General Science

Choose the correct answer: the pH of a neutral solution at 25°C is approximately:

A 1
B 0
C 14
D 7

Select the best answer: the chemical symbol for sodium is:

A Sn
B So
C Na
D S

Which option is correct? the chemical symbol for potassium is:

A P
B Pt
C K
D Po

Identify the correct answer: the most abundant gas in Earth's atmosphere is:

A hydrogen
B oxygen
C carbon dioxide
D nitrogen

For competitive-exam preparation, answer: the basic unit of life is the:

A tissue
B organ system
C organ
D cell

Choose the correct answer: the functional unit of the kidney is the:

A villus
B nephron
C neuron
D alveolus

Select the best answer: photosynthesis mainly occurs in the:

A mitochondrion
B chloroplast
C ribosome
D nucleus

Which option is correct? DNA stands for:

A deoxyribonucleic acid
B deoxygenated nucleic acid
C double nitrogen acid
D dinucleic acid

Identify the correct answer: vitamin C deficiency causes:

A scurvy
B beriberi
C rickets
D night blindness

For competitive-exam preparation, answer: vitamin D deficiency can cause:

A rickets
B scurvy
C beriberi
D pellagra

Choose the correct answer: the largest organ of the human body is the:

A brain
B liver
C lung
D skin

Select the best answer: insulin is produced by the:

A pancreas
B thyroid
C pituitary
D adrenal gland

Which option is correct? red blood cells mainly transport:

A oxygen
B hormones only
C bile
D digestive enzymes

Identify the correct answer: the speed of light in vacuum is approximately:

A 3 × 10^8 m/s
B 3 × 10^6 m/s
C 3 × 10^4 m/s
D 3 × 10^2 m/s

For competitive-exam preparation, answer: which organ pumps blood through the body?

A lung
B heart
C kidney
D liver