2013 HSC COURSE
HSC biology, physics, economics, english & four unit mathematics
HSC biology, physics, economics, english & four unit mathematics
Set of flashcards Details
| Flashcards | 417 |
|---|---|
| Language | English |
| Category | General Education |
| Level | Secondary School |
| Created / Updated | 10.04.2013 / 10.09.2024 |
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how an understanding of the source of variation in organisms has provided support for Darwin’s theory of evolution by natural selection
a basis of the theory of evolution is the variation that occurs among individual members of a species.
The basis of this variation is the change in genetic makeup of the individuals in a species.
It is this variation that selection acts upon
. Mutation of DNA provides a source of new variations thus supporting Darwin's theory of evolution
concept of punctuated equilibrium in evolution and how it differs from the gradual process proposed by Darwin
Punctuated equilibrium differs from Darwin's gradual evolution in that evolution is seen as long periods where there is little change in organisms, followed by a shorter period where there are rapid changes.
Evolution is a sudden process rather than slow gradual change.
The evidence for this comes from the fossil record where there are mass extinctions of organisms followed by the appearance of new species and the limited number of transitional fossils
Difficulties of defining health and disease
Disease is any condition that adversely affects the function of any part of a living thing.
Health is the wellbeing of the organism.
The definition of disease above is very broad.
Disease can cover a wide range of conditions that fit the above definition including minor conditions as well as the more obvious diseases.
Health varies on a daily basis and is not just the absence of disease.
Health varies with age and the susceptibility to disease. It is a state of physical, mental and social wellbeing.
it is possible for a person to be healthy and have a disease at the same time
the terms are used in general conversation and have different meaning to the scientific definition.
how the function of genes, mitosis, cell differentiation and specialisation assist in the maintenance of health
Genes are the units of inheritance. They control the process of protein synthesis. They assist the maintenance of health by regulating the cell cycle and limiting the growth and reproduction of cells.
Genes provide the code for proteins that are needed for growth and repair.
Enzymes, which control all body processes, are proteins and thus have been produced from the codes of genes.
Mitosis is cell division that produces identical cells. These cells are important for growth and reproduction. Each day millions of cells die and are replaced by the process of mitosis.
Cell differentiation is the process undergone by the cells that are formed after mitosis. Each cell has the genetic information necessary to produce all types of cells. However, each cell normally differentiates to become a specialised cell, with a specialised structure and function.
Many types of cells have specialised roles in maintaining the health of an organism. For example, there are specialised blood cells that produce antibodies to attack a disease causing micro-organism.
Links between gene expression and maintenance and repair of body tissue
Gene expression refers to the transfer of information from a gene to produce a protein or RNA.
e.g If you cut yourself, the genetic code contained in all your cells is used to form the new tissue to repair the damage from the cut.
Gene expression results in the maintaince and repair of body tissue
distinguish between infectious and non-infectious disease
An infectious disease is one that is caused by an organism and that can be transferred from one person to another. The transfer may be direct, where the disease-causing organisms, such as viruses or bacteria, pass directly from person to person, or it may be carried out by an intermediary (called a vector), such as a blood-sucking insect. Examples of infectious diseases are colds, influenza, chicken pox, herpes and measles. Non-infectious diseases are diseases that are not due to disease-causing organisms. They include genetic diseases, such as Down syndrome, haemophilia, and those that are related to lifestyle or environment, such as cardiovascular disease and skin cancer.
why cleanliness in food, water and personal hygiene practices assist in the control of disease
There are huge numbers of disease causing organisms.
Most of them are microscopic and can enter the body through any body opening.
The intake of food and water provide an easy way for micro-organisms to enter our bodies.
Therefore, minimising the number of such organisms in our food and water reduces the risk of infection.
Good personal hygiene ensures that body openings, including broken skin, are clean, so that the number of micro-organisms that might gain entry to our bodies is kept low.
Since we cannot see individual micro-organisms we take precautions that we know will help to protect us.
Examples of precautions include, washing hands after going to the toilet, cleaning wounds, boiling water and water treatment of water that doesn't come from a known safe source to make sure untreated sewage does not get into food or water supplies.
the conditions under which an organism is described as a pathogen
A pathogen is any organism that can produce a disease. Pathogens range from viruses so small that thousands will fit side by side in one millimetre to tapeworms that can be several metres long. They are all infectious. Pathogens may live outside the body, such as the fungus that causes ringworm, inside particular organs, such as parasitic worms in the intestine, in tissues or inside cells.
DNA hybridisation
biochemistry process in which the DNA of 2 species is compaired.
Heat is used to break the hydrogen bonds between strands of DNA
2 seperated strands of seperate animals are allowed to cool togethor, reforming hydrogen bonds between complementary base pairs
The greater the amount of bonding the more closely related genetically the two animals are
This is tested by the amount of heat required to break apart the combined strand.
Circulatory System
Composed of the pulmonary and systemic system
Pulmonary system goes from the heart to the lungs and back
Systemic system goes from the heart to the rest of the body and back
Passive transport in the kidneys
passive transport doesnt require energy. It is the movement of molecules across a concentration gradient
All water reabsorption in the kidneys by osmosis is passive
Crossing over
Occurs at prophase 1
genetic material is swapped between homologous chromosomes resulting in each chromatid being of different genetic make up
Divergent evolution / adaptive radiation
evolution in which species become less and less similar as a result of experiencing different selective pressures
e.g. Australian marsupials Koalas are herbivores, Womban burrowing herbivores, tassie devil carnivores evolved from a possum like ancestor
Independant assortment
Occurs at metaphase 1
Chromosomes line up at the equator with homologous chromosomes side by side.
However the order of the homologous chromosomes is random
Therefore the genetic makeup of the gametes is random as well
Preperation of a wet mount
1. take a thin sample
2. place on slide
3. add 2-3 drops of water using a pipette
4. lower cover slip at a 45 degree angle slowly
5. use tissue to wipe off excess water
Pulse Oximetry
non invasive method of measuring Hb saturation
a probe is connected to ear or finger
2 light waves with different wave lengths are sent. The light is partly absorbed by the Hb depending on the saturation of Hb.
Through the comparison of the amount of light that make it through from each the Hb saturation may be calculated
Can be used in recovery, response to medicine, asthma checking, sedation
Why Mendels experiments were not recognised
1. mendel was not a recognised scientist
2. presented work at a local insignificant science meeting
3. other scientists did not understand his work or its significance
4. no knowledge at the time about DNA or chromosomes
5. idea of dominant and recessive genes went against accepted idea of the blending of characteristics
