+ All Categories
Home > Documents > THE LIVING WORLD 10th Grade - Biology. THE LIVING THING Plants and animals exhibit considerable...

THE LIVING WORLD 10th Grade - Biology. THE LIVING THING Plants and animals exhibit considerable...

Date post: 18-Dec-2015
Category:
Upload: eugenia-bruce
View: 218 times
Download: 0 times
Share this document with a friend
Popular Tags:
20
THE LIVING WORLD 10th Grade - Biology
Transcript

THE LIVING WORLD10th Grade - Biology

THE LIVING THING• Plants and animals exhibit considerable diversity at the cellular level. • During the evolution of organisms, diversity has occurred in the structure and functions of the

cells. For example, algae are generally aquatic, and the lower group of algae are unicellular, filamentous or colonial in their forms.

• The higher algae like Kelp and Sargassum are multicellular. Plants are deep rooted and widely branched. They have longer life span and show diversity in reproduction.

Diversity of plants and animals• The approximate number of species so for identified is about 1,672,000.• According to modern classification plants and animals are classified into five major kingdoms

Monera – 9,000, Protista – 59,950, Mycota , Plantae – 2,89,640 and Animalia – 11,70,000.

Major divisions of the Kingdom Plantae• Bryophyta - 24,000 species• Pteridophyta - 10,000 species• Gymnosperms - 640 species• Angiosperms - 255,000 species

MULTICELLULAR ALGAE

• Most of the algae are multicellular and have a flat plant body called thallus.

• These algae are non-vascular plants. They are identified under plant kingdam.

• They are classified into three groups, namely : Red algae, Brown algae and Green algae.

• Ex : Red Algae - Batrachospermum Polysiphonia• Brown Algae - Sargassum, Ectocarpus• Green Algae - Spirogyra, Ulothrix• Algae are mostly aquatic. Members of red and

brown algae grow attached to rocks, corals and other plants of the ocean.

• Members of green algae are mostly freshwater forms found in ditches, ponds, lakes and rivers. A few of them are found in oceans and on lands, or grow attached to other plants.

• Algae are capable of carrying out photosynthesis.

MULTICELLULAR ALGAE• Agar is obtained from a red alga called ‘Gelidium’. It

is used in bakery and meat packing industry. It is also used as a medium for culturing bacteria.

• A red alga called Porpyra is used as a condiment and in the preparation of soup.

• An alga called Microcystus grows upto 100 feet in length.

• Algin is a useful substance obtained from brown alga. It is used in the preparation of ice cream, chocolates and in the preparation of a Japanese food “Kombu”.

• Some species of algae are preserved and used in the preparation of cattle feed.

• The dead bodies of marine algae along with other dead organisms of the sea, undergo decay and release methane gas.

• When algae grow in decaying water tanks, the oxygen liberated will be utilized by microbes and thus water gets purified.

MULTICELLULAR ALGAE

• Green algae contain the green pigment called chlorophyll. • In Red algae chlorophyll ‘a’ and ‘b’ pigments are found. In addition, a red pigment called• phycoerythrin and a blue pigment called phycocyanin are found. Hence, the plant body• shows red colour. In Brown algae chlorophyll ‘a’ and ‘c’ pigments are found. In addition,

xanthophyll pigments are found in abundance. Hence, these algae are brown in colour.• The cellwall of algae is composed of cellulose and pectin. Usually the cells are uninucleate.• Reproduction takes place both by asexual and sexual means.• Sexual reproduction takes place by the fusion of male and female gametes.• Asexual reproduction takes place by the production of spores. • Vegetative propagation is by the fragmentation of thallus. Each bit of the thallus will

separate from the mother plant and grow into a new plant.• Many types of algae are used in industrial processes. A giant alga named Laminaria is used

in the production of potassium chloride and iodine.

BRYOPHYTA

• These plants are found both on moist land and in water. Hence, they are commonly called as amphibians of the plant kingdom.

• Bryophytes are multicellular plants having the features of eukaryotes.

• The plant body is a flattened, thalloid structure and can be differentiated into stem, leaves and rhizoids. In these plants, root-like structures called ‘rhizoids’ are present.

• Some plants of this group grow horizontally in the soil. Ex : Riccia (Liverwort) Some plants grow vertical to the soil surface. Ex : Mosses (They exhibit simple shoot system and leaves).

• The common examples of bryophytes are Marchantia, Riccia, Funaria and Mosses.

• The life cycle of bryophytes includes two successive generations called gametophyte and sporophyte.

gametophyte sporophyte

gamete producing plants

spore producing plants

prominent and larger in size and manufacture food with the help of chloroplasts.

smaller in size and depend on gametophytes for food.

