Biology Paper 1

What is the function of the cell wall?

It keeps the structure of the cell and supports it

What is a prokaryotic cell?

A cell where it’s DNA is not enclosed in a nucleus

What is the function of a red blood cell?

To transport oxygen around the body

Give 3 adaptations of a red blood cell

Biconcave, large SA to volume ratio, no nucleus

What is the function of a nerve cell?

It sends electrical signals around the body

what are the adaptations of a nerve cell?

Long axon, has dendrites(helps connect to other cells), mylain sheath(insulator)

Function of the sperm cell

To fertilise the egg

Electron vs light microscope

Electron: can see sub cellular structures, higher resolution, see in B&W, expensive, use electrons to see image, only dead organisms

Light: use light beams to see image, lower resolution, see in color, can use living organisms

What is resolution?

Ability to see 2 or more objects separately

List the adaptations of a sperm cell

Enzymes in acrosome, streamlined head (to reduce energy loss), (list more)

What is the function of the palisade cell?

Photosynthesis

List the adaptations of the palisade cell

Has chloroplasts, found on the top layer of the leaf

What is the function of the root hair cell?

It absorbs ions (minerals and water) from the soil

List the adaptions of the root hair cell

Thin cell membrane, have mitochondria(?), long SA(?), no chloroplast, long projections

What is diffusion?

Particles moving from a high to low concentration

Name the factors that affect the rate of diffusion (find more)

SA, concentration, temperature

How is ___(e.g. lungs) adapted for gas exchange?

High volume of blood flow, one cell thick, large SA to volume ratio (need specific explanations?)

What is osmosis?

The transport of water particles from a high concentration to a low concentration through a semi permeable membrane

Give one example of osmosis in a plant

When water is moving through the xylem which is found in leaves normally (?)

Give one example of active transport & why is it needed there?

• When the roots absorb minerals and water from the soil

• Bc it goes against gravity

What is active transport?

Particles moving from a low concentration to a high concentration using energy

What is a stem cell

An unspecialised cell

What are adult stem cells? Where are they found?

• Unspecialised cells which can ONLY turn into a limited type of cells

• Found in bone marrow

What are embryonic stem cells? Where are they found?

• Stem cells which can turn into any type of cell

• Embryos

what is a communicable disease?

it can be spread to others

what is a pathogen?

a microorganism which causes a disease

name the 4 types of pathogen

bacteria, fungi, virus, protist

how can pathogens spread

air, water, physical contact, animals (vectors)

how do bacteria make you ill?

they release toxins in your body

how do viruses make you ill

invades cell, multiply/ reproduce, burst out, then destroy cell

examples of bacterial diseases

gonorrhoea, salmonella, tuberculosis, e-coli, cholera

symptoms of gonorrhoea

pain when urinating, yellow discharge

symptoms of salmonella

vomiting, fever, diarrhoea, high fever, stomach cramp, cold sweat

what happens during phagocytosis

white blood cells track, engulf, absorb, destroy cell

what are antigens

protein marks

why are antibodies a specific defence

bc they are specific to the protein markers e.g. antigen

what is the function of an antitoxin

they neutralises toxins produced by bacteria

how to control the spread of communicable disease

herd-immunity, get rid of vectors, condoms, vaccination, antibiotics, wash hands

what does a vaccine contain

small does of deadened or weakened pathogen

how does a vaccination protect against a specific pathogen

pathogen enter body → WBC = engulf = antibodies produced → memory cells = can kill faster

what is heard immunity

when 95% of the population is vaccinated

what non-specific systems does the body use to prevent pathogens getting into it

hair, skin, nose mucus, stomach acid, tears

what three functions do white blood cells have

antibiotics, antitoxins, memory cells (?)

what is a communicable disease

it can be spread onto others

what is a pathogen

a microorganism which causes a disease

name 3 examples of a viral diseases

flu, HIV, AID, measles, tobaco mosaic virus