Urine

2.75 Recall that urine contain water, urea and salts.

Urine contains salt and water and urea.

Salt and water affects the concentration of the tissue fluid.
Which is called Osmoregulation.

The removal of the urea is part of the process of the excretion of metabolic waste.

The excretion of salt, water and urea, varies and depends on the condition of which a person is working.

ADH

Describe the role of ADH in regulating the water content of the blood.

Anti Diuretic hormone is produced in a region of the brain know as the hypothalamus. Like all hormones in flow through the blood stream and it's target is the kidney.

It controls and alters the quantity of water in blood. So ADH has the ability to make the blood more or less concentrated.

ADH targets the collecting duct. It allows more water to come out of the collecting duct. It makes the collecting duct more porous.  the consequence is that the urine becomes more concentrated.

Glucose reabsorption

2.73 understand that selective re-absorption of glucose at the proximal convoluted tubule.

The same process for water, happens for glucose.
Except Urine does/should not contain glucose

If glucose is tested positive in Urine, this is a condition called Diabetes.

This is because in the proximal convoluted tubual, glucose is removed and is taken back into blood.

2.72 Water re-absorption

2.72 Understand that water is reabsorbed into the blood from the collecting duct.

When ultrafiltration occurs it tends to filter out more water and as the filtrate passes along the tubule, when i reaches the collecting duct, water is removed from the filtrate and returned back to blood vessels (blood stream)

The water is selected and it's been re-absorbed.

this is selective re-absorption of water. This occurs in the collecting duct.

Ultrfiltration

2.71 Describe ultrafiltration in the browmam's capsule and the composition of the glomerular filtrate.

Nephron - filtration of blood
results in filtered blood and urine

Urine is composed largely of water, salts and urea (n)

Ultrafiltration = the filtration of molecules

in the bowman's capsule, blood comes in through the afferent arteriole (wide) at high pressure, and leaves through the efferent arteriole (Narrow). This process develops a high pressure in the glomerulous.

The high pressure of blood forces the liquid (Plasma, contents dissolved in blood) out of the blood vessel, into the bowman's capsule, plasma turns into glomerula filtrate (H2O, Salts, A.A., Glucose and urea)

Nephron Structure

2.70 describe the structure of a nephron, to include Bowman's capsule and glomerulus, convoluted tubules, loop of Henle and collecting duct.

The outer lighter colored region is known as the cortex.

The darker inner region is the medulla.

In the middle, there is a space called the pelvic region. this is where the urine collects and drains down the ureter.

The different colours are cause by the millions of tubular structures in the kidney.

The tube starts on the edge of the medulla and moves directly upwards and out into the cortex. It then winds before dipping down into the medulla and then back up and then another short twisted section before hitting a dead end.

The "dead end" is called the bowman's capsule.

The tubular structure is known as the Nephron.

The tube is made up of twisted sections known as the convoluted tubules. The tube going through the cortex and medulla is known as the collecting duct.

The loop knot of blood vessels is known as the Glomerulous.

The first twisted section is know as the proximal (DCT)

There are millions of these Nephrons in a single kidney.

Urinary system

2.69 Describe the structure of the urinary system, including the kidneys, ureters, bladder and urethra.

The urinary system has two kidneys (right and left)
each has it's own separate blood supply.

They carry out the process of excretion, filtration and osmoregulation.

Each kidney has a ureter which leads to the bladder (carries urine).

There is a common bladder or simply 1 bladder for both ureters

Then then urine is conducted to the outside of the body to be excreted down the urethra which travels down through the vagina or penis.

Osmoregulation

2.68b Understand how the kidney carries out it's role of osmoregulation. 

Osmo referring to osmosis
Regulation referring to control

The tissue fluid which surrounds the cells in our body must be isotonic whith the cytoplasm of these cells. This means that the amount of water going into and out of these cells is equal and the cells will remain the same size, shape and maintain their function.

The danger to the tissue is that blood curculating into the tissue, would be concentrated causing a hypertonic (remove too much water) tissue fluid or very dilute cause a Hypotonic(add too much water) tissue fluid.

To maintain an isotonic, the composition of blood must be controlled.
Blood forms the tissue fluid.

The role of the kidney, is to control the composition of our blood.
Excess water and salts can be removed and excreted down through the ureter.

By controlling the content of water and salts in the blood, the kidney keeps the blood and therefore tissue fluid isotonic with the cell cytoplasm which maintains the function of the cells.

Excretion

2.68a Understand how the kidney carries out it's roles of excretion and osmoregulation.

