paper 2 Flashcards
1
Q
what is the main function of insulin?
A
to help the liver convert glucose to glycogen
2
Q
what is the primary and secondary mechanism by which an IUD prevents pregnancy?
A
primary- preventing the implementation of the egg in the uterus
secondary- preventing fertilisation by making the uterus a hostile environment for the sperm
3
Q
why is ecology important?
A
helps us protect and conserve our natural world for future generations
4
Q
what is ecology?
A
the study of how living organisms interact with each other and their environment
5
Q
what is each monomer of the polymer DNA called?
A
nucleotide
6
Q
what are the 3 parts of a nucleotide?
A
a phosphate
a sugar
base
7
Q
are all the bases in a nucleotide the same in a strand of DNA?
A
no but the phosphates and sugars are
8
Q
what are the 4 different bases found in DNA?
A
A- adenine
T- thymine
C- cytosine
G- guanine
9
Q
how do 2 nucleotides bond?
A
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)
10
Q
what is a long chain of sugar and phosphates that are connected called?
A
a sugar-phosphate back bone
11
Q
what is the structural function of the bases in DNA?
A
to hold the 2 strands of phosphate and sugar chain’s together
12
Q
what are the pairs of bases in DNA? what is this pattern/ rule called?
A
A and T
C and G
complementary base pairing
13
Q
what is a gene?
A
a portion of DNA that codes for a specific protein
14
Q
what is a triplet in terms of DNA?
A
a sequence of 3 bases that codes for a specific amino acid
15
Q
how is a protein formed by DNA?
A
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
16
Q
what are the main uses of protein in the body?
A
enzymes
structural protein
hormones
17
Q
why do proteins have unique shapes and what does this allow?
A
they are each made from different sequences of amino acids and this allows for them to carry out a particular function
18
Q
what part of the brain controls muscle coordination?
A
cerebellum
19
Q
what part of the brain is responsible for making decisions?
A
cerebral cortex
20
Q
how should a person eye adjust to form clear image of a near object?
A
-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
21
Q
why does a person with hyperopia have difficulty seeing near objects?
A
their lens is to thin so light focuses behind the retina so the image is not clear
22
Q
what is an example of a receptor?
A
light receptors in the eye
23
Q
what is a synapse?
A
a junction between 2 neurons
24
Q
give an example of a sense organ involved in a reflex?
A
skin
25
do synapse speed ip or slow down the transmission of impulses?
slow down
26
what happened when ciliary muscles contract?
they have a smaller diameter which means suspensory ligaments loosen
27
how does the lenses change when the eye is focusing on a nearer object?
thickens and become more rounded so it is more convergent
28
why can long-sighted people no see near objects
their lenses cannot be thickened enough so the light is focused behind the retina
29
how can long-sightedness be correlated?
convex lenses which refract light rays inwards more this focus the rays of light onto the retina
30
what are the 2 parts of the nervous system?
the central nervous system (brain and spinal cord)
peripheral nervous system (all the other nervous)
31
what is the chemical that diffuses between 2 neurons called?
neuron transmitter
32
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.
33
what is the white surface that covers the eye called?
the sclera
34
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
35
what is myopia and hyperopia?
myopia- short sightedness
hyperopia- long sightedness
36
what type of treatments are available for site issues?
glasses,contact lenses or laser eye surgery
37
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
38
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
39
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. 
40
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
41
Is the nervous or endocrine system faster?
nervous is faster
42
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
43
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
44
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
45
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
46
What is urea?
A toxic substance that contains ammonia thats from amino acids obtained from excess proteins broken down by the liver
47
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
48
what did kidneys filter out?
glucose,mineral ions and urea and wayer
49
what is negative feedback?
response to change something so that he returns to normal conditions
50
what hormone is sent to the kidneys from the pituitary gland to help stabilise water levels?
ADH- anti diuretic hormone
51
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.
