The study of cells, their physiological properties, structure, environmental interaction, division, life cycle, and death, as well as the organelles they contain. Also known as cytology.

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7 views

Choose the intruder [on hold]

A. Antibody B. Antibiotics C. Micro-tubule D. Cholesterol I couldn't find a link between any of these 3 components to actually find an intruder.
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23 views

When frozen rain moves up and down within an anvil cloud, _____ is formed [on hold]

When frozen rain moves up and down within an anvil cloud, _____ is formed. A. hail B. snow C. thunder D. lightning
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24 views

Are the three different cones really distinguishable?

Our retina has three different cones (S,M and L) for the colors blue (S), green (M) and red (L). But the sensitivity of these cones do overlap each other. For example, the S is sensitive for 400-500nm ...
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7 views

Obout oxygen presence in krebs cycle [duplicate]

Q- If oxygen is not utilized in the cycle then why it is present in the Krebs Cycle?
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0answers
15 views

Post-translation modifications of proteins that are regulated in breast cancer [closed]

I have a set of proteins which are up regulated in breast cancer. I was asked to find post-translational modifications (PTMs) for them, which I found based on databases but my question is that, what ...
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0answers
14 views

What are extracellular matrix pathways?

I was reading a research paper dealing with acute myeloid leukemia and the term "extracellular matrix pathway" came up. What does it mean? I found literature on extracellular matrix, but I'm not sure ...
-1
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0answers
27 views

Where does transamination and deamination take place?

The only information I know is about deamination,it occurs in the liver and kidney. But in which part of the cell does deamination occur? To which tissues is transsamination specific to and in which ...
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0answers
44 views

“Safety Valve” of Cell [closed]

Safety Valve of Cell is - A) Peroxisome B) Glyoxysome C) Spherosome D) Lysosome . I answered option D) . I thought that if cell's metabolic function becomes exhausted , then Lysosome acts as a ...
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0answers
16 views

Do Tumor-Infiltrating T Cells Experience Any Prolonged Effects Due To Hypoxia After They Return To Normoxia?

Adoptive cell transfer (ACT) therapy using tumor-inflitrating lymphocytes (TIL) is at the cutting edge of immuno-oncology treatments involving metastatic melanoma and other indications (1). The idea ...
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1answer
54 views

Does the formation of water inside the mitochondrial matrix help contribute to the proton gradient during the electron transport chain?

Does the synthesis of water in the final step of the electron transport chain significantly increase the electrochemical gradient across the matrix? I understand that pumping protons out of the matrix ...
3
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2answers
71 views

Why does azithromycin not affect human mitochondria?

Drugs like tetracyclines, macrolides and aminoglycosides bind to prokaryotic ribosomes. It is interesting that our body too having mitochondria, which have prokaryotic ribosomes, there is little(?) ...
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0answers
29 views

How does DNA organise a cell's physical position within a body?

How do cells "know" where they are supposed to be in relation to other cells, in forming the physical shape of the body? If you have ever tried to organise or choreograph the physical positions of a ...
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0answers
11 views

Does alcohol affect water potential across a tonoplast? If so, would it cause it to explode or implode?

This was a question I saw in a biology exam I recently sat. I know it affects the r-groups of the transport proteins, causing them to change shape and become leaky, but does it also affect water ...
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1answer
26 views

What is the difference of function between palisade and spongy layers of leaf? [closed]

I was just wondering what is the difference between palisade and spongy layers of leaf?
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1answer
84 views

What is the mass of an E.coli cell?

I'm trying to get into Biology, reading introductory texts. A discussion on E.Coli estimates the mass of the cell from $$density =1g/mL=1g/cm^3$$ and $$volume=1µm^3$$ From this I get $$ mass=density × ...
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1answer
29 views

Does common X-like picture represent one doubled chromosome or two homologous chromosomes?

