TLS Online TPP Program

#Question id: 18003


In a typical angiosperm, what is the sequence of structures encountered by the tip of a growing pollen tube on its way to the egg? 
1. micropyle 2. style 
3. ovary 4. stigma 

#Unit 9. Diversity of Life Forms
  1. 4 → 2 → 3 → 1 
  2. 4 → 3 → 2 → 1 
  3. 1 → 4 → 2 → 3 
  4. 1 → 3 → 4 → 2 
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TLS Online TPP Program

#Question id: 9180

#Unit 9. Diversity of Life Forms

Which of the following statements can be accurately made about light in aquatic environments?

TLS Online TPP Program

#Question id: 15153

#Unit 8. Inheritance Biology

In this problem we will explore some of the many ways that mutations in two different genes can interact to produce different Mendelian ratios. Consider a hypothetical insect species that has red eyes. Imagine mutations in two different unlinked genes that can, in certain combinations, block the formation of red eye pigment yielding mutants with white eyes. In principle, there are two different possible arrangements for two biochemical steps responsible for the formation of red eye pigment. The two genes might act in series such that a mutation in either gene would block the formation of red pigment. Alternatively, the two genes could act in parallel such that mutations in both genes would be required to block the formation of red pigment.
Further complexity arises from the possibility that mutations in either gene that lead to a block in enzymatic activity could be either dominant or recessive. If the crosses is made between a wild type insect with red eyes and a true breeding white eyed strain with mutations in both genes. Such considerations yield the Pathways in parallel with recessive mutations in both genes, determine the phenotype of the F1 progeny and the expected phenotypic ratio of red to white eyed insects in the F2.

TLS Online TPP Program

#Question id: 16089

#Unit 7. System Physiology – Animal

Non-shivering thermogenesis

TLS Online TPP Program

#Question id: 9601

#Unit 9. Diversity of Life Forms

The relative lengths of the frog and mouse branches in the phylogenetic tree indicate that

TLS Online TPP Program

#Question id: 3645

#Unit 3. Fundamental Processes

The single-stranded bubble created in DNA replication is coated with _____________ to protect it from breakage and to prevent the DNA renaturing.