Module 1 Study on Your Own

Question 1

1.1 Certain muscles are attached to your skeleton by tendons. What kind of tissue makes up tendons?

Answer 1

The text says that connective tissue attaches one thing to another in your body. That’s what the tendons are doing: attaching muscles to the skeleton. Thus, the tendons are made of connective tissue.

Question 2

1.2 Although we did not explicitly list them, we discussed several levels of organization in the human body. List each level.

Answer 2

1. organism
2. organ system
3. organs
4. tissues
5. cells
6. organelles
7. molecules

Question 3

We already discussed shivering as a response to the body being cold. Here’s basically how it works. Receptors in the skin send temperature information to the hypothalmus, a structure in the brain. If the hypothalmus decides that the temperature is too low, one thing it can do is send instructions via the nervous system to the muscles. These instructions cause the muscles to start moving rapidly, which we observe as shivering. This increased movement warms the body.

Answer 3

Answer the following questions based on the question.

Question 4

1.3 Is this a negative or positive feedback system?

Answer 4

This s clearly a negative feedback system, because the stress (temperature decreases) results in the opposite effect (temperature increases).

Question 5

1.4 What is the control center for the system?

Answer 5

The control center is the hypothalmus.

Question 6

1.5 What is the effect?

Answer 6

The effector is the structure that actually causes the change that is opposite of stress. The muscles are the effectors, because they generate the heat.

Question 7

1.6 Based on the description is the endocrine system involved in this process

Answer 7

No. Since hormones are not mentioned. the endocrine system is not involved.

Question 8

1.7 A microbiologist is looking at a cell under a microscope. It has a large number of Golgi apparatuses in it. What, most likely, is the cell’s major function?

Answer 8

The cell probably secretes chemicals. The Golgi apparatus packages chemicals to send outside the cell.

Question 9

1.8 Substances regularly travel into and out of cells. If a substance travels into a cell what is the first structure it will encounter?

Answer 9

The plasma membrane is the boundary of the cell which makes it the first structure encountered by any substance attempting to enter the cell.

Question 10

1.9 What part or parts of Figure 1.4 (p. 16) illustrate transcription and what part or parts illustrate translation?

Answer 10

Trasnlation – the middle structure

Translation - the bottom illustration

Question 11

1.10 Suppose an mRNA strand has the following nucleotides:

Answer 11

uracile, guanine, cytosine, uracil adenine, adenine

Question 12

1.10a How many codons are on the mRNA?

Answer 12

2 codons in this sequence (there are 3 nucleotides in a codon)

Question 13

1.10b How many tRNAs will bind to this strand?

Answer 13

2 tRNA (each tRNA binds to a single codon)

Question 14

1.10c What are the nucleotide sequences of the anticodons on those tRNAs?

Answer 14

the first tRNA will have adenine, cytosine, guanine it its anticodon, and the second tRNA will have adenine, uracil and uracil in its anticodon

Question 15

1.10d What was the original sequence of nucleotides on the DNA strand from which this mRNA strand was formed?

Answer 15

adenine, cytosine, guanine, adenine, thymine, thymine

Question 16

1.11 A human cell has 46 chromosomes. If the illustration in Figure 1.5 (p.17) were of a human cell, how many “X” shapes would there be in the prophase and metaphase illustrations?

Answer 16

Remember, each “X” is a chrmosome and its duplicate. The duplication happens during interphase, and te X-shape is a result of that. In the end, then, there will only be one “X” shape for every chromosome, so there will be 46 chromosomes.

Question 17

1.12 Supposed you placed a cell in a nonpolar fluid. Suppose further that the plasma membrane was disturbed. In this kind of environment, could the plasma membrane reassemble? Why or why not?

Answer 17

The plasma would not reassemble. The outside in this example is nonpolar, so the phospholipids on the outerpart of the membrane would not know where to point.

Question 18

1.13 In each of the cases below, indicate which path (dissolving through the phospholipids, channel proteins, charged channel proteins, or carrier proteins) the molecule will take to the center of the cell.

Answer 18

a. Chloride ions
b. simple sugars
c. fatty acids
d. water molecules

Question 19

1.13a chloride ions

Answer 19

The chloride ions since charged will go through charged channel proteins.

Question 20

1.13b simple sugars

Answer 20

Simple sugars are larger molecules. Glucose is an example. Since we talked about glucose needing carrier proteins, it should make sense that simple sugars in general need carrier proteins.

Question 21

1.13c fatty acids

Answer 21

Fatty acids are fat soluble and will dissolve through the phospholipids

Question 22

1.13d water molecules

Answer 22

Water molecules go through the channel proteins.

Question 23

1.14 A glucose molecule travels into a cell via a carrier protein. If that process required no ATP, what can you say about the relative concentration of glucose inside and outside of the cell?

Answer 23

the concentration of glucose inside the cell is lower than that outside the cell

Question 24

1.15 A calcium ion travels outside a cell from the inside. This process requires ATP. What can you say about the relative concentration of calcium ions inside and outside of the cell?

Answer 24

the concentration of calcium is higher outside the cell than inside