Answer:
Basement membrane
Explanation:
Epithelial tissues is one of the four types of tissues. They are widespread throughout the body and form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands .
They perform a lot of functions such as absorption, excretion, filtration, diffusion, and sensory reception.
They are anchored to the underlying connective tissue by basement membrane. A thin, fibrous, extracellular matrix of tissue.
The basement membrane acts as a mechanical barrier that prevents malignant cells from invading the deeper tissues.
D.
A fixed allele is homozygous within a population so D should be the correct answer.
Hope this helps!
Variation,inheritance,selection,time
