthropoda
Von Siebold
9,00,000
-do-
-do-
-do-
-do-
Mollusca
Johnston
60,000
-do-
-do-
-do-
-do-
Echinodermata
J. Klein
6000
-do-
-do-
Radial
-do-
Hemichordata
Bateson

-do-
-do-
Bilateral
-do-
Chordata

45,000
-do-
-do-
Bilateral
-do-

COMPARISON OF DIFFERENT PHYLA (NON-CHORDATES)
Phyla
Features
Porifera (Sponges)
Cnidaria (Coelenterata)
Ctenophora
(Acnidaria or Comb Jellies or sea walnuts)
Platyhelminthes (Flatworms)
Aschelminthes (Nemathelminthes/ Roundworms)
Habit and habitat
Aquatic (mostly marine). Sedentary. Solitary or colonial. Coloured.
Aquatic (mostly marine).
Solitary or colonial.
Sessile or free swimming
Exclusively marine.
Solitary and pelagic.
Mostly endoparasites. Some are free-living. Mainly aquatic.
Free living, aquatic and terrestrial or parasitic in plants and animals.
Digestive system
Absent. 
Digestion is intracellular.
Water transport (canal system) to gather food.
Incomplete. Carnivorous.
Intracellular and extracellular digestion.
Incomplete.
Intracellular and extracellular digestion. Mouth & 2 anal pores.
Incomplete. Branched alimentary canal with mouth. Anus absent. In parasites alimentary canal absent.
Complete. Tubular alimentary canal with mouth, muscular pharynx, intestine and anus. Mouth may possess teeth.
Respiratory system
Absent. Respiration by canal system
Absent
Absent
Absent
Absent
Circulatory system
Absent. Circulation by canal system
Absent
Absent
Absent
Absent
Excretory system
Absent. Excretion by canal system.  Ammonotelic.
Body surface. Ammonotelic
Body surface. Ammonotelic
Flame cells for excretion and Osmoregulation. Ammonotelic
An excretory tube to remove body waste through excretory pore. Ammonotelic
Nervous (Neural) system
Absent.
Only a network of neurons.
Only a network of neurons.
Ladder-like.
A brain and nerve cords, connected by transverse nerves
Circumpharyngeal ring with dorsal and ventral nerves.
Reproductive system
Hermaphrodite.
ARP by fragmentation budding or by gemmules (internal buds)
SRP by the formation of sperms and ova.
Fertilization internal.
Polyp reproduces asexually (budding) and medusa sexually. Medusa forms monoecious or dioecious.
Fertilization external.
Only SRP.
Hermaphrodite. 
Fertilization external.
ARP (by fragmentation & regeneration) and SRP.
Hermaphrodite.
Fertilization is internal.
Sexes are separate (Dioecious).
Sexual reproduction.
Internal fertilization.
Larva
Leucosolenia: Parenchymula
Sycon: Amphiblastula
Higher sponges: Rhagon.
Aurelia: Ephyra
Obelia & Adamsia: Planula
Hydrula,
Hydratuba
Ciliated Cydipid larva
Taenia: Bladder worm
(Cysticercus), Hexacanth & Oncosphere
Fasciola: Miracidium, Sporocyst/Gamocyst/ zoocyst, Redia, cercaria, & metacercaria
No
Other features
1cm-1m length. Millions of minute pores (ostia).
Body wall with outer layer of flat cells (pinacocytes) and inner layer of flagellated cells (choanocytes or collar cells). Body is supported by calcareous or siliceous spicules and spongin fibres. Spongocoel (body cavity) and canals are lined with choanocytes.
Spongocoel opens out by osculum. Highest degree of regenerating capacity.
Tentacles with cnidoblasts (stinging cells).
A central gastro-vascular cavity (coelenteron) with a single opening (mouth) on hypostome.
Polyp & Medusa are 2 kinds of body forms. Show polymorphism and alternation of generation (metagenesis).
Corals have a skeleton made up of CaCO3.
Locomotion is by 8 vertical external rows of ciliated comb plates.
Tentacles present. Special adhesive cells (colloblasts) on tentacles. Mesoblast present. Shows Bioluminescence.
Unsegmented, dorso-ventrally flattened body (except in tape worms).
Hooks and suckers in parasitic forms.
Some of them absorb nutrients from the host through their body surface.
The first group showing cephalization.
Syncitial epidermis.
Thick cuticle.
Sexual dimorphism (females are longer than males).
Examples
Sycon (Scypha), Spongilla (fresh water sponge), Euspongia (Bath sponge)
Hydra, Obelia, Physalia (Portugese man of war), Aurelia, Adamsia (Sea-anemone), Pennatula (Sea pen)), Gorgonia (Sea fan), Meandrina (Brain coral) etc.
Ctenoplana, Pleurobrachia, Cestum, Hormiphora
Taenia solium (Tape worm), Fasciola (Liver fluke), Planaria, Blood fluke (Schistosoma), Dog tapeworm (Echinococcus)
Ascaris (Roundworm), Ancylostoma (Hookworm), Enterobius, Wuchereria (Filarial worm)
COMPARISON OF DIFFERENT PHYLA (NON-CHORDATES)
            Phyla


