(i) Fertilization in human females takes place in the fallopian tube (oviduct). (ii) The inner lining of the uterus, called the endometrium, becomes thick, soft, and richly supplied with blood vessels each month. This provides a warm, nutrient-rich environment to receive the fertilized egg and suppoRead more
(i) Fertilization in human females takes place in the fallopian tube (oviduct).
(ii) The inner lining of the uterus, called the endometrium, becomes thick, soft, and richly supplied with blood vessels each month. This provides a warm, nutrient-rich environment to receive the fertilized egg and support the growing embryo.
The developing embryo gets nutrition from the mother’s blood through a special tissue called the placenta. The placenta forms a connection between the embryo and the mother’s uterus. Tiny finger-like structures, called villi, grow into the uterine tissue, increasing the surface area for exchange. ThRead more
The developing embryo gets nutrition from the mother’s blood through a special tissue called the placenta. The placenta forms a connection between the embryo and the mother’s uterus. Tiny finger-like structures, called villi, grow into the uterine tissue, increasing the surface area for exchange. The mother’s blood vessels surround these villi and supply oxygen, glucose, amino acids, and other nutrients, which diffuse into the embryo’s blood. At the same time, waste products from the embryo pass into the mother’s blood for removal.
When the egg is not fertilized, it cannot develop into an embryo. The unfertilized egg disintegrates within the fallopian tube, and the hormone levels of estrogen and progesterone start to decline. As a result, the thickened uterine lining, which had been prepared to receive a fertilized egg, is noRead more
When the egg is not fertilized, it cannot develop into an embryo. The unfertilized egg disintegrates within the fallopian tube, and the hormone levels of estrogen and progesterone start to decline. As a result, the thickened uterine lining, which had been prepared to receive a fertilized egg, is no longer maintained. The lining breaks down and is shed from the body through the vagina in the form of menstrual bleeding. This marks the start of a new menstrual cycle.
(i) Differentiate between self-pollination and cross-pollination. Self-pollination: Transfer of pollen from the anther to the stigma of the same flower or another flower on the same plant. Cross-pollination: Transfer of pollen from the anther of one plant to the stigma of a flower on a different plaRead more
(i) Differentiate between self-pollination and cross-pollination.
Self-pollination: Transfer of pollen from the anther to the stigma of the same flower or another flower on the same plant.
Cross-pollination: Transfer of pollen from the anther of one plant to the stigma of a flower on a different plant of the same species.
(ii) A – Stigma: Receives pollen grains during pollination.
B – Style: Provides a passage for pollen tube to reach the ovary.
C – Ovary: Contains ovules; after fertilization, ovary develops into a fruit.
ANSWER: [C] Explanation: When a piece of magnesium ribbon is ignited, light and heat are produced. Magnesium ribbon on burning in air is an exothermic reaction.
ANSWER: [C]
Explanation: When a piece of magnesium ribbon is ignited, light and heat are produced. Magnesium ribbon on burning in air is an exothermic reaction.
When a girl is born, the ovaries already contain thousands of immature eggs. On reaching puberty, some of these start maturing. One matured egg is released every month by one of the ovaries. The two oviducts unite into an elastic bag-like structure known as uterus. (i) Write the site of fertilization in human female. (ii) How does the uterus prepare itself to receive and nurture the growing embryo? Explain.
(i) Fertilization in human females takes place in the fallopian tube (oviduct). (ii) The inner lining of the uterus, called the endometrium, becomes thick, soft, and richly supplied with blood vessels each month. This provides a warm, nutrient-rich environment to receive the fertilized egg and suppoRead more
(i) Fertilization in human females takes place in the fallopian tube (oviduct).
(ii) The inner lining of the uterus, called the endometrium, becomes thick, soft, and richly supplied with blood vessels each month. This provides a warm, nutrient-rich environment to receive the fertilized egg and support the growing embryo.
See lessHow does the developing embryo get nutrition from the mother’s blood? Explain.
The developing embryo gets nutrition from the mother’s blood through a special tissue called the placenta. The placenta forms a connection between the embryo and the mother’s uterus. Tiny finger-like structures, called villi, grow into the uterine tissue, increasing the surface area for exchange. ThRead more
The developing embryo gets nutrition from the mother’s blood through a special tissue called the placenta. The placenta forms a connection between the embryo and the mother’s uterus. Tiny finger-like structures, called villi, grow into the uterine tissue, increasing the surface area for exchange. The mother’s blood vessels surround these villi and supply oxygen, glucose, amino acids, and other nutrients, which diffuse into the embryo’s blood. At the same time, waste products from the embryo pass into the mother’s blood for removal.
See lessWhat happens when the egg is not fertilized?
When the egg is not fertilized, it cannot develop into an embryo. The unfertilized egg disintegrates within the fallopian tube, and the hormone levels of estrogen and progesterone start to decline. As a result, the thickened uterine lining, which had been prepared to receive a fertilized egg, is noRead more
When the egg is not fertilized, it cannot develop into an embryo. The unfertilized egg disintegrates within the fallopian tube, and the hormone levels of estrogen and progesterone start to decline. As a result, the thickened uterine lining, which had been prepared to receive a fertilized egg, is no longer maintained. The lining breaks down and is shed from the body through the vagina in the form of menstrual bleeding. This marks the start of a new menstrual cycle.
See less(i) Differentiate between self-pollination and cross-pollination. (ii) Identify A, B and C in the diagram given below and write one function of each.
(i) Differentiate between self-pollination and cross-pollination. Self-pollination: Transfer of pollen from the anther to the stigma of the same flower or another flower on the same plant. Cross-pollination: Transfer of pollen from the anther of one plant to the stigma of a flower on a different plaRead more
(i) Differentiate between self-pollination and cross-pollination.
(ii) A – Stigma: Receives pollen grains during pollination.
B – Style: Provides a passage for pollen tube to reach the ovary.
C – Ovary: Contains ovules; after fertilization, ovary develops into a fruit.
See lessWhich of the following is the correct observation of the reaction shown in the above set up?
ANSWER: [C] Explanation: When a piece of magnesium ribbon is ignited, light and heat are produced. Magnesium ribbon on burning in air is an exothermic reaction.
ANSWER: [C]
Explanation: When a piece of magnesium ribbon is ignited, light and heat are produced. Magnesium ribbon on burning in air is an exothermic reaction.
See less