Geography
Which country has the largest population (2026)?
A) China
B) India
C) USA
D) Indonesia
B) India
In a DNA double helix, adenine (A) pairs with which base?
A) Guanine (G)
B) Cytosine (C)
C) Thymine (T)
D) Uracil (U)
C) Thymine (T)
Which is the longest river in the world by natural length?
Nile
When a cell performs aerobic respiration, where is the electron transport chain located?
Inner mitochondrial membrane
What is the largest desert in the world?
A) Sahara
B) Arabian
C) Antarctic Desert
D) Great Sandy Desert
C) Antarctic Desert
Protein "denaturation" primarily disrupts which level of structure?
A) Primary structure (amino acid sequence)
B) Secondary and tertiary structures (hydrogen bonds, hydrophobic interactions)
C) Only disrupts disulfide bonds
D) Directly hydrolyzes peptide bonds
B) Secondary and tertiary structures
Which country has the most time zones?
France
From glycolysis to the completion of the citric acid cycle, what is the net yield of ATP, NADH, and FADH2 per 1 molecule of glucose?
A) Net yield of 4 ATP, 10 NADH, 2FADH2
B) Net yield of 2 ATP, 6 NADH, 2FADH2
C) Net yield of 2 ATP, 10 NADH, 2FADH2
D) Net yield of 4 ATP, 8 NADH, 4FADH2
C) Net yield of 2 ATP, 10 NADH, 2FADH2
The Dead Sea, located in West Asia, is actually a large saltwater lake. Because of its extremely high salt content, fish cannot survive there. However, its extreme buoyancy allows even non-swimmers to float easily and read. What is the main reason for the Dead Sea's name?
A) The water is black and looks terrifying
B) The water is too deep; the bottom is unseen
C) The high salt content prevents fish and plants from surviving
D) Large waves frequently occur
C) The high salt content prevents fish and plants from surviving
After the β-adrenergic receptor is activated, which of the following descriptions regarding signal transduction is correct?
A) Activates phospholipase C (PLC), prompting IP₃ to release calcium ions.
B) Activates adenylyl cyclase through the Gs protein, promoting ATP → cAMP , which in turn activates PKA.
C) Directly activates tyrosine kinase, phosphorylating downstream proteins.
D) Inhibits adenylyl cyclase, decreasing cAMP concentration.
B) Activates adenylyl cyclase through the Gs protein, promoting ATP → cAMP , which in turn activates PKA.