Features
Annelida
(Segmented worms)
Arthropoda
(Joint-legged animals)
Mollusca
(Soft bodied animals)
Echinodermata
(Spiny skinned animals)
Hemichordata
Habit and habitat
Terrestrial, fresh water or marine.
Free living or parasitic.
Cosmopolitan.
Generally aquatic. Few are terrestrial.
Exclusively marine.
Marine
Digestive system
Complete. Pharynx, oesophagus, stomach, intestine etc.
Complete and well developed. Well developed mouth parts.
Complete and well developed. Salivary glands and liver.
Complete. Ventral (lower) mouth and dorsal (upper) anus.
Complete
Respiratory system
Cutaneous respiration. Some have branchial (gill) respiration
Either by Gills or trachea, or book gills or book lungs.
Gills in aq. forms and pulmonary sac in terrestrial forms.
Dermal branchiae (gills) or papulae and tube feet.
Gills
Circulatory system
Closed type
Open type
Open type
Reduced and open type.
Open type
Excretory system
Nephridia for excretion and Osmoregulation. Aq. forms ammonotelic & terr. forms ureotelic
Either Antennary glands or Malpighian tubules or coxal glands. Aq. forms ammonotelic and terr. forms uricotelic.
By Metanephridia. Ammonotelic or ureotelic.   
Absent.
Diffusion through gills. Ammonotelic.
Proboscis gland
Nervous (Neural) system
A pair of cerebral ganglia (brain) and a double ventral nerve cord connected by lateral nerves.
A nerve ring followed by a double ventral ganglionated nerve cord.
Paired ganglia and their connectives.
Circum oral nerve ring and radiating nerves No brain.
Simple
Reproductive system
SRP. Earthworms & leeches are hermaphrodites.
Neries is dioecious.
Sexes are separate. External fertilization in aq. forms. Internal fertilization in land forms. Mostly oviparous.
Sexes are separate. Oviparous.
Sexes are separate.
Fertilization external.
Ciliated free swimming larva. 
Sexes are separate.
Fertilization external.
Larva
Free swimming trochophore larva.
Squilla: Alima
Butterfly, Silk moth: Caterpillar
Lepas: Cypris
Hermit crab: Glaucothoe
Beetles & Honeybee:  Grub
Housefly: Maggot   
Crab: Megalopa       
Simplest crustacean larva: Nauplius
Rock Lobster: Phyllosoma
Lobsters: Schizopod or Mysis Mosquito: Wriggler 
Cancer (Crab): Zoea
Limulus: Trilobite   
Glochidium, trochophore and veliger. Some have no larva.
Starfish: Bipinnaria
Ophiura: Ophiopluteus
Echinus: Echinopluteus
Holothuria: Auricularia
Antedon: Doliolaria
Tornaria
Other features
1mm – 2.5 m length. True segmentation.
Longitudinal and circular muscles which help in locomotion.
Locomotory organs are setae (in earthworm) or parapodia (in Neries).
Largest phylum.
Jointed appendages.
3 regions: head, thorax & abdomen.
Body is covered by chitinous cuticle (exoskeleton).
Sensory organs (antennae, compound & simple eyes, statocysts or balance organs) are present.
Second largest phylum.
Body has head, visceral mass (visceral hump) & muscular foot. Anterior head region has sensory tentacles.
Univalve or bivalve calcareous shell. Feather-like gills have respiratory and excretory functions.
Mantle & radula seen.
Body is covered with spines for protection. Head absent. Calcareous endoskeleton (ossicles) present. Water vascular system for locomotion, respiration & food capture & transport. Great power of autotomy and regeneration. Larva bilaterally symmetrical.
Worm-like cylindrical body composed of an anterior proboscis, a collar and a long trunk.
Examples
Pheretima (Earthworm), Hirudinaria (Blood sucking Leech), Neries, Aphrodite, Chaetopterus, Bonellia
Spider, Scorpion, Crab, Prawn, Insects etc.
Economically important insects: Apis, Bombyx, Laccifer.
Vectors: Mosquitoes (Anopheles, Culex & Aedes), Housefly etc.
Gregarious pest: Locusta.
Living fossil: Limulus (King crab)
Pila (Apple Snail), Achatina (Land snail), Pinctada (Pearl Oyster), Sepia (Cuttlefish), Loligo (Squid), Octopus (Devil fish), Aplysia (Sea Hare), Dentalium (Tusk shell),
Chaetopleura (Chiton)
Asterias (Starfish), Echinus (Sea Urchin), Echinocardium, Antedon (Sea Lily), Cucumaria (Sea Cucumber), Ophiura (Brittle Star).
Balanoglossus (Tongue worm), Saccoglossus, Glossobalanus
 PHYLUM CHORDATA
Phylum chordata is divided into 3 subphyla: Urochordata, Cephalochordata and Vertebrata

