Chapter 17 - Chapter 17: The Reproductive System 1. How...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 17: The Reproductive System 1. How does the reproductive system differ from other body systems? The rest of the body's systems work to ensure the survival of the individual animal they are part of, whereas the reproductive system works to ensure the survival of the species of animal. It interacts with other body systems, but purely reproductive structures are not essential to the life of an animal. Another difference from other body systems is that the reproductive system requires a second animal (of the opposite sex) to fully carry out its function, which is to produce a brand new animal (the offspring). 2. Why is the reproductive system of an individual animal considered only half a system? It is considered only half a system because it requires a second animal (of the opposite sex) to fully carry out its function. 3. What is the difference between the diploid chromosome number and the haploid chromosome number? In which body cells is each found? The total number of chromosomes in the nucleus of each of the body’s cells (except for the reproductive cells) is the same for all members of a species. This number is called the diploid chromosome number , which is always an even number because the chromosomes occur in pairs. The diploid chromosome number is sometimes expressed generically with the abbreviation 2n. The n is a mathematical expression that represents a number, and the 2 indicates that the number is doubled (diploid). The number of chromosomes in the reproductive cells is half the number in all other cells in the body. This is called haploid chromosome number . It has to be reduced to half the diploid number so that when the spermatozoon and the ovum come together, the total number of chromosomes in the fertilized ovum gets back to the diploid number. 4. Which reproductive cell, the ovum or the spermatozoon, determines the genetic sex of the offspring when fertilization occurs? Spermatozoon 5. How does cell division by meiosis differ from cell division by mitosis? Most of the body’s cells divide through a process called mitosis . When a cell divides by mitosis, each of its chromosomes first produces a duplicate copy of itself. When the two daughter cells pull apart, half the chromosomes go to one cell and half go to the other. Each of them ends up with an identical full diploid set of chromosomes. The genetic makeup of the two daughter cells is exactly the same as each other and as the parent cell. This ensures that the genetic information in all of the body's cells (except for the reproductive cells) stays exactly the same. Reproductive cells are produced by meiosis, in which the chromosomes do not produce duplicate copies of themselves before the daughter cells pull apart. Half of the total chromosomes (one from each diploid chromosome pair), including one sex chromosome, go to each daughter cell. Which chromosomes go to which daughter cell is entirely random. The chromosomes merely pull apart into their new cells. In this way the genetic material of the
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/03/2012 for the course NRM 2406 taught by Professor Dabbert during the Spring '12 term at Texas Tech.

Page1 / 6

Chapter 17 - Chapter 17: The Reproductive System 1. How...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online