People with sickle-cell anaemia have haemoglobin
S and are homozygous recessive
A and are heterozygous recessive
S and are heterozygous recessive
A and are homozygous recessive
Correct answer is A
No explanation has been provided for this answer.
The difference and similarities among living things account for
diversity
stability
competition
evolution
Correct answer is D
No explanation has been provided for this answer.
The water-retention capacity of a soil indicates its
fertility
capilarity
aeration level
pH level
Correct answer is B
No explanation has been provided for this answer.
In a drought, plants suffer from water stress which could result in
reduced biochemical activities
enhanced chemical activities
enhanced microbial activities
reduced phototropic activities
Correct answer is A
No explanation has been provided for this answer.
Ecological succession ends with the formation of a stable
niche
population
pioneer community
climax community
Correct answer is D
No explanation has been provided for this answer.