An organism that has been extensively used to test the chromosomes theory of heredity is
Drosophila melanogaster
Muscar domestica
Zea mays
Homo sapiens
Correct answer is A
No explanation has been provided for this answer.
75%
50%
25%
100%
Correct answer is A
A heterozygote for sickle-cell anaemia = AS
Crossing two AS persons, we have one AA, two AS, and one SS.
∴ The probability that the children are either carriers or sicklers = ¾
= 75%
If a DNA strand has a base sequence TCA, its complementary strand must be
ATG
TAG
GAT
AGT
Correct answer is D
No explanation has been provided for this answer.
The pioneer organisms in ecological succession are usually the
mosses
lichens
ferns
algae
Correct answer is B
No explanation has been provided for this answer.
Soil fertility can best be conserved by the activities of
Earthworm
Man
Rodent
Microbes
Correct answer is D
No explanation has been provided for this answer.