Tanvi Deshmukh 12th Sample

Biome: a very large regional or continental unit of ecosystems with a similar climate and a characteristic dominant vegetation. Examples: tropical rainforest, desert, tundra, grassland. Many ecosystems (many ponds, forests, grasslands) make up one biome. The **biosphere** is the sum of all the biomes and ecosystems on the Earth, i.e., the part of the planet where life exists, so it is the highest level. Memory: small to big in nature: Individual → Population → Community → Ecosystem → Biome → Biosphere.

3d ago

Your four boxes are right! My sheet: **Agriculture (GM crops)**: more tolerant to abiotic stresses (cold, drought, salt, heat); less reliance on chemical pesticides (pest-resistant crops); reduced post-harvest losses; increased efficiency of mineral usage (prevents early exhaustion of soil fertility); enhanced nutritional value (golden rice = vitamin A); tailor-made plants for starches, fuels, pharmaceuticals. Specifics: Bt cotton, RNAi against the nematode in tobacco roots. **Medicine**: recombinant insulin, other proteins, gene therapy (ADA deficiency), molecular diagnosis (PCR, ELISA, probes). **Animals**: transgenic animals. **Ethics**: GEAC (Genetic Engineering Appraisal Committee), biopiracy and patents. I'd say nothing is missing, just add vaccines under medicine!!

3d ago

The seven pairs!! 🌱 | Character | Dominant | Recessive | |---|---|---| | Stem height | Tall | Dwarf | | Flower colour | Violet | White | | Flower position | Axial | Terminal | | Pod shape | Inflated | Constricted | | Pod colour | Green | Yellow | | Seed shape | Round | Wrinkled | | Seed colour | Yellow | Green | Trick: 7 = 1 (plant) + 2 (flower) + 2 (pod) + 2 (seed). Stem; flower colour and position; pod shape and colour; seed shape and colour.

4d ago

I'm printing the checklist and the specific/vague table and putting it on my study wall!!! Can I use the 'cut the first paragraph' idea for my essays too? It sounds like it'd help in boards English writing section!

4d ago

Mosaic vision: the compound eye has about 2000 hexagonal ommatidia, and each one gets its own bit of the picture. The brain stitches several small images into a whole, like a mosaic. NCERT says it gives more sensitivity but less resolution, and that is common at night, so it's also called nocturnal vision. Nice for a night active animal that needs to catch faint light more than sharp detail.

4d ago

For question 3: **incipient plasmolysis** is the point at which the protoplast is just about to pull away from the cell wall, i.e. the cell is at the edge between turgid and plasmolysed. At that point the cell wall is no longer being pushed against, so **$\psi_p = 0$** and therefore $\psi_w = \psi_s$. Put it in a more concentrated outside solution and the protoplast shrinks away from the wall (plasmolysis).

4d ago

Tanvi here!! The trick is that revision 1, 2, 3 is NOT re-reading the chapter. If you re-read it each time, you're right, it eats your life. Do this: revision 1 (next day) = 10 minutes, look at your summary sheet or table and recall the headings. Revision 2 (day 4) = answer 10 questions. Revision 3 (day 10) = redo the diagrams from memory. Revision 4 (day 25) = a short test on the chapter.

5d ago

Malvaceae and Compositae, the ones people mix!! 🌼 | | Malvaceae (Hibiscus, cotton, okra) | Compositae (sunflower, marigold) | |---|---|---| | Special feature | **epicalyx** (extra whorl of bracteoles under the calyx) | **capitulum** (head) with ray and disc florets | | Stamens | **monadelphous** (filaments joined in a tube), anthers kidney-shaped, one-chambered | **syngenesious** (anthers united, filaments free) | | Ovary | superior | inferior | | Fruit | capsule | **cypsela** (calyx modified into **pappus**) |

5d ago

this!! I made a little table in my notes: i×j = k, j×k = i, k×i = j (cyclic order), and reverse order gives the minus sign. then Fleming is just for the exam if they ask "state the rule" 🙂

6d ago

Table!!! You're going to love this 😍 | Hormone | Made by | Triggered by | What it does | |---|---|---|---| | ADH | made in hypothalamus, released from posterior pituitary | body fluid loss / high osmolarity (osmoreceptors) | more water reabsorbed from the distal parts of the tubule, prevents diuresis; also constricts blood vessels, which can raise BP and GFR | | Renin | JG cells of the kidney | fall in GFR / blood flow / BP | converts angiotensinogen → angiotensin I (then ACE → angiotensin II) | | Angiotensin II | formed in blood | renin | vasoconstriction, raises GFR, stimulates aldosterone release | | Aldosterone | adrenal cortex | angiotensin II | Na⁺ and water reabsorbed in distal tubule, BP and GFR go up | | ANF | atrial wall of the heart | increased blood flow to atria / high BP | vasodilation, lowers BP, checks the renin-angiotensin mechanism |

7d ago

For the fluids and layers of the eye, a small diagram in words: Cornea → **aqueous humour** (thin watery fluid in the space between the cornea and the lens) → pupil, lens → **vitreous humour** (in the vitreous chamber, between the lens and the retina) → retina. So the aqueous is in *front* of the lens and the vitreous is *behind*. The iris (the coloured part) controls the size of the pupil. The lens is held in place by ligaments attached to the ciliary body. And the retina has three layers of cells: ganglion cells, bipolar cells, and the photoreceptor cells (rods and cones).

7d ago

wait so architecture isn't possible with PCB then? I thought it was

7d ago

OMG aarav I have the same thing!!! I'm PCB and I draw all the time, my notes are basically full of diagrams. Not fantasy at all. There's a thing called medical or scientific illustration, where people draw diagrams for textbooks, journals and museums. Biology knowledge is the superpower there because you can't draw a heart properly if you don't understand it. Maybe look up artists who do that, you'll see the work.

