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N5 Biology > Life on Earth > Flashcards

Life on Earth Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

habitat

A

the place where an organism lives

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2
Q

population

A

all the members of one species living in a habitat

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3
Q

community

A

all the plants, animals and micro-organisms living in a habitat

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4
Q

species

A

a group of organisms that can interbreed to produce fertile offspring

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5
Q

producer

A

a green plant that makes its own energy (food) using sunlight

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6
Q

consumer

A

an animal that eats another organism (plants or animals)

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7
Q

herbivore

A

an organism that eats plant material only

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8
Q

omnivore

A

an organism that eats a mixture of both plant and animal material

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9
Q

carnivore

A

an organism that eats animal material only

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10
Q

predator

A

an animal which hunts and kills other animals for food

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11
Q

prey

A

an animal which is hunted and killed for food by the predator

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12
Q

biodiversity

A

the number and abundance of species

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13
Q

food chain

A

a diagram which shows the transfer of energy between organisms

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14
Q

food web

A

a diagram which shows inter-connected food chains

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15
Q

ecosystem

A

all the organisms living in a particular habitat and the non-living parts which the organisms interact with

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16
Q

organism

A

any individual living thing

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17
Q

predation

A

a relationship between 2 organisms in which one hunts, kills and eats the other

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18
Q

niche

A

the role that an organism plays within a community

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19
Q

parasitism

A

a relationship between 2 organisms in which one benefits or lives off of the other- with a certain amount of disadvantage to the host

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20
Q

sampling

A

studying part of an area rather than the whole thing, making sure that you study a representative portion

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21
Q

indicator species

A

species that by their presence or absence indicate environmental quality/ levels of pollution

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22
Q

pitfall traps

A

a method of sampling non-flying invertebrates in an area by placing concealed pits for them to fall into

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23
Q

abiotic factors

A

non-living factors
eg pH, temperature, light intensity and soil moisture

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24
Q

light intensity

A

a measure of how much light energy falls on an area in any given time

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25
Q

quadrat

A

equipment used to sample plants or very slow moving animals, usually a large square split into smaller squares

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26
Q

light meter

A

equipment used to measure light intensity

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27
Q

biotic factors

A

living factors- they come from the activity of a living thing
eg competition for resources, disease, food availabilty, grazing and predation

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28
Q

pH

A

a measure of whether a solution such as the soil water is acidic, alkaline or neutral

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29
Q

soil thermometer

A

equipment used to meaure the soil temperature

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30
Q

grazing

A

an example of a biotic factor that can affect the distribution of organisms

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31
Q

light intensity- possible sources of error and the solution

A
  • the observer may stand in the way of the light casting a shadow on the light sensitive panel.- ensure that observers are standing to one side of the light meter

-light intensity may change from one moment to another due to clouds making comparisons between areas invalid- take all measurements as near as possible during periods of similar light intensities i.e samples taken at the same time of day if study is over some time.

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32
Q

temperature- source of error and the solution

A

probe not inserted deep enough into the soil- insert probe into soil to half its depth

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33
Q

soil moisture- sources if error and solutions

A

-soil from previous sample may still be on the surface of the probe- clean probe before and after each reading with a paper towel

-samples are taken at different depths- place a marker around the probe to ensure it is pushed to the same depth for readings.

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34
Q

soil pH source of error and solution

A

soil from a previous sample may still be on the surface of the probe- clean probe before and after each reading with a paper towel

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35
Q

how is light intensity measured

A

the switch on the meter is set at the light meter position. The meter is held so that the light sensitive panel is directed towards the light source to be measured

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36
Q

how is temperature measured

A

thermometer is placed in the soil or air until temperature is constant

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37
Q

how is soil moisture measured

A

the switch in the meter is set at the moisture meter position. The moisture probe is pushed into the soil and the reading is taken from the scale once the pointer has stopped moving.

