2.75 - urine

- urine contains water, urea and salts
- salt , water and urea amount vary with how well a person is operating

2.74 - ADH

- ADH - anti- divretic hormone
- it is produced in the brain in the hypothadumus
- ADH goes through the blood from the brain and its target is the kidney
- the effect is to control and alter the quanity of the deposition of water in the blood
- this makes the blood more or less concentrated
- ADH targets the collecting duct
- this allows more water to come out of the collecting duct
- this makes the collecting duct more porous
- the urine would be more concentrated and the volume decreases

2.73 - glucose re-absoption

- glucose goes from the glomerula filtrate to the blood
- urine does not contain glucose
- in the proximal convaluted tubule glucose is removed and is taken back to the blood

2.72 - water re-absorption

- when the filtration occurs in the bowman's capsule, it will filter out too much water
- when it reaches the collecting duct, water is removed form the collecting duct
- the water is then returned to the blood
- this is selected re-absoption of water

2.71 - ultrafiltration

- the filtration begins at the bowmans capsule
- blood comes in with high pressure, goes through the glomerulus
- the blood comes out of a narrow blood vessel - this gives the blood even higher pressure
- the high pressure forces the plasma out of the blood vessel and into the bowmans capsule
- this causes glomerula filtrate which contains water, salts, amino acids, glucose and urea

2.70 - nephran structure

- nephra - the part in the kidney which does the filtration and composition of the blood
- outer layer of the nephra is called the cortex, the next layer is the medalla and the space is called the pelvic which is where the urine collects
- the kidney is made up of millions of tubular structures (nephra)
- the dead end of the nephra is known as the bowman's capsule
- the twisted sections are the convoluted tubules and the straight parts as the the collecting duct
- the loop is known as the loop of henle
- the first twisted section is called the proximal and the second part is the distal

2.69 - urinary system

- in the urinary system, there are two kidneys
- from each kidney there is a tube that leads to the bladder called the ureter
- this carries urine from the kidney to the bladder
- the urine travels through the bladder down the urathra

2.68b - osmoregulation

- osmoregulation - to control osmosis
- the cells in the body are surrounded by tissue - this is isotonic and means the same amount of fluid is passing through all cells and are maintaining their shape
- if the blood going into the tissue is highly concentrated then its hypertonic or vey dilute hypotonic tissue fluid
- this would cause either too much or too little fluid going into the tissue
- we want to keep it isotonic
- the kidneys controls the composition of the blood
- the kidneys remove excess water and salts, these are then excreted so it does not get into our blood stream

2.68a - excretion

- urea (nitrogen) come from amino acids, urea is toxic to us in excess - the role of the kidney is to get rid of it
- blood circulates to the liver, its then broken down into the molecule urea
- it re-enters into the blood stream and goes into the kidneys, these will then filter the urea form the blood
- water then goes into the urea to form urine, this drains down the ureters and goes into the bladder

2.67b - human organs of excretion

- in humans, the lungs, kidneys and skin are organs of excretion
- the waste that lungs excrete is carbon dioxide
- the kidneys excrete excess water, urea (from amino acids) and salts
- skin excretes water and salts (sweat) and some urea

2.67a - excrection in plants

- when photosynthesis occurs it gives off carbon dioxide and oxygen as waste products
- respiration is also a form of excretion in plants, and it gives off carbon dioxide and water

3.34 - causes of mutation

- mutations can be increased by ionising radiation like sunlight, x-rays or gamma rays
- they can also be increased chemically like tars in tobacco, this causes mutations to the base sequence which can result in cancers

3.33 - antibiotic resistance

3.32 - types of mutation

- new alleles which cause mutation can be beneficial, harmful or neutral
- beneficial alleles can improve the effect of an enzyme
- a harmful one would be a non-functional enzyme
- a neutral mutation may have no effect at all, or for years but then develop into a beneficial or harmful one due to environmental change

3.31 - evolution

- evolution is natural selection
- evolution: change form of organisms or change in frequency of alleles
- natural selection: mechanism of evolution, discovered by charles darwin
- for example, staphloccus aurus which is a lung and skin infection was susceptible to being killed by methecilline, this was called MSSA
- from random mutation one form could break down the methecilline and this was the resistant form called MRSA
- MRSA increases because the MSSA was being killed of because it was susceptible but the MRSA was resistant
- this is natural selection

