my views

There is a large variety of living organisms on our planet earth. All organisms differ in their sizes, forms and structures. All organisms grow and after a definite lifespan they perish. Before death the organisms produce individuals like themselves to continue their species.

IMPORTANCE OF REPRODUCTION:

1. REPRODUCTION is a biological process in which an organism gives rise to offspring similar to itself. It allows perpetuation of species.

2. It increases population of a species.

3. It plays important role in evolution by transmitting favorable variations from one generation to anotherBINARY FISSION.

4. REGENARATION SEXUALLY REPRODUCING ORGANISM

FROM the very first chapter of class-xii biology I enjoy learning about various types of reproduction-asexual & sexual reproduction .also it arises in me a curiosity about the importance of reproduction.

Again it’s a very vital query to me why certain organisms resort to sexual & asexual reproduction. It’s very interesting to learn about advantages, disadvantages & significances. The vegetative propagation techniques are applicable in practical life but earlier I had no knowledge about its scientific I interpretation. The regularly seen parts can be units of vegetative reproduction this is awesome!!!!!!!!!!!! Before reading this chapter I hadn’t noticed the post fertilization changes. Applying theoretical knowledge to practical field is great.

SEXUAL REPRODUCTION IN FLOWERING PLANTS::

As the name suggests this chapter deals with the sexual reproduction in angiosperms.

I feel very lucky to be a learner & for these new approaches its venture is getting new every day.

These colorful flowers not only add beauty to nature but also are the main rep0roductive part of a plant ---- a carrier of a plant’s generation. It’s important androecium & gynoecium are the primary organs. Even the whole process of fertilization in a whole lot is interesting.

Double fertilization

The pollinating agents are wind, water, insects of which the insect pollinators attract me most. I love the beautiful looking bees sucking nectar from flowers reminds me of many popular poems & songs.

It’s a special thing of double fertilization in angiosperms. This case is somewhat confusing at the beginning but our respected BioSir DR.SABYASACHI MAJUMDAR helps me to get a clear idea about it.

Next come the post fertilization developments------endosperm development, embryo development, seed &ultimately fruit.

Fruit, yes fruit delicious to eat and fulllllllllllll of vitamins and minerals. The fruits are very interestingly classified into true and false fruits. It’s too astonishing for me that apples are actually false fruits!!!

Another topic related to fruits is parthenocarpy.parthenocarpy is the term allotted to the phenomenon of seedless fruits like bananas. This parthenocarpy can be induced by plant growth hormones like auxins. Even we know that ethylene is sometimes sprayed to fruits to hasten the ripening that could be injurious to health.

It’s a very practical topic related to production of desirable characters in a flowering plant by EMASCULATION(for bisexual flowers), BAGGING, SPRINKLING POLLENS OF DESIRABLE CHARACTER HOLDING MALE FLOWER,REBAGGING.I had to give a lot of time to artificial hybridization. Firstly only the definition of apomixis and polyembryony was clear to me but the next question which arises in my mind is what the reasons behind these phenomenons are? When I get the answers I was very happy. The reasons could be -----A diploid egg cell (formed without meiosis during megasporogenesis) may develop into embryo without fertilization.

Polyembryony can arise if more than one egg is formed in embryo sac or more than one embryo sac formed in an ovule or synergids/nucellus develop into an embryo.

In artificial hybridization the knowledge of POLLEN-PISTIL INTERACTION is a must. Actually this chapter seems to me a new venture in the land of knowledge--- in the land of biology

SEXUAL REPRODUCTION IN HUMAN BEINGS:

This chapter is a sophisticated one which examines a teacher’s approach to his/her students and side by side is a chapter which each and every student is interested to read. First of all there is an introduction to primary sex organs, duct systems; accessory glands of male and female humans.Infact it’s totally unbelievable that so little conditions can lead to healthy reproductive life otherwise can raise complications.