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38
Q

how is soil pH measured

A

pH meter probe is placed into the soil and the needle is allowed to stabilise

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39
Q

what is the energy transfer in photosynthesis

A

light energy–> chemical energy

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40
Q

what is the word equation for photosynthesis

A

light
carbon dioxide + water –> glucose + oxygen
chlorophyll
raw materials products

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41
Q

what are the 3 uses for glucose produced in photosynthesis

A
  • some is immediately used for RESPIRATION to provide the energy required by the plant
    -some is converted into the STRUCTURAL carbohydrate CELLULOSE to build cell walls
  • some is converted into the STORAGE carbohydrate STARCH. this is stored by the plant in the leaves and can be converted back into glucose when required for respiration
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42
Q

what is the structure of starch

A

long chain of glucose molecules which coil uo to form a starch grain

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43
Q

what is the structure of cellulose

A

bundles of chains of glucose units are branched to form fibres

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44
Q

properties of starch

A

large in size so cannot diffuse of the cell
insoluble in water

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45
Q

properties of cellulose

A

insoluble
freey permeable

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46
Q

what are the 2 stages of photosynthesis called

A

stage 1- light reactions
stage 2- carbon fixation

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47
Q

what does stage 1 look like

A

light energy
|
chlorophyll
|
ADP+Pi ) chemical energy ( water
ATP ) ( hydrogen+oxgygen
| | |
passed onto passed onto diffuses out
second stage second stage of cell

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48
Q

description of light reactions

A

the light energy from the sun is trapped by chlorophyll in the chloroplasts and is converted into chemical enery which is used to generate ATP. water is split to produce hydrogen and oxygen. Oxygen diffuses out of the cell

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49
Q

what does stage 2- carbin fixation look like

A

hydrogen ATP ADP + Pi
\ \ /
————————————–glucose
/
carbon dioxide
(from the air)

enzyme controlled reaction

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50
Q

description of carbon fixation

A

the ATP and hydrogen from stage one are combined with carbon dioxide from the air to produce glucose. These reactions are enzyme controlled

51
Q

What are the 3 ways in which photosynthesis is measured

A

Production of oxygen over a set period of time
Uptake of carbon dioxide over a set period of time
Production of glucose over a set period of time

52
Q

What is a limiting factor

A

A limiting factor slows down or decreases the rate of a process because it is in short supply.

53
Q

What are the 3 main limiting factors

A

Temperature
Carbon dioxide concentration
Light intensity

54
Q

Why does light intensity effect photosynthesis

A

The first stage will be altered as it is light dependant

55
Q

How does temperature effect photosynthesis

A

Temperature will alter stage 2 as it depends on enzymes for it to work

56
Q

How does carbon dioxide concentration effect photosynthesis

A

It will alter the second stage as it is a raw material required in the second stage.

57
Q

How can the rate of photosynthesis be measured

A

By counting the number of oxygen bubble produced from a green aquatic plant based on the light intensity

58
Q

How can carbon dioxide concentration be shown

A

Can be shown by the colour of the hydrogen carbonate (bicarbonate) indicator in the tube
Yellow is very high concentration
Red is medium concentration
Purple is very low concentration.

59
Q

How do you find out the limiting factor on the slope

A

Look at the label on the x-axis

60
Q

What is carbon fixation

A

The second stage of photosynthesis where glucose is synthesised

61
Q

What is chlorophyll

A

Traps light energy from the sunn

62
Q

What are enzymes

A

Controls the series of photosynthesis reactions

63
Q

What energy is found in ATP

A

Chemical energy

64
Q

What is the limiting factor on a sunny day in winter

A

Temperature

65
Q

What is light reactions

A

The first stage of photosynthesis in which water is split

66
Q

What is ATP

A

An energy rich molecule synthesised during the light reaction

67
Q

What is the limiting factor in a cloudy day

A

Light intensity

68
Q

What carbohydrate is used to make cell walls

A

Cellulose

69
Q

What byproduct of water splitting diffuses out of the leaf

A

Oxygen

70
Q

What is a chloroplast

A

A leaf organelle which is the site of photosynthesis

71
Q

When is growth maximum

A

When there are no limiting factors

72
Q

What is produced by water splitting and combines with carbon dioxide to produce glucose

A

Hydrogen

73
Q

What is growth

A

The increase in biomass of living things which can provide food for other organisms

74
Q

What are resources

A

All the things needed by an organism or population to survive e.g food water shelter, nutrients etc.

