Diversity In Living Organisms

DIVERSITY IN LIVING ORGANISMS : 

DIVERSITY IN LIVING ORGANISMS

INTRODUCTION : 

Every organism whether plant or animal is unique in itself. There is a wide diversity in the flora (plants) and fauna (animals) in the world. The diversity we see today is the result of 3.5 billion years of organic evolution. During the course of this evolution several species vanished from the surface of the Earth and became extinct. It is estimated that more than fifty times the existing species have become extinct. With such a vast number of organisms - both living and extinct, it becomes impossible to study every one of them at individual level. This task of studying the diversity of living organisms can be made easier and more effective if the various organisms are arranged in an orderly manner. INTRODUCTION

PORIFERA : 

The simplest multicellular animals. The cells are loosely held together and do not form tissues Aquatic in habitat (mostly marine) Ostia (pores) are present all over the body, with a single large opening on top called osculum Food and oxygen enter the organism along with water into a canal system Support system made up of tiny needle-like formations. They may be made of silica, calcium or spongin fibres  Reproduction may be sexual, asexual or budding Example: Sycon, Spongilla, Euptectella PORIFERA

COLLENTERATA : 

Two layered body which is radially symmetrical Aquatic in habitat which includes both fresh water and marine The outer layer has tentacles armed with stinging cells cnidoblasts which can release venom into the victim. The inner layer encloses a body cavity called gastro vascular cavity  Animals in this group exist in two types of individuals called zooids - polyps and medusae. Polyps are fixed and lead solitary or colonial life, while medusae are free swimming  Alternation of generation takes place in colonial forms. Polyps and medusae alternate with each other during the life cycle Reproduction is usually asexual i.e., by budding in the polyp form and sexual in medusa form Exoskeleton made of lime is found in corals  Example: Hydra, Obelia, Aurelia, Metridium COLLENTERATA

PLATYHELMINTHES : 

Simplest triploblastic organisms showing bilateral symmetry Mostly parasites in other animals Body in dorsoventrally flat and leaf-like or ribbon-like with bilateral symmetry  The body cavity has only one opening which serves as both the mouth and the anus  Hermaphrodites i.e, male and female sex organs present in one individual Example: Planaria, Liver Fluke, Tape Worm PLATYHELMINTHES

ANNELIDA : 

Occur in moist soil, fresh water and sea  Body is soft and segmented, triploblastic with bilateral symmetry  First animal with the coelom (body cavity) Body is covered by a non-chintinous cuticle which may have chitinous setae, or parapodia Reproduction is generally sexual, but some may reproduce asexually by rejuvination i.e, by regrowing broken segments Example: Nereis (sand worm), Aphrodite (sea mouse), Pheretima (earthworm), Hirudinaria (leech) ANNELIDA

ARTHROPODA : 

This is the largest phylum with almost 80% of the animal kingdom  Body is bilaterally symmetrical and segmented. It is divided into head, thorax and abdomen  Possess jointed legs which may be modified for walking, swimming feeding and feeling  Exoskeleton is chitinous which is shed periodically by moulting Body cavity is reduced and filled with blood (haemocoel)  Respiration is by lungs, book lung and trachea Example: Apis (honey bee), Araneae (Spider), Palaemon (prawn), Scolopendra (Centipede) ARTHROPODA

MOLLUSCA : 

Aquatic in habitat but some land forms are also seen Body is soft and divided into three regions (head, dorsal visceral mass and ventral foot) Body enclosed in a hard calcareous she Breathe through gills, land molluscs have lungs Sexes are separate Example: Chiton, Pila (snail), unio (fresh water mussel), octopus MOLLUSCA

ECHINODERMATA : 

Marine in habitat  Body is radially symmetrical, star shaped, spherical or elongate, Exoskeleton is spiny Head is absent and five radially arranged arms present Locomotion is with the help of tube feet  Sexes are separate Example: Asterias (star fish), Echinus (sea urchin), Holothuria (sea cucumber), Antedon (feather star) ECHINODERMATA

Animal KingdomVertebrates : 

Animal KingdomVertebrates

What is a Chordate? : 

All chordates have 4 basic features that are present at some point during their life cycle Hollow Nerve Cord – Nerve cord in which nerves branch out at regular intervals Notochord – Long supporting rod that runs throughout body Pharyngeal Pouches – Paired structures in throat Muscular Tail – Extends beyond anus Only 4-5% of animals are chordates Examples = Fish, Amphibians, Reptiles, Birds What is a Chordate?

