BIOLOGY UNIT 2 SET 3 QUIZ

Question 1

How are cancer cells different from normal cells?

Answer 1

Cancer cells are different from normal cells because cancer cells usually don’t die at all while normal cells follow the normal cell cycle of growth, division and death. Instead, cancer cells don’t die. They keep on multiplying which can lead to the formation of abnormal cells.

• which can attack different parts of the body like the breast (breast cancer), the lungs (lung cancer), liver (liver cancer), and pancreas.

Question 2

Compare and contrast the causal agent(s) for HIV/AIDS and Cancer. (Similarities and Differences)

Answer 2

• HIV/AIDS and cancer are similar because both weaken the immune system.
• The difference between the two is that HIV/AIDS is a contagious disease transferred by bodily fluids/sexual contact. Cancer is a non contagious disease and is caused by the over dividing and refusal to die by cells.

Question 3

Why might chemotherapy used to kill cancer cells also kill cells like hair follicle cells?

Answer 3

Chemotherapy uses radiation to kill fast growing cancer cells and hair follicles are also fast growing so it kills them as well which is why people lose hair when going through Chemotherapy.

Question 4

What body system does cancer weaken?

Answer 4

The immune system; it weakens it.

Question 5

What is the function of the small intestine?

Answer 5

The function of the small intestine is to absorb nutrients and water from digested food.

Question 6

Why is the function of the small intestine important to maintaining homeostasis?

Answer 6

This function is important to maintain homeostasis because it makes sure the body gets the needed nutrients and water to function properly and to regulate the body’s fluid balance by absorbing water which prevents dehydration and maintains a stable internal environment within the human body.

Question 7

Explain why severe diarrhea can be dangerous to maintaining homeostasis in the body.

Answer 7

Diarrhea can be dangerous to maintain homeostasis in the body by taking away the necessary nutrients and water that regulate homeostasis within the human body.

Question 8

Compare and contrast the viruses that cause AIDS and Rotavirus. (Similarities and Differences)

Answer 8

Similarities:
- The viruses that cause AIDS and Rotavirus are both infectious agents that require a host cell to replicate. Both have a significant impact on global health as well as they both have preventative measures like vaccines.

Differences:
- AIDS is transmitted through sexual contact and in rare cases blood while Rotavirus is transmitted primarily through contaminated food or water, airborne droplets, and contact with contaminated surfaces.

Question 9

From your understanding based on the activities in this unit, describe the effect of severe diarrhea osmosis in cells.

Answer 9

The loss of water would cause dehydration and affect the balance of fluids inside and outside cells. The severe loss of nutrients and water through the principle of osmosis the water leaves the cell which then causes the cell to shrivel.

Question 10

What evidence from the rotavirus case study explains why more than 85% of Rotavirus deaths occur in Southeast Asia and Africa?

Answer 10

The distribution of improved sanitation levels explains why more than 85% of Rotavirus deaths occur in southeast Asia and Africa. This is because Southeast Asia and Africa have 37% and 33% of improved sanitation levels while the rest have at least 60% or more improved sanitation levels.

• Rotavirus is an infectious virus which is why it’s important to have high sanitation levels in your country.

Question 11

What body system does Rotavirus affect?

Answer 11

The digestive system because it infects and kills the cells along the small intestine track which takes away nutrients and water from the body.
- This causes one of the symptoms like diarrhea.

Question 12

Cellular Mechanism of Rotavirus: (What and how infected)

Answer 12

The infectious disease called Rotavirus is known as an RNA virus that can infect cells that line the small intestine, which absorb nutrients and water. When Rotavirus kills/infects these intestine cells, unabsorbed nutrients and water leave the body quickly through diarrhea/vomit which makes the human weak and dehydrated.

• The disease Rotavirus is transmitted through contaminated food or water, airborne droplets, and contact with contaminated surfaces.

Question 13

Cellular mechanism of Cancer? (What and how)

Answer 13

= genetic mutation

It develops over several years and in most types of cancer, as an original cancer cell divides through many cell cycles, a mass of cells develops that can form a tumor. Some types of cancer vary in tumor production. The cancer cells crowd the blood and prevent normal blood cells from carrying out their functions.

There is not a found causal cause but scientists notice that you can get cancer from genetics, and environmental factors and behavioral factors like smoking.

Question 14

Describe the structure of a chromosome.