3.30 - mutation

- mutation is rare in genetic material but can be inherited
- a change in the base sequence can result in a entirely different protein

3.29 - species variation

- variation = differences in phenotype
- variations of phenotype means they have different genotypes and live in a different environment
- there are different types of variation populations
1) all due to a variation genotype i.e. blood type
2) due to genotype and environment i.e. humans
3) environmental variation (no genotype) i.e. language

3.20b - pedigree 2

3.20a - pedigree diagrams

3.21b - genetic probabilities

3.21a - genetic probabilites

3.18b - genotype

- phenotype is controlled by the genotype
- genotype is a combination of 2 allels
- allel key - R = red  r = white

3.18a - phenotypes

- same species
- phenotype is what we can see i.e. red petal flower, white petal flower
- red petal x red petal = red petal
- white petal x white petal = white petal
- red petal x white petal = red petal
- red petal - dominant
- white petal - recessive

3.2 - fertitlisation

- fertilisation produces a zygot which turns into an embryo
- during meiosis the diploid number in a male and female will half (36)
- during sexual reproduction, these fuse together which then forms one cell - this is fertilisation and called a zygot
- the cell goes through mitosis, the cells divide all with a 2n diploid number (46) - this develops into an embryo

3.10 - menstrual cycle

- oestrogen and progesterone are both hormones
- endrocrine gland - hormones through the blood - target tissue (effect)
- ovary is the endrocrine gland for oestrogen
- in the first half of the cycle, the lining of the uturus becomes increasingly thick, this is the effect of oestrogen
- oestrogen flows through the blood to our brain which releases a second hormone called lutenising hormone
- at day 13, this will release an egg
- the folical which once held the egg now produces progestrone
- the progestrone then prevents the lining of the uturus from breaking down
- if the egg is not fertilised then this leds to the break down of the lining which causes menstrual periods

2.9b - female reproductive system

- ovary produces the eggs
- oviducts carry eggs to the uterus, and fertilization takes place
- uterus wall is a muscle

- lining of uterus developes the fertilized egg and turns into the embryo 

- cervix is the entrance to the uterus 

- uterus space is where the embryo developes 

- vagina collects sperm cells from the penis 

3.9a male reproduction system

- bladder stores urine
- testis produce sperm through meiosis
- epididymis is where the sperm is stored in the testis
- vas deferens is the tube which carries sperm cells to the penis
- prostate adds 20-30% of the semen
- seminal vesticals produce 70% of the semen
- urethra is the tube which connects the testis and SV, takes semen to the penis
- penis carries sperm into vagina

3.12 - amniotic fluid

- in the space of the embryo is the aminiotic fluid
- this fluid cannot be compressed and it absorbs pressure
- fluid causes floating because the childs bones cannot support them yet as they are not hard
- this means with any blows to the outside uterus it will prevent damage to the unborn child

2.24c - mitosis 3

- nucleus breaks down - prophase
- chromosomes become visable as 'pair of chromotids'
- protein molecules (spindle, spindle fibre) extend
- chromotids will move to the centre of the spindle
- metaphase - chromotids is attached to the spindle fibre by the centrimere - chromotids are in the middle
- anaphase - fibre shortens splitting the chromotids apart and halves the centrimere
- telophase - formation of 2 nuclei, opposite ends of the cell
- cytokinesis - cell splits into 2

3.24b - mitosis 2

- DNA replication - copying chromosomes
- held together by centralimere - 'pair of chromotids'
- interphase of cell cycle - DNA replication

3.24a - mitosis 1

- mitosis- cell division - growth
- diploid (number of chromosomes in nucleus)
- it will divide into 2
- each have a diploid nucleus which is identical
- indentical because: 1. same number of chromosomes 2. same set of chromosomes

3.16 DNA and genetic information

- sugar phosphate backbone
- in the middle has 4 bases: adenine, thymine, cytosine and guanine
- held together by A-T, C-G (the base pairs)
- the order of bases is always the same (ATGC)
- this all constructs protein for the cytoplasm