BRYOPHYTA

• Mosses are tiny little plants generally making their apearance after the rains.• They are found growing on moist walls, tree trunks and on the ground. When they grow in

plenty they cover the substratum. Mosses found growing on• rocks are called rock mosses. Some mosses grow in marshy places and are called bog mosses. • Bryophytes reproduce by sexual and vegetative methods. • During vegetative reproduction, the thallus breaks into pieces and each piece grows into a

new plant.• Sexual reproduction occurs by the male and female gametes. • Structures called antheridium and archegonium are found in adult gametophytes.• Male gametes are produced in antheridium, Female gametes are produced in archegonium.• Moss plants are used in packing flowers. In gardens, moss pads are constructed while growing

creepers.

PTERIDOPHYTA

• Pteridophytes are included in the group called “tracheophytes”, because they have the vascular tissues (xylem and phloem) to conduct water and mineral salts.

• Ferns and other related plants are called pteridophytes.

• These are found in gardens, moist soil, on the walls and in all cool and shady regions.

• These are the first terrestrial plants to develop vascular tissues to transport food and water from one part of the plant to another.

• The plant body is differentiated into root, stem and leaves.

• Examples : Nephrolepis (fern plant) Selaginella, Adiantum, Lycopodium.

• There are two generations in the life cycle namely sporophyte and gametophyte. .

• . Walking ferns’• Marsilea, Salvenia, Azolla are the floating ferns of

tanks, ponds etc. The leaves of the fern adiantum• touch the ground, develop roots and become new

plants. These are commonly called ‘Walking ferns’

sporophyte gametophyte.

The adult plant body is a sporophyte.

The gametophyte is small but is an independent structure called prothallus

The sporophyte reproduces asexually by producing spores.

Male gametes are produced in antheridium and female gametes are produced in archegonium, both found in the prothallus.

Sexual reproduction involves the fusion of male and female gametes

GYMNOSPERMS

• Gymnosperms are a group of seed-bearing vascular plants. However, seeds are not enclosed in fruits.

• Gymnosperms grow in dry but cold climatic regions. These are perennial and evergreen plants. Ex : Cycas, Pinus.

• Some plants of this group are large trees and some are shrubs. The vascular system is well developed with xylem and phloem.

• The most prominent feature of these plants is the production of two kinds of spores namely microspores and megaspores.

• They are produced in structures called microsporophylls and megasporophylls respectively.

• These plants produce multicellular structure called cones (They are called cones because of their shape).

• They are of two types namely male and female cones.• Microsporophylls produce male sex cells and megasporophylls

produce female sex cells.• Sexual reproduction involves the fusion of these cells to form a

‘zygote’. • The zygote is covered by a thick coat and together they

represent the seed.

ANGIOSPERMS

• Meaning of angisoperms• In Greek Angion = capsule Sperma = seed• Angiosperms are the most evolved among plants. In

these plants, the seeds are enclosed in a structure called fruit.

• Angiosperms are commonly called as flowering plants. They are found in moist soil, desert, fresh water habitats. Ex : Maize, Coconut, Wheat, Paddy, Pearl Barley, Millet, Mustard, Horsegram, Red Gram, Bean etc.

• Based on the general organization of the plant body, angiosperms can be grouped into herbs, shrubs and trees.

• Vascular tissues are well developed. Flowers are the reproductive organs.

ANGIOSPERMS

• Flowers may be produced singly in the axil of the leaf or a cluster of flowers may be found together. A special branch bearing a cluster of flowers is called inflorescence.

• Seeds are produced in flowers. Seeds are of two types. 1. Monocotyledonous 2. Dicotyledonous

• In fibrous root system, the primary root dies before the plants mature. Roots develop from the base of the stem and branch profusely.

• A single main or central root is absent.• In taproot system, the primary root from the

radicle of the seed grows to become the main or central part of the root system. It produces many secondary and tertiary branches.

Monocotyledonous Dicotyledonous

Monocot seeds contain onlyone cotyledon (seed leaf)

dicot seeds contain two cotyledons

During germination the cotyledon remains below the soil

cotyledons appears above the soil

In monocot leaves, veins run parallelly. Monocot plants have fibrous root system,

dicot leaves, veins are found in the form of a network.dicot plants have tap root system.

VERTEBRATES

Vertebrates represent a major group among the advanced animals called chordates.

