What happens during fertilisation in humans after many sperms reach close to the ovum?
Secretions of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida
All sperms excepts the one nearest to the ovum lose their tails
Cells of corona radiata trap all the sperms excepts one
Cells of corona radiata trap all the sperms excepts one
A.
Secretions of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida
The process of fusion of a sperm with an ovum is called fertilisation. During fertilization, a sperm comes in contact with the zona pellucida layer of the ovum and induces changes in the membrane that blocks the entry of additional sperms. Thus, it ensures that only one sperm can fertilise an ovum. The secretions of the acrosome help the sperm enter into the cytoplasm of the ovum through the zona pellucida and the plasma membrane.
Which one of the following pairs is wrongly matched while the remaining three are correct?
Penicillium - Conidia
Water hyacinth - Runner
Bryophyllum - Leat buds
Bryophyllum - Leat buds
About which day in a normal human menstrual cycle does rapid secretion of LH (popularly called LH surge) normally occurs?
14th day
20th day
5th day
5th day
Bacillus thuringiensis forms protein crystals, which contain insecticidal protein
binds with epithelial cells of midgut of the insect pest ultimately killing it
is coded by several genes including the gene cry
is acitvated by acid of pH of the foregut is the insect pest
is acitvated by acid of pH of the foregut is the insect pest
The technique called gamete intra-fallopian transfer (GIFT) is recommended for those females
who cannot produce an ovum
who cannot retain the foetus inside uterus
who cervical canal is too narrow to allow passage for the sperms
who cervical canal is too narrow to allow passage for the sperms
Read the following statement having two blanks (1 and 2).
A drug used for ..... (1) ...... patients is obtained from a species of the organism ....... (2).....The one correct option for the two blanks is.
|
Blank – 1
|
Blank – 2
|
|
Heart
|
Penicillium
|
|
Blank – 1 |
Blank – 2 |
|
Organ - transplant |
Trichoderma |
|
Blank – 1 |
Blank – 2 |
|
Swine flu |
Monascus |
|
Blank – 1 |
Blank – 2 |
|
Swine flu |
Monascus |
Silencing of mRNA has been used in producing transgenic plants resistant to
bollworms
nematodes
White rusts
White rusts
Which one of the following animals may occupy more than one trophic levels in the same ecosystem at the same time?
Sparrow
Lion
Goat
Goat
Consider the following statements ( I - IV) about organic farming.
I. Utilises genetically modified crops like Bt cotton
II. Uses only naturally produced inputs like compost.
III. Does not use pesticides and urea
IV. Produces vegetables rich in vitamins and minerals.
(II), (III) and (IV)
(III) and (IV) only
(II) and (III) only
(II) and (III) only
Both, hydrarch and xerarch successions lead to
medium water conditions
xeric conditions
highly dry conditions
highly dry conditions
