Biology 1.1 Flashcards
1
Q
What is the order of neurones in the nervous system
A
- Stimulus (change in environment)
- Recpetor
- Sensory neuron
- Relay neuron (control centre)
- Motor neuron
- Effector
2
Q
what is a homeostatic mechanism
A
the maintenance of a constant internal environment
3
Q
What is the gap between our neurones called
A
A synapse
4
Q
What type of impulse is a nerve
A
electrical
5
Q
What happens when a nerve crosses a synapse
A
- the electrical impulse triggers chemical neurotransmitter chemicals
- the chemicals fuse with the cell membrane and diffuse across the synapse
- They dock into the receptor neurone and create a new electrical impulse
6
Q
Is Adrenaline in a negative feedback loop
A
No
7
Q
Is thyroxine in a negative feedback loop
A
Yes
8
Q
What is a negative feedback loop
A
a homeostatic mechanism that makes a change when the body detects a change and needs to return to normal
9
Q
Where is adrenaline released
A
Adrenal glands (above kidneys)
10
Q
Where is thyroxine stimulating hormone released
A
pituitary gland
11
Q
What happens when the brain detects and increased level of thyroxine
A
- The brain signals the pituitary gland to release less stimulating hormone
- This acts on the thyroid gland meaning that less thyroxine is released
12
Q
Where is thyroxine released
A
thyroid
13
Q
What does decreasing thyroxine levels cause
A
- Lower metabolism
2. Lowers rate of protein synthesis
14
Q
What are 2/3 effects of adrenalin
A
- Dilating pupils to allow more light
- Increase breathing rate to allow more oxygen in our blood so we can react more quickly
- Blood from digestive system is redirected to our skeletal muscles for faster movement
15
Q
What does adrenaline need to be produced
A
a scary situation
16
Q
What does thyroxine need to be produced
A
insulin (eat oily fish)
17
Q
What is the endocrine system
A
chemical messenger involved in the negative feedback loop
18
Q
What is Glycogen
A
Glycogen = excess glucose turned insoluble to be stored as spare
19
Q
What is Glucagon
A
stimulates the breakdown of glycogen back into glucose
20
Q
What is insulin
A
stimulates the breakdown of glucose back into glycogen
21
Q
What is type 1 diabetes
A
The pancreas does’t produce enough insulin
22
Q
What is type 2 diabetes
A
The cells no longer respond to the insulin which is being made (they still make enough insulin)
23
Q
What is the treatment for type 1 diabetes
A
- Insulin injections every meal time
2. Watch their diet and excessive regime
24
Q
WHat is the treatment for type 2 diabetes
A
- Eat a low carb diet due to glucose being heavily in carbs
2. Exercise regularly
25
What happens to blood glucose after eating a meal
blood glucose rises
26
What organ detects rise in blood gluco
pancreas
27
What does the pancreas release in response to rising blood glucose
insulin
28
What happens to insulin when it reaches the liver
It turns the glucose into glycogen
29
Where are the LH and FSH hormones produced
pituitary gland
30
Where is oestrogen produced
Ovaries
31
Where is progesterone produced
empty egg follicle
32
What does FSH do
stimulates release of oestrogen and matures the egg
33
What does LH do
stimulates ovulation/ release of an egg
34
What does oestrogen do
thickens the uterus lining
35
What does progesterone do
Maintains the uterus lining and controls LH and FSH levels
36
What does a woman use if she wants to increase fertility
LH and FSH
37
What does a woman take if she wants to reduce fertility
progesterone + oestrogen because it stops the egg being released
38
What are some negative side effects of contraception
1. Don't prevent STD's
2. Nausea
3. Irreversible
39
What is the photosynthesis symbol equation
6CO2 + 6H2O --> C6H12O6 + 6O2
40
What is the photosynthesis word equation
Carbon dioxide + water --> glucose + oxygen
41
what does a gene do
control the characteristics of a being
42
what is a phenotype
physical appearance of a gene (tall)
43
What is a a genotype
the allelles of a gene (TT, Tt)
44
what is an allele
different forms of a gene
45
what is a gamete
reproductive cells such as egg and sperm
46
what is a dominant gene
only needs one allele to show up
47
what is a recessive gene
needs both alleles to show up
48
what is homozygous