Answer 14

• mass of long, thin fibers. (chromatin)
• chromatin; it’s a combination of DNA and protein molecules.
• two copies called sister chromatids which contain identical copies of the DNA.
• Almost all genes are found in the cell nucleus in multiple chromosomes.

Question 15

What are the stages of the cell cycle and describe what occurs in each stage. (Interphase: G1,S,G2 / Mitosis)

Answer 15

Interphase (Interphase is what’s responsible of the span of the division of all cells):

G1:
- In the G1 stage, the growth of the cell and the increase in cytoplasm occurs.

S:
- In the Synthesis stage, duplication of chromosomes/DNA occurs.

G2:
- In the G2 stage, growth and preparation for cell division and mitosis occurs.

Mitosis
- In the mitosis stage, the division of the nucleus occurs.

Question 16

Describe the process of DNA replication.

Answer 16

• enzymes unwinds the double helix creating room for replication, the enzyme breaks the hydrogen bonds between the two strands of DNA, separating them and forming two single-stranded templates.
• RNA primers initiate the process and these primers are necessary for DNA polymerase to start adding nucleotides that match with the corresponding base pair already in the original DNA.
• DNA polymerase will add nucleotides to the 3’ end of the RNA primer, making a new strand complementary to the original strand.
• The result is two identical DNA molecules, each with one original strand and one new strand.

Question 17

Explain how DNA replication is semi-conservative.

Answer 17

DNA replication is semi-conservative because of the process of DNA replication.
- When each helix is made it has one copied helix strand. This means that one helix replication leads to two daughter delices which each obtain one of the original helical strands.

Question 18

What are the structures that play a role in mitosis? (Include when they appear and their function.)

Answer 18

• The nucleus
  :is the control center of the cell, containing chromosomes made of DNA that carry instructions for protein synthesis. Proteins are essential for structure and enzyme functions, speeding up chemical reactions. During prophase, the chromosomes condense and become visible under a light microscope.
• Centrioles
  :are paired organelles in the cytoplasm that participate in cell division. They duplicate and move to the cell poles, anchoring the spindle fibers. New centrioles form during the S phase of the cell cycle.
• Microtubules
  :are miniature tubes that act as the cell’s skeleton. During mitosis, they rearrange into spindle fibers that attach to chromosomes and help move them. The mitotic spindle begins to develop during prophase, with microtubules assembling between the centrosomes to pull the duplicated chromosomes apart.

Question 19

Describe each stage of mitosis. (Prophase, Prometaphase, Metaphase, and Anaphase)

Answer 19

Prophase -Chromosomes condense, spindle fibers form, and chromosomes are captured by spindle.

Prometaphase - the nuclear membrane breaks down, and chromosomes attach to spindle fibers

Metaphase - Chromosomes align along the equator of the cell, with one chromatid facing each pole.

Anaphase - Sister chromatids separate, spindle fibers attach to kinetochores shorten and pull chromatids towards the poles, and free spindle fibers lengthen and push the poles of the cells apart.

Telophase - Spindle fibers disintegrate, nuclear envelopes form around both groups of chromosomes, and chromosomes revert to their extended state.

Question 20

What occurs during cytokinesis?

Answer 20

The physical process of Cytokinesis is when the cytoplasm and organelles which then completes the process of dividing the cells.
- During cytokinesis, the cell equator gets pinched at by the cell membrane and the cytoplasm splits. This process differs between animal cells and plant cells.

Question 21

What is the difference between cytokinesis in a plant cell and an animal cell?

Answer 21

• In a plant cell, vesicles gather in the center of the cell during telophase to form a cell plate, which grows outward and eventually becomes part of the cell wall, resulting in two daughter cells.
• In an animal cell cytokinesis involves the formation of a cleavage furrow, where a ring of actin and myosin microfilaments contracts to pinch the cell into two.

Question 22

How is cell division controlled?

Answer 22

Cell division is controlled by a system of proteins to prevent the formation of tumors. Internal controls by the name checkpoints also regulate every phase of cell division. These checkpoints allow the cell cycle molecules to move up a stage in the cell cycle.

Question 23

What is the difference between a benign and malignant tumor?

Answer 23

• A benign tumor isn’t a malignant (cancerous) tumor. It grows more slowly than a cancerous tumor, has even borders and, unlike cancerous tumors, it won’t spread to other parts of your body.
• • a benign tumor is a tumor that can cause problems if they grow in and disrupt certain organs but can often be removed by surgical procedure.
• Which differs from a malignant tumor which is a tumor that can spread into neighboring tissues and other parts of the body, displacing normal tissue and interrupting organ function.