52
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
53
what female hormones are involved in a mental cycle?
FSH
oestrogen
LH
Progesterone
54
describe the menstrual cycle in terms of the hormones and their functions?
The pituitary gland secretes FSH, which stimulates a follicle to develop in the ovaries. as this follicle develops, it begins to secrete oestrogen, the oestrogen inhibits the production of FSH from the pituitary gland and causes the lining of the uterus to develop and repair. As the level of oestrogen increases. It triggers the pituitary gland to release the hormone, LH LH triggers ovulation, which causes the egg to be released from the ovaries, and turns the follicle into the corpus luteum. The corpus luteum, then secretes, progesterone, and oestrogen and inhibits any production of LH and FSH from the pituitary gland. If the egg does not become fertilised then the corpus luteum dies, and progesterone levels drop which causes menstruation.
55
what are examples of non hormonal contraceptives?
Avoiding sex /family, planning
A vasectomy or having your tubes tied
condom
diaphragm- stop sperm entering the vagina
56
example of hormonal contraception
-FSH inhabiting pill- no egg mature
-progesterone injection/implant- stops egg release
-IUD- stops egg embedding in the lining
57
How does IVF work?
eggs are collected from the mothers ovaries after inducing their release with LH injections
They’re taking to be fertilised in a lab with the preferred fathers sperm
The viable embryos, and then reinserted back into the mothers uterus to develop into a baby
58
what are two types of fertility treatments and what are the pros and cons?
FSH or LH injections:
pro- they are simple
con- may not be effective could have side effects
IVF :
pro- have a child that is genetically related to both parents
con-Expensive mentally and physically draining and often ends in multiple pregnancies 
59
What is a Adeline and its purpose?
It’s a hormone released by the adrenal gland which increases the blood flow and breathing rate to prepare the body/ you for fight or flight
60
what happens if the thyroid is not secreting enough thyroxine?
The hypothalamus in the brain releases TRH, which causes the pituitary gland to release TSH, which causes the thyroid to release more thyroxine. This is an example of negative feedback.
61
What are gibberellins and what do they do?
gibberellins are plant hormone that induces the germination of seeds and promotes flowering and increase fruit size 
62
what is the function of Ethene implants?
It’s a hormone that causes ripening
63
What do you auxins in plants control?
they control shoot and root growth by moving to the side of the plant the experience the least amount of sunlight
64
why do auxins gather in the shaded side of a shoot?
they are destroyed by sunlight, so move to the shaded side of the plant
65
do auxins inhibit or exhibit growth in roots?
they inhibit growth by gathering at the bottom of the root so that it grows downwards
66
what are some industrial uses of auxins?
Weedkillers
Rooting powders
Promoting growth and tissue cultures
67
what are the two types of tropism and where do they occur ?
Phototropism occurs in sheets due to sunlight and auxin
Geotropism occurs in roots due to gravity and auxin
68
what is meiosis?
the process by which gametes are made its a type if cell division that produces genetically different cells
69
what are some differences between mitosis and meiosis?
-mitosis produces 2 genetically identical daughter cells from a single parent cell -meiosis produces cells genetically different from the parent cells and contain half the amount of DNA (23 chromosomes)
-the nucleus divide’s twice in meiosis and produce 4 daughter cells
- mitosis is involved in healing and growing
-meiosis is involved in genetic variation
70
what are some similarities between meiosis and mitosis?
both produces new cells and involves division of the nucleus and they both start with a single parent cell
71
describe meiosis
-the 23 chromosomes in a diploid cell and copied
-cell now contains 46 chromosomes and similar chromosomes pair up and swap genes between them
-cell divides to produce 2 diploid cells
-these cells then divide again to produce 4 haploid cell
- these cells are then ready to fuse with another gamete (an egg or sperm cell)
72
what is a gamete?
a reproductive cell of an animal or plant
73
what are the gametes in plants?