PROTOCHORDATA (ACRANIATA)
VERTEBRATA (CRANIATA)
Urochordata (Tunicata)
Cephalochordata
·   Notochord present only in larval tail
·   Body is covered by test made up of tunicin
·   Exclusively marine
·   Retrogressive metamorphosis
·   Hermaphrodite
·   E.g. Ascidia, Salpa, Doliolum etc
·   Notochord from head to tail region and is persistent throughout the life
·   Exclusively marine
·   Fish-like
·   No definite coelom
·   Sexes are separate
·   E.g. Branchiostoma (Amphioxus or Lancelet)
·   Possess notochord during the embryonic period
·   Notochord is replaced by a cartilaginous or bony vertebral column in the adult
·   Ventral muscular heart
·   Kidneys for excretion & osmoregulation
·   Paired appendages which may be fins or limbs
Vertebrata: Has 2 divisions- Agnatha and Gnathostomata
Agnatha (Jawless): Includes 1 class: Cyclostomata:


·   All are ectoparasites on some fishes.
·   Elongated body.
·   6-15 pairs of gill slits for respiration.
·   Sucking and circular mouth without jaws.
·   No scales and paired fins.
·   Cartilaginous cranium and vertebral column.
·   Circulation closed type.
·   Marine, but migrate for spawning to fresh water. After spawning, they die. Their larvae, after metamorphosis, return to ocean.
·   E.g. Petromyzon (Lamprey) and Myxine (Hagfish).
Gnathostomata (bears jaw):2 super classes (Pisces & Tetrapoda)
Pisces (Fishes- bears fins): 2 classes
Tetrapoda (bear limbs): 4 classes
Chondricthyes
Osteichthyes
Amphibia
Reptilia
Aves (Birds)
Mammalia
·   Marine.
·   Heterocercal caudal fin.
·   Cartilaginous
endoskeleton.
·   Gill slits without operculum.
·   Skin with placoid scales.
·   Teeth are modified placoid scales which are backwardly directed.
·   No air bladder so they have to swim constantly to avoid sinking.
·   Sexes are separate. In males pelvic fins bear claspers.
·   Internal fertilization.
·   Many of them viviparous.
Examples
Scoliodon (Dog fish), Pristis (Saw fish), Carcharodon (Great white shark), Trygon (Sting ray), Torpedo (Electric ray- have electric organ).

