B4 It's A Green World Flashcards
Describe how to carry out sampling using pooters
Pooters are containers with a straw device, used to suck in small animals so that they can be identified and counted.
Describe how to carry out sampling using nets
Nets are used to catch animals such as butterflies or fish, allowing you to count and record numbers of animals.
Describe how to carry out sampling using pitfall traps
Pitfall traps are small containers buried in the ground which collect small animals, allowing you to sample the animals in the area.
Describe how to carry out sampling using Quadrats
Quadrats are square frames of a standard area. They are put on the ground to define an area. The numbers of organisms of particular species in the frame can then be counted.
Describe a method to show the variety of plants and animals living in a small areas such as a 1m Quadrat
Not sure
Explain how the distribution of organisms can be affected
Presence of other living organisms
Physical factors
Define biodiversity
Variety of different species living in a habitat
Give examples of natural ecosystems and artificial ecosystems
Native woodlands and lakes - natural
Forestry plantations and fish farms - artificial
Formula for population size (capture-recapture)
(Number in first sample + Number in second sample)/ number of marked in second sample
Explain the effect of sample size on the accuracy of an estimate of population size
These methods only provide estimates of the population, because it allows us to sample areas in the habitat, not the entire habitat. The greater the sample size the greater the accuracy of the estimate of the population
Explain the assumptions made when using capture-recapture data
- no death, immigration or emigration
- identical sampling methods are used
- marking doesn’t affect their survival rate
Explain the difference between ecosystem and habitat
A habitat is where many plants and animals live.
An ecosystem includes all the living things in the area (community), and how they interact with the physical conditions around them
Explain the difference between community and population
Number of organisms of a particular species in an area is called population
A community is all the living things in an area
Describe how to map the distribution of organisms in a habitat using a transact line
You can count the organisms that touch the tape, such as plants on the ground, to study their distribution.
Explain what it means for an ecosystem to be described as self supporting in all aspects other than an energy source
An ecosystem is self-sufficient, which means that it needs nothing supplied to it, except energy from the Sun
Describe zonation
Gradual change in the distribution of species across a habitat
Explain how a gradual change of an abiotic factor can result in the zonation of organisms in a habitat
Abiotic factors include water, sunlight, oxygen, soil and temperature.
Compare the biodiversity of a natural and artificial ecosystem
A natural ecosystem will have a greater biodiversity as they will be a greater range of organisms
Explain the reasons for the differences in biodiversity in natural and artificial ecosystems
Humans control what organisms live in an artificial ecosystem and remove unwanted species
Word equation for photosynthesis
Water + Carbon dioxide—–> Glucose + Oxygen
Oxygen is the water product
Glucose made in photosynthesis is transported as soluble sugars but is stored as insoluble sugars
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Glucose and starch can be converted to other substances in plants to be used for energy, growth and storage products
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Explain why plants grow faster in the summer
More light
More warmth
Plants carry out respiration as well as photosynthesis
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Describe the development of the understanding of the process of photosynthesis
- the view of Greek scientists was that plants gained mass only by taking minerals from the soil
- Van Helmont’s experimental conclusion that plant growth cannot be solely due to nutrients from the soil
- Priestly’s experiment showed that plants produce oxygen
Explain how experiments using isotopes have increased our knowledge about photosynthesis
Oxygen is produced by photosynthesis comes from water and not carbon dioxide
Describe the two stages of photosynthesis
- light energy is used to split water, releasing oxygen gas and hydrogen ions
- carbon dioxide gas combines with the hydrogen to make glucose
Describe the conversion of glucose and starch to other substances in plants and their use
Glucose for energy (respiration)
Cellulose for cell walls
Proteins for growth and repair
Starch, fats and oils for storage
Explain why insoluble substances such as starch are used for storage
- does not move away in solution from storage areas
- does not affect water concentration within cells
Describe how photosynthesis can be increased by providing:
- more carbon dioxide
- more light
- higher temperature
Explain the effects of limiting factors on the rate of photosynthesis
Carbon dioxide - often the factor in shortest supply, limiting factor of photosynthesis
NOT SURE ASK
Explain why plants carry out respiration at all times
They respire at all times because respiration releases energy required by the plant to grow and survive
Explain why plants take in carbon dioxide and give out oxygen during the day and do the reverse at night
Plants photosynthesise at a faster rate than they respire, taking in more carbon dioxide for photosynthesis and releasing the extra oxygen produced.
Plants respire but do not photosynthesise. Oxygen is taken into the leaf and waste carbon dioxide is released.
Chlorophyll pigments in chlorophyll absorb light energy for photosynthesis
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Entry points of materials required for photosynthesis
Water enters through the root hairs
Carbon dioxide through stomata
Exit point of materials produced in photosynthesis
Oxygen through stomata
Broader the leaf, means more sunlight is absorbed
Name an
How are leaves adapted for efficient photosynthesis
Broad so large surface area
Thin so short distance for gases to diffuse
Contain chlorophyll and other pigments to absorb light from different parts of the spectrum
Have a network of vascular bundles for support and transport
Guard cells which open and close the stomata
Explain how the cellular structure of a leaf is adapted for efficient photosynthesis
Epidermis is transparent
Palisade Layer at the top contains the most number of chloroplasts
Air spaces in the spongy mesophyll allow diffusion between stomata and photosynthesising cells
Internal surface area to Volume ratio is very large
Carotenoids include carotene and xanthophyll, chlorophyll a and b allow the plant to absorb a greater range of light with different wavelengths
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Substances move in and out of cells by diffusion through the cell membrane
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Describe diffusion
Movement of substance from a region high concentration to low concentration
Water moves in and out of plant cells by osmosis through the cell membrane
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Plant cell wall provides support to the plant and lack of water can cause the plant to wilt
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Explain how carbon dioxide and oxygen diffuse in and out of plants through the leaves
To get into a cell, particles pass through the cell membrane. The membrane will only allow small molecules through. This is fine for oxygen and carbon dioxide as they are both small molecules. The process of diffusion does not use energy, because the molecules move spontaneously from regions of high concentration to regions of low concentration.
Water moves in and out of cells through the cell membrane
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Explain the net movement of particles by diffusion from an area of high concentration to an area of low concentration as a consequence of the random movement of particles
NOT SURE
Describe how molecules enter and leave cells by diffusion
Through the cell membrane
Explain how the rate of diffusion can be increased
A shorter distance
Larger surface area
Greater concentration gradient
Describe the term osmosis
Movement of water across a partially-permeable membrane from an area of high concentration to an area of low concentration
It is a type of diffusion
Describe the term partially permeable
A membrane that will allow some molecules through and not others
Explain how plants are supported by the turgor pressure within cells
Water pressure acting against inelastic cell wall
Explain wilting
Lack of turgor pressure
What is plasmolysed cell
When the cell contents collapse away from the cell wall
