ANSWER IN BRIEF
*INDEX-TOPIC SEARCH
- Describe : Ascent of sap.
ANS:
- Plants absorb water and minerals from the soil through root hairs.
- Water along with minerals then moves through root cortex and endodermis to reach the root xylem.
- From root xylem they enter the interconnected stem xylem which branches into leaves.
- This transportation of water and minerals from the roots to the leaves is known as the ascent of sap.
- Plants absorb water and minerals from the soil through root hairs.
- Explain : Rhesus factor.
ANS:
- Blood contains an antigen called Rh factor (Rhesus factor).
- A person with Rh antigen in blood is called Rh +ve and one lacking it is called Rh -ve.
- Incompatibility of Rh factor causes problems.
- If an Rh +ve man marries an Rh -ve woman, the birth of the first child is normal. But mother's blood forms antibodies against Rh antigen.
- If the second child is Rh +ve, the antibody in mother's blood reacts with the Rh antigen of the foetus and causes problems, sometimes leading to the death of the child.
- Blood contains an antigen called Rh factor (Rhesus factor).
- Describe excretion and osmoregulation in amoeba.
ANS:
- Amoeba is a fresh water unicellular organism.
- It has a contractile vacuole for excretion and osmoregulation.
- The waste produced in the cell enters contractile vacuole along with water.
- The size of the contractile vacuole gradually increases and then it moves closer to the plasma membrane.
- It bursts after touching the plasma membrane and releases the excretory substances into the surrounding water by diffusion.
- Amoeba is a fresh water unicellular organism.
- Give reason : An Rh(-ve) woman should not marry an Rh(+ve) man.
ANS: [Refer to last two points mentioned in the answer about Rhesus factor].
- Distinguish between xylem and phloem.
ANS:
- Distinguish between blood and lymph.
ANS :
- Distinguish between artery and vein.
ANS :
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