Give reason for each of the following: [5]
(i) A high rate of transpiration is recorded on a windy day rather than on a
cooler day.
(ii) Haemophilia is more common in males than in females.
(iii) Washing away of fertilizers from agricultural fields to water bodies
results in death of aquatic animals.
(iv) Meiosis is called reduction division
(v) Wooden doors swell in rainy season.
Answers
Answer:
1. The wind is one of the external factors that increase the rate of transpiration. The wind carries away the moisture present in the atmosphere by making it dry enough so that it can absorb more water vapors from the plants. This result in high rate of transpiration in a windy atmosphere than on a calm day
2. These disorders affect males more often than females because females have an additional X chromosome that acts as a “back-up.” Because males only have one X chromosome, any mutation in the factor VIII or IX gene will result in hemophilia.
3. Rain water carries soil particles (sediment) and dumps them into nearby lakes or streams. ... In addition, other pollutants like fertilizers, pesticides, and heavy metals are often attached to the soil particles and wash into the water bodies, causing algal blooms and depleted oxygen, which is deadly to most aquatic life.
4.The process of meiosis involves two divisions of the genetic material. The first division is called the reduction division – or meiosis I – because it reduces the number of chromosomes from 46 chromosomes or 2n to 23 chromosomes or n (n describes a single chromosome set).
5.Swelling of wooden doors during rains is caused by the process of imbibition. The process of adsorption of water by solid particles of a substance without forming a solution is called imbibition