Take This Quiz To Know About More Apoptosis And Necrosis!

Explanation
Apoptosis refers to programmed cell death, which is a natural process that occurs in multicellular organisms to eliminate unnecessary or damaged cells. It is a tightly regulated process that involves a series of biochemical events leading to the controlled dismantling and removal of cells. Apoptosis plays a crucial role in various physiological processes such as development, tissue homeostasis, and immune response. Therefore, the correct answer is "Programmed cell death."

Explanation
Apoptosis is a programmed cell death that occurs in response to various stimuli. Nutrition deficiency can lead to apoptosis as the cell lacks essential nutrients for survival. DNA damage can trigger apoptosis to prevent the replication of damaged DNA and maintain genomic stability. Radiation damage can also induce apoptosis as a protective mechanism against further DNA damage. Therefore, all of the given reasons can cause a cell to undergo apoptosis.

Explanation
Mitochondria is the correct answer because it is the organelle that actively participates in animal apoptosis. Apoptosis is a programmed cell death process that occurs in multicellular organisms, including animals. Mitochondria play a crucial role in this process by releasing proteins that initiate the cell death cascade. They release cytochrome c, which activates caspase enzymes, leading to cell death. Additionally, mitochondria also regulate the balance between pro-apoptotic and anti-apoptotic proteins, further influencing the apoptotic process. Therefore, mitochondria are actively involved in animal apoptosis.

Explanation
Bfl 1 is an anti-apoptotic protein. Apoptosis is a programmed cell death process, and anti-apoptotic proteins help to prevent this process. Bfl 1 is a member of the Bcl-2 family of proteins, which are known for their role in regulating apoptosis. These proteins can inhibit apoptosis by blocking the activation of pro-apoptotic proteins or by directly preventing the release of cytochrome c from the mitochondria. Therefore, Bfl 1 qualifies as an anti-apoptotic protein. NOXA and Bim, on the other hand, are pro-apoptotic proteins, meaning they promote apoptosis rather than inhibiting it.

Explanation
Lymphomas are a type of cancer that is caused by a defect in the process of apoptosis, which is programmed cell death. Apoptosis is a natural process that helps to eliminate damaged or abnormal cells from the body. When this process is disrupted or defective, it can lead to the uncontrolled growth and accumulation of lymphocytes, which are a type of white blood cell. This abnormal cell growth can result in the development of lymphomas.

Explanation
Tumor necrosis factor is an extracellular messenger of apoptosis in the body. It is a cytokine that plays a crucial role in the regulation of cell death. Tumor necrosis factor can induce apoptosis in certain cells, particularly in cancer cells, by activating specific signaling pathways. This makes it an important mediator of cell death in various physiological and pathological processes. Phosphatidylserine is also involved in apoptosis, but it is not specifically mentioned as an extracellular messenger. Serotonin is a neurotransmitter and is not directly associated with apoptosis. Therefore, the correct answer is tumor necrosis factor.

Explanation
During apoptosis, a process of programmed cell death, a significant number of cells die in a healthy adult. The range of 50-70 billion cells dying is a reasonable estimate for the number of cells undergoing apoptosis. This programmed cell death is crucial for maintaining tissue homeostasis, eliminating damaged or unnecessary cells, and regulating cell populations within the body.

Explanation
Necrosis is a type of cell death that occurs due to various reasons. Cell injury can lead to necrosis when cells are exposed to extreme conditions or toxins that cause damage beyond repair. Cancer cells can also undergo necrosis when they outgrow their blood supply and nutrients, leading to cell death. Infections can trigger necrosis by causing inflammation and tissue damage. Therefore, all the given options - cell injury, cancer, and infection - can be reasons behind necrosis.

Explanation
Lamin is a protein that plays a crucial role in maintaining the structure of the nucleus. During apoptosis, the activation of caspases leads to the cleavage of lamin, causing the nucleus to shrink and fragment. This fragmentation is a characteristic feature of apoptosis and is essential for the orderly disassembly of the cell. Therefore, the activation of lamin is responsible for the shrinking of the nucleus during apoptosis.

Explanation
Apaf-1 is involved in the cascade for caspase activation in apoptosis. Apoptosis is a programmed cell death process that is essential for maintaining tissue homeostasis and eliminating damaged or unwanted cells. Caspases are a family of proteases that play a central role in apoptosis. Apaf-1 (Apoptotic protease activating factor 1) is a key protein in the apoptosome complex, which is responsible for activating caspases and initiating the caspase cascade in apoptosis. Therefore, Apaf-1's involvement in the cascade for caspase activation in apoptosis is the correct answer.