1.
Anaphase: Sister chromatids separate at the centromeres. Daughter chromosomed are moved to opposite poles of the cell. Motor proteins move the chromosomes along the spindle microtubules. kinetochore microtubules shorten. The cell elongates due to lengthening of nonkinetochore microtubules.
2.
The continuity of life is based on the reproduction of cells, or __________
Explanation
The continuity of life relies on the process of cell division. Cell division is the mechanism by which cells reproduce, allowing for the growth, development, and repair of organisms. Through cell division, a single cell divides into two daughter cells, each containing a complete set of genetic information. This process ensures that genetic material is passed on from one generation to the next, maintaining the continuity of life.
3.
Living Organisms are reproduced by two methods. ___________. Offspring are identical to the original cell or organism. Involves inheritance of all genes from one parent clone.___________. Offspring are similar to parents, but show variations in traits. Involves inheritance of unique sets of genes from two parents.
Explanation
Living organisms can reproduce through two methods: asexual reproduction and sexual reproduction. Asexual reproduction involves the production of offspring that are identical to the original cell or organism. This process does not involve the inheritance of genes from two parents but instead results in clones. On the other hand, sexual reproduction leads to the production of offspring that are similar to their parents but show variations in traits. This method involves the inheritance of unique sets of genes from both parents.
4.
A______ is a group of genetically identical individuals from the same parent.
Explanation
A clone is a group of genetically identical individuals from the same parent. This means that all the individuals in the clone have the same genetic material as the parent, making them identical to each other. Cloning can occur naturally, such as in asexual reproduction, or it can be done artificially in a laboratory setting. Cloning has been used in various fields, including agriculture and medicine, to produce genetically identical organisms for specific purposes.
5.
Binary Fission. "______ ___ ______"
6.
Binary fission occurs in_______ ________. Two_____ cells arise from ______ cell.
Explanation
Binary fission is a form of asexual reproduction in which a single prokaryotic cell divides into two identical daughter cells. This process is commonly observed in prokaryotic organisms such as bacteria. In binary fission, the parent cell replicates its genetic material and then splits into two daughter cells, each containing a complete set of genetic material. These daughter cells are identical to each other and to the parent cell, as they arise from the division of a single cell. Therefore, the correct answer is prokaryotic cells, identical, one.
7.
In Unicellular organisms, division of one cell _______ the entire organism.
Explanation
In unicellular organisms, division of one cell reproduces the entire organism. This means that when a unicellular organism divides, it creates two identical daughter cells, each capable of independent life. This process allows unicellular organisms to multiply and increase their population.
8.
Multicellular organisms depend on cell division for: Development from a fertalized cell, growth, repair.
Correct Answer
A. True
Explanation
Cell division is essential for multicellular organisms for several reasons. Firstly, it is necessary for the development of an organism from a fertilized cell, as the cell divides and differentiates into specialized cells and tissues. Additionally, cell division is responsible for growth, as cells continuously divide and increase in number. Lastly, cell division plays a crucial role in repairing damaged tissues and replacing old or dying cells. Therefore, it is true that multicellular organisms depend on cell division for development, growth, and repair.
9.
Cell divion is an integral part of the______. the life of the a cell from formation to its own division.
Correct Answer
B. Cell cycle
Explanation
Cell division is an integral part of the cell cycle, which encompasses the entire life of a cell from its formation to its own division. The cell cycle consists of a series of events that occur in a specific order, including growth, DNA replication, and cell division. Therefore, the correct answer is the cell cycle.
10.
Most cell division_____ results in daughter cells with identical genetic information, DNA
Correct Answer
A. Mitosis
Explanation
Mitosis is the correct answer because it is the process of cell division that occurs in somatic cells, resulting in the formation of two daughter cells that are genetically identical to the parent cell. During mitosis, the DNA is replicated and then divided equally between the two daughter cells, ensuring that they have the same genetic information as the parent cell. Meiosis, on the other hand, is a type of cell division that occurs in germ cells and results in the formation of gametes (sperm and egg cells) with half the genetic information of the parent cell. Gametes are also not identical to the parent cell.
11.
A special type of divison ______ produces non identical daughter cells (gametes, or sperm, and egg cells.
Correct Answer
Meosis
Explanation
Meiosis is a special type of cell division that produces non-identical daughter cells, specifically gametes or sex cells such as sperm and egg cells. During meiosis, the parent cell undergoes two rounds of division, resulting in four haploid cells with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction as it introduces genetic variation among offspring, contributing to the diversity of species.
