Biology paper 1

• What is the word equation for photosynthesis?

  Carbon dioxide + water + sunlight -> glucose + oxygen
• Explain why the walls of the left ventricle are thicker than the walls of the right?

  • left ventricle transports all around body whereas the right ventricle only transports blood to the lungs
  • left ventricle needs more muscle to generate higher blood pressure to push blood further.
• What is the correct sequence in a reflex arc

  • receptor
  • Sensory neurone
  • relay neurone
  • motor neurone
  • Effector
• What is fsh 


  A hormone that causes an egg to mature in the ovary
• Function of oestrogen and progesterone

  • maintains the lining of the uterus
  • Incase egg is fertilised and implanted
• One similarity between phloem and xylem?

  • no nucleus
  • both plant transportation systems
• Three difference between mitosis and meiosis?

  • mitosis produces 2 daughter cells - whereas meiosis produces 4
  • Mitosis has one cell division- meiosis has 2
  • Mitosis produces diploid cells - whereas meiosis produce haploid cells
  • Mitosis produces genetically identical cells - meiosis genetically different cells
• What is homeostasis?


  regulation of internal conditions of an organism to maintain optimum conditions in response to external/internal changes
• Where would you find pacemaker cells in the heart and what do they do?

  • found in the wall of the right atrium and regulates heart rate
  • By sending electrical impulses to heart muscles
• Where are sieve plates found and what is their function ?

  • found in phloem
  • allows movement of sucrose
• What is osmosis?

  • movement of water from a high to low concentration through a partially permeable membrane
• What does a potometer actually measure?

  • volume of water taken up by the shoots
  • Transpiration
• What is diffusion ?

  • net movement of particles from a high to low concentration DOWN the concentration gradient
• Where is genetic information found in a bacterial cell?

  cytoplasm
• What is translocation?

  • the transport of dissolved sugars from leaves to other parts of the plant in the phloem
• What is the pathway of blood around the heart?

  • vena Cava brings deoxygenated blood from body
  • the blood passes from heart to lungs in the pulmonary artery
  • In the lungs the blood collects oxygen
  • Oxygenated blood passes from the lungs to heart in the pulmonary vein
  • This blood is then pumped from heart to the body in the aorta
• Why are leaves broad and flat in shape?

  • to increase surface area and increase rate of photosynthesis
• Which direction can an impulse pass across a synapse

  • only from the neurone that contains the vesicles to the neurone that contains the receptor sites
• Which blood vessel have a valve at the junction between the blood vessel and the heart?

  • aorta
  • pulmonary artery
• What is mitosis?

  • the divisions of cells to produce new cells
  • mitosis allows certain organisms to reproduce asexually
  • These new cells are needed to replace those that die/damaged
• What is active transport ?

  • molecules that moves against the concentration gradient from a low to high concentration that requires engery
• How do xylem cells transport water?

  • up the stem ( from the roots) to the shoots and leaves
• Features of phloem

  • elongated living cells
  • Permeable
  • Transports glucose and amino acids
• Features of xylem

  • elongated DEAD cells with lignin
  • Has no end
  • Impermeable
• difference between transpiration and translocation?

  • translocation occurs in the phloem where transpiration occurs in xylem
  • Translocation transports dissolved sugars where transpiration transports water and minerals
• Which hormone can be used as a selective weedkiller?

  Auxin
• Features of capillaries

  • very thin walls so diffusion pathway is short
  • this allows substances to diffuse rapidly between blood and body cells
  • Carries both oxygenated and deoxygenated blood between veins and arteries
• Which environmental conditions would cause rate of transpiration to be greatest in a plant ?

  High temperature and low humidity.
• Which molecules are all polymers?

  • DNA
  • amino acids
  • starch
• One similarity between mitosis and meiosis

  • DNA replicates
• How are mineral ions absorbed by plant roots?

  Active transport
• One effect of ethene on plant development?

  • stimulates fruit ripening
• What is the function of veins?

  To carry deoxygenated blood back to the heart.
• Describe how deoxygenated blood moves through the heart ?

  • it first enters the right atrium through the vena cava
  • Right atrium contracts and pushes it into the right ventricle
  • right ventricle contracts and pushes it to the lungs to be oxygenated
• Functions of capillaries

  • to transport blood,nutrients and oxygen to the cells in organs and body
  • Take waste products away from the tissues
• Describe how alveoli and villi are adapted to increase absorption?

  • both increase surface area so diffusion is maximised
  • Both have one-cell wall thick so diffusion pathway is shorter
  • Both have good oxygen supply which maintains concentration gradient
  • Villi have microvili which will further maximises surface area and diffusion
• Which hormone controls the permeability of the collecting duct?

  ADH (antidiuretic hormone)
• Urine is transported from the bladder through The…

  • urethra
• What is the effect of ADH on the collecting duct of the kidney tubule?

  • ADH increases permeability to water therefore increases reabsorption
• What are the factors that limit photosynthesis?

  • co2 concentration
  • temperature
  • Chlorophyll in the leaves