Biology B1: Cells, Living Processes and Biodiversity

Life at every scale

Biology B1 looks at life from the smallest scale to the whole living world. Every organism is built from cells: animal cells have a nucleus, cytoplasm, a cell membrane and mitochondria, and plant cells add a cell wall, chloroplasts and a vacuole. Cells carry out living processes. In photosynthesis, plants use light energy to turn carbon dioxide and water into glucose, giving out oxygen. In respiration, all living cells release energy from glucose. Substances move in and out of cells by diffusion and osmosis. Zoom out and organisms live together in ecosystems, linked by food chains from producers to consumers, with energy lost at each step. The range of living things in a place is its biodiversity. This module surveys cells, processes and biodiversity.

Biology words

Learn these before you match anything, and keep photosynthesis and respiration clearly apart.

Photosynthesis against respiration

Two key processes are easy to confuse because they are almost mirror images of each other.

How living things fit together

Read biology from small to large. Cells are the units, and they group into tissues, organs and whole organisms. Each living thing runs on processes: plants build food by photosynthesis, and every cell frees energy by respiration. Organisms then share an ecosystem, connected by food chains that run from a producer to the consumers that eat it, with energy lost at every link. Trace that ladder, from a single cell up to the biodiversity of a habitat, and the topic hangs together.

Match the term to its meaning

Which process is this?

A green plant in sunlight takes in carbon dioxide and water and makes glucose, releasing oxygen. Which process is this?

• Photosynthesis.
• Respiration.
• Diffusion.
• Digestion.

Cells and processes

Select the TWO true statements about cells and living processes.

• Plant cells have chloroplasts for photosynthesis
• Respiration happens in all living cells
• Only plants need to respire
• Animal cells carry out photosynthesis

Energy lost in a food chain

A plant captures 1000 units of energy. Only 100 units pass to the animal that eats it. Subtract to find how many units of energy are lost at that step.

Order a food chain

Put this food chain in order, starting with the source of energy.

• The Sun, the source of energy
• A green plant, the producer
• A rabbit, the primary consumer
• A fox, the secondary consumer

Complete the biology facts

The building block of every living thing is the _____. Plants make glucose using light energy in _____. All living cells release energy from glucose in _____. The variety of living things in an area is its _____.

Match the organism to its role

Spot the true biology facts

Tap the TWO statements that are true about the living world.

• Photosynthesis uses light to make glucose
• Energy is lost at each step of a food chain
• Animals make their own food by photosynthesis
• Plant cells never respire

Explain the living world

Read each case and choose the best response, with a reason.

• A student says a fox is a producer because it is at the top of the food chain. How should this be corrected?
• A student asks why a long food chain supports fewer top predators than short ones. What is the reason?
• A student thinks only plants respire because only plants photosynthesise. How should this be corrected?

Explain cells, processes and biodiversity

A student is revising Biology B1. Explain how life works from the level of cells up to whole ecosystems.

• Name the main parts of a plant cell
• Explain what happens in photosynthesis
• Explain what happens in respiration and where it occurs
• Explain how a food chain transfers energy from a producer
• Finish by explaining what biodiversity means