The cell membrane is selectively permeable because of its molecular structure. Based on this, which one of these would not diffuse directly through the cell membrane

The large molecules like proteins composed of more than 1000 amino acid, mRNA molecules

Explanation:

The cell membrane of a cell is composed of the amphipathic molecules called lipids. The phospholipids are arranged in a way that their inner side is always hydrophobic therefore thy are considered hydrophobic molecules.

The hydrophobic molecules can diffuse easily and the small molecule can easily pass through the cell membrane but it restricts the entry of the larger molecules like the large proteins and the nucleic acid which can be diffused only with the process of either facilitated diffusion or the endocytosis or exocytosis.

Thus, the large molecules like proteins composed of more than 1000 amino acid, mRNA molecules are correct.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.