Answer:
I think it is B
Explanation:
The meaning of abrasion is friction and repeated impact by water, ice or wind.
Answer:
C, basic contractile unit of muscle fiber.
Explanation:
If you read the definition of sarcomere, this is what it says: "<u>A sarcomere (Greek σάρξ sarx "flesh", μέρος meros "part") is the complicated unit of striated muscle tissue. It is the repeating unit between two Z lines. Skeletal muscles are composed of tubular muscle cells (myocytes called muscle fibers or myofibers) which are formed in a process known as myogenesis</u>."
hope this helps.
Answer:
The correct answer is option - d. Production of primary spermatocytes.
Explanation:
The accessory cells or supporting cells present within the seminiferous tubules of reproductive system termed as the Sertoli cells. They play various roles in the body and reproductive system.
Sertoli cells make blood-testis barrier in adjacent Sertoli cells in the seminiferous tubules. These cells secrete different types of enzymes and hormones such as inhibin which are also secreted by ovary and placenta in females. Sertoli cells produce seminiferous tubular fluid to provide nutrition to the sperm. Apoptotic germ cells are timely eliminated by these cells.
Thus, the correct answer is option D. Production of primary spermatocytes.
Bacteria are unicellular microorganisms that can be found everywhere in the environment. Viruses are microorganisms that can only reproduce within the cells of a host organism.
The differences between viruses and bacteria include;
- Viruses do not have any cell and are considered between living and non-living things, while bacteria have one cell (Unicellular) and are living organisms.
- Viruses are smaller in size (20-400 nm) when compared with bacteria (1000 nm).
- Viruses do not have a cell wall but a protein coat is present, while bacteria have a cell wall that is composed of peptidoglycan.
- Viruses require a living cell to reproduce, while bacteria can reproduce by itself.
- The DNA or RNA of viruses is enclosed inside a coat of protein, while that of bacteria floats freely in the cytoplasm within the cell.
