Answering techniques for sci

(Transfer to other knowt account)

Extra

Power=energy transferred or converted/time taken

Live wire(switches and fuses fit inside)most dangerous 240V

Neutral completes circuit provides returning path

Safety measure?

Add a fuse to prevent excessive current flow

Effect of adding more light bulbs/resistors in series + parallel circuit

Series

Adding bulb in series increases the effective resistance of the circuit. A smaller current is thus drawn from the batteries. Current through is less than _A(initial current flowing through)less bright

Parallel

Adding bulb in parallel decreases the effective resistance of the circuit. A larger current is thus drawn from the batteries. Current and potential difference remains the same. Still as bright

Move on to other books first

Definitions if they ask

Energy-capacity to do work

Principal of conservation of energy-energy cannot be created or destroyed-transferred from one object to another-converted from one form to another

Take note the hydroelectric energy uses GPE first biofuels uses CPE

What instrument is used to measure force?-spring balance

Definition of force-push or a pull that one object exerts on another object

Eg. Alice thinks that no force is acted on a stationary object is she right? Explain

No. We can only conclude that there’s no net force acting on it(balanced force)

Describing motion(IMPT)

_is moving_(direction) in a (constant acceleration/etc) because there is a constant non zero net force

What happens to rest of the energy

-used to overcome friction and some of it is converted to heat and sound energy

NEXT

kinetic theory of matter-matter is made of numerous tiny particles which are in a constant random motion

Describe solid particles

-strong forces of attraction between particles

-packed in a closely packed, fixed regular position

-motion-vibrate against each other in fixed arrangements

Describe liquid particles

-Stronger than gas weaker than solids sttraction

-packed closely,random arrangement

-slide past one another

Describe gas particles

-weak force of attraction

-far apart each other with a random arrangement

-move at high speeds freely and randomly

Ans tech

-why does ball expand when heated

When _is heated its particles gain energy and vibrate more vigorously about their fixed positions Distance between particles increase so volume of ball increases

AYAYAYAYAAYAAYY

transfer of heat ans tech

IDPE(conduction)

Identify-material(maybe air spaces;making it a good/bad conductor)

Direction-hence heat flows from (hotter region) to (colder region)

Process-By conduction

Effect-At a faster/slower rate

Convection

_gets heated. Particles expands, becomes less dense and rises

Cooler (smt) becomes more dense and sinks to the bottom, setting up a convection current

For cooling through convection

_becomes cooler. Particles contract, becomes more dense and sinks

Warmer (smt) becomes less dense and rises setting up a convection current

Why’s it better to use dull black surfaces for radiation?

-better emitters and absorbers of infrared radiation -absorbs/emit at higher rate

-(shiny just opposite)

Higher temp-faster emission for radiation + larger surface area=faster rate for emit or absorption

Also use IDPE for I just state one variable above and change process to radiation ❤❤😍

Applications

Vacuum between two walls

-prevent convection and conduction cause there’s no medium

Silvered wall lining

-shiny so it is a good reflector and prevents radiation

Having a cap

-prevents convection and evaporation prevents hot air from escaping

LIGHT SEC 1 and i suck

concave-curved surface bends inwards, images formed are virtual upright and magnified

convex-curved suface bends outwards, images formed are virtual upright and diminished

regular vs diffused

angle of incidence is all the same vs angle of incidence are diff at diff points

refractive index=n=c/v C IS ALWAYS 3.00 × 10(square 8)

Why does (smt) appear bend from (smt)

As light exits from (smt) which has a higher refractive index into (smt), which as a refractive index of 1.00(if its air), it undergoes refraction. Hence, light rays seen by the eye traces back to an image which appears to be shallower than the object

good and bad light

infrared good-found in remote controllers to control our devices-bad-it gets trapped in atmosphere which causes global warming

visible light good-allows photosynthesis to happen-light pollution

ultraviolet rays good-exposure allows us to get vitamin d-bad-overexposure can cause harm to eyes and skin cancer

CELLS

division of labour

-it occurs at the cellular level ; is the sharing of diff functions in an organism through cells, tissues and organs. This ensures smooth running and effective working for the diff parts of the organism as a whole

root hair cell

long narrow extention-increases surface area to volume ratio so that there is an increase in the rate of absorption between water and mineral salts

thin cell wall-reduces distance so water and mineral salts can be diffused at a faster rate

large centralled vacuole-large water storage

red blood cells

haemoglobin-stores oxygen

absense of nucleus-so that more haemoglobin can be stored into the red blood cells, thus more oxygen is transported

biconcave shape-increases surface area to volume ratio to increase rate of diffusion for oxygen

sperm cell

streamline shape-increases the speed for sperm to swim to the egg

flagellum-propells sperm to egg so sperm can reach the egg faster

mid-piece is packed with mitochondria-mitochondria provides energy for the flagellum to move faster

eyepiece

body tube

base and arm

revolving nosepiece

diaphragm

objective lens

stage

coarse adjustment knob

fine adjustment knob

light source.

👄 MOUTH

Flashcard 2 — Function of the mouth
Q: What happens in the mouth?
A:

• Food is ingested.

• Teeth carry out mechanical digestion by breaking food into smaller pieces.

• Food is mixed with saliva.

• Saliva contains the enzyme amylase, which begins the chemical digestion of starch into maltose.

KEY WORDS: ingestion, mechanical digestion, saliva, amylase, starch → maltose

💧 SALIVARY GLANDS

Flashcard 3 — Function of salivary glands
Q: What is the function of the salivary glands?
A: They produce saliva, which:

• moistens/lubricates food, making it easier to swallow.

• contains amylase, which digests starch into maltose.