2 copies of the same allele
49
what is heterozygous
2 different alleles
50
What are girl and boy genotypes
```
girl = XX
boy = XY
```
51
What type of reproduction is meiosis
sexual
52
how many cells does meiosis produce
4
53
how many divisions doe meiosis have
2
54
what type of cell does meiosis leave
haploid (half set of chromosomes)
55
does meiosis produce variation or clones
it produces variation so therefore no clones
56
does meiosis increase survival chance
yes it allows natural selection
57
how fast is meiosis
slow
58
where does meisosis occur and what is it used for
occurs producing gametes and is used for sex cells
59
what type of reproduction is mitosis
sexual
60
how many cells does mitosis produce
2
61
how many divisions does mitosis have
1
62
what type of cell does mitosis leave
diploid (full set of chromosomes)
63
does mitosis produce variation or clones
it produces clones so has no variation
64
does mitosis increase survival
no because they are all clones so would be wiped out quickly
65
what speed is mitosis
fast
66
where does mitosis occur and what for
it occurs in the growth and repair of cells and is used in Bacteria and humans
67
what is a genome
the entire genetic makeup of an organism
68
how many chromosomes do humans DNA have
46 chromosomes (23 pairs)
69
what is a nucleus made of
chromosones
70
what are chromosones made from
DNA
71
what is DNA made from
genes
72
what are genes made from
proteins (string of amino acids folded together to make an enzyme)
73
what was the purpose of the human genome project
looked at communicable and inherited diseases to gather a better understanding of them to find a cure
74
When was the human genome project
year 2003
75
How many genes are in one genome
21,000
76
what is polydactyl
extra toes and fingers
77
what causes polydactyl
a dominant inherited allele
78
what is cystic fibrosis
causes mucus to be thick and sticky
79
Why is cystic fibrosis life threatening
mucus lines our airways and trachea to trap dirt from going into our lungs. We then swallow the mucus where it is killed in our stomach. The thick and sticky mucus of cystic fibrosis narrows the airways and makes it hard to breath. It also means it can't be swallowed and the bacteria builds up in the trachea, causing infection
80
where is mucus released
epithelial tissue
81
when is screening for a genetic disorder used
to see if an embryo will be born with a disease / condition
82
what are 3 positives of screening for genetic disorders
1. saves money because it can be terminated and parents don't pay to look after a disabled child
2. laws are in place to make sure it is safe
3. child and parents can avoid poor quality of life
83
what are 3 negatives of screening for genetic disorders
1. expensive
2. concerns that people may do it to pick out and change desired characteristics
3. can occasionally give false results and damage healthy embryos
84
what are 3 methods of screening for genetic disorders
1. analysis fIVF embryo
2. analysis of placenta
3. analysis of embryonic fluid (amniocentesis)
85
what is natural selection
when species have a genetic change to deal with environmental changes. The strongest survive and pass those genes on allowing evolution.
86
what is a species
group of organisms with similar characteristics that can produce fertile offspring
87
What are 3 types of variation potential
1. genetic
2. environmental
3. both
88
give 2 examples of genetic variation
1. Blood type
2. Gender
3. Facial features
89
give 2 examples of environmental variation
1. accent
2. hair colour
3. scars and tatoos
90
give 2 examples of both variation
1. height
| 2. weight
91
List 2 characteristics of the old horse
1. 5 toes for good grip and won't sink
| 2. short to avoid brambles and vines in the forest
92
list 2 characteristics of the new horse
1. hoof to run on grassland
| 2. Tall to run faster
93
what is selective breeding
when humans select what animals and plants to breed to achieve a desired characteristic
94
what is genetic engineering
modifying the genome of an organism by adding a desired organisms gene to the nucleus
95
what are the problems with selective breeding
lots of inbreeding reduces variety in gene pool, making them prone to disease.
