A bilobed, dithecous anther has 100 microscopes mother cells per microsporangium. How many male gamepophytes this anther can produce?

An anther has 1200 pollen grains. How many pollen mother cells must have been there to produce them?

Long Answer Questions Five mark Each QUESTIONS FROM CBSE BOARD EXAMINATIONS : A flower of tomato plant following the process of sexual reproduction produces 240 viable seeds. Answer the following questions giving reasons: (a) What is the minimum number of pollen grains that must have been involved in the pollination of its pistil? (b) What would have been the minimum number of ovules present in the ovary? (c) How many megaspore mother cells were involved? (d) What is the minimum number of microspore mother cells involved in the above case? (e) How many male gametes were involved in this case?

Short Answer Questions Three mark Each (a) The diagram given below shows the transverse section of a young anther. Identify the parts a, b, c and d. (b) The developmental stages of male gametes in plants consist of microsporogenesis and male gametophyte. Arrange the following terms in their correct developmental sequence. Pollen grain Sporogenous tissue Anther Microspore tetrad Pollen mother cell Male gamete.

Two tailors A and B earn Rs 150 and Rs 200 per day respectively. A can stitch 6 shirts and 4 pants while B can stitch 10 shirts and 4 pants per day. How many days shall each work it it is desired to produce (at least) 60 shirts ands 32 pants at a minimum labour cost? Solve the problem graphically.

A manufacturer has three machines I, II and III installed in his factory. Machines I and II are capable of being operated for at most 12 hours whereas machine III must be operated for at least 5 hours a day. She produces only two items M and N each on the three machines are given in the following table: SHe makes a profit of Rs 600 and Rs 400 on items M and N respectively. How many of each item should she produce so as to maximise her profit assuming that she can sell all the items that she produced? What will be the maximum Profit?

A manufacturing company makes two types of television sets, one is black and white and the other is colcoured. The company has resources to make atmost 300 sets a week. It takes Rs.1800 to make a black and white set and Rs.2700 to make a colured set. The company can spend not more thatn Rs.648000 a week to make television sets. if it makes a profit of Rs.510 per black and white set and Rs.675 per coloured set. how many sets of each type should be produced so that the company has maximum profit?

Consider the following four statements (A-D) and select the option which includes all the correct ones only: Single cell Spirullina can produce large quantities of food rich in proteins, minerlas, vitamins, etc. Body weightwise, the micro-organism Methylophilus methylotrophus may be able to produce several time more proteins than the cows per day Common button mushrooms are a very rich source of vitamin-C A rice variety has been developed which is very rich in calcium.

An oil company requires 13000, 20000 and 15000 barrels of high grade, medium grade and low grade oil respectively, Refinery A produces 100, 300 and 200 barrels per day of high, medium and low grade oil respectively whereas refinery B produces 200, 400 and 100 barrels per day respectively. If A costs Rs 400 per day and B costs Rs 300 per day to operate, how many days should each be run to minimise the cost of requirement?