KEY WORDS: saliva, amylase, starch → maltose

🥖 OESOPHAGUS

Flashcard 4 — Function of oesophagus
Q: What does the oesophagus do?
A: It transports food from the mouth to the stomach by peristalsis.

KEY WORDS: transport, peristalsis

⚠ Important: There is no significant digestion or absorption in the oesophagus.

🥣 STOMACH

Flashcard 5 — Functions of stomach
Q: What happens in the stomach?
A:

• Food is stored temporarily.

• Muscular walls churn food, carrying out mechanical digestion.

• The stomach produces hydrochloric acid, which provides an acidic condition for protease to work and helps kill bacteria.

• Protease begins the digestion of proteins into smaller molecules.

KEY WORDS: churning, mechanical digestion, hydrochloric acid, acidic, protease, proteins

🟠 PANCREAS

Flashcard 6 — Function of pancreas
Q: What does the pancreas do?
A: It produces digestive enzymes and releases them into the small intestine.

These enzymes digest:

• carbohydrates

• proteins

• fats

KEY WORDS: digestive enzymes, small intestine, carbohydrates, proteins, fats

🟢 LIVER

Flashcard 7 — Function of liver
Q: What does the liver do in digestion?
A: The liver produces bile.

Bile:

• neutralises stomach acid entering the small intestine.

• provides an alkaline condition for intestinal enzymes.

• emulsifies fats into tiny droplets, increasing the surface area for lipase to act.

KEY WORDS: bile, neutralise, alkaline, emulsification, surface area, fats

🟡 GALL BLADDER

Flashcard 8 — Function of gall bladder
Q: What does the gall bladder do?
A: It stores and releases bile produced by the liver into the small intestine.

KEY WORDS: stores, releases, bile, small intestine

⚠ The liver produces bile.
The gall bladder stores bile.

🧬 SMALL INTESTINE

Flashcard 9 — Functions of small intestine
Q: What happens in the small intestine?
A: It is the main site of digestion and absorption.

• Digestion is completed here.

• Digestive enzymes break food into small, soluble molecules.

• These soluble molecules are absorbed into the bloodstream through the walls of the small intestine.

KEY WORDS: digestion, absorption, small soluble molecules, bloodstream

🩸 SMALL INTESTINE — ABSORPTION

Flashcard 10 — Why is the small intestine good at absorption?
Q: How is the small intestine adapted for absorption?
A: It has many villi, which:

• greatly increase surface area.

• have a thin wall.

• contain many blood capillaries for efficient transport of absorbed nutrients.

KEY WORDS: villi, large surface area, thin wall, blood capillaries

🟤 LARGE INTESTINE

Flashcard 11 — Function of large intestine
Q: What does the large intestine do?
A: It absorbs water from the undigested food, forming faeces.

KEY WORDS: absorption, water, faeces

🟫 RECTUM

Flashcard 12 — Function of rectum
Q: What does the rectum do?
A: It stores faeces temporarily before they are removed from the body.

KEY WORDS: stores, faeces

🚪 ANUS

Flashcard 13 — Function of anus
Q: What is the function of the anus?
A: It is where faeces are expelled from the body during egestion.

KEY WORDS: egestion, faeces, expelled

🔥 THE 4 PROCESSES

Flashcard 14 — Ingestion

Q: Where does ingestion occur?
A: Mouth

Flashcard 15 — Digestion

Q: What is digestion?
A: The breakdown of large, insoluble food molecules into small, soluble molecules that can be absorbed.

Flashcard 16 — Absorption

Q: What is absorption?
A: The movement of small, soluble digested food molecules through the wall of the small intestine into the bloodstream.

Flashcard 17 — Egestion

Q: What is egestion?
A: The removal of undigested food/faeces from the body through the anus.

⭐ SUPER IMPORTANT EXAM TABLE

🧠 Easy sequence to memorise

Mouth → Oesophagus → Stomach → Small intestine → Large intestine → Rectum → Anus

And remember:

Ingestion → Digestion → Absorption → Egestion

Mouth = IN
Small intestine = ABSORB
Anus = OUT

🩸 Blood Vessels Flashcards

🔴 ARTERIES

Q: What is the function of arteries?
A: Arteries carry blood AWAY from the heart to the organs and tissues.

How do arteries carry out their job?

Arteries have:

• Thick muscular walls → withstand the high pressure of blood pumped out by the heart.

• Thick, strong walls → prevent the blood vessel from bursting under high pressure.

• Elastic walls → stretch when blood is pumped into them and recoil to help maintain blood pressure and blood flow.

• Small lumen → helps maintain the high pressure of blood.

🧠 ARTERY = AWAY

🔵 VEINS

Q: What is the function of veins?
A: Veins carry blood TOWARDS the heart from the organs and tissues.

How do veins carry out their job?

Veins have:

• Valves → prevent backflow of blood.

• Large lumen → allows blood to flow through easily despite the low pressure.

• Thinner walls → because blood in veins is at lower pressure, so they don't need walls as thick as arteries.

• Skeletal muscle contraction helps squeeze veins and push blood towards the heart.

🧠 VEIN = towards the heart

🟣 CAPILLARIES

Q: What is the function of capillaries?
A: Capillaries allow the exchange of substances between the blood and body cells.

They exchange things such as:

oxygen, glucose, carbon dioxide and other dissolved substances.

How do capillaries carry out their job?

Capillaries have:

• Very thin walls — only one cell thick → substances have a short distance to diffuse.

• Very narrow lumen → red blood cells pass close to the vessel wall, allowing efficient exchange.

• Extensive network → provides a large surface area for exchange.

• Small diameter → blood flows slowly, giving more time for exchange.