Bio 9C: Wednesday, January 27, 2010Title: Cell Specialization, Part 2

Homework: Read Section 35-2 (pgs 897-900). and take notes using active

reading strategies – see assignment sheet for details.

Do Now: Look over your midterm exam In your notebook, write down:

One thing you did well One thing you could have improved on Any questions you have about the midterm

On the anonymous survey, respond to the survey questions honestly.

Today’s Objectives: Review the Midterm Exam and answer MAJOR questions (individual

issues need to be discussed after school) Describe how different types of cells have different structures to fit

their functions

Today’s Agenda

Review Midterm Exam results Class and grade results Major questions you have

Cell Specialization Investigation Worksheet w/ a partner Class discussion & brief notes

Notes on neurons and divisions of the nervous system

Midterm Exam Results

• Class Average Grade: 81• Class Median Grade: 82

• 9th Grade Average Grade: 76• 9th Grade Median Grade: 79Class Data Graphed

Grade on 2009 Midterm Exam

• Number of 9C Students with each exam score

• 19 students with passing score

A (100

-90)

B (89-

80)

C (79-

70: l

owes

t is 7

5)

D (69-

65)

F (65

-bel

ow)

0

1

2

3

4

5

6

7

Bio 9C Midterm Grades

9C

Objectives for Class:• Describe how different types of cells have different structures to fit their functions• Identify 3 specialized structures of neurons that allow them to receive and transmit signals throughout the body

Investigate Cell SpecializationSpecialized Cells have Specialized Structures

“Typical” Cell “Mystery” Cell

THE NERVOUS SYSTEMPHA Biology 9

Moretti and Dickson

Neurons:Structure and Function

Objectives for Class:• Describe how different types of cells have different structures to fit their functions• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the

body

Neuron = a specialized nerve cell Function: communicate with body organs

by sending electrical signals (impulses) Structure:

Long branches send and receive signals

Cell body coordinatesincoming and outgoing signals

Neurons:Structure and Function

Neurons:Structure and Function

Objectives for Class:• Describe how different types of cells have different structures to fit their functions• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the

body

Dendrites: branched extensions, carry impulses toward cell body

Cell Body: nucleus & organelles

Axon: Takes impulses away from cell body

Neurons:Structure and Function

Objectives for Class:• Describe how different types of cells have different structures to fit their functions• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the

body

Axon

Dendrites

Cell Bod

y

Nervous System:The 2 Major Divisions

Central Nervous System Brain and spinal cord

Brain: Processes information and controls responses

Spinal cord: Links brain to other nerves and controls reflex responses.

Peripheral Nervous System All other nerves throughout the

body Motor neurons send info

from brain to muscles Sensory neurons send info

from sense organs to brain

Image: Adam, Inc.; http://graphics8.nytimes.com/images/2007/08/01/health/adam/8679.jpg

Objectives for Class:• Identify the 2 major divisions of the Nervous System and their major components

Nervous System:Major Divisions Working Together

Objectives for Class:• Identify the 2 major divisions of the Nervous System and their major components

Bio 9C: Thursday, January 28, 2010Title: Reaction Time Lab

Homework: Complete the Reaction Time Lab analysis

Do Now: Briefly Review Pre-Lab

Today’s Objectives: Identify the 2 major divisions of the Nervous

System and their major components Identify 3 specialized structures of neurons

and explain that allow them to receive and transmit signals throughout the body

Lab: Testing the Reaction Time of Different Muscle Groups

Abstract:When a glass drops from a table and shatters, you turn your head to see what happened. This is just one example of how your nervous system senses and responds to stimuli. In this lab, we will test how fast you can react to various stimuli. First, I’ll need a volunteer with cat-like reflexes for a quick demonstration. Then, you’ll test the reaction time of different muscle groups (fingers vs. arms) by measuring how far a meter stick falls before you can catch it.

Demo Part I – Measuring Reaction Time of Finger Muscles

Complete Lab and Record Data Part II – Measuring Reaction Time of Arm Muscles

Complete Lab and Record Data

Objectives for Class:• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the body

Reaction Time Lab: Class Averages

Group Name Finger Reaction (cm) Arm Reaction (cm)

Rishab and Ashley 14.9 cm 15.7 cm

Alejandra and Rowan 14.5cm 22cm

Milly and Michael 16.4 cm 17.9 cm

Yasmine and Aaliyah 20.6 cm 18 cm

Derrell and Jasmine 12.4 14.6

Alain and Kiraleah 14.7 cm 23.5 cm

Nehemie and Hannah 13.6 cm 18.5 cm

Drishti and Maddie 15.4 cm 19.5 cm

Gustavo and Martin 13 cm 16.5 cm

Carl and Erik 10.7cm 11.6cm

Arielle and Beverly 14.4cm 17.8cm

Class Average 14.6 cm 17.8 cm

Bio 9C: Friday, January 29, 2010Title: Structure and Function of Nerve Cells

Homework: In notebook – 2 paragraphs summarizing class notes (see assignment sheet for details…)

How do the brain, spinal cord, sensory nerves, and motor nerves work together to sense and respond to a stimulus?

How does the structure of a neuron fit its function? Prepare for Monday’s in-class essay (quiz grade) by completing the last question on the Reaction Time

Lab Explain how the nervous, muscle, and skeletal systems worked together to allow you to sense

and react to the stimulus in this lab experiment.

As part of your answer: Begin with the stimulus (you can choose one of the experiments you did in class, not both). Explain how the structures of the Nervous System sense the stimulus, transport an impulse, and

transmit it to the Muscle System (10 pts) Explain how the structures of the Muscle System receive the impulse and turn into an action

(contraction). (4 pts) Explain how the Muscle System connects to the Skeletal System and causes movement (6 pts) Be sure to include appropriate vocabulary and terminology.

Do Now: What is the difference between a dendrite and an axon? How do they relate to the overall function of a neuron?

Today’s Objectives: Identify the 2 major divisions of the Nervous System and their major components Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals

throughout the body

Neurons:Structure and Function

Objectives for Class:• Describe how different types of cells have different structures to fit their functions• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the

body

Axon: Takes impulses away from cell body

Dendrites: branched extensions, carry impulses toward cell body

Cell Body: nucleus & organelles

Nerve Impulse:A “wave” of electricity that travels through the neuron

3 Steps of a Nerve Impulse:

1. Dendrites are stimulated by a stimulus (environment or other neuron).

2. Electric impulse travels to cell body.

3. Cell body sends an impulse down the axon to the axon terminals.

Objectives for Class:• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the body

Stimulus! (Sound, smell, sight, taste,

another neuron’s signal)

The “wave” of a nerve impulse

Objectives for Class:• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the body

Neurons communicate with other cells

Muscle cell

Motor neuron

Synapse:The place where a neuron connects to another cell

Other neurons

Objectives for Class:• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the body

Communication At the Synapse

1. Axon terminal releases neurotransmitter (a tiny signal molecule).

2. Neurotransmitter diffuses across synapse and signals the next cell.

3. This triggers an impulse in the next cell.

Objectives for Class:• Identify 3 specialized structures of neurons and explain that allow them to receive and transmit signals throughout the body

Communication w/ Muscle Cells