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86 Cards in this Set
- Front
- Back
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What are the components of an animal cell?
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Nucleus, cytoplasm, cell membrane, mitochondria and ribosomes
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What are the components of a plant cell?
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Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, cell wall, vacuole and chloroplasts
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What does the nucleus do?
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Contains genetic material and controls the activities of the cell
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What does cytoplasm do?
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Contains enzymes which control the chemical reactions that take place within it
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What does the cell membrane do?
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Holds the cell together and controls what goes in and out
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What do mitochondria do?
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Provide energy to the cell from respiration reactions
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What are ribosomes?
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Where proteins are made in the cell
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What does the cell wall do?
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Supports and strengthens the cell - made of cellulose
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What is contained within the vacuole?
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Cell sap
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What are chloroplasts?
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Where photosynthesis occurs - contains chlorophyll
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What are the components of a single-cell organism?
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Nucleus, cytoplasm, cell membrane and a cell wall
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What's the difference between a single-cell organism and a bacterial cell?
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Bacterial cells have no nucleus
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What is diffusion?
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The spreading out of particles from an area of high concentration to an area of low concentration
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How do substances move in and out of a cell?
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By diffusing through the cell membrane
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What is a specialised cell?
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A cell which has been differentiated to perform a specific purpose
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What is a tissue?
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A group of similar cells which work together to perform a specific function
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What is an organ?
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A group of different tissues which work together to perform a function
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What is an organ system?
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A group of organs working together to perform a function
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What is the job of xylem and phloem?
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To transport water, mineral ions and sucrose around the plant
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What is the equation for photosynthesis?
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Carbon dioxide + water => glucose + oxygen
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What does photosynthesis produce?
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Glucose
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What is a limiting factor?
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A variable that limits the rate of photosynthesis
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Name the main 3 limiting factors
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Light intensity, volume of carbon dioxide and temperature
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Name 4 ways that plants use glucose
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For respiration, making cell walls, making proteins and storing in seeds
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What do plants do with excess glucose?
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Store it as starch
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How are nitrogen ions used in plants? |
Growth an building proteins |
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What are phosphate ions used for in plants? |
Respiration and growth |
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How are potassium ions used in plants? |
Respiration and photosynthesis |
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What are magnesium ions used for in plants? |
Photosynthesis |
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What is the distribution of an organism?
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Where an organism is found
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What are the main factors that affect a plant's distribution? |
Light and carbon dioxide |
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What are the differences between a quadrat and a transect?
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A quadrat measures how common an organism is in various sample areas, whereas a transect shows how an organism's distribution changes over a certain area
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What is the population size?
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An estimate of how many of a certain type of organism are in a total area based on how many there were in a sample area
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What is an enzyme?
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A chemical which speeds up chemical reactions in the body - a natural catalyst
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What are enzymes made of?
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Long chains of amino acids, folded to produce a unique shape
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What is an active site?
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A place on the surface of the enzyme which allows it to attach to the reactants to speed up their reaction
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What is the molecule that binds to the enzyme called?
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The substrate
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What are the main three factors that affect how enzymes work?
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Temperature, pH, and substrate concentration
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Why does temperature and pH affect enzymes?
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Because they interfere with the bonds holding the enzyme together
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How does substrate concentration affect the rate of reaction?
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It increases it, until the point of saturation
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What happens when an enzyme is denatured?
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The active site is distorted, meaning the enzyme will no longer work
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What is the job of digestive enzymes?
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To break down large molecules into small ones
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What is the job of amylase?
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To break down starch into sugars
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What is the job of protease? |
To break down proteins into amino acids |
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What is the job of lipase? |
To break down lipids into glycerol and fatty acids |
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What does bile do? |
Neutralises stomach acid and emulsifies fats |
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Why do large molecules need to be broken down?
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So they are small enough to be absorbed
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What is a competitive inhibitor?
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An inhibitor which binds to the enzyme's active site in place of the substrate
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What is a non-competitive inhibitor?
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An inhibitor with a different shape to the reactant, which binds to a point on the enzyme which distorts the active site
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How can enzymes be produced industrially?
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By using fermentation
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What is respiration?
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The process of releasing energy from glucose
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What is aerobic respiration?
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Respiration using oxygen
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What is the word equation for aerobic respiration?
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Glucose + oxygen => carbon dioxide + water + (energy)
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Why does exercise increase your heart rate?
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Because more glucose and oxygen need to be supplied to your muscles
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What is glycogen?
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A form of stored glucose
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What is anaerobic respiration?
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Respiration which uses glucose to provide energy rather than oxygen
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What is the disadvantage to anaerobic respiration?
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Lactic acid is produced, which causes muscle fatigue
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What is an oxygen debt?
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After anaerobic respiration, people will breathe heavily to 'pay back' the oxygen which they didn't have as it oxidises the lactic acid which has been produced
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What is a chromosome?
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A long molecule of DNA
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How do cells make proteins?
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A gene contains the instructions to string 20 amino acids together in a particular order
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What determines a cell's type?
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The proteins which it produces
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How many chromosomes do people generally have?
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46 (23 pairs)
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What is mitosis?
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When a cell reproduces by splitting into two identical offspring
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What do we call reproduction by mitosis?
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Asexual reproduction
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What is a gamete?
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A cell which has only one copy of each chromosome
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What is meiosis?
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When a cell splits into two with only one copy of each chromosome
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What do we call reproduction by meiosis?
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Sexual reproduction
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What is a stem cell? |
An undifferentiated cell |
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What's the difference between an embryonic stem cell and and an adult stem cell? |
Embryonic stem cells can become any type, whereas those found in adult bone marrow can only become certain types |
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Why is embryonic stem cell research controversial? |
Because people argue that embryos are a potential life and therefore have the same rights as other humans. |
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Why is embryonic screening controversial? |
It may lead to 'designer babies' |
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What was the significance of Gregor Mendel's experiments? |
He discovered how characteristics in plants were passed on from one generation to the next - the foundation of modern genetics |
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What is your genotype? |
The alleles which you have |
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What is your phenotype? |
The characteristics which you exhibit |
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If someone inherits a dominant and a recessive allele, would their phenotype show the dominant or recessive trait? |
Dominant |
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What is a carrier? |
A person who carries only one recessive allele for a recessive genetic disorder so doesn't suffer with it |
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What are fossils? |
The remains of plants and animals |
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Name 3 ways fossils can form |
From gradual replacement by minerals, from leaving imprints in soft materials, and from preservation in places where decay microbes cannot survive |
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When does extinction happen? |
When an organism can't evolve quickly enough to adapt to changes in their habitat |
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What is a species? |
A group of organisms which can reproduce with each other to produce fertile offspring |
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What is speciation? |
Where organisms of the same species become so different from each other that they cannot reproduce fertile offspring, so are classified as different species |
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What two factors lead to speciation? |
Isolation and natural selection |
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Name the three stomach tissues |
Muscular tissue, glandular tissue, and epithelial tissue |
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What does muscular tissue do? |
Moves the stomach wall to churn up food |
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What does glandular tissue do? |
Makes digestive juices to digest food |
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What does epithelial tissue do? |
Covers the outside and inside of the stomach |