Different Chordates : 

Section 30-1 Nonvertebratechordates Fishes Amphibians Reptiles Birds Mammals Different Chordates

REPTILE : 

REPTILE Mostly terrestrial Heart is 3 chambered, is cold blooded Breathe through lungs Body covered with scales  Have two pairs of pentadactyl (five digit) limbs which are absent in snakes  Example:  Hemidactylus (wall lizard), chameleon, Draco (flying lizard)

AMPHIBIA : 

Live in both water and on land Respiration is by gills, lungs or skin  3 chambered heart Is cold blooded  Have two pairs of pentadactyl (5 digit) limbs which may be absent in some cases AMPHIBIA

AVES : 

Arboreal in habitat i.e, they live on trees Warm blooded. 4 chambered heart Body covered with feathers  Lungs have membranous extensions called air sacs to make the body light Mouth is surrounded by a beak. Teeth are absent  Fore-limbs are modified into wings AVES

MAMMALIA : 

Most intelligent of all organisms  Warm blooded with 4 chambered heart  Give birth to young ones The mother suckles her young ones on milk secreted by special glands called mammary glands  Body covered with hair Have two pairs of pentadactyl limbs  Breathe through lungs MAMMALIA I AM I A MAMMAL?

The Generalized Structure of a Chordate : 

Section 30-1 The Generalized Structure of a Chordate

Fish : 

Fish live in nearly every single aquatic habitat imaginable Fish are aquatic vertebrates characterized by fins, scales, and gills Fish were the first vertebrates to evolve. Fish bring in Oxygen rich water through gills and remove oxygen poor water through gill slits Closed circulatory system Four chambered heart Swim bladder controls buoyancy Most are egg laying Most move by contracting opposite muscles (S Shaped) Fish

Groups of Fish : 

Jawless Fish – Have mouths of soft tissue with no true teeth. Have no bones Only vertebrates with no vertebral column as adults Lampreys, Hagfish Chondrichthyes – Skeleton built entirely of cartilage Sharks, sea rays Osteichthyes – Bony Fish Majority of fish fall in this order Carp, sea horse, perch, etc. Groups of Fish

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Lamprey – Jawless Fish Catfish - Osteichthyes Sea Ray - Chondrichthyes Whale Shark - Chondrichthyes

Amphibians – Basic Facts : 

Amphibian = “double life” Live in both water and land Most larvae are fishlike; adults are terrestrial carnivores Larvae respire through skin/gills; Adults use lungs Descendants of ancestral organisms that evolved some, not all, adaptations for life on land First appeared 360 million years ago External fertilization Closed circulatory system; three chambered heart Amphibians – Basic Facts

Amphibians : 

Amphibians

The Life Cycle of a Frog : 

Section 30-3 Adult Frog Young Frog Fertilized Eggs Tadpoles Adults are typically ready tobreed in about one to two years. Frog eggs are laid in water and undergo external fertilization. The eggs hatch into tadpoles a few days to several weeks later. Tadpoles gradually grow limbs, lose their tails and gills, and become meat-eaters as they develop into terrestrial adults. The Life Cycle of a Frog

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"Amphibian" comes from the Greek meaning "both life". Amphibians can live on water and on land. Scientist infer that amphibians evolved from lobe-finned fishes called crossopterygians.

Biologist conclude that amphibians appeared during the late Devonian period, about 345 million years ago. : 

Biologist conclude that amphibians appeared during the late Devonian period, about 345 million years ago.

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Characteristics of Amphibians : 

Characteristics of Amphibians

Amphibians are cold-blooded, which means their blood temperature rises and falls with that of the surrounding environment : 

• Amphibians are cold-blooded, which means their blood temperature rises and falls with that of the surrounding environment

They use gills, lungs, skin, and mouth cavity in respiration. : 

They use gills, lungs, skin, and mouth cavity in respiration.

They have moist, smooth, thin skin with no scales.Feet are webbed and the toes lack claws. : 

They have moist, smooth, thin skin with no scales.Feet are webbed and the toes lack claws.

Amphibians have many prominent characteristics that are adaptations to a life spent both on land and in water:They change from an aquatic larval stage to a terrestrial adultform. : 

Amphibians have many prominent characteristics that are adaptations to a life spent both on land and in water:They change from an aquatic larval stage to a terrestrial adultform.