Question 24

Why do tumors occur?

Answer 24

: It is the cause of an extra amount of cell division in one’s body.

• Tumors occur because if the body does not find the transformed cell as abnormal and destroys it, the cell may proliferate to form a tumor.

Question 25

What are two types of cancer treatments?

Answer 25

The two types of cancer treatments are chemotherapy and high-energy radiation treatment, and surgery.

Question 26

Explain mitosis. In your explanation include the preparations that take place during interphase.

Answer 26

Mitosis is a crucial step for cell splitting and is where the division of the nucleus occurs. - To prepare for Interphase the cell replicates its DNA, grows and duplicates organelles needed for Mitosis.

Question 27

In mitosis, how does each daughter cell’s chromosomes compare to the chromosomes of the parent?

Answer 27

Each daughter cell’s chromosomes are exactly the same to the chromosomes of the parent. This is due to the fact that during mitosis the chromosomes and DNA of the parent cell are replicated to ensure that it is exactly the same as the daughter cell’s chromosomes.

Question 28

A friend of yours claims that every genetically modified single-celled organism that reproduces asexually would pass along the inserted gene to its daughter cells. Based on your work in this activity, is that claim valid? Explain.

Answer 28

Based on my work in this activity, the claim that every genetically modified single-celled organism that reproduces asexually would pass along the inserted gene to its daughter cells is valid and trustworthy. This is because in asexual reproduction there is only one gene which is the parents, this means that the DNA is copied exactly the same which means that the modified single-celled organisms which reproduce asexually would pass along the inserted gene to its daughter cells every time.

Question 29

What benefits and risks might the asexual reproduction of a genetically modified organism or cell pose?

Answer 29

BENEFITS: - If they modify the start population, all will have the inserted genes. RISKS: - There's a chance that the genetically modified organism could be introduced to unmodified organisms nearby. *Could affect other unmodified organisms.

Question 30

Why is it important for the entry into the cell cycle to be regulated?

Answer 30

Entry into the cell cycle is important to make sure that cells divide when needed which wards off uncontrolled cell growth which can lead to cancer and making sure that mutations are not duplicated to ensure proper DNA before cell replication.

Question 31

Why is it important for the progress fom one phase of the cell cycle to the next to be regulated?

Answer 31

If one stage is not done correctly it could lead to mutations and there are going to be errors in DNA if mutations are duplicated which can lead to the cells death which is why the progress from one phase of the cell cycle to the next is important. That is why there are checkpoints between each stage to verify if the cell is healthy and ready to replicate.

Question 32

A cell in the liver divides. Its offspring and all of their offspring continue to divide as fast as they grow and synthesize DNA. Is this likely to be a problem? Why or why not

Answer 32

This scenario is likely to be a problem; many cells are replicating way too rapidly. This could be harmful for the liver because a large cell mass would form due to too many cells in one area which could lead to cancer and could damage the liver tissue.

Question 33

How would you describe the structure of DNA to a 10-year-old?

Answer 33

- The structure is a double helix and it is like a coil that wraps around itself, sort of looking like a spiral staircase or a twisted ladder. - The sides of the ladder are made of sugar and phosphate molecules, these are like the rails of the ladder you hold onto. - The steps of the ladder are made of nucleotides with pairs of molecules called bases. - There are four types of bases: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). These bases always pair up in a specific way, A with T and C with G. The bases are paired with hydrogen bonds which are how the bases connect together, think of it like glue. The structure of DNA holds genes which give traits to your body and holds your genetic information.

Question 34

Write the complementary strand of DNA for the following nucleotide sequence. 5’ - A T C G C C - 3’

Answer 34

3’ T A G C G G 5’

Question 35

Arrange the following cell structures from the smallest to the largest, left to right: (2 pts) a. DNA b. Chromosomes c. Gene d. Cell e. Nucleotide f. Nitrogen Base

Answer 35

Smallest to Largest (Up to Down) 1) Nitrogen Base 2) Nucleotide 3) Gene 4) DNA 5) Chromosomes 6) Cell

Question 36

How does identifying alternate hypotheses help scientists design and analyze experiments?

Answer 36

Identifying alternate hypotheses help many scientists design and analyze experiments by giving a wide variety of viewpoints and help scientists to collaborate ideas for increased accuracy in their hypotheses.

Question 37

How does the actual method of replication ensure that the copied DNA is identical to the original DNA?

