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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 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 As a result, the thickened uterine lining, which had been prepared to receive a fertilized egg, is no longer maintained.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 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.
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