What is on common X-like picture of chromosome? Here is the image from Wikipedia: Are (for example) lower petals homologous to each other? If yes, then why (1) ...
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1answer
22 views

Using exogenous genes to reduce the set of essential amino acids?

Various organisms have sets of essential amino acids that they cannot synthesize themselves, but rather that they must obtain from food. Humans have 9 of these amino acids. However, obviously certain ...
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1answer
54 views

How do cells age and die if they are dividing into new cells?

If cells in our body keep on dividing into new cells how do they ever grow old? The only cells to grow old would be defunct cells or those who won't divide into new cells like nerve cells. What am I ...
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1answer
29 views

How do normal cell division chance into a tumor forming cell division? [closed]

Or its better to say what happens at molecular level that tumors are formed? I tried normal google search and google books but couldn't find any appropriate explanation. I am trying to understand why ...
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1answer
374 views

Why should phospholipid non-polar tails be “protected” in the membrane bilayer?

lipids are arranged within the membrane with polar head towards the outer side and non polar tails towards inner side, this ensures that the non polar tail is protected from aqueous environment. My ...
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2answers
31 views

How does the peptidoglycan layer of a bacterial cell wall help prevent osmotic lysis? [duplicate]

I recently read that penicillin works by damaging the peptidoglycan layers of a bacterial cell wall causing osmotic lysis, which is when the bacteria cell bursts due to osmotic pressure. I just ...
1
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1answer
28 views

Can a protein kinase phosphorylate both a threonine and tyrosine residue?

I know that some kinases can phosporylate both serine and threonine residues because of their structural similarities, but can such a kinase phosphorylate a tyrosine residue as well? If not, then why?...
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1answer
49 views

Photosynthesis and its subtopics [closed]

Which of the following statements about photosynthesis is true? a. Photosynthesis is an energy consuming process b. The light-dependent reactions produce the energy-rich compounds that are used up ...
3
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3answers
68 views

Doubt in a multiple choice question involving cell organelles

Find the odd one out and state the category of the rest. Chloroplast Mitochondria Nucleus Grana Now my answers are : 1st possibility : grana Category : presence of DNA in ...
3
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2answers
78 views

Is cell wall and cytoplasm an organelle?

So cell wall is an organelle? Whereas, it is not a membrane-closed organelle? Cytoplasm is an organelle? Whereas, it is not a membrane-closed organelle?
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1answer
35 views

What kind of detergent should I use in cell culture laboratory for cleaning purposes?

I work on establish a cell culture laboratory in the company where I work. All equipment are new and I want to clean lab before I start to work with cells. Is there any special detergent for cleaning ...
2
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0answers
135 views

Have people in Africa already started evolving resistance to AIDS?

Are people living in areas where AIDS is rampant (for e.g. Africa), less likely to die from it than they once were because some of the people without genes/mutations that give them resistance already ...
3
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1answer
87 views

How does a protein reach its substrate within the cell?

After a protein has been synthesized and its the final tertiary/quartenary adopted, how does it reach its substrate within the cell and what causes it to interact with it? The transcription factors ...
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2answers
99 views

How do T-cells determine which cells they've already inspected?

From what I understand, T-cells are constantly traveling in the body, inspecting cells by looking for antigens. If they're self antigens, then the T-cell doesn't attack, whereas if they're non-self, ...
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1answer
46 views

Why must DNA be packed into chromosomes during mitotic phase?

Why does DNA have to be packed into chromosomes? Why can't DNA just divide itself evenly?
4
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0answers
41 views

Does depolymerisation take place at the minus end of microtubule?

Wikipedia says that Dynamic instability refers to the coexistence of assembly and disassembly at the 'ends' of a microtubule. but Karp's Cell Biology, 7th edition says Dynamic instability ...
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1answer
63 views

Do bacteria grow on pure dry glucose?

I've accidentally touched pure glucose with my bare hands (fingers to be specific), which was intended for cell-culture. I'm worried that bacteria from my skin may start to grow on the glucose and ...
1
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1answer
45 views

Are ribosomes assembled in rough ER and Golgi body, or in the nucleolus?

