Which two of the following changes (1-4) usually tend to occur in the plain dwellers when they move to high altitudes (3500 m or more)?
1) Increase in red blood cell size
2) Increase in red blood cell production
3) Increase in breathing rate
4) Increase in thrombocytes count
Changes occurring are
(2) and (3)
(3) and (4)
(1) and (4)
(1) and (4)
A.
(2) and (3)
When a person moves to higher altitudes, the PO2 and total atmospheric pressure decrease. Hypoxia stimulates the JG - cells of the kidney to release erythropoietin hormone, which stimulates erythropoiesis in bone marrow causing polycythemia. Hypoxia will also increase breathing rate. Initially, the size of RBCs will also increase but with an increase in number of RBCs, the size of RBCs becomes normal.
The signals for parturition originate from
placenta only
placenta as well as the fully developed foetus
oxytocin released from the maternal pituitary
oxytocin released from the maternal pituitary
Restriction endonucleases are enzymes which
make cuts at specific positions within the DNA molecule
recognize a specific nucleotide sequence for binding of DNA ligase
restrict the action of the enzyme DNA polymerase
restrict the action of the enzyme DNA polymerase
The common nitrogen -fixer in paddy field is
Rhizobium
Azopirillum
Oscillatoria
Oscillatoria
The first movements of the foetus and appearance of hair on its head are usually observed during which month of pregnancy?
Fourth month
Fifth month
Sixth month
Sixth month
Darwin's finches are a good example of
industrial melanism
connecting link
adaptive radiation
adaptive radiation
Cu ions released from copper -releasing Intra Uterine Devices (IUDs)
make uterus unsuitable for implantation
increase phagocytosis of sperms
suppress sperm motility
suppress sperm motility
The permissible use of the technique amniocentesis is for
detecting the sex of the unborn foetus
artificial insemination
transfer of embryo into the uterus of a surrogate mother
transfer of embryo into the uterus of a surrogate mother
The figure given below is a diagrammatic representation of the response of organisms to abiotic factors. What do A, B, and C represent respectively?
|
A
|
B
|
C
|
|
Conformer |
Regulator |
Partial regulator |
|
A |
B |
C |
|
Regulator |
Partial regulator |
Conformer |
|
A
|
B
|
C
|
|
Partial regulator |
regulator | conformer |
|
A
|
B
|
C
|
|
Partial regulator |
regulator | conformer |
