Question

1. describe an example of a feedback mechanism. include if your example is a positive or negative feedback loop, and how feedback mechanisms, in general, maintain homeostasis. (3 pts)

concept 3 multiple choice (2 pts each)

1. which level of organization is represented by a group of different tissues working together to perform a complex function?

a. cell
b. tissue
c. organ
d. organism

1. research has shown that uncontrolled cell growth and development can lead to which of these diseases?

a. aids
b. cancer
c. hemophilia
d. down syndrome

1. what makes stem cells different from other cells in the body?

a. they are larger than other cells, and can absorb broken cells to repair them.
b. they repair cells by central nervous system → neurons (brain cell) → nerve tissue → brain.
c. they are undifferentiated cells that can turn into a number of different kinds of cells as needed.
d. they are cells that grow uncontrollably.

1. while in the womb, the webbed fingers of the embryo undergo programmed cell death, also known as

a. apoptosis.
b. cytokinesis.
c. carcinogen.
d. stem cells.

1. which of the following is an example of internal regulation during the cell cycle?

a. a gap outside of the cell (caused by a skateboarding accident) triggers cell division.
b. a cell receives a signal from the cells own nucleus to divide.
c. tumor cells continue to divide without receiving a signal.
d. hormones in the blood cause cell growth in a growing teenager.

1. organize the parts of this body system in the correct order (starting with the organism level) according to the levels of organization in a multi - cellular organism.

a. human being → central nervous system → brain → nerve tissue → neurons (brain cell)
b. human being → neurons (brain cell) → brain → central nervous system → nerve tissue
c. human being → central nervous system → neurons (brain cell) → nerve tissue → brain
d. human being → brain → central nervous system → nerve tissue → neurons (brain cell)

1. which of the following is true of malignant tumors?

a. they do not require treatment.
b. they are easily removed through surgery.
c. they can cause tumors in other parts of the body.
d. they contain cells that stay clustered together.

1. if a cell has 8 chromosomes, how many chromosomes will each of its daughter cells have after mitosis?

a. 4
b. 6
c. 8
d. 16

1. during interphase, a cell grows, duplicates organelles, and

a. divides the nucleus
b. doubles its dna
c. divides the cytoplasm
d. produces a new cell

1. which organelle is critical for cell division?

a. centrioles
b. cilia
c. vacuoles
d. vesicles

1. why is it important for cells of multicellular organisms to undergo mitosis?

a. mitosis allows for reproduction with male and female gametes.
b. mitosis increases variation within an organism.
c. mitosis produces cells that are different from the original dividing cell.
d. mitosis produces cells that are identical to the original dividing cell.

Explanation:

Question 20:

An organ is made up of different tissues working together to perform a complex function. For example, the heart is an organ with muscle tissue, connective tissue etc. working together to pump blood.

Question 21:

Uncontrolled cell growth and development leads to cancer. In cancer, cells divide and multiply uncontrollably, forming tumors.

Question 22:

Stem - cells are undifferentiated cells that can turn into a number of different kinds of cells as needed. This is their unique characteristic compared to other body cells.

Question 23:

The webbed fingers of the embryo undergoing programmed cell death in the womb is known as apoptosis. It is a normal biological process for shaping and development.

Question 24:

An example of internal regulation during the cell - cycle is when a tumor cell divides without receiving a signal. This shows abnormal regulation.

Question 25:

The correct order of organization starting from the organism level for the central nervous system is human being → central nervous system → brain → nerve tissue → neurons (brain cell). The organism is the whole entity, then the system, the organ, the tissue, and finally the cell.

Question 26:

Malignant tumors can cause tumors in other parts of the body through metastasis. They are cancerous and spread easily.

Question 27:

After mitosis, daughter cells have the same number of chromosomes as the parent cell. So if a cell has 8 chromosomes, each daughter cell will also have 8 chromosomes.

Question 28:

During interphase, a cell grows, duplicates organelles, and doubles its DNA in preparation for cell division.

Question 29:

Centrioles are critical for cell division as they help in the formation of the spindle fibers that separate the chromosomes during mitosis.

Question 30:

It is important for cells of multicellular organisms to undergo mitosis because mitosis produces cells that are identical to the original dividing cell. This is important for growth, repair, and maintenance of the organism.

Answer:

1. C. Organ
2. B. Cancer
3. D. They are undifferentiated cells that can turn into a number of different kinds of cells as needed.
4. A. apoptosis
5. C. Tumor cells divide without receiving a signal.
6. C. human being → central nervous system → brain → nerve tissue → neurons (brain cell)
7. C. They can cause tumors in other parts of the body.
8. C. 8
9. B. Doubles its DNA
10. A. Centrioles
11. C. Mitosis produces cells that are identical to the original dividing cell.