Misc Flashcards
Which blood vessel allows for the exchange of food and oxygen?
Capillaries
Where does photosynthesis occur?
Chloroplasts in the leaves of a plant
What is the name of the green pigment in the leaves?
Chlorophyll
What type of reaction is photosynthesis?
Endothermic
What type of energy is used in photosynthesis?
light energy
Give the word equation for photosynthesis
Carbon dioxide + water -> glucose + oxygen
Give the balanced symbol equation for photosynthesis
6CO2 + 6H2O → C6H12O6 + 6O2
Define the term limiting factor
anything that limits the rate of a reaction when it is in short supply
Give the limiting factors of photosynthesis
- temperature
- carbon dioxide concentration
- light intensity
- amount of chlorophyll
Describe how light intensity affects the rate of photosynthesis.
increasing light intensity increases the rate of photosynthesis until another factor becomes limiting
Describe how carbon dioxide concentration affects the rate of photosynthesis
increasing carbon dioxide concentration increases the rate of photosynthesis until another factor becomes limiting
Describe how temperature affects the rate of photosynthesis
increasing temperature increases the rate of photosynthesis as the reaction rate increases- at high temperatures enzymes are denatured so the rate of photosynthesis quickly decreases
Give the equation for the inverse square law for light intensity
light intensity ∝ 1
————
distance2
Why are limiting factors important in the economics of growing plants in greenhouses?
greenhouses need to produce the maximum rate of photosynthesis whilst making profit
How do plants use the glucose produced in photosynthesis?
- Respiration
- Convert it into insoluble starch for storage
- produced fat or oil for storage
- produce cellulose to strengthen cell walls
- produce amino acids for protein synthesis
Why is a leaf an organ?
there are many tissues inside the leaf that work together to perform photosynthesis
How is the upper epidermis adapted for its function?
- single layer of transparent cells allow light to pass through
- cells secrete a waxy substance that makes leaves waterproof
How is the palisade mesophyll adapted for its function?
tightly packed cells with lots of chloroplasts to absorb as much light as possible for photosynthesis
How is the spongy mesophyll adapted for its function?
air spaces increase the surface area and allow gases to diffuse quickly
What is the function of the guard cells?
control the opening and closing of the stomata
What is the function of the xylem?
transport water and mineral ions from the roots to the rest of the plant
Give three adaptations of the xylem
- made of dead cells
- no end wall between cells
- walls strengthened by a chemical called lignin to withstand the pressure of the water
What is the function of the phloem?
transport dissolved sugars from the leaves to the rest of the plant
What is the purpose of translocation?
transport dissolved sugars from the leaves to other parts of the plant for respiration, growth and storage
Define the term transpiration
movement of water from the roots to the leaves through the xylem
What is the purpose of transpiration?
- Provide water to keep cells turgid
- provide water to cells for photosynthesis
- transport mineral ions to leaves
Name four factors that affect the rate of transpiration
temperature, light intensity, humidity, and wind speed
What effect does temperature have on the rate of transpiration?
higher temperatures increase the rate of transpiration
What effect does humidity have on the rate of transpiration?
higher levels of humidity decrease the rate of transpiration
Why does increased light intensity increase the rate of transpiration?
stomata open wider to let more carbon dioxide into the leaf for photosynthesis
What is the function of the stomata?
allow diffusion of gases into and out of the plant
Where are most stomata found?
underside of leaves
What is the advantage to the plant of having a high number of stomata at this location?
reduces the amount of water loss through evaporation
How does pollution cause a decrease in biodiversity?
- It kills plants and animals
Name the level of organisation which best describes the interaction of living organisms with the non-living parts of their environment
- Ecosystem
Which term describes the community of living organisms interacting with the abiotic factors of a specific area?
- An ecosystem
Which risk factors are associated with an increased rate of non-communicable diseases?
- Lifestyle
- Alcohol
- Carcinogens
- Lack of exercise
- Smoking
- Diet
- Ionising radiation
The human body’s first line of defence against pathogens is the non-specific defence system. Describe TWO non- specific defence systems of the human body
Any TWO from:
- Skin- physical barrier
- Nose- hair/mucus trap pathogens
- Trachea/ Bronchi (cilia)/Ciliated cells wafting moving pathogens up and out of the airway
- Stomach- acidic environment kills pathogens
- Tears
- Phagocytes
Which plant tissue provides a protective layer covering the plant?
Epidermal tissue provides a protective layer covering the plant
Function of mitochondria
Site of respiration, which releases energy
Definition of ribosomes
Where protein synthesis occurs
Definition of active transport
The movement of molecules from an area of low concentration to high concentration against the concentration gradient, and so requiring energy
Define biodiversity
Biodiversity is the variety of different species of organisms on Earth
Give 3 ways in which water pollution can occur
- sewage
- Fertilisers
- Toxic chemicals
Give 3 reasons why deforestation has occurred in tropical areas
- Cattle farming
- Rice fields
- Using land to grow biofuels
Name 4 factors that affect the rate of transpiration
- Temperature
- Humidity
- Light intensity
- Wind movement
What does the xylem transport?