Animals such as cows now produce to much milk which can cause discomfort
96
what is selective breeding used for
1. Cows produce a higher milk yield
| 2. Disease resistant crops
97
what is genetic engineering used for
increased crop yield
| cows producing low lactose milk
98
what is bad about genetic engineering
it can destroy interdependence and food chains because they start depending on themselves
99
why is the fossil record incomplete
many organisms were soft bodied so left very little trace. Lots of fossils have also not been found
100
how are fossils formed
1. animals die and become covered in sediment
2. more pressure builds up, cutting of CO2 so it doesnt decay
3. over millions of years the skeleton builds up minerals and turns to rock
4. cracks in the rock and erosion reveal them years later
101
what is a fossil
main impression of an animal or plant from millions of yea
102
what do fossils show
the evolution of a species and the extinction
103
why are bacteria good to study
they rapidly reproduce every 20 minutes
104
how do you remember the evolutionary tree order
Keep pots clean or family gets sick
105
what is the order for evolutionary trees
```
kingdom
phylum
class
order
family
genus
species
```
106
what is a population
group of individuals of same species
107
what is a community
several different populations living in one habitat together
108
what is an ecosystem
when different ecosystems interact with one another and the abiotic/biotic factors
109
what is interdependence
species in a community depending on eachother for food, shelter , pollination. They also depend on biotic and abiotic factors
110
give 3 examples of biotic factors
1. New predator
2. New competitor
3. New pathogens and parasites
111
give 3 examples of abiotic factors
1. temperature
2. water levels
3. CO2 levels
4. Light intensity
112
what is a stable community
when biotic and abiotic factors rarely change meaning the population levels remain constant
113
what are 3 types of animal adaptation
structural (body) , behavioural (behaviour) , functional (processes)
114
give 2 examples of structural adaptation
1. sharp teeth and claws for food and fighting
2. body shape effects speed and strength
3. small surface area to volume ratio reduces heat loss
115
give 2 examples of behavioural adaptation
1. migration
2. pack hunting
3. huddling for warmth
116
give 2 examples of functional adaptation
1. hibernation to lower metabolic rate
| 2. produce less urine to conserve water
117
what is an extremophile and name an example
organisms that live in extreme environments , hot or cold to avoid competition such as bacteria
118
what to plants compete for
water, light and space
119
how are plants adapted to receive more light
grow taller to absorb more sun
| grow more leaves to absorb more sun
120
how are plants adapted to receive more water
wide reaching roots
| can expand to store water such as cacti
121
how are plants adapted to receive more space
seeds float and move through water
some seeds are sticky and are carried by animals
brightly coloured seeds
122
what tool do we use to estimate population size
a 1m x 1m quadrat
123
how do you use a quadrat
throw out the quadrat into random points on the field. Do this about 10 times for more accurate and fair results. Flowers overlapping the right and north side count but overlapping the left and south side don't count
124
what do we use to measure species distribution
transect ( tape measure
125
how is a transect used
transect is like a tape measure. Place it along the field and strategically place a quadrat along it. Do the same thing using a parallel line
126
4 stages of the water cycle
1. sun evaporates water
2. water rises and condenses to form clouds
3. clouds release precipitation
4. percolation where water trickles through ground and rivers back into ocean
127
4 stages of cycle of decay
1. plants and animals die
2. they are decomposed by decomposers such as fungi
3. the insects respire and release CO2 into air
4. the stomata of plant leaves take the CO2 for photosynthesis
128
3 stages of decay cycle in mineral ions
1. animals eat minerals in soil
2. animals go to toilet and have feces decomposed by decomposers
3. CO2 is released back into air and ions released back into soil
129
3 stages of the carbon cycle (plants)
1. plants take carbon from air
2. animals eat the plant and thus the carbon compound
3. animals respire and release CO2 back into air
130
what is Bioaccumulation
gradual accumulation of a small substances building up over time eventually reaching the top of the food chain
131
give one example of bioaccumulation
1. Insect eats pesticide
2. Bird eats insect
3. Lion eats bird
4. Lion is poisoned from the bioaccumulation of pesticides
132
What is Eutrophication
1. fertilizers washed into water encourage algae growth
2. to much algae grows and blocks sunlight from the bottom of ponds
3. plants can't perform photosynthesis and die
4. fish die because they have no plants to eat
133
what is a peat bog
mushy type of soil which has not fully decomposed because it is to acidic. This causes it to build up loads of carbon
134
why is the destruction of a peat bog bad
it speeds up the decomposition and therefore releases loads of carbon dioxide
135
why are peat bogs destroyed
1. make room for building
| 2. fertilisers
136
what 4 things does overpopulation cause
1. more waste
2. more energy
3. more food
4. more building
137
what effects does more waste required have
more sewage effecting water
| more landfill sights to produce methane
138
what effect does more energy required have
acid rain due to fossil fuel pollution
destruction of environment for fossil fuels
breathing difficulties
139
what effect does more food required have
pesticides are washed into water
trees cut down for farming land
more cows bred so more methane released
140
what effect does more building have
deforestation
destruction of peat bogs
building requires energy, adding to the greenhouse effect
