Key Vocabulary Terms

Spontaneous generation - the idea that living things can come from nonliving things
Trait - a characteristic of an organism
Diversity - the range of differences among the individuals in a population

Key Concepts

Spontaneous generation is the idea that living things can arise from nonliving things.
Francesco Redi showed that maggots came from eggs laid by adult flies, not from nonliving meat.
DNA is a chemical found in an organism's cells and stores information about the organism.
Human offspring are unique because they have a combination of DNA from each parent.
Diversity increases the likelihood that the population can survive sudden changes in the environment.

Did you learn these Objectives?

Mitosis - the process that results in two cells identical to the parent cell.
Chromosome - a rod-shaped structure that contains DNA and is found in the nucleus of a cell.
Gamete - A sex cell, such as sperm or egg.
Meiosis - the process that results in sex cells.
External fertilization - the type of fertilization that occurs outside the female's body
Internal fertilization - the type of fertilization that occurs inside the female's body

Key Concepts

Asexual reproduction does not require a mate and produces offspring more quickly than sexual reproduction.
The process of mitosis results in two cells that are identical to the parent cell.
Sexual reproduction results in unique offspring.
The process of meiosis results in four sex cells that have a half set of chromosomes.
A sperm cell inserts its nucleus into an egg cell. The nuclei of the sperm cell and egg cell join, forming a zygote with a full set of chromosomes.

Did you learn these Objectives?

Are you able to recognize the advantages and disadvantages of asexual reproduction?
Can you recognize the advantages and disadvantages of sexual reproduction?
Are you able to compare mitosis with meiosis?
Can you trace the steps in the fertilization of an egg?

Embryo - an early stage in the development of an organism
Cell differentiation - the process of cells taking on different jobs in the body
Nymph - a young insect that looks like the adult.
Marsupial - a mammal that gives birth to young that are very undeveloped
Uterus - an organ in most female mammals that holds and protects an embryo
Placenta - A tissue that provides the embryo with food and oxygen from its mother's body.
Gestation time - the period of development of a mammal, from fertilization until birth.

Key Concepts

The zygote undergoes many cell divisions and differentiation of cells, resulting in an embryo.
The young of a butterfly go through different states of development (egg, caterpillar, pupa) that look very different from the adult.
When a fish lays thousands of eggs it increases the chances of the species' survival.
Marsupials give birth to young that are very underdeveloped and that complete their development outside the mother's body, in an external pouch.
Gestation time is the period from fertilization of a mammal egg until birth occurs.

Did you learn these Objectives?

Investigation 9 "Graphing Gestation Times" (Optional, must complete 10 total investigations)

Key Concepts and Objectives

You will use your skills of observing, comparing and contrasting, graphing, and drawing conclusions to answer the question: "how do gestation times of different animals compare with each other?".
You will use a bar graph to compare different gestation times.

Scrotum - the sac that holds the testes.
Testosterone - male sex hormone
Penis - the male organ that delivers sperm to the female body.
Vagina the tube-like canal in the female body through which sperm enter the body
Prostate gland - the gland that produces the fluid found in semen
Semen - a mixture of fluid and sperm cells
Estrogen - female sex hormone
Progesterone - female sex hormone
Ovulation - the process of releasing an egg from an ovary
Fallopian tube - a tube through which eggs pass from an ovary to the uterus
Menstruation - the process during which an unfertilized egg, blood, and pieces of the lining of the uterus exit the female body.
Pregnancy- the development of a fertilized egg into a baby inside a female's body
Umbilical cord - the cord that connects an embryo with the placenta
Fetus - an embryo after eight weeks of development in the uterus
Adolescence -the teenage years of a human
Puberty - the period of rapid growth and physical changes that occurs in males and females during early adolescence.

Key Concepts

During fertilization sperm travels from the testes through the urethra and into the female's body through the vagina. From the vagina, the sperm travel through the uterus and into the fallopian tubes where one sperm unites with an egg.
During ovulation an egg is released from an ovary into a fallopian tube.
During menstruation, an unfertilized egg, blood, and pieces of the lining of the uterus pass out of the female body through the vagina.
During gestation food and oxygen for the embryo pass from the mother's blood to the embryo's blood through the placenta.
During puberty males and females go through many physical changes: both begin to grow hair under their arms and in the area of their sex organs; Females' breasts enlarge and menstruation begins.

Did you learn these Objectives?

Are you able to identify the parts of the male and female reproductive systems in humans?
Can you define ovulation and menstruation?
Are you able to describe the main events of pregnancy?
Can you describe changes that occur in males and females during puberty?

Chapter Summary and Review

See page 238-239

Chapter 9 Review answers are