Note: Urea contains Nitrogen, which is toxic in the body and cannot be stored.

The original form of Nitrogen and potentially toxic to the body are amino acids (normally used for growth). When they are in excess, they are toxic and must be removed.
This is the role of both the liver and the kidneys.

Stage 1: blood circulates to the liver and the amino acids are broken down and converted into the molecule we call Urea, which then circulates to both kidneys.

Stage 2: The kidneys will filter the urea from the blood and the urea will be added to water to form urine which drains down the ureters and collects in the bladder

Stage 3: the Urea is now removed from the body as Urine (through the bladder)

Stage 4: The filtered blood returns to the circulation in the veins with the toxic amino acids removed.

Excretion in plants and Humans

2.67a Recall the origin of carbon dioxide and oxygen as waste products of metabolism and their loss from the stomata of a leaf.

1. Photosynthesis = Co2 + H2O ---> C6H12O6 + O2 (the oxygen is an example of excretion


2. Respiration = C6H12O6 + O2 ---> ATP + CO2 + H2O (The carbon dioxide is given off by the plant as a waste. Another form of excretion).

2.67b Recall that the lungs, kidneys and skin are organs of excretion

1. The lungs excrete Carbon dioxide waste from respiration.

2.The kidneys excrete excess water, Urea (Nitrogen waste from amino acids) and Salts


3. The Skins excretes water and salts (Sweating) and a little bit of Urea (Not much)

The Excretion comes out through the sweat gland

Causes of mutation

Antibiotic resistance

Types of Mutation

Mutation

Species variation

Pedigree diagrams

3.20a Understand how to interpret family pedigrees

3.20b

Genetic probabilities

3.21b Predict the probabilities of outcomes from mono hybrid crosses

F1 cross.

Between an F1 offspring crossed with an F1 offspring.

The parent phenotype is a red petal crossed with a red petal and the parent genotype is Rr x Rr the heterozygotes.

meiosis: The alleles need to be separated one into each type of gamete.
Half of the pollen grains would be R and the other half would be r.

Genotype offspring: RR : 2Rr : rr

These are probabilitties or chances not numbers.

Phenotype ratio (F2)   Red : Red : White

       3:1 ratio    75% red and 25% white.

These are just chances.

Genetic Probabilities

3.21a predict probabilities of outcomes from monohybrid crosses.

Monohybrid means 1 gene and so 2 alleles.

Parents:                              red              x             White petal
Genotype:                          RR              x              rr                        (R>r)
Meiosis: The gamete will contains only 1 of the 2 alleles. It has an equal chance.
1/2R and 1/2R   with     1/2r and 1/2 r

Random fertilization: eg



The genotype of the offspring is Rr

This means that the phenotype offspring is all RED.(100%)

Codiminance

3.18c recall the meaning of the terms: dominant, recessive, homozygous, heterozygous, phenotype, genotype and codominance

Fertilization

3.2  Understand that fertilization involves the fusion of a male and female gamete to produce a zygote that undergoes cell division and develops into an embryo.

The process begins with the adult male (cell in testis)    +     Adult female (cell in ovary)

These cells have a complete set of chromosomes. This is called being diploid (2n)
For humans it's 46.

These cells divide in the testis to produce a half sets (Gametes). These are know as the sperm cells the the adult male.
This process of cell division is called meiosis.

We got from a diploid to a haploid number (n). This is a half set.
This would be 23 for humans.

In sexual reproduction these cells are brought together and they are joined or fused together, and from a single cell. This is known as fertilization. Combining two half sets of chromosomes to form a full set of chromosomes. eg. 23 + 23 = 46.

This cell is known as a zygote. This is a new cell which is a combination of the male and female chromosomes.

After this mitosis occurs in which the cells will divide.

Female reproductive system

P1 x P1 Cross (b)

P1 x P1 Cross

Genotypes

Phenotypes

3.18 recall the meaning of the terms: Dominant, recessive, Homozygous, Heterozygous, phenotype, genotype and codominance.

Male reproductive system

3.9 a recall the structure and function of the male reproductive system.

Bladder - To store Urine
testis - carry out the process of meiosis that produces the gametes called the sperm cells.
Epididymis - Store sperm cells.
Vas Deferens - pushes the sperm cells to penis
prostate - adds about 20/30% of semen sugars and is also alkali.
Seminal Vesicles - 70% of semen "                                           "
Urethra - Common tube which joins the left and right testis and vas defrence. It is also the exit of urine.
Penis - Carry sperm cells into the vagina.