I mean all the components, such as ribosomal RNA (rRNA) are synthesized in the nucleolus, but is the whole ribosome structure assembled in the nucleolus or is it also done in the rough endoplasmic ...
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1answer
110 views

Is metastatic cancer always lethal if uncured?

Can matastases spread in different parts of the body of an animal suffering from cancer grow in a limited way, such as not to cause much more harm that a benignant tumor in those parts of the body ...
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1answer
90 views

Which are the last cells of the human body to die?

When somebody dies, which are the last surviving cells of his/her body? Those of hair, nails, or some other obscure but resilient cells? Shedding light on why and how they are so vital might boost ...
2
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1answer
31 views

Question about Enzyme Inhibition in relation to Aspirin

I've been trying to learn a bit more about pharmacology, so bear with my ignorance. In short, I see that aspirin (in part) works by inhibiting cycloxygenase isoenzymes and that this inhibiting is ...
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1answer
37 views

Can you replace glucose with glycerol in cell media?

In order to feed an animal cell in process called Respiration, can I replace Glucose with Glycerol? The Equation bellow: Glycerol + Oxygen -> Water + Carbon Oxide
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0answers
32 views

What a cell needs to survive? [closed]

I'm looking specifically at animal cells. I'm not sure if it needs only Glucose and Oxygen for Aerobic respiration.
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0answers
31 views

How do cells grow (ie. gain mass)? [closed]

I have some basic knowledge of the cell cycle. However, I don't understand how cells grow in the Gap phases. How do cells grow? And how does consumed food transfer mass to cells?
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1answer
83 views

Why are considered to be exceptions to the cell theory? [closed]

If I am not mistaken, the cell theory states that: All living organisms are made up of one or more cells Cells are the smallest units of life Cells arise from pre-existing cells Aseptate fungal ...
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0answers
20 views

DNA. mRNA, tRNA [closed]

Can someone explain to me how transcription and translation works, especially the part about codes. And does amino acids has code or is it the tRNA?
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0answers
17 views

If spore possesses 10 chromosomes with 20 picogram DNA then calculate the amount of DNA in prophase II?

Options : a) 20 b) 10 c) 40 According to me, it should be 20 because a cell in prophase II is haploid after completing meiosis I reduction division. Also, spores are haploid, so amount of DNA should ...
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0answers
20 views

Production of energy in the form of ATP is concerned with?

Following are the options : a) Mitochondria b) Elaioplast c) Chloroplast d) Preoxisome e) Golgi Bodies Answer 1 - a) and b) Answer 2 - a) , c) and d) According to me , the answer is 2 because due ...
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1answer
33 views

What information do bipolar cells encode?

Short version: I don't see what information on-centre bipolar cells are actually capturing. Longer: Actually, the question could be extended to on-centre retinal cells as well, but I'll focus on ...
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0answers
20 views

Synthetic biology: examples of cell orientation driven by genes or genetic modification

First of all, forgive for the naive question. I know that genes can drive the shape of cells, as the sickle-shaped red blood cells. On the spirit of synthetic biology or tissue engineering, does ...
0
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1answer
59 views

Electron Transport Chain in Mitochondria [closed]

I was researching cellular respiration, and this is a rather confusing part. I need help understanding the purpose of Complex II and how the ATP Synthase generates the energy to turn ADP to ATP.
5
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1answer
39 views

Are there differing organelle to cytoplasm ratio in animal cells?

Could anyone provide me with examples of cells with high organelle to cytoplasm ratios (heavily packed), and examples of cells with low organelle to cytoplasm ratios (sparsely packed)?
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0answers
33 views

Barcode exchange between neighbouring cells

I am currently interested in equipping animal cells in a tissue with individual barcodes. These barcodes should get amplified in the cells (not to a cell degrading extent, of course), and also ...