🦠 1. Life, Classification & Pathogens
This type of organism makes its own food using photosynthesis and has chloroplasts.
What is a plant?
This organelle controls the activities of the cell and contains genetic material.
What is the nucleus?
This biological molecule is the body's main source of energy and includes sugars and starch.
What are carbohydrates?
This gas is taken into leaves for photosynthesis.
What is carbon dioxide?
This process releases energy from glucose inside cells.
What is respiration?
This group contains organisms such as mushrooms and moulds.
What are fungi?
Put these structures in order from smallest level of organisation to largest: organ, tissue, organelle, organ system, cell.
What is organelle → cell → tissue → organ → organ system?
This food test turns blue-black when starch is present.
What is the iodine test?
This organelle contains chlorophyll and is the site of photosynthesis.
What is the chloroplast?
This organ is the main site of gas exchange in humans.
What are the lungs?
This type of cell contains membrane-bound organelles, including a nucleus and mitochondria.
What is a eukaryotic cell?
A plant cell has a structure that an animal cell does not. It helps support the cell and give it structure. This is the… and it is made from...
What is the cell wall, made from cellulose?
This enzyme breaks down starch into maltose.
What is amylase?
A plant is given plenty of water and carbon dioxide, but is kept in darkness. Which factor is limiting the rate of photosynthesis?
What is light intensity?
These tiny structures inside the lungs are surrounded by capillaries and are the main site of gas exchange.
What are the alveoli?
A virus contains genetic material surrounded by a protein coat but has no cellular structure and cannot reproduce without a host cell. This is one reason viruses are not considered…
What are living organisms?
A microscope produces an image measuring 24 mm of a cell that is actually 60 μm wide. This is the magnification of the image.
What is ×400?
An enzyme works best at pH 2. At pH 7, its activity is extremely low. This suggests that pH has affected the enzyme's…
What is the active site?
These tiny openings in the epidermis of a leaf allow gases to move into and out of the leaf.
What are stomata?
During inhalation, the diaphragm contracts and moves in which direction?
What is downwards?
A scientist examines an unknown microorganism. It is single-celled, has a cell wall, cell membrane, cytoplasm, ribosomes and a circular loop of DNA, but no nucleus. The organism is most likely a…
What is a bacterium?
Bonus - Explain why this organism is classified as prokaryotic.
A cell is observed using a microscope at ×800 magnification. Its image measures 4.8 mm. What is the actual size of the cell, expressed in micrometres?
What is 6 μm?
4.8 mm = 4800 μm
4800 ÷ 800 = 6 μm
An enzyme is heated from 20°C to 80°C. Its rate of reaction initially increases but then rapidly falls to almost zero. Explain what has happened to the enzyme.
What is:
1. The enzyme initially increased in kinetic energy, increasing successful collisions.
2. After it's optimum temperature, it has been denatured because high temperature has changed the shape of its active site, so the substrate can no longer bind effectively?
A plant is placed in bright light with plenty of water. Increasing the light intensity further has almost no effect on the rate of photosynthesis. The plant is now limited by another factor. Name one likely limiting factor and explain why.
What is temperature or carbon dioxide concentration, because increasing light intensity cannot increase the rate if another factor required for photosynthesis is insufficient?
Explain THREE adaptations of alveoli that allow oxygen to diffuse rapidly from the air into the blood.
What are:
Bonus point: A moist surface also helps gases dissolve before diffusing.