Essential BioFacts from Year 10

RESPIRATORY SYSTEM

SPECIALISED CELLS

DIFFUSION OSMOSIS TRANSPORT ACROSS MEMBRANES

GAS EXCHANGE IN THE LUNGS

BREATHING

nasal cavity

nostrils

larynx (voice box)

trachea (windpipe)

bronchus (-i)

lung

diaphragm

bronchiole

pleural membrane

alveolus (-i)

= system for taking in O2

and giving out CO2

O2

CO2

O2CO2

capillary from pulmonary artery

capillary to pulmonary vein

red blood cell(carrying O2)

blood plasma(carrying CO2)

CO2

O2

capillary wall(1 cell layer)

alveolus wall(1 cell layer)

SMOKING

• diaphragm contracts (flattens)

• external intercostal muscles contract

• rib cage movesout and upward

• lungs expand• air rushes into lung

INHALATION EXHALATION

diaphragm

• diaphragm relaxes(moves upward)

• internal intercostal muscles contract

• rib cage movesdown and inward

• lung vol decreases• air flows out of lungs

intercostal muscles

• TAR- lung cancer- emphysema (reduced SA of alveoli)- bronchitis (cilia in bronchi damaged, build up of bacteria)

• NICOTINE- addiction- cardiovascular disease (arteries constricted, reduced bloodflow, reduced O2 supply, can cause heart attack and strokes)

• CARBON MONOXIDE (CO)- binds to haemoglobin (less O2

transported): tiredness, dizziness- pregnancy: reduced birth mass

O2CO

O2

osmosis diffusion facilitateddiffusion

H2OO2

CO2

glucose, ionsamino acids

PASSIVE TRANSPORT

ACTIVE TRANSPORT

energy

carrierprotein

channelprotein

con

cen

trat

ion

gra

die

nt

solute H2O

= the movement of molecules from high to low concentration

= the movement of water from high to low water concentration (from low to high solute concentration) across a selectively-permeable membrane

time

time H2Osolute

selectively-permeable membrane

time

concentration gradients

EFFICIENCY• large SA (many alveoli)• short diffusion distance

(only 2 layers of cells)• large concentration gradient(blood flow + breathing)

red blood cell(transport of oxygen)

white blood cell(pathogen destruction)

neurone(nerve impulse transmission)

sperm cell(fertilisation)

ciliated epithelial cell(clearing of airways)

palisade cell(photosynthesis)

guard cell(control of stomatafor gas exchange)

root hair cell(uptake of water + minerals)

nucleus(genetic information)

mitochondria(respiration)

ribosome(protein production)

cytoplasm(chemical reactions)

cell membrane(control of entry + exit )

cell wall(supports cell shape, stops cell bursting)

chloroplast(photosynthesis)

permanent vacuole(contains cell sap to keep cell turgid)

egg cell(fertilisation)

CELLS + ORGANELLES

ANIMAL CELL PLANT CELL

EFFICIENCY:• large SA

large SA/V ratio• short diffusion

distance• large concentra-

tion gradient• high temperature

stimulus too hot too cold

receptors - receptors in skin (skin temp.)- receptors in brain (blood = core body temp.)

control centre - thermoregulatory centre in hypothalamus

effector - mainly skin

response - hair lie flat: heat lost by radiation

- sweat glands open: sweat evaporation cools body

- vasodilation: blood flowsthrough capillaries nearsurface: heat lost byradiation

- hair stand up: air trapped reducing heat loss

- sweat glands close: no sweat produced

- vasoconstriction: lessblood flow to surface: lessheat lost by radiation

- shivering: releases heat

stimulus blood sugar too high blood sugar too low

receptors - pancreas

control centre - pancreas releasesinsulin into blood

- pancreas releasesglucagon into blood

effector - liver + muscle cells

response - insulin receptors onliver + muscle cells sense insulin in blood

- glucose is taken upinto cells: levels inblood decrease

- glucose is stored asglycogen

- insulin receptors onliver + muscle cells sense glucagon in blood

- glycogen is brokendown into glucose

- glucose is released into blood: levelsincrease

Essential BioFacts from Year 10

THERMOREGULATION

CIRCULATORY SYSTEM

HOMEOSTASIS

GLUCOSE REGULATION

DIABETES • TYPE 1- any time, mostly juvenile onset- pancreas does not secrete insulin- insulin injections needed

HEART

left atrium

left ventricle

right ventricle

right atrium

vena cava

vena cava

pulmonary artery

aorta

pulmonary vein

heart wall

AV valve

pulmonary artery

aorta

BLOOD

pulmonary artery

pulmonary vein

vena cava aorta

body

• ARTERIES- small lumen- thick, elastic, muscular wall - high blood pressure

• VEINS- large lumen- thin wall - valves- low blood pressure

• CAPILLARIES- wall: 1 cell layer- exchange of substances e.g. glucose with cells

