The mass of living material at a tropic level at a particular time is called
gross primary productivity
standing state
net primary productivity
net primary productivity
D.
net primary productivity
The total dried biomass of living organisms present at a trophic level at a particular time is known as standing crop.
Standing state is the amount of inorganic nutrients present at any time in the soil or water of ecosystem. The gross primary productivity is the total organic matter synthesised by producers during photosynthesis per unit time and area while net primary productivity is weight of organic matter stored by producers in unit area/volume per unit time.
Secondary succession takes place on/in
bara rock
degraded forest
newly created pond
newly created pond
In an ecosystem the rate of production of organic matter during photosynthesis is termed as
net primary productivity
gross primary productivity
secondary productivity
secondary productivity
Which of the following represents the correct combination without any exception?
| Characteristic | Class |
| Mammary gland; hair on body; pinnae; two pairs of Limbs | Mammalia |
| Characteristic | Class |
| Mouth ventral, gills without operculum; skin with placoid scales; persistent notochord | Chondricht hyes |
| Characteristic | Class |
| Sucking and circular mouth; jaws absent, integument without scales; paired appendages | Cyclostomata |
| Characteristic | Class |
| Sucking and circular mouth; jaws absent, integument without scales; paired appendages | Cyclostomata |
Select the correct option:
| Column I | Column II | |
| A | Synapsis aligns homologous chromosomes | 1. Anaphase-II |
| B | Synthesis of RNA and protein | 2. Zygotene |
| C | Action of enzyme recombinase | 3. G2-phase |
| D | Centromeres do not separate but chromatids move towards opposite poles | 4. Anaphase-I |
| 5. Pachytene |
Capacitation refers to changes in the
Sperm before fertilization
Ovum before fertilization
Ovum after fertilization
Ovum after fertilization
Which of these is not an important component of initiation of parturition in humans?
Increase in oestrogen and progesterone ratio
Synthesis of prostaglandins
Release of oxytocin
Release of oxytocin
Which of the following viruses is not transferred through semen of an infected male?
Hepatitis B virus
Human immunodeficiency virus
Chikungunya virus
Chikungunya virus
Which of the following cells during gametogenesis is normally dipoid?
Primary polar body
Spermatid
Spermatogonia
Spermatogonia
