Which substance is in higher concentration in blood than in glomerular filtrate?

 The substance that is in higher concentration in the blood than in the glomerular filtrate is Plasma proteins.

Explanation:
Plasma proteins are higher in concentration in blood than in glomerular filtrate. The plasma fluid that filters out from glomerular capillaries into Bowman's capsule of nephrons is called glomerular filtrate. It is a non-colloidal part and possesses urea, water, glucose, amino acids, vitamins, fatty acid, uric acid, creatinine, salts, etc. RBCs, WBCs, platelets and plasma proteins are the colloidal parts of the blood and do not filtered out from glomerulus. 

1. Water: Water is freely filtered through the glomerulus. The concentration of water in the blood and in the glomerular filtrate is roughly the same since water passes through the glomerular membrane easily.
2. Glucose: Glucose is also freely filtered through the glomerulus. The concentration of glucose in the blood and in the glomerular filtrate is initially the same. However, under normal conditions, most of the glucose is reabsorbed in the proximal convoluted tubule, so it does not appear in significant amounts in the final urine.
3. Urea: Urea is a small molecule and is freely filtered at the glomerulus. Its concentration in the blood and in the initial glomerular filtrate is roughly the same. However, urea is partially reabsorbed in the renal tubules, leading to a higher concentration in the blood eventually.
4. Plasma Proteins: Plasma proteins (such as albumin) are large molecules that are not freely filtered through the glomerular membrane due to their size and, in some cases, charge. Therefore, the concentration of plasma proteins in the blood is significantly higher than in the glomerular filtrate, where their presence is minimal or non-existent under normal conditions.

Out of the given options, the concentration of plasma proteins is indeed much higher in the blood than in the glomerular filtrate because the filtration barrier in the glomerulus generally prevents these large molecules from passing through. Therefore, the correct answer is Plasma proteins.