male gametes are contained in pollen which is released from the anther
female gamete is the ovary which is produced from the ovules
74
how do plants reproduce asexually and what does this produce?
by mitosis and produce clone cells which means they are genetically identical
75
what are advantages of sexual and asexual reproduction in plants?
sexual- better adapted to the environment so more resistant to change
asexual- only one organism is needed to reproduce
76
what is a genome and where is it stored?
is the entire genetic code in an organism which is stored in the DNA
77
what is DNA?
a double helix polymer which stores genetic code
78
why is it important we understand genes?
help us map out and identify the cause if different disorders
79
what is genotype?
an organisms specific genetic code
80
what is phenotype?
how the genetic code of someone is expressed in their physical characteristics
81
describe protein synthesis
-base sequence of DNA is copied into a template molecule call mRNA this is called transcription
-mRNA then passed into the cytoplasm where translation happens
-the mRNA molecule attaches to a ribosome
-amino acids are brought to the ribosome it has attachment to by a tRMA
-the ribosome connects the correct amino acids to the core triplet bases
-once the protein chain is complete it folds into a unique shape so it can perform its specific functions
82
what are alleles?
different versions of the same gene
83
what are genetic characteristics determined by?
the type and quantity of proteins synthesised
84
what type of allele is BB and Bb?
homozygous
heterozygous
85
what is variation a result of?
genetic and environmental factors
86
what is Charles Darwin’s theory of evolution?
-random mutation results in variation
-some organisms become better adapted to environment because of a variation caused by mutation so they are more likely to survive
-they will reproduce more and these desirable characteristics will be passed on over time and become more pronounced
87
what was lamarcks theory on evolution?
-mutation/adaptations are a result of the environment affecting characteristics inherited by offspring and its not random
88
how is bacteria and Darwin’s theory of evolution related?
antibiotics resistant bacteria develops randomly and more dominant and resistant bacteria will survive and multiply more
89
why is it necessary that antibiotics are not overly prescribed and the full course is taken?
if not all bacteria is killed those most resistant will reproduce and become resistant to the antibiotics same with over prescribing
90
what is considered a species?
organisms that can produce fertile offspring
91
what is selective breeding?
breeding organisms that have desired characteristics to produce offspring in which they are more prominent
92
what is genetic engineering?
the insertion of a gene into an organisms genome so it synthesises a specific protein to achieve a desired characteristic
93
what are the pros and cons of GM crops?
increase the yeild and nutrition
may have unknown side effects
94
describe the process of genetic engineering
-desired gene is cute from another organisms DNA using an enzyme
-gene is inserted into a vector eg. plasmid
-vector inserts the gene into cells of another organism in early development
-organism will develop with the desired characteristics
95
why does the cells have to be in early development for genetic engineering?
to ensure every cell synthesises that specific protein
96
what is tissue culture?
a way of making clones of plants by extracting a small group of cells from a plant and placing then inna growth medium with growth hormone and then placing that in a incubator
97
what is cutting?
way of making plant closer by cutting a small part if a plant and dit the end in rooting hormone powder and replanting it as a separate organism
98
how do you clone an animal?
-nucleus is taken from the cell of the organism to be cloned and is inserted into an egg cell
-electric shocks and induces onto the egg cell which cause it to split and develop
-the developing cells are inserted into the surrogate mother
-the cells develop and the clone is born
99
who created the classification system?
carl Linnaeus
100
king
Philip
came
over
for
good
soup
kingdom
phylum
class
order
familu
genus
species
101
what is a binomial name and how is it decided?
naming of a species depending on their genus and species name according to the classification system
102
what are the 3 domains?
archaea- extremophiles
bacterial/true bacteria
eukaryota- everything else
103
what is interdependence?
how organisms depend on each other for survival
104
what are abiotic and biotic factors?
abiotic are non living factors eg.light,temp
biotic is living things eg.food,predators
105
what are quadrats used for?
in sampling to estimate the size of a population in a certain area
106
whay does using a transect allow?
to observe the change in population density over a distance
107
what does a food chain show?
the direction of biomass transfer between organisms
108
what are the 5 trophic levels?
producer eg. plants
primary consumer eg.rabbit
secondary consumer eg. fox
tertiary consumer eg.bear
109
what is an apex predator?
a predator that has no predators its at the top of the food chain
110
what is the carbon cycle?
