262634
After double fertilization, a mature ovule has
1 1 diploid and I haploid cell
2 1 diploid and 1 triploid cell
3 2 haploid and 1 triploid cell
4 1 haploid and 1 triploid cell.
Explanation:
Double fertilization found only in angiosperms. -Each embryo sac receives two male gametes,one male gamete fuses with egg cell to form zygote, this is called syngamy or generative fertilization, second male gamete fuses with secondary nucleus \((2 n)\) to form primary endosperm nucleus, this act of fertilization is called triple fusion or vegetative fertilization. Thus fertilization take place twice in the same embryo. This fusion of two male gamets to two different structure (one is zygote and other is PEN) is called double fertilization. It include syngamy as well as triple fusion. It was discovered by Nawaschin (1898) in fritillaria and lilium. After double fertilization a mature ovule has one diploid cell (zygote) and one triploid cell (PEN) .
AIIMS-2013
Sexual Reproduction in Flowering Plants
262677
Double fertilization is fusion of :
1 two eggs
2 two eggs and polar nuclei
3 ond male gamete with egg and other with synergids
4 one male gamete with egg and other with secondary nucleus
Explanation:
Double fertilization is fusion of one male gamete with egg and other with secondary nucleus. Double fertilization is consist of two steps. \(1^{\text {st }}\) step is fusion of one male gamete and egg cell which results in the formation of zygote and this process is called as fertilization. \(2^{\text {nd }}\) step is the fusion of another male gamete with polar nuclei which results in the formation of endosperm and this step is known as triple fusion. Endosperm provide nutrition to the developing embryo.
The ploidy level of the plant is diploid Hence, the ploidy level of nucleus is \(2 \mathrm{n}\). Polar nuclei is present in embryo and is haploid (n). Two polar nuclei \((n+n)\) and male gamete (n) fuse to form endosperm which is triploid (3n). Megaspore mother cell is the one which is going to form 4 haploid megaspores by meiosis so again being a parent cell their ploidy is \(2 \mathrm{n}\). The female gametophyte is also haploid; therefore the ploidy is \(\mathrm{n}\).
AIIMS-26.05.2018 Shift-I
Sexual Reproduction in Flowering Plants
262639
Nucellar polyembryons occurs in
1 Corchorus
2 Citrus
3 Carthamus
4 Zea mays
Explanation:
Nucellar polyembryony occurs in citrus. It is a condition in which seed contains more than one embryo. Nucellus is central part of ovule that encloses the female gametophyte. Sometimes these nucellar cells are begin to divide and extend into embryo sac, results in nucellar polyembryony. Polyembryony wa discovered by Leeuwenhoek (1719).
262634
After double fertilization, a mature ovule has
1 1 diploid and I haploid cell
2 1 diploid and 1 triploid cell
3 2 haploid and 1 triploid cell
4 1 haploid and 1 triploid cell.
Explanation:
Double fertilization found only in angiosperms. -Each embryo sac receives two male gametes,one male gamete fuses with egg cell to form zygote, this is called syngamy or generative fertilization, second male gamete fuses with secondary nucleus \((2 n)\) to form primary endosperm nucleus, this act of fertilization is called triple fusion or vegetative fertilization. Thus fertilization take place twice in the same embryo. This fusion of two male gamets to two different structure (one is zygote and other is PEN) is called double fertilization. It include syngamy as well as triple fusion. It was discovered by Nawaschin (1898) in fritillaria and lilium. After double fertilization a mature ovule has one diploid cell (zygote) and one triploid cell (PEN) .
AIIMS-2013
Sexual Reproduction in Flowering Plants
262677
Double fertilization is fusion of :
1 two eggs
2 two eggs and polar nuclei
3 ond male gamete with egg and other with synergids
4 one male gamete with egg and other with secondary nucleus
Explanation:
Double fertilization is fusion of one male gamete with egg and other with secondary nucleus. Double fertilization is consist of two steps. \(1^{\text {st }}\) step is fusion of one male gamete and egg cell which results in the formation of zygote and this process is called as fertilization. \(2^{\text {nd }}\) step is the fusion of another male gamete with polar nuclei which results in the formation of endosperm and this step is known as triple fusion. Endosperm provide nutrition to the developing embryo.
The ploidy level of the plant is diploid Hence, the ploidy level of nucleus is \(2 \mathrm{n}\). Polar nuclei is present in embryo and is haploid (n). Two polar nuclei \((n+n)\) and male gamete (n) fuse to form endosperm which is triploid (3n). Megaspore mother cell is the one which is going to form 4 haploid megaspores by meiosis so again being a parent cell their ploidy is \(2 \mathrm{n}\). The female gametophyte is also haploid; therefore the ploidy is \(\mathrm{n}\).
AIIMS-26.05.2018 Shift-I
Sexual Reproduction in Flowering Plants
262639
Nucellar polyembryons occurs in
1 Corchorus
2 Citrus
3 Carthamus
4 Zea mays
Explanation:
Nucellar polyembryony occurs in citrus. It is a condition in which seed contains more than one embryo. Nucellus is central part of ovule that encloses the female gametophyte. Sometimes these nucellar cells are begin to divide and extend into embryo sac, results in nucellar polyembryony. Polyembryony wa discovered by Leeuwenhoek (1719).