Larvae have two-chambered hearts; adults have three-chambered hearts and well-developed circulation. : 

Larvae have two-chambered hearts; adults have three-chambered hearts and well-developed circulation.

Biologists have identified about 2,375 living species of amphibians and have classified them into four orders : 

Anura – Frogs & Toads Urodela – Salamanders Trachystoma – Mud eels Apoda - Caecillians Biologists have identified about 2,375 living species of amphibians and have classified them into four orders

Frogs and toads make up the Order Anura ("without a tail"). : 

Frogs and toads make up the Order Anura ("without a tail").

Salamanders and other amphibians with legs and tails make up the Order Urodela ("visible tail"). : 

Salamanders and other amphibians with legs and tails make up the Order Urodela ("visible tail").

Apoda includes caecilians, a tropical, burrowing worm-like amphibians that is often Legless : 

Apoda includes caecilians, a tropical, burrowing worm-like amphibians that is often Legless

Mud eels are great examples of Trachystoma : 

Mud eels are great examples of Trachystoma

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that allow for are that provide that allow are and have special adaptations such as larvæ they live in adults they live on means as Amphibians “Double life”

Groups of Amphibians : 

Salamanders – Long bodies and tails Adults are carnivorous Usually live in moist woods Frogs and Toads – Lack tails Frogs have long legs and are usually tied to water Toads have shorter legs and not as closely tied to water Caecilians – Legless animals that burrow in moist soil Have fishlike scales Groups of Amphibians

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Spotted Salamander Poison Dart Frog Fire Bellied Toad Caecilian

Reptiles – Basic Facts : 

All reptiles have: Dry, scaly skin – helps prevent loss of body water in dry environments Terestrial eggs – first animals to develop amniotic eggs that didn’t need to be deposited in water Respire using lungs Internal Fertilization; Most are egg-laying Ectotherms – cannot internally regulate body temperature; cannot live in cold climates Behavior controls body temp. (swimming, burrowing, basking, etc.) Closed circulatory system; double loop; Heart = two atria/one or two ventricles Reptiles – Basic Facts

Groups of Reptiles : 

Lizards and Snakes Have legs & clawed toes (lizards) external ears, moveable eyelids Highly evolved specialized forms (venom) Crocodiles and Alligators Long, typically broad snout and squat appearance All are carnivorous Protective of young; carry hatchlings in their mouth Live in tropics and subtropics Alligators live in freshwater Crocodiles live in fresh or saltwater Groups of Reptiles

Groups of Reptiles : 

Turtles and Tortoises – All are shelled Turtles are aquatic; tortoises are terrestrial Tuatara – Primitive reptiles found on small, remote islands Groups of Reptiles

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Coral Snake Sea Turtle Galapagos Tortoise Tuatara

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Nile Crocodile North American Alligator

Birds – Basic Facts : 

Nearly 10,000 modern bird species Birds are closely related to reptiles (scales on legs) Have outer covering made of feathers, two legs used for walking or perching, and forelimbs modified into wings Feathers separate birds from all other animal species Feathers provide insulation for warmth; can generate on body heat Beak/Bills adapted to type of food they eat Highly efficient respiratory system; lungs only exposed to Oxygen rich air Internal fertilization; amniotic eggs; many mate for life Birds – Basic Facts

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Section 31-2 which are that also that power that provide that ensure have the followingadaptations to flight Birds

Groups of Birds : 

More than thirty orders of birds Some of the most common Perching Birds – largest order; many are songbirds (sparrows, crows, cardinals, etc.) Birds of Prey – fierce predators with hooked bills; large talons (condors, hawks, owls, eagles, etc.) Herons & Relatives – Wade in aquatic habitats (storks, herons, cranes) Ostriches & Relatives – flightless birds move by running or swimming (ostriches, emus, etc.) Groups of Birds

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Purple Finch Red-Tailed Hawk Stork Emu

Mammals – Basic Facts : 

First true mammals appeared 220 million years ago Mammals flourished after dinosaurs became extinct – 65 million years ago Basic characteristics Hair Mammary glands – produce milk to nourish young Breathe air Four chambered heart Endotherms – can generate own body heat Internal fertilization; care for young Mammals – Basic Facts

Thanks For Patience : 

Thanks For Patience

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Thanks For Watching

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THANK YOU By-TUSHAR SHARMA & RAGHAV JAIN & TARUN DHALL & GROUP