Answer 37

The polymerase uses each strand of DNA as a template and copies it to complement and correspond with the base pairs already in the original data so it is guaranteed that the copied DNA is identical to the original DNA.

Question 38

Why is DNA so packaged up within the nucleus?

Answer 38

The nucleus is so small for the DNA to be so long, so it twists itself to save space.

Question 39

Explain how DNA provides information that directs the processes in a cell.

Answer 39

By storing genetic instructions within its sequence of nucleotides (A,T,C,G), which are then "read" by the cell to produce proteins.

Question 40

Explain cancer and what happens in the cell cycle when one has cancer?

Answer 40

Cells grow and divide uncontrollably due to disruptions in the normal cell cycle, caused by genetic mutations that bypass the body's usual checks and balances, allowing damaged cells to replicate without stopping, - leading to the formation of tumors that can spread to other parts of the body;

Question 41

Why do cells undergo mitosis?

Answer 41

Cells undergo mitosis to enable growth and development of an organism by creating new cells that are genetically identical to the parent cell, as well as to replace old or damaged cells that need to be repaired throughout an organism's life.

Question 42

Predict the percentage of asexually produced offspring that will inherit an inserted gene from a genetically modified parent.

Answer 42

100% - it is asexually replicated so thats why.

Question 43

Explain the structures that are responsible for the ability of rotavirus to only infect specific types of cells.

Answer 43

- Selective binding mechanism in viruses.

Question 44

Which cell organelles and structures are involved in protein production?

Answer 44

1)Ribosomes 2) rough endoplasmic reticulum 3) golgi apparatus 4) DNA

Question 45

Explain why HIV must infect a host cell.

Answer 45

HIV needs to infect a host cell because it is unable to reproduce on its own and also lacks the organelles and structures which allow it to reproduce. Once it infects the nucleus and the DNA of the host cell, it can take over the cell’s organelles and reproduce as a virus cell.

Question 46

Explain how the HIV virus uses specific structures to enter the cell.

Answer 46

The proteins on the surface of the HIV virus bind to receptors (CD4) on the exterior of the host cell and this allows the virus to fuse with the cell.

Question 47

List the structures and organelles inside the cell that an HIV virus needs if it is to reproduce.

Answer 47

1) cytoplasm 2) DNA in the nucleus 3) ER 4) golgi apparatus 5) cell membrane 6) ribosomes 7) vesicles

Question 48

Describe how HIV uses each structure and organelle during the infection proces

Answer 48

- cytoplasm - the virus needs the room and space in the cytoplasm in order to convert the virus’s rna into dna . - nucleus - synthesises the virus’s dna and sends this out of the nucleus - rough ER - makes virus proteins - golgi apparatus - makes receptors that go to the exterior of the cell - cell membrane - uses the receptors to enter the cell - ribosomes - the infected host cell have ribosomes which are used to convert the HIV viral RNA into proteins necessary for the virus to replicate - vesicles - transport components like proteins and genetic material to nearby cells

Question 49

Which classes of proteins were shown in the HIV infection animation and what function did each of those classes of proteins perform in the virus infection cycle?

Answer 49

a) receptors and enzymes b) - receptors - allow the virus to enter the cell - enzymes - convert viral RNA into dna and they are used to reproduce new viruses

Question 50

How did your ideas about the steps of the HIV infection inside a cell change before and after viewing the simulation?

Answer 50

Before the simulation I thought the virus infected other organelles before hijacking the nucleus, however the simulation showed me that the virus, once its rna is converted into dna, has a straight path to the nucleus.

Question 51

If you were a researcher of HIV/AIDS, explain which part of the infection process you would be most be interested in if you were trying to find a way to: a. prevent HIV from entering cells. b. prevent HIV from reproducing.

Answer 51

a) - the bonding of the proteins, on the HIV virus cell, to the receptors, on the host cell, during the process of the virus entering the cell. In order to prevent this you could attack the proteins on the exterior of the virus cell and this would prevent it from entering the cell. b) - investigate the hijacking of the nucleus, and preventing it from reproducing could be caused by stopping the viral rna being converted into dna, or prevent viral proteins being made in the golgi apparatus.

Question 52

HIV infects cells of the immune system, while rotavirus infects cells of the intestine. What structures do you think are responsible for the ability of each virus to only infect specific types of cells?

Answer 52

The proteins can only bind to certain types of receptors on other cells. For example hiv proteins can only bind to the receptors immune cells however they can’t bind to the receptors on intestinal cells.