Plant hormones (biology only) key terms

plant hormones

Chemicals produced by plants that regulate growth, development, and responses to environmental stimuli.

coordination

The process by which plant hormones work together to control and direct plant growth and responses to stimuli.

Phototropism

A growth response in plants where they bend towards light due to the unequal distribution of plant hormones.

Gravitropism

A growth response in plants where roots grow downwards and shoots grow upwards in response to gravity, influenced by the distribution of plant hormones.

phototropism

In Control and coordination, phototropism means a growth response in plants where they bend or grow towards light. This matters in Plant hormones (biology only) because it supports the learning objective to describe phototropism as a plant growth response to light. Use phototropism only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

light

A form of electromagnetic radiation that plants detect and respond to for growth and development.

gravitropism

A growth response in plants where roots grow downward in response to gravity, while shoots grow upward.

geotropism

The directional growth of a plant in response to gravity, often observed as roots growing downwards and stems growing upwards.

auxin

A plant hormone that regulates growth by promoting cell elongation, particularly in shoots and roots.

unequal growth

The differential growth of plant parts caused by the uneven distribution of auxin, leading to directional growth responses.

gibberellins

In Control and coordination, gibberellins means plant hormones that play a crucial role in promoting seed germination and growth. This matters in Plant hormones (biology only) because it supports the learning objective to explain (HT only) that gibberellins are important in initiating seed germination. Use gibberellins only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

seed germination

The process by which a seed develops into a new plant, initiated by environmental factors and hormones like gibberellins.

ethene

In Control and coordination, ethene means a plant hormone that regulates cell division and is involved in the ripening of fruits. This matters in Plant hormones (biology only) because it supports the learning objective to explain (HT only) that ethene controls cell division and fruit ripening. Use ethene only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

fruit ripening

The process by which fruits mature and develop flavor, texture, and color, often controlled by ethene.

gibberellin

A plant hormone that promotes growth and is involved in processes such as seed germination and flowering.

ethene

In Control and coordination, ethene means a plant hormone that regulates processes including fruit ripening and cell division. This matters in Plant hormones (biology only) because it supports the learning objective to state (HT only) that the detailed mechanisms of gibberellin and ethene action are not required. Use ethene only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

Required Practical 8

An investigation that examines how light or gravity influences the growth of newly germinated seedlings.

Phototropism

A plant growth response where shoots grow towards light, influenced by the distribution of plant hormones.

plant growth data

Measurements and observations recorded to assess the growth of plants, typically including length and other relevant parameters.

labelled biological drawings

Illustrations of plants that include annotations to highlight specific structures or features relevant to their growth and development.

control variables

Factors that are kept constant during an experiment to ensure that the results are valid.

light direction

The orientation from which light is provided to plants, influencing their growth responses.

auxins

In Use of plant hormones (HT only), auxins means plant hormones that promote growth and are used as selective weed killers in agriculture. This matters in Plant hormones (biology only) because it supports the learning objective to describe (HT only) the use of auxins as selective weed killers. Use auxins only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

selective weed killers

Herbicides that target specific plant species, often utilizing auxins to control unwanted vegetation.

auxins

Plant hormones that promote root formation and are used as rooting powders for plant cuttings.

rooting powder

In Use of plant hormones (HT only), rooting powder means a substance containing auxins that encourages root development in plant cuttings. This matters in Plant hormones (biology only) because it supports the learning objective to describe (HT only) the use of auxins as rooting powders for plant cuttings. Use rooting powder only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

auxins

Plant hormones that promote root formation and are used in tissue culture to encourage growth.

tissue culture

A technique used to grow new plants from cells or tissues in a controlled environment, often utilizing auxins.

ethene

In Use of plant hormones (HT only), ethene means a plant hormone that regulates various aspects of growth, including the ripening of fruit. This matters in Plant hormones (biology only) because it supports the learning objective to describe (HT only) the use of ethene to control fruit ripening during storage and transport. Use ethene only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

fruit ripening

The process by which fruits mature and develop flavor, texture, and color, often influenced by ethene.

gibberellins

In Use of plant hormones (HT only), gibberellins means plant hormones that promote growth and are used to end seed dormancy. This matters in Plant hormones (biology only) because it supports the learning objective to describe (HT only) the use of gibberellins to end seed dormancy. Use gibberellins only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

seed dormancy

A period during which seeds are inactive and do not germinate, often requiring specific conditions to break.

gibberellins

Plant hormones that promote growth and are particularly important in stimulating flowering.

flowering

The process by which plants produce flowers, often stimulated by the presence of gibberellins.

gibberellins

In Use of plant hormones (HT only), gibberellins means plant hormones that promote growth and are used to increase fruit size. This matters in Plant hormones (biology only) because it supports the learning objective to describe (HT only) the use of gibberellins to increase fruit size. Use gibberellins only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

fruit size

The measurement of the dimensions of fruit, which can be enhanced by the application of gibberellins.

plant hormones

In Use of plant hormones (HT only), plant hormones means chemicals that coordinate and control plant growth and responses. This matters in Plant hormones (biology only) because it supports the learning objective to evaluate (HT only) agricultural and horticultural uses of plant hormones, including benefits, risks and effects on biodiversity. Use plant hormones only in this subtopic-relevant sense so the definition stays concise, curriculum-specific, and useful for AQA GCSE Biology revision. Students should use this term accurately when they explain the biology, identify symptoms, or justify an answer in GCSE Biology questions.

biodiversity

The variety of life in the world or in a particular habitat or ecosystem, which can be affected by the use of plant hormones in agriculture and horticulture.