paper 2 Flashcards
what is the main function of insulin?
to help the liver convert glucose to glycogen
what is the primary and secondary mechanism by which an IUD prevents pregnancy?
primary- preventing the implementation of the egg in the uterus
secondary- preventing fertilisation by making the uterus a hostile environment for the sperm
why is ecology important?
helps us protect and conserve our natural world for future generations
what is ecology?
the study of how living organisms interact with each other and their environment
what is each monomer of the polymer DNA called?
nucleotide
what are the 3 parts of a nucleotide?
a phosphate
a sugar
base
are all the bases in a nucleotide the same in a strand of DNA?
no but the phosphates and sugars are
what are the 4 different bases found in DNA?
A- adenine
T- thymine
C- cytosine
G- guanine
how do 2 nucleotides bond?
the phosphate of one nucleotide bonds to the sugar of the nucleotide next to it and this process repeats so the sugar and phosphates form one big chain (polymer of monomers)
what is a long chain of sugar and phosphates that are connected called?
a sugar-phosphate back bone
what is the structural function of the bases in DNA?
to hold the 2 strands of phosphate and sugar chain’s together
what are the pairs of bases in DNA? what is this pattern/ rule called?
A and T
C and G
complementary base pairing
what is a gene?
a portion of DNA that codes for a specific protein
what is a triplet in terms of DNA?
a sequence of 3 bases that codes for a specific amino acid
how is a protein formed by DNA?
each triplet code forms a specific amino acid
these amino acids join and then fold into a specific shape by itself and form a protein
what are the main uses of protein in the body?
enzymes
structural protein
hormones
why do proteins have unique shapes and what does this allow?
they are each made from different sequences of amino acids and this allows for them to carry out a particular function
what part of the brain controls muscle coordination?
cerebellum
what part of the brain is responsible for making decisions?
cerebral cortex
how should a person eye adjust to form clear image of a near object?
-ciliary muscles contract
-which means they have a smaller diameter
- so suspensory ligaments relax
- causing the lenses thickens and become more curved so its more convergent
- and light rays can focus on the retina
why does a person with hyperopia have difficulty seeing near objects?
their lens is to thin so light focuses behind the retina so the image is not clear
what is an example of a receptor?
light receptors in the eye
what is a synapse?
a junction between 2 neurons
give an example of a sense organ involved in a reflex?
skin
do synapse speed ip or slow down the transmission of impulses?
slow down
what happened when ciliary muscles contract?
they have a smaller diameter which means suspensory ligaments loosen
how does the lenses change when the eye is focusing on a nearer object?
thickens and become more rounded so it is more convergent
why can long-sighted people no see near objects
their lenses cannot be thickened enough so the light is focused behind the retina
how can long-sightedness be correlated?
convex lenses which refract light rays inwards more this focus the rays of light onto the retina
what are the 2 parts of the nervous system?
the central nervous system (brain and spinal cord)
peripheral nervous system (all the other nervous)
what is the chemical that diffuses between 2 neurons called?
neuron transmitter
describe the reflex arc?
receptors in the sense organ detects the stimulus and send electrical impulses along sensory neurons. At the end of the sensory neuron. There is a synapse where a chemical call a neurotransmitter is released and this diffuses across the sensory neuron to a relay neuron in the central nervous system, this chemical triggers electrical impulse in the relay neurone that then travels across along until it reaches another synapse which will then release a neurotransmitter that diffuses across to a motor neuron. The neurotransmitter triggers electrical impulses to travel across it to the effect of where response is carried out.
what is the white surface that covers the eye called?
the sclera
what are the different cells found in the retina and what do they do?
rod cells- detect light intensity
cone cells- sensitive to red,green,blue wavelengths of light,provide colour information
what is myopia and hyperopia?
myopia- short sightedness
hyperopia- long sightedness
what type of treatments are available for site issues?
glasses,contact lenses or laser eye surgery
what is Thermoregulation?how does it work?
how the body regulates its internal temperature it does this by the brain, detecting blood temperature, and then sending nervous and hormonal signals to effectors
How does the body responds when its internal temperature is too high?
sweat glands produce water, which evaporates taking away, heat, and blood vessels dilate, which is known as vasodilation this increase blood flow to the skin to increase the rate of heat loss
How does the body respond when its internal temperature is too low?
blood vessels contract which is called VSO restriction this reduces the rate of heat loss and you shiver which causes muscles to produce more heat. 
What is the endocrine system?
A system of glands that secrete hormones to send signals to affecters
these hormones are transport around the body via the blood
Is the nervous or endocrine system faster?
nervous is faster
What are the six glands involved in the endocrine system and what did they do?
thyroid-controls growth and metabolism
Pituitary gland - send signals to other glands
Pancreas - secretes insulin
Ovaries - releases, eggs, and secretes hormones involved in reproduction
Testes -produce sperm
Adrenal- adrenaline for fight or flight
How does the pancreas respond to high blood glucose levels?
The pancreas secretes insulin
Causes glucose to move from the bloodstream into cells to be used for respiration
Excess glucose is converted into glycogen as energy stores in the liver
how does the pancreas respond to low blood glucose levels?
Pancreas secretes glycagon
Causes the liver and muscles to convert glycogen back into glucose
this is an example of negative feedback
how does the body dispose of excess water?
it’s removed from the blood by the kidneys to the bladder, where it’s mixed with urea to make urin
What is urea?
A toxic substance that contains ammonia thats from amino acids obtained from excess proteins broken down by the liver
why is the function of the kidneys important?
if there was too much water in the blood, then too much wood, water would move into cells by osmosis, and causing to be turgid, which are causing to burst also
too little water may cause the cells to become flaccid, and water was moved out by osmosis
what did kidneys filter out?
glucose,mineral ions and urea and wayer
what is negative feedback?
response to change something so that he returns to normal conditions
what hormone is sent to the kidneys from the pituitary gland to help stabilise water levels?
ADH- anti diuretic hormone
True or false more, ADH is produced when water levels are too high 
false, when water levels are too high, less ADH is made some more water is sent to the bladder to leave the body as urine.
What treatment is required, and why if the kidneys don’t work properly
diocese is needed otherwise urea another mineral ions would build up and poison you