12.
Eukaryotic chromosomes are composed of ______.
Correct Answer
C. Chromatin
Explanation
Eukaryotic chromosomes are composed of chromatin. Chromatin is a complex of DNA, RNA, and proteins that condenses to form chromosomes during cell division. It is the material that makes up the structure of chromosomes and contains the genetic information of an organism.
13.
Every eukaryotic species has a characteristic number of chromosomes in each cell nucleus. ______ ______. (non reproductive cells_ have two sets of chromosomes. ________. (reproductive cells: sperm and egsg) have half as many chromosomes are somatic cells.
Correct Answer
Somatic cells. Gametes
Explanation
Somatic cells are non-reproductive cells in eukaryotic species that have two sets of chromosomes. On the other hand, gametes, which include sperm and eggs, have half as many chromosomes as somatic cells. This is because during the process of reproduction, gametes need to combine with another gamete to form a complete set of chromosomes in the offspring. Therefore, the correct answer is somatic cells and gametes.
14.
The cell cycle is an ordered sequence of events for cell division. it consists of two stages.________, and ________ _______.
Correct Answer
Interphase, Mitotic phase.
Explanation
The cell cycle is a process that cells go through in order to divide and reproduce. It consists of two main stages: interphase and the mitotic phase. Interphase is the longest stage, where the cell grows and prepares for division by duplicating its DNA. The mitotic phase is the shorter stage, where the cell actually divides into two daughter cells. During this phase, the duplicated DNA is evenly distributed to each daughter cell.
15.
Interphase: duplication of cell contents
Correct Answer
A. G1-growth, increase in cytoplam.... S-duplication of chromosomes....G2-growth,preparation for division
Explanation
The correct answer is the sequence of events that occur during the interphase of the cell cycle. During the G1 phase, the cell grows in size and increases its cytoplasmic content. This is followed by the S phase, where the chromosomes are duplicated. Finally, during the G2 phase, the cell continues to grow and prepares for cell division. This sequence of events is essential for the proper progression of the cell cycle and the accurate division of genetic material.
16.
Mitosis progresses through a series of stages: Prophase, Prometaphase, metaphase , Anaphase
Correct Answer
B. False
Explanation
Prophase, Prometaphase, Metaphase, Anaphase, and Telophase.
17.
Interphase in the cytoplam contains what?
Correct Answer
A. Cytoplasmic contents double, Two centromsomes
Explanation
During interphase, the cytoplasmic contents of a cell double, which means that the amount of cytoplasmic material increases. Additionally, two centromeres are present during interphase. Centromeres are specialized regions of a chromosome that play a crucial role in cell division by connecting the chromosomes to the spindle fibers. Therefore, the correct answer is "Cytoplasmic contents double, Two centromsomes."
18.
Interphase in the nucleus.
Correct Answer
B. Chromosomes duplicate during the S pHase, Nucleoli, sites of ribosome assembly, are visible.
Explanation
During interphase in the nucleus, the chromosomes duplicate during the S phase. Additionally, nucleoli, which are responsible for ribosome assembly, are visible. This indicates that the cell is in a phase of active growth and preparing for cell division. The duplication of chromosomes ensures that each daughter cell will receive a complete set of genetic material. The visibility of nucleoli further supports the idea of active cell metabolism and protein synthesis.
19.
How many cells are available by the end of interphase
Correct Answer
C. 46
Explanation
Interphase is the longest phase of the cell cycle, where the cell grows and prepares for division. During interphase, the cell undergoes DNA replication, resulting in two identical copies of each chromosome. Since each chromosome consists of two sister chromatids, the total number of chromatids is doubled. Therefore, by the end of interphase, there are 46 chromatids or 46 cells available for division.
20.
How many chromosomes are present in one cell?
Correct Answer
A. 46
Explanation
In humans, each cell typically contains 46 chromosomes. Chromosomes are thread-like structures that carry genetic information in the form of genes. They are found in the nucleus of cells and come in pairs, with 23 pairs of chromosomes in total. These pairs consist of one chromosome inherited from the mother and one from the father. Therefore, the correct answer is 46, as it represents the total number of chromosomes present in one cell.
21.