Spermatogenesis & oogenesis the two interesting processes of gametogenesis.But HORMONAL CONTROL of spermatogenesis seems somewhat complicated

GnRH LH (leydig cells)-→testosterone→development of secondary sexual characters

FSH (SERTOLI CELLS) →stimulates spermatogenesis

But the process of oogenesis is a complex one to me specially the diploid & haploid condition.

Next comes the topic menstrual cycle. The menstrual cycle is studied under 4 phase

I. MENSTRUAL CYCLE

II. FOLLICULAR PHASE

III. OVULATORY PHASE

IV. SECRETORY PHASE

To me the hormonal changes are really confusing…..

LUTEINIZING HORMONE(LH)(ABOUT 14^TH DAY)	INDUSES RUPTURE OF GRAAFIAN FOLLICLE & OVULATION
FOLLICLE STIMULATING HORMONE(FSH)(14^TH DAY)	STIMULATES GROWTH OF FOLLICLES

Structure of sperms & ova are very significant according to me.

The most awaited topic is fertilization during which entry of sperm induces the formation of ovum from secondary oocyte. . This picture reminds me of the scene of 3 idiots!!!!!!!!!!!!

The most interesting part for me is implantation. Under this falls –CLEAVAGE, better to say holoblastic cleavage-, morula isn’t it a funny name & blastula, gastrula.What an evolution of name!!!!!!!!!!!!!

The facilitating topic embryonic development –the period of 9 months for which every mother waits…

I called it facilitating because it is hard to think how chorionic villi and the uterine endometrium tissue gets interdigited to form placenta, which performs functions of nutrition provider as well as endocrine function. Thus the chapter is filling in me knowledge about reproduction in humans. Finally the process of parturition and lactation are really thrilling. The Igs present in colostrum are significant indeed.

REPRODUCTIVE HEALTH:

According to me this chapter is totally to increase consciousness about reproduction in teenagers like us. First this chapter begins with lots of government data which are really boring. But statistics is one way to highlight a govt’s achievements and drawbacks.

Later this chapter unleashes the evolution in contraceptives. This shows how according to need the natural methods are replaced by barrier methods then IUDs later pills & sterilization.

Medical termination of pregnancy is a burning issue. Just passing the laws is not at helpful but the

Law enforcers should keep their open .if girls are not there will be no MOTHER.A SOCIETY WITHOUT MOTHER ………Is it possible?????????

IN VITRO FERTILISATION

STDs	Causative agent
Syphilis	*Treponema pallidum*
Gonorrhoea	*Neisseria gonorrhoea*
Chlamydiasis	*Chlamydia trachomatis*
Trichomoniasis	*Trichomonas vaginalis*
AIDS	*HIV*
HEPATITIS-B	*HEPATITIS VIRUS*
Genital herpes	*HPV*

The symptoms of STDs and PIDs should be known properly.

The topic of infertility is a new & interesting topic.reasons is as

v Physical

v Congenital

v Diseases

v Drugs

v Immunological

v Psychological

The ARTs helping the couple to have children are :

INVITRO FERTILISATION(IVF)

EMBRYO TRANSFER(ET)

ZYGOTE INTRA FALLOPIAN TUBE(ZIFT)

INTRA UTERINE TRANSFER(IUT)

GAMETE INTRA FALLOPIAN TRANSFER(GIFT)

INTRA CYTOPLASMIC SPERM INJECTION(ICSI)

ARTIFICIAL INSEMINATION (AI)

Amniocentesis –a prenatal diagnostic technique often misused for female foeticides.

PRINCIPLES OF INHERITENCE AND VARIATION:

GENETICS-A NEW DOMAIN:

Mendel’s experiment on garden peas for 7 years used mathematical logic & statistical analysis.

He studied the inheritance of each of 7 contrasting characters by conducting monohybrid and dihybrid crosses. He also conducted test crosses.

How patient was Mendel!!! His observations inferred that the form of trait appearing in F1 HYBRID IS DOMINANT but the other is recessive.

