Biology 12th class Question Bank

                                            Sheet 1

1. What do you mean by spermetogenesis ? explain the whole process of Spermetogenesis .
   
2. Describe oogenesis .
   
3. Explain the process of megasporogenesis ?               
   
4. Write about the structure of pollen .
   
5. What is sporopollenin ?
   
6. What do you mean by bio fortification ?
   
7.  WIDAL test is used for which disease , explain ?
   
8. What do you mean by drugs ? Explain any two type of drugs .
   
9. Write the definition of pollution ?
   
10. What is SCP ?
    
11. Write difference between inbreeding and out breeding ?
    
12. What is Asexual type of Reproduction ?
    
13. Explain food Chain ?
    
14. What is  the difference between convergent and divergent evolution ?
    
15. Explain secondary treatment of sewage purification ?

What Are the Main Features of an Octopus?

                                           Octopus 

Classification -                                               
 Kingdom - Animalia
Phylum - Mollusca
Class-   Cephalopoda
Order - Octopoda 
 Sub- order -  Incirrinus
Genus - Octopus 


Commonly name - Devil fish or Octopus .

Habitat -   They live in depth of shallow and coastal water .

General Feature -

•      They are  soft bodied , eight limbed , marine animals .
  
  
•     They follow radial symmetry .
•     Octopus are unisexual .
  
  
•    Octopus has three chambered closed circulatory system .
  
  
•    Octopus has highly complex nervous system with a central brain and large number of ganglion  .
  
  
•     They  do not have any skeleton in their body ; only muscles are present in whole body .
  
  
•     Octopus contain venom  which is used to inject the prey for making them immobilize . The venom they injected is so powerful that it  kill the person in less than 30 minute .
   
•    They are carnivores .
  
  
•     They can camouflage themselves to get protection from predators .
  
  
•      They respire through gills .
  
  
•     They have external fertlisation .
  
  
•     Octopus have two nephridia for excretory system .
  
  
•     They have well developed digestive system with the mouth , pharynx , radula and salivary glands .     

 
 
 

Top Topics In Biology 

Aurelia Aurita Life Cycle: Characterstics, Classification	Ant Life Cycle	Difference between Prokaryotic & Eukaryotic cells | Biology Blog
Obelia Life Cycle, classification , Labelled  Diagram | Biology Blog	Kreb Cycle Steps With Diagram , Steps & Products	Types of Eggs of Animals in Zoology (Embryology ) | Biology Blog
What are the Important  features of Sycon	Herdmania's Life: Anatomy, Behavior, Reproduction, and Habitat	DNA Transcription Process | Central Dogma | RNA Polymerase

 

    

Hemichordata: Classification , Characteristics & Diagrams

                                        Hemichordata 

Hemichordata is a marine animal distributing in all over the world named by Delle Chiaje in 1829. The word Hemichordata is coming from the Greek word Hemi means half and Chordae means string. About 90 species of it have been described by scientists till now.

Classification of Hemichordata -

• Kingdom - Animalia
• Phylum - Hemichordata                         
• class-  Enteropneusta and pterobranchia
• Higher classification - Deuterostome

Commonly name - Acorn  worms

Habitat - Hemichordata is a marine invertebrate living in the depth of solid substratum like under rocks, in the mud.

General Feature -

•  Hemichordata has some features of the chordate family.
  
  
• They follow bilateral symmetry.
  
  
•  The body is divided into three portions -  collar, trunk, and proboscis lobe.
  
  
•  Reproduction in Hemichordata is of sexual type.
  
  
• The glomerulus is present in the form of an excretory organ.
  
  
•  They have an open circulatory system.
  
  
• Fertilization is external. They have sometimes indirect development through a swimming tornaria larva.  
  
  
• The central nervous system is absent; all the nervous tissue is concentrated in the collar which is connected to the nervous system of the epidermis or outer covering.
  
  
• They have pharyngeal gill slits for respiration.
  
  
• Coelom is divided into three area : protocoel , mesocoel , metacoel .  

Obelia Life Cycle, classification , Labelled Diagram

                                      Obelia Life Cycle

Obelia is named after a Greek word, "obelus," which means "a loaf on a spit." These are marine creatures that live in shallow coastal waters. They attach to the ocean floor, growing upward like a furry plant, which is why they're sometimes called "Sea fur" or "hydrozoites."

Obelia goes through three important life phases: polyp, blastostyles, and medusa

🔬 Classification of Obelia:

• Kingdom - Animalia
• Phylum - Cnidaria
• Class - Hydrozoa
• Order - Leptothecata
• Family - Campunulariidae
• Genus - Obelia

General Feature -

•   Obelia is generally marine and colonial animals.
  
