Haemophilia is more commonly seen in human males than in human females because
this disease is due to an X- linked dominant mutation
a greater proportion of girls die in infancy
this disease is due to an X- linked recessive mutation
this disease is due to a Y- linked recessive mutation
C.
this disease is due to an X- linked recessive mutation
Haemophilia is a hereditary (recessive X- linked) disease caused due to fault in genes, controlling the factors VIII and IX, on X chromosome.
Males have one X and Y chromosome each. Y chromosome does not carry any gene for blood clotting. Therefore, this condition is usually seen in males as they carry only one faulty X chromosome.
Females are generally the carrier of the disease as in females, two faulty X- chroromsomes are needed to cause the disease.
Epithelial cells ofthe intestine involved in food absorption have on their surface
pinocytic vesicles
phagocytic vesicles
zymogen granules
micro-villi
Secretin and cholecystokinin are digestive hormones. They are secreted in
oesophagus
ileum
duodenum
pyloric stomach
In contrast to annelids the platyhelminthes show
radial symmetry
presence of pseudocoel
bilateral symmetry
absence of body cavity
Protein synthesis in an animal cell occurs
only on the ribosomes present in cytosol
on ribosomes present in cytoplasm as well as in mitochondria
only on ribosomes attached to the nuclear envelope and endoplasmic reticulum
on ribosomes present in the nucleolus as well as in cytoplasm
An acromian process is characteristically found in the
pelvic girdle of mammals
skull of frog
pectoral girdle of mammals
sperm of mammals
Parkinson's disease (characterized by tremors and progressive rigidity of limbs) is caused by degeneration of brain neurons that are involved in movement control and make use of neurotransmitter
acetylcholine
norepinephrine
dopamine
GABA
One of the examples of the action of the autonomous nervous system is
knee-jerk response
pupillary reflex
swallowing of food
peristalsis of the intestines
Which of the following pairs is correctly matched?
Cartilaginous joint - Skull bones
Hinge joint - Between vertebrae
Fibrous joint - Between phalanges
Gliding joint - Between zygapophyses of the successive vertebrae
The ability of the venus flytrap to capture insects is due to
chemical stimulation by the prey
a passive process requiring no special ability on the part of the plant
specialized "muscle-like" cells
rapid turgor pressure changes