Next come the laws which are:

1st. LAW OF DOMINANCE

2nd. LAW OF SEGREGATION

3rd.LAW OF INDEPENDENT ASSORTMENT

These laws are very deep thought ones.

The test cross is the funniest as the recessive character is saying “hey I have not gone I was just hidden”.

Now the question of dominance arises. It is of types as incomplete dominance & codominance.

The AB blood group of humans is e.g. of codominance………. Interesting, very interesting.

Sex determination is another important interesting topic.

TYPE	FEMALE	MALE	CONCLUSION
XOTYPE(INGRASSHOPPER)	XX	XO	MALEHETEROGAMETY
XY(INHUMANS&DROSOPHILA)	XX	XY	MALEHETEROGAMETY
ZW(IN HENS)	ZW	ZZ	FEMALEHETEROGAMETY

Morgan observed that when two genes in a dihybrid cross are located on the same chromosome the proportion of parental gene combination in the progeny was much higher than the recombination of genes.

Mutation that creates ROHIT of KOI MIL GAYA from an idiot to a genius & gift SPIDERMAN is unbelievable. This is of types----------

a) Gene mutation-point & frame shift

b) Chromosomal mutation

Pedigree analysis is important method to study human genetics.

GENETIC DISORDERS:A)MENDELIAN DISORDERS B)CHROMOSOMAL DISORDERS

MENDELIAN DISORDERS: Haemophilia –sex-linked recessive disorder.

Even Queen Victoria was a carrier of hemophilia.

Sickle cell anaemia- an autosome linked recessive trait. The defect is caused by substitution of glutamic acid by valine at 6^th position of β globin chain of the haemoglobin molecule.

Phenyl ketonuria-autosomal recessive trait. Mental retardation

CHROMOSOMAL DISORDERS:

DOWN’S SYNDROME-CAUSED by presence of extra copy of ch 21

Symptoms- short suture small round head, partially open mouth with furrowed tongue.

Klinefelter’s syndrome- presence of extra x ch in male.

Symptoms- tall suture with feminized physique

Turner’s syndrome- caused due to absence of one of the X ch. In female.

Symptoms- poor development of breasts, webbed necks, rudimentary ovaries.

HEALTH IS WEALTH

In this busy buzz world we often consume junk foods .do we ever notice its calorific value or take steps to burn the calorie. Here is a search conducted by me to create awareness about our food habits.

Let’s take a look at the food items over which we just jump for:

Grilled Sandwich
Stuffed paratha
Fruit salad
Idli I sambar pizza.
Vada sambar
Dahi wada
Fried rice
Noodles
Mini Meals
Pizza
Chips
Panipuri
Aloo chat
Bhelpuri
Kebabs
Fried chicken
Hamburger
French fries
rolls
Pao bajhi

Beverages

coffee
Aerated drinks
Fresh fruit juice
Milkshake
Mock tails

· Soup (Hot Beverage)

· Tea

· Lassi

Now come on let’s have a taste drive and look test at our fave harmful eateries!

PANIPURI:

In fact one of my favorite junk food .Typically, 5–8 panipuris are served over a portion on a triangular plate made from dry Sal leaves. Some places offer panipuris prepared on a whole plate, but the popular way for them to be served is one-at-a-time from a road-side vendor. Customers hold a small plate and stand around the vendor’s cart. The server then starts making one panipuri at a time and gives one to each individual. While many regions in India have their own variations of the panipuri, the most famous ones are from Kolkata called 'Phuckha'.

In Lucknow, this dish is known as "Pani Ke batashe”.

There are 25 calories in Pani Puri

Food Items	Cals	Fat	Carbs	Protein
Banana medium	105	0.4g	27.0g	1.3g
Tamarind	50	1.5g	10g
Plain yogurt	150	8g	11.4g	8.5g

Ø You could burn off the 25 calories from this Pani Puri in a variety of ways:

Ø Wii baseball for 7 mins.

