Give an example of a single gene whose alteration affects language.

Mutation of the FOXP2 gene runs in families whose members have severe difficulty with the fine movements of speech and with grammar, and the normal protein controls the expression of other genes while the brain develops.

Why can a change in one gene have such widespread effects on the brain?

Some genes code for regulatory proteins that switch many other genes on or off, so a change in one of them alters the expression of a whole set of genes.

How does an inherited fault in a single enzyme damage the developing brain in phenylketonuria?

The child cannot convert phenylalanine to tyrosine, so phenylalanine accumulates to concentrations that are toxic to the developing brain and cause severe intellectual disability.

Why is phenylketonuria a good illustration of genes and environment acting together?

The faulty gene causes damage only if the diet supplies phenylalanine, so a strictly controlled diet from birth allows a child with the same genotype to develop normally.

Eduqas A-Level Biology A400QS

Biological Molecules

Topic overview Inorganic ions and the properties of water Monosaccharides and disaccharides Polysaccharides, storage and structure Lipids, triglycerides and phospholipids Amino acids and protein structure Condensation, hydrolysis and the food tests

Cell Structure and Organisation

Topic overview The nucleus and the endomembrane system Mitochondria, chloroplasts and other organelles Prokaryotic cells and viruses Cell theory, microscopy and measuring cells Comparing cells and the levels of organisation

Cell Membranes and Transport

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Enzymes

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Nucleic Acids and Their Functions

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Importance of ATP

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Photosynthesis

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Microbiology

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Inheritance

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Variation and Evolution

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Homeostasis and the Kidney

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The Nervous System

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Immunology and Disease: Disease and Its TransmissionImmunology

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Immunology and Disease: AntibioticsImmunology

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Immunology and Disease: The Immune ResponseImmunology

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Human Musculoskeletal Anatomy: Skeletal TissuesMusculoskeletal

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Human Musculoskeletal Anatomy: Structure and Function of the SkeletonMusculoskeletal

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Human Musculoskeletal Anatomy: JointsMusculoskeletal

Topic overview Types of joint in the human body The structure of a synovial joint Osteoarthritis and rheumatoid arthritis Joints as levers Antagonistic muscle action in the forelimb

Neurobiology and Behaviour: The BrainNeurobiology

Topic overview The structure of the human brain The functions of the cerebrum, cerebellum and medulla oblongata The hypothalamus and the control of the endocrine system The sympathetic and parasympathetic nervous systems Sensory and motor areas, the homunculus and language

Neurobiology and Behaviour: NeuroscienceNeurobiology

Topic overview Non-invasive study of the brain: CT and MRI Functional imaging: fMRI, PET and EEG Brain development and critical periods Neuroplasticity Gene expression, brain development and mental illness

Neurobiology and Behaviour: BehaviourNeurobiology

Topic overview Innate behaviour: escape reflexes, kineses and taxes Habituation and imprinting Classical and operant conditioning Primate societies and the costs and benefits of group living Insect castes, dominance hierarchies, territory and courtship

Neurobiology and Behaviour: Neuroscience

Gene expression, brain development and mental illness

3 things to know
Component 3

Overview

Gene expression, single gene whose alteration affects language and epigenetic change.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Give one benefit and one risk of being able to identify children at raised genetic risk of mental illness.

Key term

What is meant by gene expression?

Key term

How can genes influence the development of the brain?

Questions from this subtopic

Each one with the model answer underneath.

1
What is meant by gene expression?
Model answer
Gene expression is whether a gene is switched on in a particular cell and transcribed, and how much of its protein is made.
2
How can genes influence the development of the brain?
Model answer
They code for the proteins that control how neurones divide and migrate, guide growing axons to their targets, and form the receptors and transmitters at synapses, so an altered protein alters the wiring.
3
Give an example of a single gene whose alteration affects language.
Model answer
Mutation of the FOXP2 gene runs in families whose members have severe difficulty with the fine movements of speech and with grammar, and the normal protein controls the expression of other genes while the brain develops.
4
Why can a change in one gene have such widespread effects on the brain?
Model answer
Some genes code for regulatory proteins that switch many other genes on or off, so a change in one of them alters the expression of a whole set of genes.
5
How does an inherited fault in a single enzyme damage the developing brain in phenylketonuria?
Model answer
The child cannot convert phenylalanine to tyrosine, so phenylalanine accumulates to concentrations that are toxic to the developing brain and cause severe intellectual disability.
6
Why is phenylketonuria a good illustration of genes and environment acting together?
Model answer
The faulty gene causes damage only if the diet supplies phenylalanine, so a strictly controlled diet from birth allows a child with the same genotype to develop normally.

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