Unit A Reproduction

UNIT
A
Review
Reproduction
Unit Summary
In this unit, you have learned about the growth and reproduction of cells and
complete organisms. The molecule that allows identical daughter cells to be
produced by cell division is DNA. The information contained in DNA is unique
to each individual of a species. Asexual reproduction passes on the identical
DNA to each new organism. In sexual reproduction, parents contribute a copy
of half of their DNA to their offspring through meiosis. The variety of traits
produced through sexual reproduction allows organisms to adapt to changing
environments. DNA contains the genetic code for all the instructions for life.
Thus, DNA controls the growth and development of all living things.
Changes in DNA can be harmful, causing diseases such as cancer.
Beginning with DNA at the cellular level, add words and arrows to make a
concept map that shows your understanding of the relationships between the
following terms:
• chromosomes
• replication of chromosomes
• nuclear membrane • ribosomes
• proteins
• sister chromatids
Using one or more of these terms, expand your concept map to include other
key ideas and vocabulary in this unit. Use diagrams, symbols, and text to
illustrate the relationships.
Review Key Ideas and Vocabulary
1. Approximately how many cells are in the
human body?
(a) 1 million
(c) 1 billion
(b) 100 million
(d) 100 trillion
2. Which of the following is a function of cell division?
(a) growth and repair (c) reproduction
(b) production of energy (d) both (a) and (c)
3. Which statement explains why cells divide?
(a) The nucleus gets too big.
(b) The volume is too large.
(c) The size is too small.
(d) There is not enough cytoplasm.
4. Which organism reproduces using cell division?
(a) humans
(c) Paramecium
(b) multicellular plants (d) blue whales
D
B
C
A
E
Figure 1
Use Figure 1 to answer questions 5 to 8.
5. Which structure produces the ribosomes?
(a) A (b) B (c) C (d) D
6. Which structure contains DNA?
(a) A (b) B (c) C (d) E
144 Unit A Reproduction
NEL