Each of the male testes is composed of lobules, compartments which contain one to three seminiferous tubules each.
a. within these structures, cells undergo spermatogenesis, the production of sperm.
b. during this process, spermatagonia divide to produce primary (2n) spermatocytes.
c. after these spermatocytes move away from the outer wall and increase in size, they undergo meiosis to produce secondary spermatocytes with 23 chromosomes (n).
d. secondary spermatocytes undergo a second division to produce four spermatids also with 23 chromosomes each.

Which organelle releases chemicals that break down large food particles into smaller ones?

Food provides molecules that serve as fuel and building material for all organisms. plants undergo photosynthesis and make their own food. other organisms, like us and the horse seen above, are consumers and eat food. how do all organisms use food as fuel? be sure to include the name of the process in your answer. me.

After reading the paragraph below, answer the questions that follow. researchers have created a robot that has a very thin leg that is moved by cardiac (heart) cells contracting in unison. the robot, made of a polymer similar to that used in making contact lenses, is bathed in heart cells with supporting cells, which then attach to the robot and provide movement as they contract. all of the cardiac cells working together can cause the robot leg to move in a way that individual cells could not. this is an example of a. emergent properties of cells. b. energy flow through an ecosystem. c. adaptation. d. internal environment regulation.