In Our Element
Which famous scientist discovered the electron?
Joseph Thompson
What are hormones? What system are they a part of?
A hormone is a chemical messenger secreted from glands and is a part of the endocrine system.
Define a dependent, independent and control variables.
Dependent Variables: The variable that is measured.
Independent Variable: The variable that is changed.
Controlled variables: The variable is kept the same.
Who proposed the pudding model of the atom?
Joseph Thomson
What some sources of sensory information that the nervous system may received about the internal or external environment?
The nervous system collects sensory information from the 5 senses: sight, sound, touch, smell, feel.
What is an isotope? Provide an example of an unstable isotope.
Isotopes are variations of elements with the same number of protons but different number of neutrons. An example of an isotope is Carbon-14.
Draw a labelled diagram of a neuron and identify the cell body, axons, myelin sheath, node of Ranvier and axon terminal.
Describe what it means to have a fair test.
A fair test refers to removing any experimental bias, for instance, by controlling all variables except for the independent variable. This enables the researchers to test what they are stating in the aim that they are testing.
What are noble gases and where are they found on the periodic table?
Noble gasses are Group 8 elements and are not reactive as they have a full outer shell.
What are the types of neurons and what are their functions?
Sensory: carry impulses from sense organs (eyes, ears, etc) to the spinal cord and brain
Motor: carry impulses from the brain and spinal cord to muscles and glands
Interneurons: connect sensory and moto neurons and carry impulses between them
Describe the difference between nuclear fission and nuclear fusion.
Nuclear fission is when the nucleus of one larger unstable isotope breaks down to form two small atomic nuclei.
Nuclear fusion is when two small nuclei fuse to form one larger nuclei.
Both involve the nuclear emissions.
Compare and contrast the function of the Central Nervous System and Peripheral Nervous System and describe their components.
CNS is the central nervous system which includes the brain and spinal cord. The brain receives and processes sensory information, initiates responses, stores memory’s and generates thoughts and emotions. The spinal cord coordinates the responses and conducts signals to and from the brain. Whilst the Peripheral Nervous System is further categorised into motor neurons and sensory neurons. Motor neurons relay impulses from the CNS to muscles and glands. Sensory neurons however relay impulses (messages) from the sensory organs to the CNS. Moreover, it also includes the somatic nervous system (controls voluntary movements) and the autonomic nervous system (controls involuntary responses). It also includes, sympathetic division (‘flight or fight’) and the parasympathetic division (‘rest or digest’).
Describe the 5 things that need to be included in a table AND a graph (each).
Graph:
- title
- axis title + units
- scale
- Plotting of AVERAGE results (if this has been provided/calculated)
- appropriate graph (line/column)
Table:
- Title
- Enclosed table
- Heading +Units
-Data included without units
-IV on left column, DV right columns
Describe the 3 different types of radioactive emissions and what could be used to stop them.
Alpha particles- Helium nucleus (+2 charge) can be stopped by a piece of paper (ionising)
Beta particles- an high speed electron electron (-1 charge) can be stopped by a layer of clothing or a few mm of aluminium foil. (ionising)
Gamma Radiation- electromagnetic radiation can be stopped by a few inches of lead or a several feet of concrete.
Provide an example of a gland, hormone produced target organ and effect on body.
What information can the group that an element belongs to tell us about it?
The group that an element belongs to tells us how many electrons are found in the outer (valence) shell. E.g. Group 1 elements all have 1 electron in the valence shell, Group 7 elements all have 7 electrons in the valence shell, etc. The group that an element belongs to also can show us how chemically reactive it is. E.g. Group 1 and Group 7 electrons are very reactive whereas Group 8 elements are not reactive at all.
Define a negative feedback loop and describe an example of how a negative feedback loop can bring homeostasis.
A negative feedback loop is a series of steps used to inhibit the change that moved one aspect of the body away from homeostasis.
E.g.
https://theponds-h.instructure.com/courses/10434/assignments/221026
Define reliability, validity and accuracy.
Reliability refers to the CONSISTENCY of results. The more data is collected the easier it will be to determine if results are consistent or not.
Validity refers to how well the experimental method address the aim of the experiment. This includes controlling variables, having a control group (if applicable), removing sources of experimental bias.
Accuracy refers to how close the results obtained are close to an agreed value. This can be affected by the errors in the system (e.g. calibration errors) and observational errors (e.g. reaction time) as well as the random errors (e.g. environmental factors).
Describe the arrangement of the periodic table and state the scientist who was responsible for the modern arrangement of the periodic table.
The periodic table is arranged so that the metals are on the left hand side of the periodic table, the non-metals are on the right hand side of the periodic table and the semi-metals are on the centre-right side of the periodic table. Elements are also arranged in increasing atomic number and into 18 groups (dependent on the number of valence electrons present). All elements on a particular period (row) all have the same number of electron shells.
Compare and contrast the Endocrine and Nervous System in terms of their function, organs involved, method of function and speed at which they perform their function.
The endocrine system regulates a bodily response to a stimulus using hormones, S=slow response, long-lasting. The nervous system also regulates a bodily response to a stimulus however uses electrical impulses to do this, therefore they are faster in their response and short lived. Major organs involved in the endocrine system are glands, hypothalamus, pituitary, thyroid, thymus, adrenal, pancreas, ovaries, and testes. (glands produce hormones). Main organs of the nervous system include: the brain, spinal cord, and the network of nerves that extend from the central nervous system to the extremes of the body.
Does reactivity increase or decrease down Group 1 and Group 7? Explain your answer.
The reactivity increases down Group 1 as the valence electrons are further away from the nucleus there is less electrostatic force pulling (which results in a lower electronegativity) them towards the nucleus therefore they are easy to lose.
The reactivity decreases down Group 7 as the valence electrons are further away from the nucleus (resulting in a decrease in electronegativity). This means that Fluorine is more reactive than Iodine.
Evaluate the effectiveness of the three lines of defence in achieving the aim of the immune system.
Purpose of immune system is to protect the body from pathogens that could cause disease.
First line of defence- to provide barriers to the entry of pathogens into the body. (GENERALISED RESPONSE)- Physical and chemical barriers- skin, stomach acid
Second line of defence- to eliminate as much of the pathogen as possible before it can reproduce (GENERALISED RESPONSE)- Phagocytosis
Third line of defence- to kill specific pathogens and gain immunity to a pathogen (SPECIFIC RESPONSE)- production of antibodies
How could you improve the accuracy, reliability and validity of an experiment?
Accuracy can be improved by including equipment that reduces/eliminates error from the observer (e.g. reaction time- use a camera to record experiment so that slow mo can be used to work out exact time measured), equipment (e.g. using a digital measuring scale instead of an analogue one).
Reliability can be better determined by replicating the experiment many times (100s times!)
Validity can be better determined by identifying whether aspects of the experimental method deviated from the aim of the experiment (e.g. was there a variable that wasn't controlled that might impact on the results obtained?)
Write the equation for the following two nuclear decay reactions:
(1) Alpha decay of Uranium-233 (Z=92)
(2) Beta decay of Thorium-234 (Z=90)
Describe the different ways in which infectious diseases can be transmitted.
Describe how vaccinations work.