·   Marine & fresh water.
·   Homocercal caudal fin.
·   Bony endoskeleton.
·   Terminal mouth.
·   4 pairs of gills covered by an operculum on each side.
·   Scales are Cycloid, ctenoid etc.
·   Air bladder for buoyancy.
·   Sexes are separate.
·   Fertilisation external.
·   Mostly oviparous.
·   Development direct.
Examples
Marine: Exocoetus (flying fish), Hippocampus (sea horse), Sardine, Mackeral, Tuna, Remora (sucker fish), Pomfret, Cybium               Fresh water: Labeo (Rohu), Catla (Katla), Clarias (Magur), Tilapia, Anabas (Climbing perch)               Aquarium:
Betta (Fighting fish), Pterophyllum (Angel fish) etc.
· Aquatic larval life & terrestrial adult life.
· For breeding they require a watery environment.
· Pentadactyl limbs.
· Moist skin without scales.
· A tympanum represents ear.
· Alimentary canal, urinary & reproductive tracts open into a Cloaca which opens to exterior
· Respiration is by gills (in larva), lungs & skin
· 3-chambered heart (2 auricles + 1 ventricle).
· Poikilotherms
· Sexes are separate. Fertilisation external.
· Oviparous.
· Development is indirect.
Examples
Bufo (Toad), Rana (Frog), Hyla (Tree frog), Salamandra (Salamander), Ichthyophis (Limbless amphibia), Ambystoma (Tiger salamander), Rhacophorus (Flying frog)
·   Dry & cornified skin, epidermal scales or scutes. Snakes and lizards shed their scales as skin cast.
·   Tympanum represents ear
·   Limbs- 2 pairs (if present).
·   3-chambered heart (but a septum partially separates ventricle). Heart is 4-chambered in crocodiles.
·   Poikilotherms.
·   Fertilisation internal.
·   Oviparous.
·   Development is direct.
Examples
Chelone (Turtle), Testudo (Tortoise), Chameleon (Tree lizard), Calotes (Garden lizard), Crocodilus (Crocodile), Alligator, Gavialis (gharial) Hemidactylus (Wall lizard), Sphenodon (Tautara), Draco (flying dragon or flying lizard), Phrynosoma (horned lizard), Varanus (monitor).
Poisonous snakes: Naja (Cobra), Bangarus (Krait), Vipera (Viper), Crotalus (rattle snake), Enhydrina (sea snake) etc.
Non-poisonous snakes: Python, Typhlos (blind snake), Dryophis (tree snake)
·   Presence of feathers.
·   Possess beak.
·   Forelimbs are modified into wings.
·   Hind limbs have scales and are modified for walking, swimming, or clasping tree branches.
·   Skin is dry without glands except the oil gland at the base of the tail.
·   Long, hollow and pneumatic bones.
·   Digestive tract with additional chambers, the crop and gizzard
·   Heart is 4-chambered
·   Homoiotherms (warm-blooded)
·   Double respiration. Air sacs connected to lungs.
·   No urinary bladder.
·   Fertilisation is internal.
·   Oviparous.
·   Development is direct.
Examples
Corvus (Crow), Columba (Pigeon), Psittacula (Parrot), Struthio (Ostrich), Pavo (Peacock), Gullus (Fowl), Bubo (Owl), Aptenodytes (Penguin), Neophron (Vulture) etc.
·   Presence of mammary glands (milk producing glands).
·   2 pairs of limbs for walking, running, climbing, burrowing, swimming or flying.
·   Skin with hair
·   External ear (Pinnae)
·   Heterodont, thecodont, diphyodont.
·   4-chambered heart.
·   Homoiotherms.
·   Respiration by lungs.
·   Sexes are separate.
·   Fertilisation internal.
·   Viviparous (except Echidna and Platypus).
·   Development is direct.
Examples
Ornithorhynchus (Platypus), Macropus (Kangaroo), Pteropus (flying fox), Camelus (Camel), Macaca (Monkey), Rattus (Rat), Canis (dog), Felis (Cat), Elephas (Elephant), Equus (Horse), Delphinus (Common Dolphin), Balaenoptera (blue whale), Panthera tigris (Tiger), Panthera leo (lion)