Posts

Showing posts from November, 2022

11.) State differences between the events of meiosis and mitosis.

Image
   11.) State differences between the events of meiosis and mitosis.  A.) Meiosis Meiosis is a type of cell division that results in the formation of four daughter cells each with half the number of chromosomes as the parent cell.   Mitosis Mitosis is the type of cell division that results in the formation of two daughter cells each with the same number and kind of chromosomes as the parent cell. Table of Contents Introduction Key Differences Mitosis – Overview Meiosis – Overview Similarities Conclusion Difference Between Mitosis And Meiosis Introduction In single-celled organisms, cell reproduction gives rise to the next generation. In multicellular organisms, cell division occurs not just to produce a whole new organism but for growth and replacement of worn-out cells within the organisms. Cell division  is always highly regulated and follows a highly orchestrated series of steps. The term cytokinesis refers to the division of a cell’s cytoplasm, while mi...

10.) Describe the different phases of meiotic prophase – I. Mention the chromosomal events during each stage.

Image
  10.)    Describe the different phases of meiotic prophase – I. Mention the chromosomal events during each stage. A.) Prophase-I occurs over a long duration and involves several complicated changes in meiotic cell division. It is important because genetic recombination and variation in sexually reproducing organism occurs due to the events of this phase. Leptotene (i) The chromatin network opens out and threads become clear. (ii) The chromosomes are thin, slender and long. (iii) Chromosome number is diploid. Zygotene (i) Corresponding chromosomes become intimately associated. (ii) The process of pairing is known as synapse. It is so exact that pairing is not merely between corresponding chromosomes but between corresponding individual units. (iii) The chromosomes become shorter and thicker. Pachytene or Pachynema (i) The synaptic chromosomes become very intimately associated. (ii) The pair of chromosomes becomes short and thick. (iii) Crossing over occurs at this stage. ...

9.) How much time will two E. Coli cells take to become 32 cells if the average duplication time of E. coil is 20 minutes? What is the role of centrioles apart from spindle formation?

Image
  1.      9,)  How much time will two E. Coli cells take to become 32 cells if the average duplication time of E. coil is 20 minutes? What is the role of centrioles apart from spindle formation?  A,) How much time will two E. Coli cells take to become 32 cells if the average duplication time of E. coil is 20 minutes?  1 hour - 20 minutes These are the 4 subsequent cell divisions to produce 16 cells and each division takes =20 min No. of cells formed after each division is 2  to form 32 cells, the E.coli cells need to undergo 5 division cycles, ( 2 5   ) = 32 cells The duration for each cycle is 20 mins. Therefore, the total time required for 5 cycles is 20 X 5 =100 min  or 1 hr 40 mins 1.      What is the role of centrioles apart from spindle formation? The two centrioles in the centrosome lie perpendicular to each other. Each has organisation like a cart wheel. These form the basal body of cilia and flagella of plan...

7.) Write an essay on different phases of mitosis with suitable diagrams.

Image
7.)     Write an essay on different phases of mitosis with suitable diagrams. A.) Mitosis Definition “Mitosis is that step in the cell cycle where the newly formed DNA is separated and two new cells are formed with the same number and kind of chromosomes as the parent nucleus.” Mitosis is a process of asexual reproduction observed in unicellular organisms. Read on to explore what is mitosis, and the different stages of mitosis. What is Mitosis? Cell division is the driving process of reproduction at the cellular level. Most eukaryotic cells divide in a manner where the ploidy or the number of chromosomes remains the same, except in the case of germ cells where the number of chromosomes is halved. Mitosis Diagram showing the different stages of mitosis Mitosis is the phase of the cell cycle where the nucleus of a cell is divided into two nuclei with an equal amount of genetic material in both the daughter nuclei. It succeeds the G2 phase and is succeeded by cytoplasmic division...

5.) Summarize the eukaryotic cell components in the tabular format in terms of structure and function.

Image
5.)  Summarize the eukaryotic cell components in the tabular format in terms of structure and function. AA.) What is a Eukaryotic Cell? Eukaryotic cells have a nucleus enclosed within the nuclear membrane and form large and complex organisms. Protozoa, fungi, plants, and animals all have eukaryotic cells. They are classified under the kingdom Eukaryota. They can maintain different environments in a single cell that allows them to carry out various metabolic reactions. This helps them grow many times larger than the prokaryotic cells. Also refer:  Difference between Prokaryotic and Eukaryotic Cells Characteristics of Eukaryotic Cells The features of eukaryotic cells are as follows: Eukaryotic cells have the nucleus enclosed within the nuclear membrane. The cell has mitochondria. Flagella and cilia are the locomotory organs in a eukaryotic cell. A cell wall is the outermost layer of the eukaryotic cells. The cells divide by a process called mitosis. The eukaryotic cells contain ...

1.) Compare and contrast the structure of a generalized plant cell, animal cell, and prokaryotic cell. Which features are common to all cells? Which are specific to just prokaryotes, or just plants, or just animals?.

Image
1.     1.)   Compare and contrast the structure of a generalized plant cell, animal cell, and prokaryotic cell. Which features are common to all cells? Which are specific to just prokaryotes, or just plants, or just animals? A)  A Prokaryotic Cells Prokaryotes were the first organism to evolve on this planet and still retain the simplest cell structure. Prokaryotic cells are generally small, unicellular and are very common. They can be found anywhere – in soil, water, skin, intestines etc. Bacteria are also prokaryotic cells. Thus, theoretically, bacteria are living on our skin as well as in our intestines. It is also important to note that prokaryotic cells do not contain a nucleus. There are many parts of prokaryotic cells: Cell Wall:  A layer of peptidoglycan that surrounds the cell and thus protects the cell. The cell wall is always present, and also helps to maintain the cell’s shape and prevent the cell from bursting open. Plasma Membrane:  The ...