You can physically see the of a trait, but not the .

1.) a. phenotype
b. genotype

2.) a. genotype
b. phenotype

The correct answer for the blank is -

1.) A. Phenotype

B. Genotype

Phenotype corresponds to the physical appearance of a particular characteristic or morphological form in an individual.

Example - Hair color, plant height, skin color.

On the other hand, genotype corresponds to the genetic makeup of an individual. It is depicted by the gene that is present in the individual organism. Example- Genotype for dwarf height in pea plant is 'tt', which carries both recessive gene variants.

Thus, we can physically see the phenotype of a trait, but not the genotype.

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

the answer is sex-linked recessive.