Chordates exhibit the following characteristic features.1. Presence of a solid supporting structure on the dorsal side of the bodycalled notochord.2. Presence of a dorsal, tubular nerve cord.3. Presence of openings in the pharynx called gillslits, atleast in the embryonic stages.• Those chordates in which the notochord is replaced in the adult by a vertebral column

are grouped under vertebrata. • All other animals other than chordates, are described as invertebrates or non-

chordates.• Vertebrates are characterized by the presence of a backbone or vertebral column which

forms a major component of the skeletal system. • The skeletal system consists of hard rigid structures called bones which provide

support to the body. • They also provide surface for the attachment of muscles.• The body is divided into head, trunk and limbs.

VERTEBRATES

• Digestive system consists of mouth, pharynx oesophagus, stomach, intestine and many associated glands. Respiratory organs are well developed.

• They are in the form of gills in aquatic forms and lungs in terrestrial forms.• Heart is ventral in position and is chambered. • Excretory organs are in the form of a pair of kidneys. • Nervous system consists of dorsal tubular nerve cord which becomes differentiated into brain

and spinal cord.• Vertebrates are unisexual. Only sexual reproduction is seen.• Vertebrata is grouped into the following 5 classes.• (1) Pisces (2) Amphibia (3) Reptilia (4) Aves (5) Mammalia

PISCES

PISCES

commonly called fishes.

Fishes are aquatic vertebrates with a streamlined or spindle shaped body

Mouth is at the terminal end of the body. Jaws are provided with teeth

Skin is covered with scales which provide protection. Skin contains mucous glands

Locomotor structures are in the form of paired and unpaired fins

Digestive system is well developed with an alimentary canal and associated glands

Respiration is typically by pharyngeal gills. Heart is two chambered

Fishes are cold blooded (poikilothermic) animals. Nervous system is well developed with brain and spinal cord.

Internal skeleton is either cartilagenous or bony. These are unisexual animals. They reproduce sexually

AMPHIBIA

commonly called amphibians

first vertebrates, adapted living successfully on both land and in water.

Mouth is provided with jaws. Nostrils are exposed above the mouth

The body is divisible into head, trunk and limbs. The skin is very soft and moist due to secretion of mucous glands.

Fore limbs have four digits while hind limbs have five digits each. Some amphibians are limbless. Ex : Ichthyophis

Well developed digestive system with alimentary canal, and associated glands

Respiration is by gills, skin, buccal cavity and lungs. A three chambered heart is found

cold blooded animals. Nervous system is well developed with a brain, a spinal cord and 10 pairs of cranial nerves and an autonomous nervous system.

These are unisexual animals. They reproduce sexually. Fertilization is external.. lay eggs on stagnant water. ‘Metamorphosis’ is seen in the life cycle of these animals. Ex : Frog, Toad, Salamander, Ichthyophis

AMPHIBIA

REPTILIA

commonly called reptiles

first terrestrial vertebrates

elongated body covered by a dry skin bearing an exoskeleton of horny scales

forelimbs and hind limbs have five digits each (pentadactyle).. Some of the reptiles like snakes, are limbless

Digestive system consists of mouth, pharynx, oesophagus, stomach, small intestine, large intestine and associated glands

Respiration takes place through lungs. The heart is three chambered.

Reptiles are also cold blooded animals. Nervous system consists of a brain a spinal cord and 12 pairs of cranial nerves.

Reptiles are unisexual animals. They reproduce by sexual methods. All reptiles are egg laying (oviparous) animals. Ex : Chameleon, Snake, Tortoise, Crocodile, House lizard etc.

REPTILIA

AVEScommonly called birds

found in different habitats like water and land.

The body is covered by feathers diversified with various colors

Feathers help in protection, maintaining body temperature and loss of water. sexual attraction

Forelimbs are modified into wings which help in flight. Hind limbs are variously adapted for running walking, swimming and wading.The body is very light and the bird can fly without friction. The bones are hollow, light and filled with air. Such bones are called pneumatic bones.Lungs are specialized for storing excess air. The voice box or syrinx is found at the base of trachea. Nervous system is more evolved than in reptiles. 12 pairs of cranial nerves are found.

A four chambered heart is present. Birds are active warm blooded (homeothermic) animals. Heart beat is very rapid than other animals.unisexual, reproduce by sexual methods. All are oviparous and eggs are covered by calcareous shells.Ex : Ostrich, Parrot, Hawk, Pigeon, Penguin, Flamingo, Arctic tern etc

AVES

MAMMALIA

commonly called Mammals

bear mammary glands to feed their young ones

most evolved animals in the animal kingdom. The skin is covered by hairs

Mouth is provided with jaws bearing teeth. The eyes have movable eyelids and eyelashes. Ear has a fleshy external pinna.

Limbs are pentadactyl, ending in claws or nails.

