Sunday, 24 March 2013
Friday, 22 March 2013
|Question 1. What is the term used for secretions of endocrine glands responsible for changes taking place in the body?|
|Answer :The secretions of endocrine glands responsible for
changes taking place in the body is called hormones.Hormones are chemical
substances, which are released by endocrine glands directly into the blood stream.. The changes which occur at onset of
puberty and adolescence are controlled by
Thursday, 21 March 2013
- Question 1. Explain the importance of reproduction in organisms.
- Answer : The process of reproduction in organisms is essential for the continuation of theirs respective species. The reproduction in organisms is very important as it ensures the continuation of similar kinds of individuals, generation after generation.In larger context, reproduction in various species of animals and plants kingdom, forms part of ecosystem and which helps in maintaining it, by evolution chain.
Wednesday, 20 March 2013
Question 1. Indicate whether the following statements are True (T) or False (F).
- Unicellular organisms have one-celled body. (T/F)
- Muscle cells are branched. (T/F)
- The basic living unit of an organism is an organ. (T/F)
- Amoeba has irregular shape. (T/F)
Tuesday, 19 March 2013
Things to remember..When, we compared the two quantities in terms of ‘how many times’. This comparison is known as the Ratio. We denote ratio using symbol ‘:’ Consider the following example : DIsha’s weight is 15 kg and her father’s weight is 60 kg. How many times Father’s weight is of Isha’s weight? It is 4 times.
∴ The ratio of father’s weight to Disha’s weight = 60/15 = 4/1= 4:1
1. There are 20 girls and 15 boys in a class.
(a) What is the ratio of number of girls to the number of boys?
(b) What is the ratio of number of girls to the total number of students in the class?