2003 - WAEC Biology Past Questions and Answers - page 4
31
Forest conservation includes the following except
A
prevention of bush-fires
B
extensive felling of forest trees
C
replacing of harvested trees by planting seedlings
D
selective exploitation of forest trees
correct option: b
Users' Answers & Comments32
Legumes incorporate nitrogen gas into their proteins because
A
of the presence of Azotobacter in their roots
B
they possess root nodules containing Rhizobium
C
they have a well developed root system
D
they are autotrophic
correct option: b
Users' Answers & Comments33
Which of the following is an example of discontinuous variation?
A
the range in height of a pea plant from 30cm to 50cm
B
Offspring, including the two male cats and three female cats
C
the colour of pear plants grown in the dark
D
the adult body weight ranging from 50 kg t0 95 kg
correct option: b
A characteristic of any species with only a limited number of possible values shows discontinuous variation (i.e It can only be a discrete number of values). Human blood group is an example of discontinuous variation. In the ABO blood group system, only four blood groups are possible (A, B, AB or O). There are no values in between, so this is discontinuous variation.
Here are some examples: blood group, sex (male or female), eye color etc.
34
Which of following pairs of scientists discovered the Rhesus factor in human blood?
A
Hooke and Lavine
B
Darwin and Landsteiner
C
Landsteiner and Lavine
D
Hooke and Darwin
correct option: c
Users' Answers & Comments35
The organic molecule (s) present in the nucleus is/are
A
DNA
B
Protein, RNA andDNA
C
RNA and ATP
D
RNA
correct option: b
Users' Answers & Comments36
In an experiment, a red-flowered plant was crossed with another red-flowered plant and the following results were obtained: 448 red flowers and 154 white flowers in the F1 generation.
Which of the following represents the phenotypic ratio of the above genetic cross?
Which of the following represents the phenotypic ratio of the above genetic cross?
A
1:2:1
B
4:1
C
3:1
D
2:2
correct option: c
Users' Answers & Comments37
In an experiment, a red-flowered plant was crossed with another red-flowered plant and the following results were obtained: 448 red flowers and 154 white flowers in the F1 generation.Which of the following represents the genotypes of the parents if R is for red gene and r for white gene?
A
RR X Rr
B
RR X rr
C
rr x rr
D
Rr x Rr
correct option: d
Users' Answers & Comments38
In Mendel's experiments, it was discovered that the skin of an African can be attributed to
A
a blending of black and white genes
B
recombination of genes
C
loss of the epidermis
D
mutation in the skin cells
correct option: d
Users' Answers & Comments39
Sickle-cell anaemia has persisted in the human race due to
A
lack of proper medical care for sicklers
B
carriers being more resistant to malaria
C
mosquito vectors
D
wildlife intermediate hosts
correct option: b
Users' Answers & Comments40
Which of the following is not a behavioural adaptation used by social animals?
A
Cryptic
B
Mimicry
C
Flash
D
Season
correct option: d
Users' Answers & Comments