Amniotic Fluid

3.12 Understand how the developing embryo is protected by amniotic fluid fluid.

Amniotic fluid: The fluid surrounding a fetus within the amnion.
Amnion: The innermost membrane that encloses the embryo of a mammal, bird, or reptile.


One of the functions of the amniotic fluid is that it can protect the developing embryo. The fluid which is largely water cannot be compressed. When we try to squeeze it, ti absorbs the pressure. 

The Placenta

3.11 describe the role of the placenta in the nutrition of the developing embryo.



First of all,. a placenta is a flattened circular organ in the uterus of pregnant eutherian mammals, nourishing and maintaining the fetus through the umbilical cord.


When a child is still in the uterus, it is a water filled environment (amniotic fluids). At that time a child cannot digest or breath and is unable to carry out excretion.


How does the child net nutrition?


It has the placental structure growing out of the developing embryo. It does not grow out of the mother.
Also, the blood vessels inside the placenta are the CHILD's blood vessels. 


Things like glucose, fats and amino acids would travel through the mothers blood stream and into the wall of the uterus. These nutrients will then cross into the child's blood at the placenta.


The placenta has a large surface area and the barrier is very thin.
The child also produces molecules that are sent back into the maternal blood (e.g. CO2 and urea).

Mitosis

3.24 a. Understand that the division of a diploid cell by mitosis produces two cells which contain identical sets of chromosomes.

Remember that mitosis is a form of cell division which results in growth. And that growth occurs by an increase in the number of cells.

The number of chromosomes in the nucleus is called the diploid number (2n)
For humans 2n = 46, for cats 2n = 38.

In the process of mitosis, the cell will divide into two cells both with a nucleus each. Inside the nucleus we find that each cell has a diploid nucleus. These cells are identical. Sometimes called daughter cell.

They have the same number of chromosomes and they have the same set of chromosomes.



3.24 b. Understand that the division of a diploid cell by mitosis produces cells which contain identical sets of chromosomes.

The initial cell has to copy the chromosomes it has. Copying the chromosomes is a process called DNA replication. In this process each chromosome undergoes a copying process to form an identical copy of itself.

With all the same gene and alleles and these two copies are held together by a structue arround the center region known as the centro-mere (Holding the two chromosomes together).

We refer to these cells as a pair of Chromatids.

during this process the nucleus is still intact. Which means you cannot see this process happening.

This is known as the Interphase of the cell cycle.

3.24 c.

DNA replication occurs during the Interphase

First sing that a cell is entering the process of mitosis, is when we see the break down of the nuclear membrane. The nucleus breaks down.

This is a phase known as the pro phase. When it breaks down, the chromosomes become visible.

With the nucleus gone, inside the cell a network of protein molecules known as the spindle, and the spindle fibers, and these extend from one pole of the cell to the other.
What occurs during late prophase, is that the chromosome pair will move toward the spindle and join one of them at the Centromere.

Next we have the Metaphase. During which the chromosomes are in the middle arranged along the equator of the cell.

Then we have the Anaphase. In the Anaphase the fiber shortens pulling the two Chromatids appart.
Here we have the separation of the pair.

The end of mitosis is at the stage of Tilophase. When the nucleus begins to reform around the chromosomes at either end of the cell. this will be the new nucleus of the new cell.



A phase know as cytokinesis where the cell splits into two (this isn't regarded as part of mitosis)

DNA and genetic information

3.16 Describe a DNA molecule as two strands coiled to form a double helix, the strands being linked by a series of paired bases: adenine (A) with Thvmine (T), and Cvtosine (C) with guanine (G).

Chromosomes are likely to contain thousands of genes.

At the gene loci you find a double helix.
They appear to be parallel.


These bases are holding together these two helix.

They are held together by pairing A - T and C - G.
These are known as the base pairs. This is always found in the DNA.

The order of molecules: A-C-T-G-A-A-C-C-A-G is what we call a gene.
The order of the basses ATGC and the number of the bases.

Genes

3.15 Understand that a gene is a section of a molecule of DNA

DNA molecule Example

This is showing the double helix shape characteristic.

This gene caries the information that forms that characteristic of the organisms. This could be a blood group, or even an eye color.

They are located in the nucleus. And the information is passed to the cytoplasm the genetic information is transformed into a protein which controls the production of the characteristic.

Chromosomes

3.14 Recall that the nucleus of a cell contains chromosomes on which genes are located.

Chromosomes= Genetic information of the cell.
If you opened a nucleus up you would find chromosomes

It is composed of a molecule called DNA (Deoxyribo nucleic acid) which forms a shape known as the double helix.