262634
After double fertilization, a mature ovule has
1 1 diploid and I haploid cell
2 1 diploid and 1 triploid cell
3 2 haploid and 1 triploid cell
4 1 haploid and 1 triploid cell.
Explanation:
Double fertilization found only in angiosperms. -Each embryo sac receives two male gametes,one male gamete fuses with egg cell to form zygote, this is called syngamy or generative fertilization, second male gamete fuses with secondary nucleus \((2 n)\) to form primary endosperm nucleus, this act of fertilization is called triple fusion or vegetative fertilization. Thus fertilization take place twice in the same embryo. This fusion of two male gamets to two different structure (one is zygote and other is PEN) is called double fertilization. It include syngamy as well as triple fusion. It was discovered by Nawaschin (1898) in fritillaria and lilium. After double fertilization a mature ovule has one diploid cell (zygote) and one triploid cell (PEN) .
AIIMS-2013
Sexual Reproduction in Flowering Plants
262677
Double fertilization is fusion of :
1 two eggs
2 two eggs and polar nuclei
3 ond male gamete with egg and other with synergids
4 one male gamete with egg and other with secondary nucleus
Explanation:
Double fertilization is fusion of one male gamete with egg and other with secondary nucleus. Double fertilization is consist of two steps. \(1^{\text {st }}\) step is fusion of one male gamete and egg cell which results in the formation of zygote and this process is called as fertilization. \(2^{\text {nd }}\) step is the fusion of another male gamete with polar nuclei which results in the formation of endosperm and this step is known as triple fusion. Endosperm provide nutrition to the developing embryo.
The ploidy level of the plant is diploid Hence, the ploidy level of nucleus is \(2 \mathrm{n}\). Polar nuclei is present in embryo and is haploid (n). Two polar nuclei \((n+n)\) and male gamete (n) fuse to form endosperm which is triploid (3n). Megaspore mother cell is the one which is going to form 4 haploid megaspores by meiosis so again being a parent cell their ploidy is \(2 \mathrm{n}\). The female gametophyte is also haploid; therefore the ploidy is \(\mathrm{n}\).
AIIMS-26.05.2018 Shift-I
Sexual Reproduction in Flowering Plants
262639
Nucellar polyembryons occurs in
1 Corchorus
2 Citrus
3 Carthamus
4 Zea mays
Explanation:
Nucellar polyembryony occurs in citrus. It is a condition in which seed contains more than one embryo. Nucellus is central part of ovule that encloses the female gametophyte. Sometimes these nucellar cells are begin to divide and extend into embryo sac, results in nucellar polyembryony. Polyembryony wa discovered by Leeuwenhoek (1719).
262634
After double fertilization, a mature ovule has
1 1 diploid and I haploid cell
2 1 diploid and 1 triploid cell
3 2 haploid and 1 triploid cell
4 1 haploid and 1 triploid cell.
Explanation:
Double fertilization found only in angiosperms. -Each embryo sac receives two male gametes,one male gamete fuses with egg cell to form zygote, this is called syngamy or generative fertilization, second male gamete fuses with secondary nucleus \((2 n)\) to form primary endosperm nucleus, this act of fertilization is called triple fusion or vegetative fertilization. Thus fertilization take place twice in the same embryo. This fusion of two male gamets to two different structure (one is zygote and other is PEN) is called double fertilization. It include syngamy as well as triple fusion. It was discovered by Nawaschin (1898) in fritillaria and lilium. After double fertilization a mature ovule has one diploid cell (zygote) and one triploid cell (PEN) .
AIIMS-2013
Sexual Reproduction in Flowering Plants
262677
Double fertilization is fusion of :
1 two eggs
2 two eggs and polar nuclei
3 ond male gamete with egg and other with synergids
4 one male gamete with egg and other with secondary nucleus
Explanation:
Double fertilization is fusion of one male gamete with egg and other with secondary nucleus. Double fertilization is consist of two steps. \(1^{\text {st }}\) step is fusion of one male gamete and egg cell which results in the formation of zygote and this process is called as fertilization. \(2^{\text {nd }}\) step is the fusion of another male gamete with polar nuclei which results in the formation of endosperm and this step is known as triple fusion. Endosperm provide nutrition to the developing embryo.
The ploidy level of the plant is diploid Hence, the ploidy level of nucleus is \(2 \mathrm{n}\). Polar nuclei is present in embryo and is haploid (n). Two polar nuclei \((n+n)\) and male gamete (n) fuse to form endosperm which is triploid (3n). Megaspore mother cell is the one which is going to form 4 haploid megaspores by meiosis so again being a parent cell their ploidy is \(2 \mathrm{n}\). The female gametophyte is also haploid; therefore the ploidy is \(\mathrm{n}\).
AIIMS-26.05.2018 Shift-I
Sexual Reproduction in Flowering Plants
262639
Nucellar polyembryons occurs in
1 Corchorus
2 Citrus
3 Carthamus
4 Zea mays
Explanation:
Nucellar polyembryony occurs in citrus. It is a condition in which seed contains more than one embryo. Nucellus is central part of ovule that encloses the female gametophyte. Sometimes these nucellar cells are begin to divide and extend into embryo sac, results in nucellar polyembryony. Polyembryony wa discovered by Leeuwenhoek (1719).