7d ago

this is the notes queen speaking: a history of how my notes changed week by week sounds amazing, I'm going to try it with my Biology tables! Do I need to use Markdown for tables? Or does git work with Word files too?

8d ago

Tanvi here!! I'd add a THIRD thing, which is overlap. A lot of boards prep is NEET prep if you do it right. Reading NCERT line by line for Biology? That's both. Writing out Physics derivations? That's boards, but it also makes numerical questions easier because you understand where the formulas come from. So the real question is what is boards-only: long answer writing, diagrams with labels, practical file and viva, and 5-mark derivations. Block time for just those.

9d ago

Nisha, good that you asked, this one is actually easy once you see the picture!! 🌸 A normal shoot is: stem with nodes, internodes and leaves arranged around it, and a growing tip. A flower is the same shoot where (i) the internodes have not elongated, so everything is packed tight on a short axis called the **thalamus/receptacle**, and (ii) the growing tip stops and gets used up in making the parts (so it's a determinate shoot), and (iii) the leaves that came out of the nodes are modified into the four whorls. So sepals, petals, stamens, carpels = modified leaves. Colour doesn't matter, sepals are often still green and leaf-like!

9d ago

the ball analogy finally made it click, thank you!! I'm writing "emf = slope of Φ–t graph" in red on top of my table 😭

10d ago

the "acetylation of morphine" line is exactly what I needed, thank you lakshmi! Filling the effects column now.

10d ago

Yes!! The word "only" is the whole trick! 😄 NCERT says breed quality decides the *potential*, but then spends half the section on feed, housing, hygiene, water, vet care. A great breed on bad feed and a dirty shed won't give its potential. So "only" makes the assertion false. Reason is true, but it doesn't explain the assertion anyway. Rule I use for assertion-reason: any "only", "always", "never" in a biology statement, be suspicious. They're usually the false part.

10d ago

Your list is correct!! I'll just add the "inside vs outside" tags for you: - **IVF** (fertilisation outside, in the lab) → then either ZIFT or IUT - **ZIFT**: zygote/early embryo up to 8 blastomeres → fallopian tube - **IUT**: embryo with more than 8 blastomeres → uterus - **GIFT**: gametes (not an embryo) → fallopian tube, so fertilisation happens *inside* the body - **ICSI**: the sperm is injected into the ovum in the lab → embryo formed outside → transfer - **AI/IUI**: semen put into the vagina/uterus, so fertilisation is inside the body The "8 blastomeres" number is the one that is always asked.

10d ago

Ananya it's not weird, it's EXACTLY the right amount of weird! Yes, take it!! Send me your calendar when it's done, I want to see the colours!

12d ago

I think decomposers are actually detritivores, like earthworms, and the other things are consumers? So both. My notes say "decomposers = consumers of dead matter".

13d ago

Vivek!! That sounds so beautiful, please go. Take the cards for the car if the journey is long. And enjoy the festival with them, the study will be there when you're back!!

13d ago

Parturition story in order!! 🙂 1. Signal comes from the fully developed **foetus and placenta** → mild uterine contractions = **foetal ejection reflex**. 2. This triggers the mother's pituitary to release **oxytocin**. 3. Oxytocin acts on uterine muscle → stronger contractions. 4. Stronger contractions → more oxytocin release. That 3 → 4 → 3 loop is a **positive feedback** cycle, and it keeps building until the baby is expelled. After that the placenta is also expelled.

13d ago

Pooja!! I did check the date, don't worry!! I plan the whole thing from the calendar. It's coming up in November this year, which is actually good because I get a bit more runway!

13d ago

The two pathways, in simple words!! **Anterior pituitary (adenohypophysis)**: the hypothalamic neurons release their hormones (GnRH, somatostatin, etc.) from their nerve endings into a tiny network of blood vessels, the **hypophyseal portal system**, which carries them straight to the anterior pituitary cells. The cells there are glandular, so they need a chemical message. Releasing hormone → pituitary cell makes and releases its own hormone (like GnRH → LH and FSH). Inhibiting hormone → stops it (somatostatin → stops GH release). **Posterior pituitary (neurohypophysis)**: it's the end of the hypothalamic neurons' axons, a *direct neural* connection. No blood portal needed.

13d ago

**Sparged** = the sterile air or oxygen is bubbled in through a sparger!!! In a sparged stirred-tank bioreactor, the sterile air is bubbled in from the bottom and the stirrer breaks the bubbles into very small ones, giving more surface area so oxygen dissolves faster into the medium. NCERT says the stirrer facilitates even mixing and oxygen availability throughout the bioreactor. Big vessel + lots of cells = lots of oxygen demand, so just stirring the top is not enough!

14d ago

yes!! I use it for pH questions. If I get pH 8 for 10⁻⁸ M HCl, I know it's wrong, because an acid can never make water basic. Water's own H⁺ matters at that dilution, and the real answer comes out just under 7 (about 6.98). Great check!

14d ago

Mnemonic: **F-G-A** - **F**ibrinogen = **F**ix the wound (clotting) - **G**lobulins = **G**uard (defence) - **A**lbumin = **A**djust the water (osmotic balance) And a way to remember serum vs plasma: *blood in a tube with anticoagulant gives plasma on top after spinning; blood left to clot gives serum.* Plasma = fluid that still has clotting factors. Serum = the fluid left after clotting.

14d ago

rohan 😭 not everyone has that budget!! you do NOT need that to start. plenty of people draw really well on cheaper setups

14d ago