Sections of this molecule are called genes. And one chromosome will have many genes (possibly thousands)
Each gene contains the information for the construction of a protein. The protein gives the characteristic associated with the genes (e.g. blood group).


Different organisms have different number of chromosomes.
Cat 38, Chicken 78, Chimp 42 and human 46.


Chromosomes are known to operate in pares known as homologous pairs. 
 
If you go to the same loci on the homologous pair you'll find the same gene.


So there are 2 versions of each gene for 1 characteristic.
These versions are called Alleles.

Sexual and Asexual reproduction

3.1 Describe the differences between sexual and asexual reproduction

Organisms that show sexual reproduction show sexes which helps us identify a male and a female.
In Asexual reproduction there are NO sexes.



Sexually reproducing organisms produce cells called Gametes, which tend to form in the Male (Sperm cell) and in the female (egg cell)
Asexually reproducing organisms, don't have Gametes.

The type of cell division that produces Gametes is called meiosis which has a number of effects. One of these effects is to half the total adult number of chromosomes in the Gamete cell. In Humans the total number of chromosomes is 46 per cell but in gametes the total is 23. Going from 46 down to 23 during reproduction is the process of meiosis
In Asexual producing populations there is no meiosis but there is mitosis in ucariotic (how do you spell?) cells and binary fissim procariotic (How do you spell?) bacterial cells. In this process the number of chromosomes is maintained constant (eg. a cell with 20 chromosomes is divided into two cells which 20 chromosomes. These 2 cells are identical.

In sexually reproducing population you find the process of fertilization. In which gamete cells fuse together (Male and female)
In asexual reproduction there is no fusing and no fertilization.


In the population of sexual reproducing organisms you find variation (differences). It is broad.
In asexual reproducing population, there is a very small variation in the population which is mainly because of mutation. Otherwise they are identical. This is known as a clone.

The Carbon Cycle

4.9 Describe the stages in the carbon cycle, including respiration, photosynthesis, decomposition  and combustion.

1. Photosynthesis:  CO2 and H2O are combined using chlorophyll and that light energy is trapped and used to form organic molecules such as glucose. Here the carbon is coming from the atmosphere. Photosynthesis is responsible for reducing the atmospheric CO2.

2.Feeding: We can look at the food chain and how carbon passes through the different trophic levels. So here the consumer takes in the carbon from the producer (Above) and uses this to reconstitute it's own body material and grows. and so on and the carbon passes through the food chain.

3. Respiration: C6H12 + O2 ----> Energy + CO2 + H2O   Adds CO2 through the atmosphere.

4. Decomposition: All the organisms eventually will die and their organic molecules that remain are broken down by the decomposers (bacteria and fungi) which will result in the release of the CO2 in the atmosphere

NOT COMPLETED.

Source: http://frazerbiology.blogspot.com/2011/06/414-enhanced-greenhouse-effect.html

Source: http://frazerbiology.blogspot.com/2011/06/414-enhanced-greenhouse-effect.html

4.14 The Enhanced Greenhouse effect.

4.14 understand how an increase in greenhouse gases results in an enhanced greenhouse effect and 

that this may lead to global warming and its consequences.

Pollution of Carbon dioxide, Methane and Water vapour (all greenhouse gases)
if the concentration of these increase in the atmosphere the Infra-red light will be re-emited backwaards towards the surface of earth, rather than escaping back into deep space. This will raise the average global temperature which is referred to as Global warming/

Consequences?
The Melting of Icecaps.... raised sea levels... changing ocean currents and winds
Ultimately ... Climate change.
this will result in the worlds Biome distribution changing... Deserts expanding etc.

Source: http://frazerbiology.blogspot.com/2011/06/413-greenhouse-gases.html

Source: http://frazerbiology.blogspot.com/2011/06/413-greenhouse-gases.html

4.13 Greenhouse gases

4.13 understand how human activities contribute to greenhouse gases.

The burning of fossil fuels results in more Carbon dioxide, and Nitrous oxide in the atmosphere which are greenhouse gases.

Farming cows causes a significant contribution of Methane from their digestion of crops (9% of the atmospheric gases)

Evapouration of water to form water vapour... Clouds are a significant contributor

Refrigeration/Solvents (CFC's) are associated with the absorption of UV light, and the breakdown of the Ozone layer

The Green House effect

Source: http://frazerbiology.blogspot.com/2011/06/412-greenhouse-effect.html

4.12 recall that water vapour, carbon dioxide, nitrous oxide, methane and CFC's are greenhouse gases

This diagram explains the effect very well:

(a) is the UV light from the sun (short wavelength with high energy) 

(b) + (h) show that 50% is reflected back out into deep space (by things like clouds)

(c) represents absorption on the earth's surface, where the UV light is converted into Infra-red 
(d) shows the Infra-red (longer wavelength) being emitted back out
(e) some of this is lost out to space as heat
(f) shows the greenhouse gases (water vapour, CO₂, CH₄, etc.)