Ø Swim for 2 mins.

Ø Canoeing over 5.9 mph for 2 mins.

Ø Bicycling for 2 mins.

Ø Treadmill 15% inclines @ 5mph for 2 mins.

With an average human needing around 2000-2,500 calories per day to provide the body with energy to function normally, weight gain or weight loss depends on the individual’s calorie intake and activity levels.

. Potato Chips

Calorie Count: 549 calories per 100 Gms!

Activity needed to burn off the calories: A 45 minute game of Squash or 45 minutes of high intensity workouts such as spinning or rowing

We Indians love our tea and everything that goes along with it, hence the need for a plate of biscuits along with tea. Give the biscuits a salty texture and you have a winner on your hands!

Calorie Count: 549 calories per 100 gms!

Activity needed to burn off the calories: A 45 minute game of Squash or 45 minutes of high intensity workouts such as spinning or rowing

The crunchy and deep fried Aloo bhujia is another popular snack option that people love to indulge in.

Calorie Counter: 564 calories per 100 Gms

Activity needed to burn off the calories: 1 hour of steady running is needed to burn the calories that you gained by munching on a pack of Aloo bhujia! Either it is running or 30 minutes of constant skipping.

One of the most popular street food items found in India, the Vada Pav is known to be the ‘Indianized’ cousin of the burger. Calorie Counter: 295 Cals.

Activity needed to burn off the calories: 65 minutes of steady running or an hour of playing Frisbee should help you to burn off the calories gained by eating a Vada Pav!

The one thing you always look for while going to theaters is the tub of popcorn.

The calorific chart of indian food items:

Indian Food	Calories per typical serving
Starters
Cucumber raita, 1tbsp	20
Tomato sambal, 1tbsp	20
Mango chutney, 1tbsp	60
Poppadom, each	65
Lime pickle, 1tbsp	70
Onion bajhi, each	190
Vegetable samosa, each	260
Meat samosa, each	320
Main courses
Tandoori chicken	300
Aloo gobi	330
Vegetable curry	350
Keema madras	450
Aloo saag	500
Beef madras	540
Vegetable biriyani	550
Lamb bhuna	680
Chicken tikka masala	680
Chicken curry	700
Rogan josh	700
Chicken Dansk	720
Beef Keema	780
Chicken korma	870

The calorific chart of common food items:

food	calories	Protein (gms)	Fat (gms)	Carbohydrate (gms)	Water (gms)	Vitamins
Milk	65	3.3	4	5	87	A, B2, Niacin
Butter	740	-	82	-	15	A
Cream	210	2	21	3	72	A
Cheese	310	22	25	-	44	A, B2, Niacin
Ice Cream	170	4	7	25	64	B1, B2, Niacin
Margarine	740	-	81	-	16	A
Eggs	150	12	11	-	75	A, B1, B2, Niacin
Pork (Grilled)	340	29	24	-	36	B2, Niacin
Chicken (Roast)	150	25	5	-	55
Fish (eg. Cod)	220	20	10	8	60	B1,Niacin
Beans (Boiled)	20	2	-	3	90	A
Cabbage (Boiled)	10	1	-	1	96	A, C
Carrot (Boiled)	20	0.6	-	4	91	A
Cauliflower (Boiled)	10	1.5	-	1	93	C
Cucumber (Raw)	10	0.6	-	2	96	C
Peas (Boiled)	50	5	-	8	80	A, B1, B2, Niacin, C
Potatoes (Boiled)	80	1	-	22	77	B1
Tomatoes	15	1	-	3	93	A, C
Apples	45	0.3	-	12	84	-
Bananas	80	1	-	20	70	C
Cherries	50	0.6	-	12	81	-
Grapes	60	0.6	-	15	80	C
Oranges	35	1	-	9	86	C, A
Pea Nuts (Roasted)	570	24	49	9	4	B1, B2, Niacin
Beer	30	0.3	-	2	-	-
Wine	70	-	-	-	-	-
Spirits	220	-	-	-	-	-
Coffe (Black)	-	-	-	-	-	Niacin
Bread	230	8	2	50	39	B1, Nia
Rice (White Boiled)	120	2	-	30	70	-
Cornflakes with milk	205	6.5	4	34.7	-	A1, B1, B2, Niacin, B
Chocolate Biscuits	520	6	28	67	2	B2, Niacin
Wheat Bran	200	14	6	23	8	B1, B2, Niacin

