Biology flashcards wrong questions

If two structures are 200 nm apart, what is the actual distance when magnification changes from ×40 to ×400?

200 nm.The actual distance does not change with magnification. Magnification only affects what you see.

Which structures contain cisternae?

Endoplasmic reticulum and Golgi body.Cisternae are membrane sacs found in the ER and Golgi, not in chloroplasts or mitochondria.

Which structures are found in both eukaryotic and bacterial cells?

Cell membrane, cell wall, cytoplasm Bacteria do not have nuclei or mitochondria (no membrane-bound organelles).

What type of bond holds collagen triple helices together?

Covalent bond.These are strong cross-links between helices — not hydrogen, peptide, or disulfide bonds.

Why is cysteine important in β-globin?

It affects oxygen affinity and the Bohr shift. Replacing it reduces the Bohr effect, showing it's key to hemoglobin function.

What does a triglyceride yield on hydrolysis?

Fatty acids and glycerol.

No amino acids here — it's a lipid, not a protein.

Why did glucose diffuse out of Visking tubing but starch didn’t?

A: Glucose is small enough to pass; starch is too big.

Only glucose caused a color change in Benedict’s test. Water movement isn’t shown.

What does a non-competitive inhibitor do to enzyme rate?

A: Lowers the maximum rate (Vmax).

It binds elsewhere and affects enzyme shape, reducing efficiency even if substrate is added.

Q: How does allopurinol reduce uric acid formation?

A: It binds to the active site of xanthine oxidase.

Explanation: It mimics hypoxanthine and acts as a competitive inhibitor.

Which statements about phospholipids in membranes are true?

Hydrophobic tails face inward, phospholipids provide flexibility. Explanation: Tails don’t allow ions through; polar heads face both sides, not just cytoplasm

What is the SA:Vol ratio of a 2 µm long, 0.5 µm wide bacterium?

A: 9.0 : 1.0

Explanation: Calculated using cylinder formulae. Small cells have high SA:Vol ratios.

Q: How many DNA molecules are in a chicken cell at prophase?

A: 156.

Explanation: Each of the 78 chromosomes has two chromatids (DNA copies) after replication.

What happens next in metaphase?

A: Chromosomes are aligned; next, chromatids are pulled apart (anaphase).

Explanation: Cell X was in metaphase → the next step is C: chromatids move to poles.

Which processes happen in bone marrow cells during mitosis?

A: ATP synthesis, DNA replication, translation.

Explanation: All three are active processes in dividing cells.