TLS Online TPP Program

#Question id: 7152


The size of a cell is generally controlled by the amount of DNA in the nucleus: the more DNA, the larger the cell. What do experiments in which the amount of DNA is doubled (tetraploidy in salamanders) tell us about growth control?

#Unit 5. Developmental Biology
  1. The animals grow to a normal size, and contain only half as many cells, indicating that growth is regulated at the level of absolute size, rather than cell number.
  2. The animals grow to twice the normal size, indicating that growth is regulated at the level of the number of cells present.
  3. The animals end up with cells that are twice as big, but only half as many, resulting in an animal that is half its normal size, indicating that the number of cells is the critical determinant of growth.
  4. The animals grow to a normal size, and contain only half as many cells, indicating that growth is regulated by the total amount of DNA present in an organism.
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TLS Online TPP Program

#Question id: 5464

#Unit 8. Inheritance Biology

Two varieties of maize averaging AABBCC (200 inch) and aabbcc (80 inch) in height, respectively, are crossed. The F1 progeny is quite uniform averaging 140 inches in height allowed to self fertilization. If height is control by 3 pair of polygene, what is the height of following genotype of F2 plant?

I- AaBBCC     II- aaBbCC       III- aabbCc

TLS Online TPP Program

#Question id: 5465

#Unit 8. Inheritance Biology

A pure line apple plant yielding 3.5 pound apple was crossed with a .5 pound apple yielding plant, all F1 progenies yielded apples of 2 pound, F1 plant allowed to self fertilization then what will be proportional of 3 pound, 2 pound and .5 pound respectively among offspring if character is governed by 3 pair of polygene

TLS Online TPP Program

#Question id: 5466

#Unit 8. Inheritance Biology

Researcher studies of discontinuous and continuous character, the following conclusion were made

a. Discontinuous characteristics exhibit few distinct phenotypes

b- Continuous characteristics exhibit a wide range of phenotypes

c .Continuous characteristics are frequently produced by effects of many genes

d. Continuous characteristics are frequently produced by effects of environment

Which of above conclusion is correct?

TLS Online TPP Program

#Question id: 5467

#Unit 8. Inheritance Biology

Two varieties of maize averaging 25 and 125 inches in height, respectively, are crossed. The F1 progeny is quite uniform averaging 75 inches in height. Of the 500 F2 plants, the Shortest 2 is 25 inches and the tallest 2 are 125 inches. What will be number phenotype observe in F2 progeny and number of polygene contribute for that character respectively?

TLS Online TPP Program

#Question id: 5468

#Unit 8. Inheritance Biology

Plant height is control by polygenetic trait. Plant having height 6 cm are allowed to cross with plant having height 2 cm , all F1 progeny having height uniform 4 cm were allowed selfing to produced F2 progeny in which 5 out of 320 with height of 6 cm. What will be phenotype ratio in F2 generation?

TLS Online TPP Program

#Question id: 5469

#Unit 8. Inheritance Biology

Breeding experiment was performed on pure lines of tomatoes differing in fruit weight. The plants were all grown in a controlled environment chamber providing equal environmental conditions for all individuals as far as humanly possible. The results were as follows:

a) One dominants polygene contribution?

b) What will be frequency of 20 g in F2 CLASSES?

c) Number of polygene loci for this character.