BGS, BSGS Bachelor of General Studies BSGS Natural Sciences 2

Question 1

Which organelle is responsible for producing ATP through cellular respiration in eukaryotic cells?

Accepted Answer

Mitochondria

Answer

Mitochondria are the sites of aerobic respiration and generate most of the cell's ATP via the electron transport chain.

Question 2

What is the primary greenhouse gas emitted by human agricultural activities, particularly from livestock and rice paddies?

Accepted Answer

Methane

Answer

Methane (CH₄) is produced by enteric fermentation in ruminants and anaerobic decomposition in flooded rice fields.

Question 3

In Mendelian genetics, if two heterozygous parents (Aa × Aa) are crossed, what fraction of offspring are expected to be homozygous dominant?

Accepted Answer

1/4

Answer

A Punnett square for Aa × Aa yields AA:Aa:aa in a 1:2:1 ratio, so 1/4 are homozygous dominant (AA).

Question 4

Which layer of the Earth's atmosphere contains the ozone layer that absorbs most incoming ultraviolet radiation?

Accepted Answer

Stratosphere

Answer

The ozone layer sits within the stratosphere, roughly 15–35 km above Earth's surface, shielding life from harmful UV-B and UV-C radiation.

Question 5

What type of chemical bond involves the sharing of electron pairs between two nonmetal atoms?

Accepted Answer

Covalent bond

Answer

Covalent bonds form when atoms share electrons, as seen in molecules like H₂O and CO₂.

BGS, BSGS Bachelor of General Studies Practice Test