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.
(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.
ANSWER: [A] Explanation: In test tube P: Copper sulphate solution reacts with zinc (Zn), because zinc is more reactive than copper. Zinc displaces copper from and copper is deposited as a red-brown coating on the zinc strip. In test tube Q: Magnesium sulphate solution does not react with zinc becauRead more
ANSWER: [A]
Explanation: In test tube P: Copper sulphate solution reacts with zinc (Zn), because zinc is more reactive than copper. Zinc displaces copper from and copper is deposited as a red-brown coating on the zinc strip.
In test tube Q: Magnesium sulphate solution does not react with zinc because zinc is less reactive than magnesium, so no displacement occurs.
ANSWER: [B] Explanation: An alkali is a base that dissolves in water hence, all alkalies are bases but all bases are not alkalies. Sodium hydroxide is termed as alkali as it is a strong base as well as highly soluble in water. Ferric hydroxide is also a base, but it is not an alkali as it is not solRead more
ANSWER: [B]
Explanation: An alkali is a base that dissolves in water hence, all alkalies are bases but all bases are not alkalies. Sodium hydroxide is termed as alkali as it is a strong base as well as highly soluble in water. Ferric hydroxide is also a base, but it is not an alkali as it is not soluble in water.
How 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 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 lessA zinc strip is added to two test tubes: test tube ‘P’ contains aqueous copper sulphate (CuSO4) and test tube Q contains aqueous magnesium sulphate MgSO4. Which of the following observations is correct? (a) In test tube ‘P’, zinc strip is coated with a red – brown layer, while in ‘Q’ there is no reaction. (b) Zinc strip turns black in ‘P’ and develops a white coating in ‘Q’. (c) Bubbles are observed in both test tubes ‘P’ and ‘Q’. (d) There is no reaction in either test tube.
ANSWER: [A] Explanation: In test tube P: Copper sulphate solution reacts with zinc (Zn), because zinc is more reactive than copper. Zinc displaces copper from and copper is deposited as a red-brown coating on the zinc strip. In test tube Q: Magnesium sulphate solution does not react with zinc becauRead more
ANSWER: [A]
Explanation: In test tube P: Copper sulphate solution reacts with zinc (Zn), because zinc is more reactive than copper. Zinc displaces copper from and copper is deposited as a red-brown coating on the zinc strip.
In test tube Q: Magnesium sulphate solution does not react with zinc because zinc is less reactive than magnesium, so no displacement occurs.
See lessSodium hydroxide is termed an alkali while Ferric hydroxide is not because:
ANSWER: [B] Explanation: An alkali is a base that dissolves in water hence, all alkalies are bases but all bases are not alkalies. Sodium hydroxide is termed as alkali as it is a strong base as well as highly soluble in water. Ferric hydroxide is also a base, but it is not an alkali as it is not solRead more
ANSWER: [B]
Explanation: An alkali is a base that dissolves in water hence, all alkalies are bases but all bases are not alkalies. Sodium hydroxide is termed as alkali as it is a strong base as well as highly soluble in water. Ferric hydroxide is also a base, but it is not an alkali as it is not soluble in water.
See less