  
• They are cosmopolitan in nature.
  
  
• They have tissue but lacks the organ systems. Thus, they have a tissue level of organization.
  
  
•    They show radial symmetry.
  
  
•    They are diploblastic in nature, the outer wall is called ectodermis and the inner one is called gastrodermis. Between this tow layer a sheet of gelatinous material is found called mesoglea.
  
  
• They have a single aperture, the mouth which serves both the purpose of taking food and throwing the feces. Their digestive cavity is incomplete.  
  
  
• Digestion is partially extracellular and partly intracellular takes place within the gastrodermal cells. 
  
  
•    The body shows two forms, polyp, and medusa. The polyp is cylindrical and usually fixed but may be solitary or colonial. The medusa is umbrella-like in appearance and is free-swimming, but always solitary.
  
  
• Polyps are nutritive in function.
  
  
• It is a plant-like appearance and is therefore called zoophytes. There present two types of zooids.
  
  
• The horizontal filament is known as hydrorhiza.
  
  
• The vertical filament is called hydrocauli.
  
  
•     They reproduce by both types of reproduction - asexually & sexually.
  
  
•     There is the absence of the brain in Obelia.
  
  
•     They are colonial in nature.
  
  
•     They are holozoic.
  
  
•    No circulatory system found in Obelia.
  
  
•     Fertilization is of both types - internal and external.
  
  
•     They respire by diffusion.
  
  
•     They have tissue level of organization. 

Life Cycle of Obelia - Generally, Obelia reproduces by both means; sexually as well as asexually either through polyp or through medusa.

Polyp - Polyp are the soft-bodied sedentary form of phylum Cnidaria. The upper body of polyp is surrounded by the tentacles and from the lower body, it is attached to the solid surface  . It is a type of body form in phylum Cnidaria. In phylum Cnidaria, the polyp present in either colony or individual. In Obelia, there are two types of a polyp ( Dimorphic) - Gastrozooids and another one is gonozooids.

Gastrozooids are just like flowers having tentacles surrounding a mouth helps to gather the food to eat . These Gastrozooids are connected through a cavity known as Gastrovascular cavity. Gonozooids are also called as blastozooids are cylindrical rod-like reproductive bodies present on the stalk of gastrozooids. The significant function of the gonozooids is to produce numerous small medusae. This small medusa detached after attaining maturity and moves into the surrounding water through gonopore.

"Question - how does the medusa stage fit into the life cycle of obelia?" 

let's explore this 

Asexual reproducing cycle - 

Medusa - Gonozooids produce Medusa through asexual division. Medusa produced are extremely similar to the appearance of jellyfish having tentacles outside. Medusa is free- swimming, small, saucer-shaped zooids. They will mature and detached from their parent and dispersed into the ocean. Medusa has two sides - outer convex - ex umbrella  & inner concave  - sub umbrella. A  small projection, the manubrium,  is hanging down from the sub umbrella region giving medusa an umbrella-like shape. When the food enters the mouth it reaches the manubrium and then distributed to the canal, the radial canal, and outer ring. They have also known as reproductive zooids,  producing male or female sex cells.

Sexual reproducing Cycle - The medusa of male and female gonads are fuse to form a zygote. This zygote later change into blastula by cell division. This blastula further grows to from Larva called Planula.

Now, this planula attaches to the solid substratum and starts diving asexually producing Polyp. These poly grows and forms some gastrozooids and some gonozooids. Gonozooids eventually form more medusae that will be released to mate and complete their life cycle.

Top Assignment Topics In Biology 

Aurelia Aurita Life Cycle: Characterstics, Classification	Short note on Photosynthesis	Difference between Prokaryotic & Eukaryotic cells | Biology Blog
Cell Cycle - Phases ,  Diagram , Types and Comparison	Kreb Cycle Steps With Diagram , Steps & Products	Types of Eggs of Animals in Zoology (Embryology ) | Biology Blog
What are the Important  features of Sycon	Herdmania's Life: Anatomy, Behavior, Reproduction, and Habitat	DNA Transcription Process | Central Dogma | RNA Polymerase

 

Notes On Wildlife Conservation Class 12th Biology CBSE

                         

                 Wild Life Conservation

We live in a cutting-edge world where science is advancing daily. Whether it is the sector of telecommunications or medical diagnosis, every field has developed in its own manner, but our nature is vanishing every day. We are unable to view the same wildlife and vegetation that we did as children. Slowly but surely, all species are beginning to vanish, and human exploitation is to blame.

