Proteins play key roles in olfaction. One kind of protein, called , attaches itself to hydrophobic odorant molecules so that they may dissolve in watery mucous. A second class of proteins, to which odorant molecules become bound and initiate transduction, are coded by the largest family of genes in mammals and are called . Group of answer choices

The correct answer is "Odorant-binding proteins (OBPs); Olfactory receptors (ORs)".

Explanation:

Odorant-binding proteins (OBPs) are low-molecular soluble molecules that are secreted in high amounts in the nasal mucus layer. The precise biological activity of OBPs remains unclear, however, its solubility and ability to attach to hydrophobic odorant molecules suggest that they acts as carriers. A second class of proteins called olfactory receptors (ORs), act at the genetic level by initiating transduction once odorant molecules attach to them. ORs are coded by the largest family of genes, which include more than 100 genes and pseudogenes that represent around 3% of the genome.

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.