The xylem transports water and dissolved mineral ions
If ions are in a higher concentration in a root hair cell compared to the soil, by what process do they enter the plant?
Active transport
Name 7 abiotic factors
Moisture levels, temperature, pH of soil, light intensity, wind intensity + direction, carbon dioxide levels for plants, oxygen levels for aquatic animals
3 factors that affect the rate of decay
temperature, moisture, availability of oxygen
4 biotic factors
Number of predators, presence of disease, availability of mates, competition, number of prey
1 gas produced by anaerobic decay in a biogas generator
Methane
Why does anaerobic respiration release less energy to the environment?
Anaerobic respiration is the incomplete oxidation of glucose
What is the term for the transport of sugars and amino acids in the phloem?
Translocation
How could you measure the rate of photosynthesis more accurately than counting bubbles?
Use a gas syringe
Two uses of peat from a peat bog
Burn as fuel, compost/fertiliser
What is diffusion?
Diffusion is the net movement of particles from areas of high concentration to areas of low concentration down the concentration gradient
What is the purpose of a control?
A control makes sure that the results of the experiment are due to the variables changed and nothing else
word equation for aerobic respiration in yeast
glucose -> carbon dioxide + alcohol
Suggest ONE way how the glucose produced during photosynthesis is used
- converted to starch
- converted to cellulose
- converted to lipids
- used with nitrates to form amino acids
- respiration
What is the name given to the variety of different species in a particular area?
Biodiversity
Explain why a species of plant might require the presence of particular animal in its habitat
The plant may require the animals for pollination or seed dispersal
Describe TWO adaptations of the xylem cell
- Dead cells / lose end walls forming a continuous hollow tube
- Lignin in cell walls gives strength and support
Where does the process of deamination take place?
Liver
What substance is produced by deamination?
Ammonia
What substances are removed from the body when sweating?
Urea
Ions
Water
Give 2 substances which are not filtered out of the kidney
Protein
White blood cells
Explain why proteins and white blood cells are not filtered out of the blood
They are too large to be filtered out of the blood by the permeable membrane
What substances (and how much) is reabsorbed by the kidney?
Some ions
All glucose
Some water
The water level in the body is controlled by the hormone ADH. Where is ADH released from?
Pituitary gland
How does ADH travel to the kidneys?
In the bloodstream
On a Hot day Person A is dehydrated and has not had enough water. How will the body respond?
More ADH is released
What will happen to the volume and concentration of urine produced by Person A in the scenario above?
It will become more concentrated and of a smaller volume
When the kidney fails, one option is to use dialysis as a treatment. What waste substances will move through the partially permeable membrane from the blood into the dialysis fluid?
Urea
Excess ions
Excess water
Give two advantages of treating kidney failure with dialysis rather than a transplant
- readily available
- no risk of rejection
Which plant hormone is responsible for ripening?
Ethene
What is the use of auxin in plant growth and development?
Killing weeds
Which plant hormone is responsible for controlling seed dormancy and germination?
Gibberellin
What happens to the plant cells on the dark side of the shoot when there is more auxin present?
They grow more/faster & longer
What is tropism?
A plant’s response to a stimulus
Which plant hormone is responsible for promoting flowering?
Ethene
What is phototropism?
A plant’s response to light
Why is auxin important in plant growth and development?
It promotes cell elongation
How does auxin affect the growth of the root in gravitropism?
It promotes cell growth in the root
What is the effect of auxin on the cells on the top of the root in gravitropism?
They stop growing
What is the purpose of thickening the lining of the uterus?
To allow implantation of the embryo
On which day is fertilisation most likely to occur?
14
Which hormone causes thickening of the lining of the uterus?
Oestrogen
Which hormone maintains the uterus lining?
Progesterone
Which hormone triggers ovulation?
LH
Which hormone(s) is/are released from the pituitary gland?
LH and FSH
If fertilisation and therefore pregnancy does occur, which hormone do you think remain high?
LH and Oestrogen
What affect does oestrogen have on the other hormones?
stimulate LH
inhibit FSH
What affect does progesterone have on the other hormones?
Inhibit FSH
Inhibit LH
Contraception can be used to lower the chance of pregnancy. Explain how the contraceptive pill works.
Contains hormones to stop eggs maturing
Contraception can be used to lower the chance of pregnancy. Explain how a diaphragm works.
Barrier to prevent sperm reaching the egg
Contraception can be used to lower the chance of pregnancy. Explain how spermicidal cream works.
Kills sperm
