Biology Cell Unit Homework Packet #2

Name Hour

DUE:

HW#2

Cell Size / Hypothesis / ____
Lab / Data Table / ____
Graph / ____
Questions / ____
HW #3
Cell Parts / Accuracy / ____
Reading
Questions
HW #4
Create Your / Completion / ____
Own Cell / Accuracy / ____
Analogy
______/ 5 possible points

Homework #2: Cell Size Lab

(from Biology: Living Systems, pg. 120-121)

Introduction: In this lab, you will determine the size of plant and animal cells. Your teacher will supply a millimeter ruler and a variety of plant and animal cells. You can measure the diameter of the field of view under low power with your millimeter ruler. It will be easier for you to make your measurements in millimeters. However, because cells are very small, convert your answers to micrometers. There are 1000 micrometers (m) in 1 millimeter (mm). (For example, 1.8 mm is equal to 1800 µm).

Problem: How big are cells?

Materials:Microscope

Ruler

Slides of plant and animal cells

Calculator

Methods: 1. Take out your microscope and properly set it up as we did in the

Microscope Lab.

2. Set your microscope to LOW power.

3. Record the Eyepiece and Objective magnification in Table 1.

4. Mathematically, determine the Overall magnification.

5. Use your ruler to measure the diameter of the field of view in

millimeters. Record your answer in Table 1.

6. Convert the diameter in millimeters to micrometers. Record your answerin Table 1.

7. Repeat steps 2 and 3 for MEDIUM and HIGH power.

8. Obtain a slide and estimate the number of cells across the field of view as in Figure 1. Record your answer in Table 2.

9. Individual cell size can be determined using the following equation:

(Field of view diameter) ÷ (# of cells)

Use your math skills to determine the estimated cells of each individual cell in micrometers. Record your answers in Table 2.

Data and Observations:

TABLE 1. Measuring the field of view

Setting

/ Eyepiece magnification / Objective magnification / Overall magnification / Field of View Diameter (mm) / Field of View Diameter (m)

Ex.Super Low

/ 10x / 2x / 10 mm

LOW

MEDIUM

HIGH

TABLE 2. Estimating the size of cells

Cell Type

/ Microscope Setting / # of cells / Estimated Cell Size (m)

EXAMPLE: Mosquito wing

/ Super Low / 10
Frog Blood / High
Testes / High
Corn Stem / Medium
Onion Root / High

Analysis and Conclusions:

-Prepare a bar graph that shows the relationship of cell type (X-axis) to cell size (Y-axis). Be sure to include a title, key, and labeled axis (X and Y) on your graph. DO NOT INCLUDE THE MOSQUITO WING! Neatness counts.

Post-Lab Questions:

Answer the following questions using complete sentences (neatness counts!). I will be really impressed if you use what you know about cells and cell parts to answer them.

  1. Which specific cell type was smallest? Speculate about why it is an advantage for that type of cell to be so small.
  1. Which specific cell type was largest? Speculate about why it is an advantage for the cell of that type to be large.
  1. Why do you think cells are different sizes?

Homework #3: Chapter 5 Reading Questions

(please use complete sentences)

  1. One of the parts of the cell theory states that “all living things are made of cells”. Give three examples of things that would not be made of cells.

A.

B.

C.

  1. Cells of the eye (page 723) are shaped like rods and cones. White blood cells (page 604) are shaped like bumpy round balls. Plant cells (page 583) tend to be more rectangular than animal cells. Why are cells of many different shapes and sizes?
  1. Complete the chart below with either the name or function of the appropriate cell structure.

Structure / Function
Mitochondria
Ribosome
Contains the hereditary information
Storage of water, undigested food, and or wastes
Semi-permeable membrane surrounding nucleus
Storage of digestive enzymes
Contains chlorophyll to attract sunlight energy
Golgi Body
  1. Fill in the following Venn Diagram to compare and contrast animal and plant cells. Which cell parts do they have in common? Which cell parts are unique?
  1. Predict which organ in your body is composed of cells that contain the greatest number of mitochondria. Explain your answer.
  1. In class we learned that plants have large vacuoles. Why would plant cells have larger vacuoles than animal cells?

Homework #4:CREATE YOUR OWN CELL ANALOGY

Over the past few days, you have been learning about cells and comparing them to a factory. To help you get ready for tomorrow’s quiz, I would like you to develop a different comparison. What else is a cell like? How would those parts fit into that analogy?

Work with your partner to develop your own analogy using the chart below. You must be able to use at least 10 of the cell parts that we described in class. In the first column, write the name of a cell part. In the second column, write the job the cell part would have in your analogy. In the third column, give your rationale or reason why that particular cell part would do that job in your analogy.

A cell is like a .

Cell Part / Job / Rationale