The nervous system is more evolved than other vertebrates. It consists of brain, spinal cord, cranial and spinal nerves.

Respiration takes place through lungs. The thoracic and abdominal cavities are separated by a muscular membrane called the ‘diaphragm’

The heart is four chambered with two auricles and two ventricles

Mammals are unisexual animals. Reproduce by sexual methods. Most mammals give birth to young ones except echidna and platypus. They are egg laying mammals.Ex : Kangaroo, Whale, Bat, Giraffe, Lion, Elephant, Man etc.

MAMMALIA

PISCES AMPHIBIA REPTILIA AVES MAMMALIA

commonly called fishes. commonly calledamphibians

commonly calledreptiles

commonly calledbirds

commonly calledMammals

Fishes are aquatic vertebrates with a streamlined or spindle shaped body

first vertebrates, adapted living successfully on both land and in water.

first terrestrial vertebrates found in different habitats like water and land.

bear mammary glands tofeed their young ones

Mouth is at the terminal end of the body. Jaws are provided with teeth

Mouth is providedwith jaws. Nostrils are exposed above the mouth

elongated body covered by a dry skin bearing an exoskeleton of horny scales

The body is covered by feathers diversified with various colours

most evolved animals in theanimal kingdom. The skin is covered by hairs

Skin is covered with scales which provide protection. Skin contains mucous glands

The body is divisible into head, trunk and limbs. The skin is very soft and moist due to secretion of mucous glands.

Feathers help in protection, maintaining body temperature and loss of water. sexual attraction

Mouth is provided with jaws bearing teeth. The eyes have movable eyelids and eyelashes. Ear has a fleshy external pinna.

Locomotor structures are in the form of paired and unpaired fins

Fore limbs have four digits while hind limbs have five digits each. Some amphibians are limbless. Ex : Ichthyophis

forelimbs and hindlimbs have five digits each (pentadactyle).. Some of the reptiles like snakes, are limbless

Forelimbs are modified into wings which help in flight. hindlimbs are variously adapted for runningwalking, swimming and wading.

Limbs are pentadactyl, ending in claws or nails.

Digestive system is well developed with an alimentary canal and associated glands

Well developed digestive system with alimentary canal, and associated glands

Digestive system consists of mouth, pharynx, oesophagus, stomach, smallintestine, large intestine and associated glands

The body is very light and the bird can fly without friction. The bones are hollow, light and filled with air. Such bones are called pneumatic bones.

The nervous system is more evolved than other vertebrates. It consistsof brain, spinal cord, cranial and spinal nerves.

Respiration is typically by pharyngeal gills. Heart is two chambered

Respiration is by gills, skin, buccal cavity and lungs. A three chambered heart is found

Respiration takes place through lungs. The heart is three chambered.

Lungs are specialized for storing excess air. The voice box or syrinx is found at the base of trachea. Nervous system is more evolved than in reptiles. 12 pairs of cranial nerves are found.

Respiration takes place through lungs. The thoracic and abdominal cavitiesare separated by a muscular membrane called the ‘diaphragm’

Fishes are cold blooded (poikilothermic) animals. Nervous system is well developed with brain and spinal cord.

cold blooded animals. Nervous system is well developed with a brain, a spinal cord and 10 pairs of cranial nerves and an autonomous nervous system.

Reptiles are also cold blooded animals. Nervous system consists of a brain a spinal cord and 12 pairs of cranial nerves.

A four chambered heart is present. Birds are active warm blooded (homeothermic) animals. Heart beat is very rapid than other animals.

The heart is four chambered with two auricles and two ventricles

Internal skeleton is either cartilagenous or bony. These are unisexual animals. They reproduce sexually

These are unisexual animals. They reproduce sexually. Fertilization is external.. lay eggs on stagnant water. ‘Metamorphosis’ is seen in the life cycle of these animals. Ex : Frog, Toad, Salamander, Ichthyophis

Reptiles are unisexual animals. They reproduce by sexual methods. All reptiles are egg laying (oviparous) animals. Ex : Chameleon, Snake, Tortoise, Crocodile, House lizard etc.

unisexual, reproduce by sexual methods. All are oviparous and eggs are covered by calcarious shells.Ex : Ostrich, Parrot, Hawk, Pigeon, Penguin, Flamingo, Arctic tern etc

Mammals are unisexual animals. Reproduce by sexual methods. Most mammals give birth to young ones except echidna and platypus. They are egg laying mammals.Ex : Kangaroo, Whale, Bat, Giraffe, Lion, Elephant, Man etc.

PISCES AMPHIBIA REPTILIA AVES MAMMALIA


Recommended