Therefore, it is crucial to preserve the wildlife so that our children might enjoy the benefits of nature as well. Through a number of wildlife management initiatives, our government protects them.
There are two ways for conserving wild life animals –

Exsitu Conservation -

In this method of conservation, both biotic and abiotic biodiversity components can be maintained and protected outside of their natural habitats, such as by in vitro production of plant or animal specimens.
Some  example of these are:

·         Gene banks, e.g. seed banks, sperm and ova banks, field banks:

·   

· living organisms collection for zoos, aquaria, and botanic gardens for research and public awareness.

Insitu Conservation –

Insitu conservation is seen to be a particularly flexible method of safeguarding biotic organisms in either their native habitat or in a man-made ecosystem. With the more adaptable and reproductive nature, the advantages are highly efficient in saving the population of endangered species in their natural habitat.

Example : national park , sanctuary etc

                                              

Vitamins In Biology - Definition, Classification , Types , Function

•     Vitamins are those organic compounds that are recommended in a very short amount in diet however their deficiency turns into a  specific disease.
  
  
•  The term “Vitamine” was coined from the word vital + amine since the earlier identified compounds had amino groups. Later work showed that most of them did not contain amino groups, so the letter ‘e’ was dropped and the term vitamin is used these days.
  
  
•  They are generally present in our food which we have taken for nutrition.
  
  
• · Maximum vitamins cannot be synthesized in our body on the other hand plants can synthesize almost all of them, so they are considered to be an essential food factor.
  
  
• · In our body, some of the vitamins which we are needed are secreted by the bacteria of the gut.

• ·  Different vitamins belong to various chemical classes.
  
  
• · A  small amount of vitamins used to perform specific biological functions in our body like the growth and health of the organism.
  
  
• · Vitamins are nominated by alphabets A, B, C, D, etc however  Some of them are further classified as sub-groups e.g. B1, B2, B6, B12, etc.
  
  
• · Vitamin A keeps our skin and eyes flourished.
  
  
• · Vitamin C helps the body to fight against many diseases and simply get demolished by heat during cooking. 

• · Vitamin D assists the body in using calcium needed by bones and teeth.

  Classification -Vitamins are classified into two groups depending upon their solubility in water or fat. 

• Fat-soluble vitamins -· Vitamins that are soluble in fat and oils but insoluble in water are kept in this group. These are vitamins A, D, E, and K. They are stored in liver and adipose (fat-storing) tissues.
  
  
• Water-soluble vitamins -· B group vitamins and vitamin C are soluble in water so they are grouped together.  Water-soluble vitamins must be supplied regularly in a diet because they are readily excreted in urine and cannot be stored (except vitamin B12) in our body. 

Deficiency Diseases

· Although every person may be getting a maximum diet to eat, sometimes the food may not contain a particular nutrient. If this continues over a long period of time, the person gets to suffer from certain deficiencies.

· Deficiency of one or more nutrients can result in diseases or disorders in our body. Diseases that occur due to lack of nutrients over a long period are called deficiency diseases.

1. Vitamin A——— Night blindness

2. Vitamin B1———Beriberi

3. Vitamin B2——– Ariboflavinosis

4. Vitamin B3 ——–Pellagra

5. Vitamin B5 ——–Paresthesia

6. Vitamin B6 ——–Anemia

7. Vitamin B7 —— Dermatitis, enteritis

8. Vitamin B9 & Vitamin B12 —– Megaloblastic anemia

9. Vitamin C —— Scurvy, Swelling of Gums

10. Vitamin D —— Rickets & Osteomalacia

11. Vitamin E —— Less Fertility

12. Vitamin K —— Non-Clotting of Blood. ·

·  So Every vitamin has specific functions in the body.

Vitamin P is also considered a water-soluble vitamin.

•  Vitamin P mainly comes from plant sources i.e., fruits and vegetables.
•  Brightly colored fruits and red, yellow or orange-colored vegetables are the best sources of vitamin P. Mangoes, oranges, grapefruits, lemon, cherries, blackcurrants, and plums are some good fruit sources whereas carrots, tomato, broccoli, and onions are vegetable sources.
• Green tea and red or white wines are rich sources of flavonoids.
• Milk chocolate and dark chocolate is a good source as well.
• Vitamin P is antioxidant, anti-inflammatory, antiallergenic, antiviral, and anti-carcinogenic  

Deficiency 

1. Diabetics can be deficient in this vitamin.
   
   
2. Aspirin, birth control pills, and antibiotics either block or break down bioflavonoids leading to deficiency.
   
   
3. Under major stress - when under stress, the body's systems go into overdrive and use up bioflavonoids and Vitamin C extra fast so need to be replenished quickly.