one dish everyone would enjoy in the streets.calorific value of bhelpuri is 320 cals.the saucy puffed rice with papri chats and loads of gossip is awesome!!!!!!!!!!

The deep fried pakoras, especially alur chops, piaji, begunis are mouth watering…

Now coming to our generation’s smart habits

Pizza hut

There's something for everybody — at many tables three generations are sitting down together. But that's not the reason these traditional upstarts have succeeded in storming what was once the bastion of western brands like McDonald's and Pizza Hut.

Some of the city's most famous restaurants are represented here — some of them a century old — transformed by smart uniforms, cheery signage and shining show kitchens to look every bit as clean, efficient and modern as their multinational competitors. Welcome to the future of Indian fast food.

The calorific values of different Cadburys:

Dairy Milk, Cadbury’s	1 Bar/49g	255
Dream, Cadbury’s	1 Bar/45g	250

Dairy Milk with Caramel, Cadbury’s	1 Bar/50g	240
Dairy Milk with Fruit & Nut, Cadbury’s	1 Bar/49g	240
Toffee Crisp, Nestle	1 Bar/44g	227
Crunchie, Cadbury’s	1 Bar/42g	200

Kitkat, nestle 1 bar/50g 106

Now lets take a look at our drinks:

Cola, Coke, Coca-Cola	1 Can/330ml	142
Juice, Orange, with Bits, Tropicana	1 Bottle/330ml	141
High Lights, Chocolate Drink, Dry, Cadbury	1 Sachet/10g	37
Tea, Made With Water, With Semi Skimmed Milk	1 Cup/200ml	14
Coffee, Infusion, Average, With Semi Skimmed Milk	1 Cup/220ml	14
Tea, Earl Gray, Infusion With Water	1 Mug/250ml	3
Water, Mineral or Tap	1 Glass/250ml	0

These useful facts are just FACTS unless we really face the truth of streets.

A few unfermented dishes, for instance, vegetable curry, ghugni (pea or Bengal gram boiled, sometimes with potato or meat, and then flavoured) and alu kabli (boiled potato with a highly seasoned sour preparation) also had high SPCs, and some contained pathogenic organisms. The hazards in these samples presumably arose because of poor personal hygiene, prolonged holding, repeated handling and the use of substandard water and implements at different stages, which had been observed in the diagnosis of street the street foods were prone to microbiological contamination. .

The reasons for the microbial contamination:

. Often vendors cook large portions of food and bring it to the vending place for

store and sell throughout the day so food served in the evening time have therefore typically been on

display under tepid temperatures for many hours and maybe been re‐heated for a short time during the

dayThe tidy streets have dustbins at the vending places in addition to in the worst places where the

used plates and cups lay on the ground side by side with garbage and leftovers from commodities often

piled up in the drain. Many flies, small cockroaches and crows where everywhere around the stands,

people around and near did not worry about them. The crows eat leftover food in drains, garbage bins,

sitting on parasols and if they got the chance they almost sat on the top of the commodities and food.

REPORT ON FISHES:

Fishes ,the most important food item for an indian especially for a bengali.the fishes are classified into inland fishes & marine fishes. Fish is a rich source of animal proteins.it provides employment so helps in economy of india.

On the basis of nature of source of fishjes, fish farming is of 2 types:

Capture fisheries

Culture fisheries

On visiting the local fishmarket I get to know,

Katla,rohu,mrigala etc. are fresh water major carps.

Mullets are salt water fishes.