RESPIRATION

+ + +

ANAEROBIC RESPIRATION

2 C3H6O3

glucose oxygen carbon dioxide water energy

glucose lactic acid energy

+

hepatic arteryhepatic portal vein

hepatic vein

controlcentre

effectorreceptor

stimulus

variableresponse

negative feedback

• lactic acid needs to be broken down using O2

to CO2 + H2O (repaying oxygen debt)

= disorder caused by high levels of glucose in blood

• SYMPTOMS- high glucose levels in blood- glucose found in urine- excessive urine production- dehydration + thirst

• TYPE 2- adult onset- liver + muscle cells don’t respond to insulin- regulation of glucose levels via diet

(detects stimulus)

(a change in variable)

(compares change in variable to set-point data + gives

instructions to effector)

(brings aboutcorrective change)

(corrective change returning variableto normal)

(stops any further response)

insulin

pancreas

glucose glucacon

glycogen

liver + muscle cells

sweat gland

hair

arterioles

SL valve

MITOSIS MEIOSIS

purpose to make more cells for growth and repair

to make gametes for fertilisation

location in whole body in testes and ovaries

number ofdaughter cells

1 cell 2 daughter cells 1 cell 4 gametes

number ofchromosomes

46 46 (23 pairs)DIPLOID= 2 sets of chromosomes

46 23HAPLOID= 1 set of chromosomes

variation no, genetically identical yes, genetically different

process

Essential BioFacts from Year 10

GENETIC CROSSES

CHROMOSOMES, GENES AND DNA

nucleus

chromatid

centromere

duplicated chromosome

DNAdouble helix

gene

backbone: • sugar

(deoxyribose)• phosphate base pairs:

• A pairs with T• G pairs with C

4 bases in centre: • adenine (A)• thymine (T) • guanine (G)• cytosine (C)

CHROMOSOMENUMBERS

46 46

23 (22 + X)

23 + 23= 46= 23 pairs = 22 pairs + XX or XY

23(22 + X or Y)

meiosis

mitosis

VARIATION

bB

mother (Bb)

father (Bb)

meiosis

information (code) to make a protein

B b

B BB Bb

b Bb bb

75% chance

25% chance

bB

meiosis

CO-DOMINANCE

genotype:phenotype:

WWwhite

BBblack

WBspeckled

= both alleles contribute to phenotype

INHERTIANCE OF SEX CHROMOSOMES

XX

mother

father

X Y

X XX XY

X XX XY

50% chance

50% chance

XY

PEDIGREE TREES

BB or Bb

bbbb

Bb Bb

MITOSIS AND MEIOSIS

gametes

gam

etes

GENES AND ALLELES

brown eye allele

B B

blue eye allele bb

bB

genetic variation

environmental variation

fertilisation

bB

eye colour gene existing in different versions (= alleles)

eye colour

GENOTYPE= alleles

present

HOMOZYGOUS= both alleles

are same (e.g. BB)

HETEROZYGOUS= two different

alleles (e.g. Bb)

PHENOTYPE= characteristic

shown

chromosomepair DOMINANT ALLELE

= determines phenotype

RECESSIVE ALLELE= determines phenotype

if both alleles recessive

brown eye allele is dominant

through:• random

fertilisation of gametes

• mutations

BBor Bb

bbBBor Bb

Bb

bb

= show the pattern of inheritance in families over several generations

PUNNETT SQUARE= genetic diagram

offspring

• crossing-over • random

assortment

Essential BioFacts from Year 10

MUTATIONS NATURAL SELECTION

MICROEVOLUTION IN ACTION(ANTIBIOTIC RESISTANCE)

DNA altered DNA

mutation

DNA replication+ cell division

X-raysUV light

mutagens(e.g. tar)

mutationspassed on

= changes in DNA

protein

characteristic

altered protein

altered characteristic

mutations are:• mostly harmful• sometimes neutral• rarely beneficial

SELECTIVE BREEDING

natural variation in beetle colour

randommutations

some are better adapted… (e.g. camouflage)

selection pressure(e.g. predators)

…and more likely to survive and breed…

…passing on their genes

over time: more beetles with favourable characteristics

natural variation in bacteria

randommutations

some are better adapted… (e.g. antibiotic resistance)

selection pressure(e.g. antibiotics)

…and more likely to survive and reproduce…

…passing on their genes

over time: more antibiotic resistant bacteria

natural variation in milk cows

select cow with high milk yield (production)

mate with bull from high yield milk cow family

(artificial insemination)

select high milk yield offspring, repeat process

CARBON CYCLE NITROGEN CYCLE

N2 in air and soil

plant protein

nitrate (soil)

assimilationvia roots

ammonia (soil)nitrite (soil)

protein in detritus

decomposer

nitrification nitrification

nitrifying bacteria nitrifying bacteria

animal proteinfeeding

ammonification

deathdeath + excretion

N2-fixing bacteria in soil

symbiotic N2-fixing bacteria in root nodules

nitrogen-fixation

nitrogen fixation

denitrifying bacteria

denitrification

plants

photo-synthesis

respiration

animals

dead plants and animal material

death + excretion

death

feedingdecom-position

fossil fuels

combustion

fossilisation

CO2 in air and water