75
Q

What is a pyramid of numbers

A

A diagram with the width of each bar representing the number of organisms at that trophic (feeding) level

76
Q

What is all the energy in living things eventually converted into

A

Heat

77
Q

How can energy be lost in a food chain

A

Heat, movement, undigested waste

78
Q

What is the form of energy in food

A

Chemical

79
Q

What is intraspecific competition

A

When individuals from the same species compete for all required resources
It is more intense

80
Q

What is interspecific competition

A

Competition between individuals of different species for one or a few resources required

81
Q

What is a pyramid of energy

A

A diagram with the width of each bar representing the total energy contained in the organism at that trophic (feeding) level

82
Q

What are 2 reasons why the human population continues to increase rapidly

A

Humans have no natural predators

Healthcare has greatly improved

83
Q

What is competition

A

The interaction between organisms of the same species when both require the same limited resource

84
Q

What are nitrates

A

Used to produce amino acids which are synthesised into plant proteins
Animals consume plants or other animals obtain amino acids for protein synthesis.

85
Q

Describe the nitrogen cycle

A

Nitrates are used to synthesise amino acids

Plant protein is synthesised

Animals consume plants or other animals to obtain amino acids for protein synthesis

The animals die and decomposes elf bacteria or fungi break it down.

86
Q

Describe eutrophication

A

Fertilisers are added to soil and leach into fresh water

Algal blooms form due to increase in nutrients

Algal blooms stop sunlight from reaching the plants below the water

The plants are killed as they cannot photosynthesise. Algal blooms also die as they run out of nutrients

Bacteria use the dead algae and plants as food, this causes the bacteria to increase in number.

The bacteria use up MOST of the oxygen. This reduces the oxygen that is available for the other organisms

With little oxygen available, the animals int he fresh water die

87
Q

Why are fertilisers used

A

To increase levels of essential plant nutrients that aren’t replaced naturally

88
Q

What is bioaccumulation

A

The build up of toxic substances e.g pesticides in living organisms.

89
Q

How did DDT effect bird populations

A

Birds eggs were too thin because it was difficult for the birds to absorb calcium due to the use of the insecticide. The chicks were then hatching prematurely leading to a premature death.

90
Q

3 advantages of GM crops

A

They are more productive, therefore creating a larger yield.

Could provide more flavour and nutrition

Foods are more pest resistant and stay ripe for longer, so they can be shipped longer distances and kept on shop shelves for longer

91
Q

3 arguments against GM crops

A

Herbicide and pesticide resistant crops could give rise to super weeds and pests, that would lead to newer stringer chemicals needing to be used.

They could cross-pollinate with non-gm crops which could cause ecological problems. If this were to happen to crops containing vaccines, antibiotics etc it could cause a human health nightmare.

Scientists can choose the gene to manipulate but don’t know where in the DNA to insert it, which could lead to drastic changes with unpredictable results.

92
Q

4 advantages of biological control

A

There are no problems of chemicals contaminating the environment or food chain.

Predator is specific to pest, meaning biodiversity may not be reduced

After initial set up cost, it may be much cheaper

Most pests do not become resistant to the treatment so can be used year after year

93
Q

4 disadvantages of Biological Control

A

Some of the introduced predators have become pests themselves, e,g the cane toad

It doesn’t work well in large unconfined spaces, as the predators can leave the environment

It can be initially very expensive due to high developmental costs

Not all the pests will be killed, some will remain and still cause damage, meaning pesticides may still need to be used.

