A woman with normal vision, but whose father was colourblind, marries a colourblind man. Suppose that the fourth child of this couple was a boy. This boy
must have normal colour vision
will be partially colourblind since he is heterozygous for the colourblind mutant allele
must be colourblind
may be colourblind or may be of normal vision
D.
may be colourblind or may be of normal vision
Colourblindness is a sex linked disorder (X- linked). It is always transferred from mother to son.
In the mentioned question, woman whose father was colourblind, will be the carrier of the colourblind trait. If this woman marries a colourblind man, following possibilities are possible-
(i) If woman is Normal-
(ii) If woman is Carrier-
Hence, in both the cases, boy may be colourblind or may be of normal vision.
Which of the following is not a hereditary disease?
Cretinism
Cystic fibrosis
Thalassaemia
Haemophilia
de Vries gave his mutation theory on organic evolution while working on
Althea rosea
Drosophila melanogaster
Oenothera lamarckiana
Pisum sativum
A patient is generally advised to specially, consume more meat, lentils, milk and eggs in diet only when he suffers from
kwashiorkor
rickets
anaemia
scurvy
Which one of the following makes use of RNA as a template to synthesize DNA?
Reverse transcriptase
DNA dependant RNA polymerase
DNA polymerase
RNA polymerase
A woman with 47 chromosomes due to three copies of chromosome 21 is characterized by
Down syndrome
triploidy
Turner syndrome
super femaleness
AIDS is caused by HIV that principally infects
all lymphocytes
activator B cells
T4 lymphocytes
cytotoxic T cells
If mammalian ovum fails to get fertilized which one of the following is unlikely?
Corpus luteum will disintegrate
Estrogen secretion further decreases
Primary follicle starts developing
Progesterone secretion rapidly declines
Which group of three of the following five statements (A- E) contain is all three correct statements regarding beri- beri?
A. A crippling disease prevalent among the native population of sub- Sahara Africa.
B. A deficiency disease caused by lack of thiamine (vitamin- B1).
C. A nutritional disorder in infants and young children when the diet is persistently deficient in essential protein.
D. Occurs in those countries where the staple diet is polished rice.
E. The symptoms are pain from neuritis, paralysis, muscle wasting, progressive oedema, mental deterioration and finally heart failure.
A, B and D
B, C and E
A, C and E
B, D and E
At which latitude, heat gain through insolation approximately equals heat loss through terrestrial radiation?
66 North and South
North and South
40 North and South
North and South