Plant Transport
What tissue transports water in plants?
Xylem
What organ pumps blood around the body?
Heart
What is the main function of guard cells?
To open and close stomata
What type of digestion occurs in the mouth?
Mechanical and chemical
What gas do plants take in for photosynthesis?
Carbon dioxide
What is the name of the tissue that moves sugar through a plant?
Phloem
Which blood vessels carry blood away from the heart?
Arteries
What leaf layer contains the most chloroplasts?
Pallisade mesophyll
Where are nutrients absorbed in the digestive system?
Small intestine
What gas do animals release during cellular respiration?
carbon dioxide
In what direction does xylem transport substances?
Upward only
What is the main function of capillaries?
Exchange of gases and nutrients with tissues
Describe one structural feature of arteries and explain its function.
Arteries have thick, muscular walls and elastic tissue, allowing them to withstand and maintain high pressure as blood is pumped from the heart. The elasticity helps maintain a continuous blood flow between heartbeats.
Name the two types of digestion and describe each.
Mechanical digestion involves the physical breakdown of food (e.g. chewing in the mouth, churning in the stomach).
Chemical digestion involves the use of enzymes and acids to break down complex molecules into simpler ones (e.g. amylase breaking down starch, stomach acid breaking down proteins).
Why are stomata mostly found on the underside of leaves?
Stomata are located mainly on the underside of leaves to reduce excessive water loss from direct sunlight and wind. This position still allows for effective gas exchange while helping conserve water in the plant.
Name and describe the theory that explains how water moves through a plant.
Transpiration-cohesion-tension theory
Explain why the left ventricle has a thicker wall than the right ventricle.
The left ventricle has a thicker muscular wall because it needs to pump blood to the entire body through the systemic circulation, requiring more pressure. In contrast, the right ventricle only pumps blood to the lungs, which is a shorter, lower-pressure circuit.
Compare the structural organisation of xylem and phloem in a dicot stem.
xylem and phloem are arranged in vascular bundles around the perimeter. Xylem is typically located on the inner side of each bundle (toward the centre), while phloem is on the outer side (toward the epidermis). This arrangement supports the stem structurally and allows efficient transport of water (xylem) and nutrients (phloem).
Compare the digestive tract of a herbivore and a carnivore.
Herbivores have longer digestive tracts, often with specialised structures like a large caecum or rumen to help break down cellulose in plant material.
Carnivores have shorter digestive tracts as protein is easier to digest and doesn’t require fermentation. They also have strong stomach acids to digest meat quickly.
Describe how the structure of alveoli supports gas exchange in mammals.
Alveoli have a large surface area, are one cell thick, and are surrounded by capillaries. This allows for rapid diffusion of oxygen into the blood and carbon dioxide out. Their moist lining also helps gases dissolve for easier diffusion.
Compare two structural features of xylem and phloem and explain how they relate to function.
Xylem consists of dead, hollow cells (tracheids and vessel elements) that form continuous tubes. This structure allows for efficient, unidirectional transport of water from roots to leaves without obstruction.
Phloem is made up of living cells, including sieve tube elements and companion cells. The sieve tubes have pores that allow for bidirectional flow of sugars and nutrients, enabling movement from sources (e.g. leaves) to sinks (e.g. roots or fruits).
These structural differences support their roles: xylem for passive water transport, and phloem for active nutrient distribution.
Identify all four chambers of the heart and describe the path of blood through them.
Deoxygenated blood enters the right atrium from the body via the vena cava.
It flows into the right ventricle, which pumps it to the lungs via the pulmonary artery.
Oxygenated blood returns from the lungs into the left atrium.
It then moves into the left ventricle, which pumps it to the body through the aorta.
Describe how leaf structure supports both photosynthesis and gas exchange.
Leaves have a large surface area for capturing sunlight. The palisade mesophyll contains many chloroplasts to maximise photosynthesis. The spongy mesophyll has air spaces that allow efficient gas diffusion. Stomata on the underside control gas exchange and water loss, while a thin structure ensures short diffusion distances for CO₂ and O₂. Together, these features optimise both photosynthesis and gas exchange.
Describe how structure supports absorption in the small intestine.
The small intestine has villi and microvilli that greatly increase the surface area for absorption. These structures contain capillaries and lacteals to absorb nutrients into the bloodstream and lymphatic system. The thin epithelial lining and rich blood supply allow for efficient nutrient transfer.
Explain how gas exchange structures in plants and animals are similar in function but different in structure.
In plants, gas exchange occurs through stomata and intercellular spaces; in animals, it occurs in alveoli within lungs. While structures differ (pore-like vs sac-like), both have thin surfaces, moist environments, and are surrounded by a transport system (xylem or blood vessels) to maintain concentration gradients.