1.
The majority of a cell's life.
Correct Answer
A. InterpHase
Explanation
Interphase is the correct answer because it is the longest phase in the cell cycle, accounting for about 90% of a cell's life. During interphase, the cell grows, carries out its normal functions, and replicates its DNA in preparation for cell division. It is a crucial stage for the cell to ensure proper growth and division. The other options (metaphase, prophase, anaphase, and telophase) are all stages of mitosis, which occur after interphase.
2.
During which phase of mitosis do the chromosomes line up along the middle of the dividing cell?
Correct Answer
B. MetapHase
Explanation
During metaphase of mitosis, the chromosomes line up along the middle of the dividing cell. This phase occurs after prophase, where the nuclear envelope breaks down and the chromosomes condense, and before anaphase, where the sister chromatids separate and move towards opposite poles of the cell. In metaphase, the spindle fibers attach to the centromeres of the chromosomes and align them along the metaphase plate, ensuring equal distribution of genetic material to the daughter cells.
3.
When the DNA in a cell is uncoiled and spread throughout the nucleus it is called
Correct Answer
D. Chromatin
Explanation
When the DNA in a cell is uncoiled and spread throughout the nucleus, it is called chromatin. Chromatin is the relaxed form of DNA, which allows for gene expression and DNA replication. It consists of DNA wrapped around proteins called histones, forming a structure known as nucleosomes. This uncoiled state of chromatin allows the DNA to be accessible for various cellular processes, such as transcription and DNA repair.
4.
Tightly coiled DNA is referred to as
Correct Answer
C. Chromosomes
Explanation
Tightly coiled DNA is referred to as chromosomes. Chromosomes are the condensed and organized form of DNA that are visible during cell division. They contain genetic information and are essential for the transmission of traits from one generation to the next.
5.
The sister chromatids are held together by the
Correct Answer
B. Centromeres
Explanation
The sister chromatids are held together by centromeres. Centromeres are specialized regions of DNA that act as attachment points for proteins called kinetochores. These kinetochores bind to microtubules during cell division, allowing the sister chromatids to be pulled apart and distributed to the daughter cells. Centrioles, centrosomes, and centrochores are not directly involved in holding sister chromatids together. Centrioles are involved in organizing the microtubules, centrosomes are the main microtubule organizing centers in animal cells, and centrochores are the specialized regions of the centromeres where the kinetochores are formed.
6.
Which of the following stages would this picture best represent?
Correct Answer
A. PropHase
Explanation
This picture best represents the stage of Prophase because it shows condensed chromosomes, which is a characteristic feature of this stage. During Prophase, the nuclear envelope breaks down, and the chromosomes condense, becoming visible under a microscope. This picture accurately depicts the condensed chromosomes, indicating that it is in the Prophase stage of cell division.
7.
Which of the following stages of mitosis best describes the picture below?
Correct Answer
D. TelopHase
Explanation
The picture shows a stage of mitosis where the chromosomes have reached opposite poles of the cell and are starting to decondense. This stage is called telophase. In telophase, the nuclear envelope reforms around the separated chromosomes, and the cell prepares to divide into two daughter cells.
8.
Which of the following would you find DNA being replicated?
Correct Answer
A. InterpHase
Explanation
DNA replication occurs during the interphase of the cell cycle. Interphase is the phase between cell divisions where the cell prepares for division by growing in size, replicating its DNA, and synthesizing new organelles. During interphase, the DNA molecule unwinds and separates into two strands, and each strand serves as a template for the synthesis of a new complementary strand. This process results in the formation of two identical copies of the DNA molecule, which are then distributed to daughter cells during cell division. Therefore, DNA replication would be found during interphase.
9.
Which phase of the cell cycle does this represent?
Correct Answer
D. InterpHase
Explanation
Interphase is the phase of the cell cycle where the cell prepares for division. During this phase, the cell grows, carries out its normal functions, and duplicates its DNA. It is the longest phase of the cell cycle and is divided into three subphases: G1, S, and G2. In G1 phase, the cell grows and carries out its normal functions. In S phase, the DNA is replicated. In G2 phase, the cell continues to grow and prepares for cell division. Therefore, since Interphase is the phase where the cell is not actively dividing, it is the correct answer.
10.
Which phase does this picture represent?
Correct Answer
B. MetapHase
Explanation
The picture represents metaphase because it shows the chromosomes aligned along the equator of the cell. In metaphase, the nuclear envelope has dissolved, and the chromosomes are condensed and attached to spindle fibers. This alignment is important for the equal distribution of chromosomes during cell division.
11.
When a plant cell divides during cytokinesis it forms a ________ instead of a cleavage furrow.
Correct Answer
cell plate
Explanation
During cytokinesis in plant cells, a cell plate is formed instead of a cleavage furrow. This is because plant cells have a rigid cell wall that prevents the formation of a furrow. Instead, a cell plate, which is made up of vesicles containing cell wall material, forms between the two daughter cells. The cell plate gradually expands outwards, fusing with the existing cell wall, and eventually dividing the parent cell into two separate daughter cells. This process allows for the proper separation and growth of the plant cells.
12.
Spindle fibers pull sister chromatids apart to separate poles in what phase of mitosis?
Correct Answer
A. AnapHase
Explanation
During anaphase of mitosis, the spindle fibers attach to the centromeres of sister chromatids and pull them apart towards opposite poles of the cell. This separation ensures that each daughter cell receives a complete set of chromosomes. Therefore, anaphase is the correct answer as it accurately describes the phase in which the spindle fibers play a crucial role in separating sister chromatids.
13.
Prokaryotes and eukaryotes divide in exactly the same way.
Correct Answer
B. False
Explanation
Prokaryotes and eukaryotes do not divide in exactly the same way. Prokaryotes, which include bacteria, divide through a process called binary fission, where the DNA replicates and the cell splits into two identical daughter cells. On the other hand, eukaryotes, which include plants, animals, and fungi, divide through a process called mitosis, where the DNA replicates and the cell undergoes a series of complex steps to divide into two daughter cells. Therefore, the statement is false as the division processes of prokaryotes and eukaryotes differ.
14.
What is the purpose of the cell dividing?
Correct Answer
D. All of the above
Explanation
The purpose of cell dividing is multifaceted. It allows for growth, as new cells are created to increase the size of an organism. It also facilitates repair, as damaged or injured tissues can be replaced by new cells. Additionally, cell division is responsible for creating an exact replica of itself during the process of reproduction. Therefore, all of the given options - growth, repair, and creating an exact replica - are correct purposes of cell dividing.
15.
A Human cell contains 23 chromosomes. After replication during Interphase, the cell would contain how many?
Correct Answer
B. 46
Explanation
During interphase, the cell undergoes DNA replication, where each chromosome is duplicated. Therefore, the cell would contain double the number of chromosomes after replication. Since a human cell normally contains 23 chromosomes, after replication during interphase, the cell would contain 46 chromosomes.