Animal Kingdom

Created : 2022-02-25 08:40

Animal Kingdom
Vertebrata
Structural Organisation in Plants and Animals
DNA, RNA Etc.

Basis of classification could be cell arrangement, body symmetry, nature of coelom etc.
Level of Organisms are either cellular level, tissue level, organ level.
Platyhelmenthis have digestive system with only 1 opening that serves as both the mouth and anus.
Open circulatory system is where blood is directly pumped to cells and tissues in Closed it is carried through vessels.
Sponges are mulitcellular organism that have bodies full of pores and channels to allow water to circulate through them. They are mostly assymetrical.
Diploblastic animals have their embryonic layers into 2 layers Ecto and Endoderms. Triploblastic have Mesoderm in b/w.
Body cavity lined by mesoderm is called coelom. Ex annelids, molluscs, arthropods, echinoderms etc.
Segmentation there is external and interal division with repetition of some organs ex earthworm.
Notochord is a mesodermally derived rod like structure formed on dorsal side during embryonic development of certain animals. Such animals are called as Chordates.
Phylum - Porifera : aka sponges, generally marine mostly assymetrical, multicellular. Have a special water pathway that transports food, nutrition, respiration, waste removal.
- Body made of spicules or spongin. Eggs and sperms are produced by the same individual.
Phylum - Coelenterata/ Cnidaria : Free swimming, radially symmetrical organisms.
- Contain cnidoblasts ie stinging capsule like present in tentacles and body that help them in anchorage, defence and for capturing prey
- Have single gastro vascular cavity with single opening, mouth.
- have 2 basic body forms called polyp which are sessile ie cannot move/ immobile and medusa that can move.
- reproduce sexually and a sexually.
- Ex Corals, hydras, jellyfish, sea pens, sea whips, sea fans, portugues man of war
Phylum - Ctenophora : exclusively marine, radially symmetrical, diploblastic organism aka comb jellies and use cillia/ comb plates for swimming.
- Digestion is intracellular and extracellular and show Bioluminescence.
Phylum - Platyhelminthes : are dorso ventrally flattened bodies and aka flatworms and mostly endoparasites found in animals including humans.
- Parasitic platyhelminthes have hooks and suckers.
- Some absorb nutrients directly from the host. Flame cells in them are specialised cells used for osmoregulation and excretion.
Phylum - Aschelminthes : boyd is circular in cross section aka roundworms. Can be both aquatic and terrestrial or parasitic in plants and animals.
- They have organ system level of body organisation ex a muscular pharynx, excretory tube to remove waste.
- Sexes are separate and often females are longer than males.
- Ex Roundworm, hookworm
Phylum - Annelida : Free living and sometimes parasitic having organ system level of body and bilateral symmetry.
- body surface is marked out into segments or metameres.
- have longitudnal muscles that help in locomotion
- parapodia help in swimming and Nephridia in osmoregulation and excretion.
Phylum - Arthropoda : largest phylum of Animalia that includes insects. 2/3 of all species on Earth are arthropoda.
- have organ system level of body, bilaterally symmetrical, triploblastic, segmented and coelomate animals.
- Body is covered in chitinous exoskeleton. Body has head, thorax and abdomen. Respiratory organs like gills, book lungs etc.
- Open circular system. Excretion takes place through malphigian tubules. Fertilisation is internal.
- Ex. Mosquitoes, Locusts, King Crad
Phylum - Mollusca : 2nd largest animal phylum are terrestrial, aquatic and organ level system body.
- Body is covered in calcareous shell that is unsegmented with distinct head. Muscular foot and visceral hump.
- Soft spongy layer of mantle is over the hump in between them is mantle cavity having gills. Gills perform both respiratory and excretory functions.
Phylum - Echinodermata(spiny bodied) : marine organism with organ level body that have endoskeleton of calcerous ossivles.
- Well developed digestive system and have water vascular system that help in locomotion, respiration etc.
Phylum - Hemichordata : have a rudimentary structure near collar region called stomochord that is similar to notchords.
- Has small groups of worm llike marine animals having organ level system of organisation.
- Consists of a proboscis, collar and a long trunk
Phylum - Chordata : characterised by presence of notochord, dorsal hollow nerve cord and a paired pharyngeal gill slits.
- bilaterally symmetrical, triploblastic, coelomate with organ level of organisation.
- It is divided into 3 subphyla Urochordata or Tunicata, Cephalochordata and Vertibrata. First 2 are exclusively marine.
- Vertebrata consists of notochord during embryonic period which is replaced by vertebral column in the adults.
  - Have 2,3,4 chambered heart, kidneys for excretion and osmoregulation and paired appendages ie limbs or fins.