3.15 genes

- a gene is a section of a molecule of DNA
- a gene for every charateristic
- gene turns into protein
- protein controls the charateristic

3.14 chromosomes

- choromosomes - genetic information
- the DNA forms a shape called "the double helix"
- 1000's of genes in a chromosome
- genes produces a protein which produces a characteristic e.g blood
- different species have different numbers of chromosomes, humans have 46
- they work in homologous pairs
- same gene located in the same place in each homologus pair

3.1 sexual and asexual reproduction

- sexual reproduction
- two different genders (male/female)
- gametes - sperm (male) egg (female)
- fertilisation - fuse together
- broad differences - not identical

- asexual reproduction
- no sexes, gametes or fertilisation
- clones

why aren't all living things either sexual or asexual in reproduction?

4.9- carbon cycle

- photosythesis- reduces atmospheric CO2
- feeding- carbon is being passed along the food chain
- respiration- adds CO2 to the atmosphere, all organisms
- decomposion- death of all the organisms, broken down by bacteria and fungi and releases CO2
- combustion- fossil fuels release CO2 i.e industry, cars

4.14 enhanced greenhouse gases

- when gases increase in concentration
- the UV rays are increasingly re-emitted, warming the earth
- this is global warming
- this can lead to: melting ice caps, raising sea levels
- climate change happens

4.13 greenhouse gases

- burning of fossil fuels = CO2, NO2, SO2
- farming- cows emitt methane
- evaporation of water- clouds contribute to greenhouse effect
- canned sprays- CFC's break down the ozone layer

4.12 greenhouse effect

- UV light comes from the sun
- 50% of this is reflected
- UV light is is converted as infrared and absorbed
- infrared gets emitted back out
- greenhouse gases re-emitts and re-distributes infrared
- more greenhouse gases = more heat
- CFC's break down the ozone layer

4.11 gas pollution

- burning of fossil fuels results in sulphur dioxide gas
- this comes from factories and cars
- SO2 + H2O = sulphuric acid = acid rain
- acid rain can kill fish in the lakes and rivers
- carbon monoxide - fossil fuels are burned without oxygen
- blocks haemogloblin from carrying oxygen
- can lead to death

4.7- energy efficiency

- only 10% of energy is transferred to the primary consumer from the 100% energy producer
- only 1% of that makes it to the secondary consumer
- for example, there is 100kj of the producer, only 10kj come to the primary consumer
- energy is lost by the primary consumer through respiration and undigested material
- secondary consumers could only have 1kj - this is through respiration and much more undigested material of the animal that the secondary consumers eat
- all of these will eventually die and become decomposed

4.6- energy and substances in food chains

- producer converts light energy to chemical energy in the form of organic molecules - carbohydrates, proteins and lipids
- these are bonds which are
C-H
C-O
C-C
O-H
C-N
- these all represent energy (matter)
- this energy is passed through all consumers

4.5c- pyramids

- to quantify the number of consumers per tropic level, we use a pyramid of number
- for example, 1000 carrot plants, 100 carrot flys, 10 fly catchers and 1 sparrow hawk
- this can be turned into a diagram used to illustrate this
- it must be made clear how large the organism it represents is i.e. a tree. this is because you cannot start with a small amount of energy and end with a large amount
- another method is the pyramid of biomass bio= living, mass= amount (g/km)
- a pyramid of biomass is based on the amount of dry mass in a organism
- this method is difficult because everything must be dryed out first
- the third is the pyramid of energy transfer
- this cannot be inverted
- units of enery are used (joules, kilajoules)
- units of area (m) and units of time (s/mins)
- pyramid of number is the easiest pyramid to use because the pyramid of energy is very time consuming

4.5b- food webs

- food webs show organisms feeding at different tropic levels, unlike food chains which can't show more than 2
- orgaisms can have multiple preditors
- or feed on multiple prey, these two become linked

4.5a- food chains

- food chains link all the consumers together
- there is one organism per tropic level
- food chains show the flow of matter and energy

4.4- tropic levels

- tropic = feed
- producers are plants which photosynthesis
- herbivores eat the plants, this is the primary consumer
- carnivores eat the herbivores or any other animal, this is the secondary consumer
- a carnivore eating another carnivore is a top carnivore or a tertiary consumer
- when all of these die, these are broken down by decomposers
- decomposers = fungi and bacteria