CO2 in the atmosphere
photosynthesis in plants
plants decompose,respire and are eaten all release carbon
animal eat plants and decompose
decomposed plants and animals fossilise and become fossil fuels which are burnt and release CO2
111
what do farmers do to decomposition?
utilities decomposition to produce a natural fertiliser and to produce methane gas which can be used as fuel
112
what are the negative impacts of burning peat bogs?
they are being destroyed to make compost but this release CO2 which contributes to global warming and reduces biodiversity
113
what reduces biodiversity?
human development
deforestation
burning peat bogs
114
what does a pyramid of biomass indicate?
how much biomass is transferred between trophic levels
115
how do you calculate the % of biomass absorbed l?
bio mass of 2nd level/
biomass of 1st level x100
116
why is biomass lost between trophic levels?
due to not all of it being consumed,absorbed or it being list via eg.excretion
117
what put food security at risk?
growing population,change in diet,conflicts
118
what a way of sustainable fishing?
using nets with holes that are a specific size
119
define:
population
Community
Ecosystem
Group of organisms, living in the same geographical area at the same time
An interactive group of various species in a shared/common location
A community of living organisms in a particular area 
120
what is the function of the cornea?
refracts light as it enters the eye.
121
what is a target organ?
The parts of the body which recognise and respond to the hormone secreted are called target organs or tissues.
122
what is the international naming system called?
binomial nomenclature
which literally means two names.
123
what are the different parts of the brain called and where about are they located?
-cerebrum hemispheres located at the top half of the brain
-Cerebellum located at the lower back half of the brain
-Medulla obbligato is located at the bottom of the brain and connect to the spinal cord
-Hypothalamus is found towards the front centre of the brain
124
What are the functions of the four main areas in the brain?
-The cerebrum controls, intelligence and personality,conscious thoughts and high level functions, like language
-The cerebellum controls balance and coordination and muscle activity
-The medulla controls unconscious activity
-The hypothalamus is the regulating centre for temperature and water balance in the body
125
what are the six structures found in an eye and what are their functions?
cornea-reflects light as it enters the eye
Iris- controls how much light enters the pupil
Lens- further reflects lights to focus it onto the retina
Retina- contains light receptors
Optic nerve-carries impulses between the eye and the brain
Sclera-tough white, outer layer of the eye that protects it from injury
126
How does the lens change to focus on their objects?
It becomes thicker by ciliary muscles, contracting, and suspensory ligaments loosen which causes the muscle tension to lower, so that light is refracted strongly
127
How does the lens change to focus on distant objects?
it’s pulled thin by the ciliary muscles, relaxing and suspensory ligament tightening, causing muscle tension to increase making the lens shape thin so that light is refracted slightly
128
what lens can correct shortsightedness?
Concave
129
How is water balance maintained in the body?
-if the blood becomes too concentrated, the Petula tree gland releases the hormone ADH into the blood stream
-This causes the kidneys tubules to become more permeable to water
-This means that more water is reabsorbed into the bloodstream from the tubules
-When the level returns back to normal, ADH is inhibited
130
How does kidney dialysis work?
patient’s blood is passed over a semipermeable membrane which allows /small molecules like ions and water through, but not larger, molecules like protein.
on the other side of the membrane, there is dialysis fluid which contains the normal concentration of water and ions but no urea which creates a concentration gradient that causes the urea to diffuse from the blood into the dialysis fluid. The dialysis fluid is constantly refreshed to create a large concentration gradient.