Vertebrata

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Class - Cyclostomata : all of them are ectoparasites on some fished having elongated body, circular mouth without jaws. Body is devoid of scales, they migrate for spawning to freshwater and die after spawning.
Class - Chondricythyes : have a streamlined body mouth is located ventrally. Notochord is present throughout their life. Skin has scales, jaws and predaceous in nature. Some have electric organs, poison stings and some cold blooded. Ex. Dog fish, Great White Shark, Sting Ray etc.
Class - Osteichtyes : fishes with bony endoskeleton.
Class - Amphibia : heart is 3 chambered and are cold blooded.
Class - Reptilia : do not have external ear opening but a Tympanum for ears. 3 chambered heart but crocodiles have 4 chambered.
Class - Aves : have oil glands at the base of the tail, bones have air cavities. Heart is 4 chambered and are warm blooded(homoiothermous) and able to maintain constant body temperature.
Class - Mammalia : presence of milk producing glands is most common feature.

Structural Organisation in Plants and Animals

Created : 2022-03-02 08:46

Roots can be either primary or secondary. Primary and its branches form the tap root system.
In Monocotylednous plants primary roots are short lived and replaced by large no of roots orginating from the base of the roots and are called fibrous root system.
In Banyan tree roots arise from parts other than the radicle are called adventitious roots. ![[Pasted image 20220302090202.png |400]]
Region of meristematic activity cells divide reapeatedly.
Root hairs absorb mineral and water from the plant.
hanging roots in Banyan tree is called prop roots and supporting roots in maize and sugarcane is called stilt roots.
In some plants like Rhizhopora that dwell in swamps roots come out of the ground and grow vertically upwards these are called pneumatophores they help in respiration.
Stem develops from plumule of the developing embreyo of a germinating seed they bear nodes and internodes.
Nodes are regions where leaves are born and internodes are portion b/w 2 nodes.
It conducts water, minerals and photosynthesis. Some also store food, support and protect vegetation.
Potato, Ginger, Turmeric, Zaminkand have underground stems.
Stem tendrils develop from axillary buds and grow to help plants climb. Axillary buds can also get modified into thorns.
Leaf consists of 3 main parts a leaf base, petiole and lamina. Base attaches it to the stem and lateral leaf like structure are called stipules. In some plants leafbase become swollen and is called pulvinus.
Petiole helps to hold the blade to the stem. Lamina or leaf blade is green extended part has veins ie the middlle midrib vein. Veins give support, transports water, minerals and food materials.
Reticulate venation is when veins form a network. Paralled venation is when veins are parallel to midrib.
Leaves can be simple or compound. Compound ones can be a pinnately compound leaf ie leaflets present in a common axis or Rachis having a midrib around which leaflets are arranged.
Phyllotaxy is pattern of arrangement of leaves on stem or branch. ![[Pasted image 20220302103644.png |300]]
Leaves can be modified into tendrils for climbing ex peas or into spines for defence as in cacti. Leaves of onion and garlic store food. Leaves of pitcher plant and venus flytrap is used to capture insects.
A flower is a modified shoot. Arrangement of flowers on the floral axis is called inflorescence. Its 2 types are racemose -> flowers grow along a radial axis and cymose -> main axis end points grow into flowers.
Flower is the reproductive unit in angiosperms. The swollen end of the flower is called a thalamus. Various parts of the flower are callyx, corolla, androcium and gynoecium.
Actinomorphic is when flowers are arranged in a radial symmetry and Zygomorphic is when assymetric.
Hypogamous flower has gynoecium at the highest position other parts are below it. Perigynous it is situated in centre and other parts of the flower located on rim of the thalamus almost at same level. In perigynous ovary is enclosed by thalamus.
Calyx : outermost whorl of flower, protects the flower in the bud stage. Gamosephalous is when sepals are united and polysephalous is sepals free.
Corolla : Composed of petals usually bright colours to attract insects for pollination. Gamopetalous is when petals are united and Polypetalous is petal free.
Androceium : Composed of stamens ie the male reproductive organ it consists of a stalk/filament and an anther. Anthers have 2 lobes and each lopers has 2 chambers containing the pollen sacs that produces the pollen grains. Staminode is a sterile stamen.
Gynoecium : has one or more carpels each carpel consists of 3 parts Stigma, style and ovary. Ovary is the large basal part over which is a long elongated tube called the style. Style connects ovary to the stigma. Stigma contains the tip of style and is the receptive surface of the pollen grain.
Arrangement of ovules within the ovary is known as placentation.
Fruit is a mature ripened ovary developed after fertilisation if it is formed without fertilisation it is called parthenocarpic fruit.
Wall of fruit is called pericarp it could be dry or fleshy.
Ovules after fertilisation develop into seeds. Seeds are made up of seed coat and an embryo.
Dicotyledonous Seed : has 2 embryonic leaves or cotyledons. Seed coat has 2 layers outer testa and inner tegmen. Hilum is scar through which it attaches to the fruit.
- Some seeds due to double fertilisation endosperms are formed for storing food.
Monocotyledonous Seed : have single embryonic leaf ex maize. Aleurone layer seperates outer covering of endosperm with the embryonic layer.

DNA, RNA Etc.

Nucleus contains chromosomes which have genes in them.
Chromosomes are long thread like structures that only present themselves when the cell is about to divide. They are present as chromatin material.
Nucleosome is fundamental subunit of chromatin. Nucleosome contains histones() that is wrapped by 2 turns of DNA.