4.3- quadrat samples

- the sample must be random (preventing bias)
- must be representative (large enough to get an accurate estimate)
- the field gets broken down into squares and numbered- then you need random numbers for the x and y coordinates
- ater the numbers are found, the organisms are then counted
- a good sample is about 10% of the actual area
- results get put in a table and you add the number of organisms and then divide by the number of quadrats

4.2- quadrats

- quadrats are used to count the population size of organisms

- quadrats are square grids made out of anything to lots of squares in the grid

- they are sampled in two areas so that both areas can be compared

obj 4.1- ecosystems

- a habitat is the abiotic factors of an ecosystem. This includes:
day and night
temperature
rainfall
humidity
geology
this describes everything which is non-biological

- a community is made up of populations of different species interacting together

- a population is the number of individuals of a particular species

-a species are organisms that reproduce

-an ecosystem is a community of organisms in a particular habitat
 

3.3b wind pollination

- the anther to the stigma is through air, carried by the wind
- light weight pollen grains are designed to float through the wind
- the anthers are exposed to the wind
- stigmas will have a large surface area- feather like structures to catch the pollen grains
- no colours, no scents, no nectories because there is no need to attract the insects

3.3a insect pollination

- the pollen gets transferred from the anther to the stigma
- pollen contains the male nuclei, this takes place by insects
- when one plant goes to another plant this is called cross pollination
- somethings that attract the insect to the flower are the colour of the petals and scents
- the value of the flower to the insect is the food and the pollen
- the anther and the filament form the stamen

photo of phototropism

2.55 rate of transpiration

- transpiration is the loss of water through the leaf causd by the evaporation which the water has to be changed from liquid to gas which diffuses through the stomatal pore
- if the concentration gradient of water has a big difference then it has a high rate of transpiration. if the difference is small then it would be a low rate of transpiration
- the factors that would cause a large difference would be- low humidity, high winds, high temperature and high light intensity. This will result in fast diffusion from inside to outside of the leaf
- the rate of transpiration depends on the factors of humidity, wind, temperature and light intensity

2.81 phototropism

http://www.youtube.com/watch?v=tE4XMg4Y_d4

- photptroism is the growth with light
- positive phototropism isthe growth towards the light
- when the stem is hit by light rays the stem will grow up
- if the light is lateral, then the stem tip will grow to its side, this is an example of positive phototropism
- auxin is a hormon which causes cell division and then causes the cell to grow up, when the light rays hit the stem it causes the auxin to move to one side (the side which the light does not hit) and therefore bending it because its only growing on one side 

2.80 geotropism

http://www.youtube.com/watch?v=76AWJiVJR1E

- geotropic is the gravity of growth response
- the roots of a seed grow down which is positive geotropism, the shoots of the seed grow up which is negative tropism
- if the seed is turned to its side then the roots will still grow positive tropism, and the shoots negative tropism

2.79 plants and stimuli

http://www.youtube.com/watch?v=GxFF7BaVyQI

- stimuli are changes in the environment- light or temperature
- receptors detect the stimuli and then turns it into a response
- responses often take the form of growth- this is called a tropism, tropism that involves light is called phototropism
- tropism that involves gravity is called geotropism
- the connection that involves the receptor to the response is called plant hormones

2.54 transpiration

http://www.youtube.com/watch?v=w0Y1llaghwc

- water turns from liquid to gas using heat from sunlight
- the evaporation is through the stomatal pores
- sunlight goes into the chloroplast for photosythesis, this will generate heat
- water is being delivered from the xylem, moves through the spongy layer
- just below the stomatal pore is where the liquid turns to gas
- water vapour diffuses into the outside atmostphere, which is a steep diffusion gradient 

2.53 root structure

- the branching pattern of roots increases the surface area which absoubtion
- the root hair is caused by the cell wall which is extended outwards
- there is an increase of surface area absorbtion of water
- the process of absorbtion: active transport of minerals from root
- plant takes up water
- water moves across coflex through the xylem
- this is the process of osmosis - dilute to concentrated