94
Q

what are algal blooms

A

sudden excessive growth of microscopic algae due to the increased nutrient levels

95
Q

what are GM crops

A

genetically modified plants which have had their genetic material altered to give them desirable qualities or remove undesirable ones

96
Q

what is nitrogen

A

an element which is the most abundant gas on the planet and is an important part of every protein

97
Q

what is biological control

A

the use of natural predators or parasites to limit the population of a pest species

98
Q

what is leaching

A

when soluble substances in the soil dissolve and are gradually washed into fresh water e.g rivers and lochs, by the rain

99
Q
A
100
Q

what are nitrates

A

a chemical containing nitrogen and oxygen which is soluble in water and easily taken up by plant roots to use in making proteins

101
Q

what are pesticides

A

a chemical used to kill pests, they are often insecticides (to kill insects) or herbicides (weed killers)

102
Q

what is mutation

A

a random change to genetic material. it can be a change to the DNA or the whole chromosome

103
Q

how can the rate of mutation be increased

A

the rate of mutation can be increased by mutagenic agents

104
Q

what are the 2 different mutagenic agents and their examples

A

radiation- gamma rays, x-rays, UV light

chemicals- colchicine, mustard gas, agent orange, benzene

105
Q

what 3 things can Mutations do

A

confer an advantage
confer a disadvantage
have no effect- neutral

106
Q

what is produced from mutation and what do they do

A

new alleles, which can result in animals and plants being better adapted to their evironment

107
Q

what does variation do

A

variation within a population makes it possible for a population to evolve over time in response to changing environmental conditions

108
Q

what is an adaptation

A

an inherited characteristic that makes an organism well suited to survival in its environment/ niche
these adaptations can be structural or behavioural

109
Q

what are the kangaroo rats behavioural adaptations

A

-active at night because the temperatures are cooler
-remains in underground burrow and is inactive during the day

110
Q

what are the structural adaptations of the desert plant

A

-thick, waxy cuticles to reduce water loss
-water stored in succulent tissues
-leaves reduced to spines to reduce leaf surface area and decreasing water loss
-long roots to reach deep water
-superficial roots which grow parallel to the soil to absorb maximum water

111
Q

what are the structural adaptations of darwins finches

A

different shape and sizes of beaks so that the birds can eat different foods
small pointed beaks to pick insects out of tree bark
big, blunt beaks to break open the coatings and shells of nuts and seeds

112
Q

what is natural selections

A

the survival of the organisms that are best adapted to their environment. those with a favourable characteristic will have a selective advantage and survive.

113
Q

describe natural selection

A
  1. sexual reproductions produces many offspring
  2. inherited variation means that organisms are different from each other
  3. struggle for survival- due to disease, inability to compete for scarce food or other resources, predation, abiotic environmental conditions
  4. survival of the fittest
  5. mating and offspring produced favoured forms of genes- alleles passed on
  6. offspring struggle for survival again
  7. survival of the fittest to pass on characteristics (alleles) to next generation
114
Q

why does survival of the fittest happen

A

because species produce more offspring than the environment can sustain

115
Q

when does natural selection occur

A

when there are selection pressures

116
Q

what happens to alleles during natural selection

A

they increase in frequency within the population

117
Q

what is speciation

A

the formation of new species, due to mutations and natural selection

118
Q

describe speciation

A
  1. large freely interbreeding population of one species
  2. isolation by barrier, could geographical, ecological or behavioural
    subpopulation A barrier Subpopulation B
  3. mutations arise in both populations (some of these confer selective advantage)
  4. natural selection over a very long time
  5. barrier removed
  6. not interbreeding to produce viable offspring occurs between members of 2 populations- because 2 different species have arisen i.e speciation has occured
119
Q

what is the order of mutation, natural selection and isolation

A

isolation
mutation
natural selection

120
Q

examples of geographical barriers

A

river, desert, sea, mountain range

121
Q

examples of ecological barriers

A

difference in temperature, humidity, pH

122
Q

example of behavioural barrier

A

different mating dances

123
Q

what does it mean when an organism is isolated

A

when 2 groups are seperated so that they cannot exchange genetic material between the groups- they cannot breed with eachother

124
Q

how is energy passed on in a food chain

A

growth

N5 Biology (1 decks)

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