Capacitation refers to changes in the
Sperm before fertilization
Ovum before fertilization
Ovum after fertilization
Ovum after fertilization
A.
Sperm before fertilization
Capacitation refers to activation of sperm cells before fertilisation. It involves reorganisation of molecules in the outer membrane of sperm head.
Capacitated sperm releases enzymes from their acrosomes to penetrate the cells and zona pellucida surrounding the egg.
Secondary succession takes place on/in
bara rock
degraded forest
newly created pond
newly created pond
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
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
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 |
Which of the following cells during gametogenesis is normally dipoid?
Primary polar body
Spermatid
Spermatogonia
Spermatogonia
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
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 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 |