(g) The I.R. light hits the greenhouse gas and absorbs it, but then re-emits it but re-distributes it, with some of the I.R. heading back to earth

The Hypothesis of The Enhanced Greenhouse effect is that if we emit more Carbon dioxide and Methane they will absorb more of the escaping infra-red radiation and emit it back to earth, raising the temperature higher. and eventually causing Climate change.

CFC's (chlorofluorocarbon's)

 have an effect on the ozone layer (O₃)

CCl₃F à sunlight à CL₂F^- + CL^-
CL^- catalyses the breakdown of O₃ to O₂, O₃ is better at absorbing UV light than O₂ so we are basically removing the protection.

Source: http://frazerbiology.blogspot.com/2011/06/412-greenhouse-effect.html

Gas Pollution

4.11 Understand the biological consequences of pollution of air by sulphur dioxide and by carbon monoxide.


Sulphur Dioxide. (SO2)
Comes from the combustion of fossil fuels, and combustion of petrols in vehicles.
In the atmosphere Sulphur dioxide combines with water vapour in clouds and forms Sulphuric Acid! this is what is known as acid rain,

SO2 + H2O = H2SO4

acid rain has many effects on plants and animals:

Trees and plants are often "burned" by the sulphuric acid
Sulphuric acid in the soil causes Calcium and Magnesium Ions to become leached* out of the soil, so the plant can't grow.
Acid rain in lakes reduces the pH to make them acidic, this causes a release of Aluminium Ions, which causes a thickening of the mucus that lines the gills, and reduces the ability to take Oxygen from water (the fish suffocates)
Leach - Make (a soluble chemical or mineral) drain away from soil, ash, or similar material by the action of percolating liquid, esp. rainwater
- the nutrient is quickly leached away

Carbon Monoxide (CO)
Fossil fuels i.e. Coal/gas are burned with insufficient (not enough) Oxygen
Carbon monoxide combines with Haemoglobin inside red blood cells and forms Carbaminohaemoglobin which blocks the haemoglobin from carrying Oxygen, therefore reducing Oxygen circulation and too much can be fatal.

Source: http://frazerbiology.blogspot.com/2011/06/411-gas-pollution.html

Energy efficiency

4.7 Explain why only about 10% of energy is transfered from one trophic level to the next

Only 10 % of the energy from one consumer moves on to the next.

What causes this?

This is because the consumer will lose energy due to respiration.

The consumer might not be able to digest all of the 100% of energy.

Energy and substances in food chains

4.6 Understand the transfer of substances and of energy along a food chain.

Producer turns light energy into chemical energy.
The chemical energy takes the form of organic molecules Including
Carbohydrates
Proteins
Lipids

These molecules (food) are composed of                    Carbon to Hydrogen bonds
                                                                                  Carbon to Oxygen bonds
                                                                                  Carbon to Carbon bonds
                                                                                  Oxygen to hydrogen bonds
                                                                                  Carbon to nitrogen
These bonds represent energy.
But Carbon, Hydrogen, Oxygen and nitrate are substances/Matter.

So as the primary consumer consumes the producer, it begins to form these substances and contain the energy which was fixed from sunlight now in the form of chemical energy.

The Primary consumer consumes this for growth, respiration and life processes.
In turn the secondary consumer consumes the primary consumer which passes on the same molecules, reorganising them into Cheetah form and so on.
The substances and energy is passed on.

Food Chains and Food Webs

4.5 a) Understand the concepts of food chains.

The food chain links the producer to the primary consumer to the secondary consumer and finally to the tertiary consumer

There is 1 organism per trophic level

Notice: in a food chain you cannot show an organism which is omnivore or an organism that's feeding 2 or more trophic levels.

Food chains show the flow of matter and the flow of energy.




b) Understand the concepts of food webs

Food webs allow us to provide a better description of the ecosystem.

The interaction the food web describes is feeding.

It allows us to show the organisms that are feeding at different trophic levels.

Feeding at different trophic levels has a number of consequences.
1. organisms can have multiple predators.
2. Feeding on multiple prey.
3. Food chain being linked