Скачать презентацию Basic Genetics Phenotype an organisms observable traits Скачать презентацию Basic Genetics Phenotype an organisms observable traits

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Basic Genetics Phenotype – an organisms observable traits Genotype – the traits that an Basic Genetics Phenotype – an organisms observable traits Genotype – the traits that an organism can pass on to its offspring through its genetic material

Basic Genetics • Genes - basic unit of heredity in a living organism • Basic Genetics • Genes - basic unit of heredity in a living organism • Genes are located on chromosomes – Threadlike structures in the nucleus of each cell • Chromosomes occur in matched pairs • Each species has a characteristic number of pairs of chromosomes in each body cell – Humans? • The two genes (alleles) that control each trait are situated at the same locus, one on each chromosome of a particular pair.

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Basic Genetics Sex Chromosomes and Sex-linked Traits Sex chromosomes may not be matched pairs Basic Genetics Sex Chromosomes and Sex-linked Traits Sex chromosomes may not be matched pairs 2 types of sex chromosomes – carry different genes X Y Female mammals have 2 X chromosomes Male mammals have X and Y chromosomes Sex-linked traits – traits that are influenced by genes on the sex chromosomes Mostly controlled by X chromosome Y chromosome – small, few genes

Basic Genetics The Genetic Code and Gene Expression Several different kinds of genes Structural Basic Genetics The Genetic Code and Gene Expression Several different kinds of genes Structural genes – contain information for the synthesis of a protein Proteins – long chains of AA’s Control cellular activity All cells of the body contain exactly the same structural genes Operator genes – control structural genes (gene expression) Function to determine whether each of its structural genes initiates the synthesis of a protein and at what rate * Major mechanism by which experience can interact with genes to influence development

Mind and Brain Chapter 2 Structure and Functions of Cells of the Nervous System Mind and Brain Chapter 2 Structure and Functions of Cells of the Nervous System

Central Nervous System: Brain • The primary function of the brain is behaviour – Central Nervous System: Brain • The primary function of the brain is behaviour – Sensing – Perceiving – Cognition – Movement

Central Nervous System: Spinal Cord • Primary relay between the external environment and the Central Nervous System: Spinal Cord • Primary relay between the external environment and the brain • The same basic components – meninges – CSF – cells

Introduction • The nervous system consists of 2 basic divisions: – The central nervous Introduction • The nervous system consists of 2 basic divisions: – The central nervous system – the brain and spinal cord – The peripheral nervous system – the part of the nervous system outside the brain and spinal cord, including the nerves attached to the brain and spinal cord

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Protecting the CNS Meninges, Ventricles, and CSF CNS - encased in bone and covered Protecting the CNS Meninges, Ventricles, and CSF CNS - encased in bone and covered by three meninges Dura mater - tough outer membrane Arachnoid membrane - weblike Pia mater - adheres to CNS surface Cerebrospinal fluid (CSF) Fluid serves as a cushion

Protecting the Brain Physical protection Skull Meninges Cerebrospinal fluid (CSF) Chemical protection The blood-brain Protecting the Brain Physical protection Skull Meninges Cerebrospinal fluid (CSF) Chemical protection The blood-brain barrier – tightly-packed cells of blood vessel walls prevent entry of many molecules

Chapter Preview To understand how the nervous system controls behavior, we must first understand Chapter Preview To understand how the nervous system controls behavior, we must first understand its parts – the cells that compose it • Cells of the Nervous System – Neurons – Glial cells • Communication Within a Neuron • Communication Between Neurons

Introduction • The brain is the organ that moves the muscles – Movement, or Introduction • The brain is the organ that moves the muscles – Movement, or behavior, is the primary function of the nervous system – Sensory neuron – a neuron that detects changes in the external or internal environment and sends information about these changes to the central nervous system – Motor neuron – a neuron located within the central nervous system that controls the contraction of a muscle or the secretion of a gland – Interneuron – A neuron located entirely within the central nervous system

Cells of the Nervous System • Neurons – Basic Structure – Soma – cell Cells of the Nervous System • Neurons – Basic Structure – Soma – cell body of a neuron which contains the nucleus. Figure 2. 1

Cells of the Nervous System • Neurons – Basic Structure – Dendrite – branched, Cells of the Nervous System • Neurons – Basic Structure – Dendrite – branched, treelike structure attached to the soma; receives information from other neurons. Figure 2. 1

Cells of the Nervous System • Neurons – Basic Structure – Axon – long, Cells of the Nervous System • Neurons – Basic Structure – Axon – long, thin, cylindrical structure that conveys information from the soma of a neuron to its terminal buttons. Figure 2. 1

Cells of the Nervous System • Neurons – Basic Structure – Terminal Button – Cells of the Nervous System • Neurons – Basic Structure – Terminal Button – bud at the end of a branch of an axon; forms synapses with another neuron Figure 2. 1

Cells of the Nervous System • Neurons – Basic Structure – Synapse – junction Cells of the Nervous System • Neurons – Basic Structure – Synapse – junction between the terminal button of an axon and the membrane of another neuron. – Neurotransmitter – a chemical that is released by a terminal button Figure 2. 4

The Principal Parts: Together The Principal Parts: Together

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Cells of the Nervous System • Neurons – Multipolar – Unipolar – Bipolar • Cells of the Nervous System • Neurons – Multipolar – Unipolar – Bipolar • Glial cells – Various types – Provide a wide variety of supportive functions

Cells of the Nervous System – Types of Neurons • Multipolar Neuron – neuron Cells of the Nervous System – Types of Neurons • Multipolar Neuron – neuron with one axon and many dendrites attached to its soma; most common type in CNS. Figure 2. 1

Cells of the Nervous System Types of Neurons • Bipolar Neuron – neuron with Cells of the Nervous System Types of Neurons • Bipolar Neuron – neuron with one axon and one dendrite attached it its soma. – sensory systems (vision and audition) • Unipolar Neuron – neuron with one axon attached to its soma; the axon divides, with one branch receiving sensory information and the other sending the information into the central nervous system. – somatosensory system (touch, pain, etc) Figure 2. 2

Copyright © 2006 by Allyn and Bacon Copyright © 2006 by Allyn and Bacon