How many chromatids are present in one cell
Correct Answer
B. 92
Explanation
In a cell, the number of chromatids is equal to the number of chromosomes. During cell division, each chromosome duplicates to form two sister chromatids held together by a centromere. Therefore, the correct answer is 92, indicating that there are 92 chromatids present in one cell.
22.
Prophase: In the ________, microtubules begin to emerge from centrosomes, forming the spindle.
Correct Answer
cytoplasm
Explanation
During prophase, microtubules start to emerge from the centrosomes, which are located in the cytoplasm of the cell. These microtubules then go on to form the spindle, an important structure involved in cell division. Therefore, the correct answer is cytoplasm.
23.
Prophase: In the _______, chromosomes coil and become compact, and the nucleoli dissappear.
Correct Answer
nucleus
Explanation
During prophase, the chromosomes in the nucleus undergo coiling and condensation, which allows them to become more compact. This compactness facilitates the movement and organization of the chromosomes during cell division. Additionally, the nucleoli, which are responsible for the production of ribosomes, disappear during prophase. This is because the cell's energy and resources are redirected towards the process of cell division, and the nucleoli are no longer needed at this stage.
24.
The _____ _______ is am apparatus of microtubles that controls chromosomes movement during mitosis.
Correct Answer
Mitotic spindle
Explanation
The mitotic spindle is an apparatus made up of microtubules that plays a crucial role in controlling the movement of chromosomes during mitosis. It helps to separate the duplicated chromosomes and ensure that each new cell receives the correct number of chromosomes. The microtubules of the mitotic spindle attach to the chromosomes and exert forces to align and separate them, ultimately leading to the formation of two daughter cells. The correct answer, "Mitotic spindle," accurately describes this important structure involved in cell division.
25.
During prophase, assembly of spindle microtubules begins in the _________, the microtuble organizing center.
Correct Answer
centrosome
Explanation
During prophase, the assembly of spindle microtubules starts in the centrosome, which is the microtubule organizing center. The centrosome plays a crucial role in cell division as it helps in the formation of the mitotic spindle, which is responsible for separating the chromosomes during cell division. It contains a pair of centrioles surrounded by pericentriolar material, which serves as a nucleation site for microtubules. As prophase initiates, the centrosome begins to duplicate, forming two centrosomes that migrate to opposite ends of the cell, preparing for the formation of the spindle apparatus.
26.
The centrosome replicates, forming ____ centrosomes that migrate to opposite ends of the cell, as spindle microtubules grow out from them.
Correct Answer
two
Explanation
During cell division, the centrosome, which is responsible for organizing the microtubules, undergoes replication. This results in the formation of two centrosomes. These replicated centrosomes then migrate to opposite ends of the cell. As the centrosomes move, spindle microtubules start growing out from them. Therefore, the correct answer is two, indicating that two centrosomes are formed during replication.
27.
An _____ (a radial array of short microtubules) extends from each centrosome. The spindle includes the centrosomes, the spindle microtubules, and the asters
Correct Answer
aster
Explanation
An aster is a radial array of short microtubules that extends from each centrosome. It is a part of the spindle, which includes the centrosomes, the spindle microtubules, and the asters. The asters play a crucial role in cell division, as they help to organize and position the spindle apparatus during mitosis or meiosis. They also aid in the separation of chromosomes by anchoring the spindle poles to the cell cortex.
28.
By the end of metaphase, how may chromosomes are present in one human cell?
Correct Answer
A. 46
Explanation
By the end of metaphase, there are 46 chromosomes present in one human cell. This is because during metaphase, the chromosomes align at the equatorial plate of the cell and are ready to be separated into two daughter cells during the subsequent stages of cell division. In humans, the normal diploid number of chromosomes is 46, with 23 pairs of chromosomes, one set inherited from each parent.
29.
By the end of Anaphase, How many chromosomes are present in one human cell?
Correct Answer
B. 92
Explanation
During anaphase, the sister chromatids of each chromosome separate and move to opposite poles of the cell. As a result, each pole receives a complete set of chromosomes. In humans, the normal diploid number of chromosomes is 46. Therefore, by the end of anaphase, there are 92 chromosomes present in one human cell.
30.
At the end of Metaphase, how many chromatids are present in one human cell?
Correct Answer
C. 92
Explanation
During metaphase, the chromosomes align along the center of the cell and each chromosome consists of two identical sister chromatids. Since humans have 46 chromosomes, there will be a total of 92 chromatids present in one human cell at the end of metaphase.