biology term 3 shells

Why do you add Iodine stain to onion cells?

To colour the cell parts to make them visible

When testing leaf for starch, why do you boil the leaf in water?

Stops reactions

When testing leaf for starch, why do you boil the leaf in ethanol?

Removes green chlorophyll

When testing leaf for starch, why do you rinse the leaf in water?

Softens it

Total magnification formula

Eyepiece Lens x Objective Lens

Function of Nucleus

Controls the cell and has the DNA

Function of Cytoplasm

Jelly-like fluid where chemical reactions happen

Function of Mitochondria

Where aerobic respiration takes place + produces energy for the cell

Function of Cell Membrane

Outer Barrier - controls what goes in and out of the cell

Function of Cell Wall

Strengthens and supports cell

Function of Chloroplasts

Site of photosynthesis

Function of Vacuole

Stores water + nutrients

What is a unicellular organism?

Organism made of only one cell

What is amoeba + how does it move?

Unicellular organism found in ponds, moves by stretching out it's cell membrane (like a caterpillar)

Word equation for Aerobic Respiration

Glucose + Oxygen —> Carbon Dioxide + Water + Energy

Why do humans need lungs!

Our bodies are too big to absorb oxygen through our skin - need lungs for a huge surface area

What is the site of gas exchange?

Alveoli

Hwo is exhaled different from inhaled air?

Has more caro on dioxide, more water vapour and less oxygen

Main role of the heart?

Act as a pump that pushes blood around the body

Why does the heart rate and breathing rate increase during exercise?

Your muscles are working harder and need more energy - body pumps more glucose + oxygen to make them faster

DNA shape

Double helix

Where is DNA stored?

Nucleus

DNA stands for…

Deoxyribonucleic Acid

What do animals compete for in an ecosystem (4)

Food, water, territory, mates

What do plants compete for?

Light, water, space, minerals

Lamarck's theory of evolution

Believed organism changed during THEIR OWN LIFETIME by using a body part more

Why was Lamarack wrong?

Changes that happen to your body during your life don' change your DNA/genes

What is biodiversity?

Variety of different living species in ecosystem

Why is biodiversity important

Keeps ecosystems stable

What is a pyramid of numbers?

Diagram that shows total, number of individual organisms at each stage of food chain

What is a pyramid of biomass?

A diagram that shows total dry mass (weight) of living material at each stage

Why is a pyramid of biomass always a perfect pyramid shape

ENERGY and MASS are lost at EVERY LEVEL

Function of Waxy Cuticle?

Prevents water loss

Function of Upper Epidermis

Protects inside of leaf + allows sunlight to pass straight through to cells below

Function of Lower Epidermis

Protects bottom of leaf + regulates gas exchange

Function of Spongy Mesophyll

Allows gases to circulate easily inside leaf for gas exchange + diffusion

Function of Palisade Cells

Absorb light for photosynthesis - filled with chloroplasts

Function of Guard Cells

Open + close stomata - let's carbon dioxide in but stops water from escaping

Why do plants need Nitrates?

needed for healthy growth

Why do plants need Magnesium?

Needed to make green chlorophyll

If a plant's leaves are yellow , what mineral deficiency is this?

Magnesium

If a plant's older leaves turn yellow and it has poor growth, what mineral deficiency is this?

Nitrogen

Variety of different living species in ecosystem

Biodiversity

all the organisms of same species living together

Population

Population

All the organisms of same species living together

Place where an organism lives

Habitat

Habitat

Place where an organism lives

2+ groups of different organisms

Community

Community

2+ groups of different organisms

Species

A group of similar organisms which can breed with one another and produce fertile offspring

A group of similar organisms which can breed with one another and produce fertile offspring

Species

Magnesium is needed to …

Make chlorophyll

What is chlorophyll?

Green pigment found in chloroplasts - absorbs sunlight to provide energy for photosynthesis

Nitrogen is used to …

Turn sugars (made in photosynthesis) into protein (needed for growth)

Biotic factors are..

Living things

Abiotic factors are

Non-living things

Examples of an abiotic factor are…

Sunlight, water, temperature, soil, air

Examples of a biotic factor are…

Plants, animals, fungi, bacteria

Where is energy lost as you go up each level in a food chain?

Respiration, movement, heat loss, Trapped in indigestible parts of body (like bones)

What do arrows in a food web show?

Direction energy passes when plant/animal is consumed

Word equation photosynthesis

Carbon Dioxide + Water = (Sunlight + Chlorophyll) Glucose + Oxygen

Yellow leaves (overall)=

Magnesium

Stunted growth=

Nitrate