Uploaded by Dwane Decker

Topic 4 Living Environment Reproduction

Topic 4: Reproduction and Development
Topic Overview
A ________________ is a group of closely related organisms that share certain
characteristic and can produce new individuals through reproduction. When individuals
reproduce, their offspring begin a period of _______________ that ends in adulthood.
Types of Reproduction
Two methods of reproduction are associated with living organisms: _________________
and ________________. _______________ involves just one parent and results in one or
more offspring that are genetically identical to that parent. ___________________ involves
two parents and results in offspring that have some genetic material (DNA) from each
Asexual Reproduction
Organisms that reproduce asexually produce their offspring in a _____________ of ways.
In some cases, they merely divide into _______, producing ________ new individual cells.
Other organisms produce special _______ that have a complete set of genetic
information, and these individual cells can develop into a new member of the species.
Still others produce an ______________ of the body that later __________ to become a
separate individual. Many_________ can develop parts that are either broken off
intentionally by _____________ or separated naturally from the _________________. In
every case, organisms produced by _____________________ have only ____ parent, and
they have the same_________________ (in the form of DNA) as the_____________.
Looking at Figure 4.1, on page 61, list four examples of asexual reproduction.
Which statement best describes the process of asexual reproduction?
1. It involves two parents.
2. It requires the combination of sperm and egg.
3. It results in variation in the offspring.
4. It involves the production of genetic copies.
Sexual Reproduction
In____________________, offspring receive half of their genes from one parent and half of
the other. The genes are carried on _____________________ in ________________(also
known as gametes or egg or sperm cells), which join in ___________________. Each
parent supplies half of the genetic information needed to form a complete individual.
The __________, which is the sex cell from the _____________, provides half of the
information; the ________, which is the sex cell from the _____________, provides the
other half.
_____________ produced by sexual reproduction combine__________ inherited from each
parent’s _____________. Since an offspring gets only half of its _________ from each
parent, it will not be _____________ to either of its parents. Also, since each
_______________ gets an unique combination of ___________ from its parents, it will
differ from its______________ (brothers and sisters).
Compared to the offspring of sexual reproduction in animals, the offspring of
asexual reproduction will
1. show greater variety
2. be more resistant to disease
3. be genetically identical to the parent
4. grow larger
___________ is a technique that accomplishes the same end results as
____________________. It’s a way of making identical ____________________. Recently,
it has been possible to produce clones of animals that ordinarily only
reproduce_____________. This is done by inserting a ____________ from a “parent”
organism’s cell (one that has a complete set of genetic information from that individual)
into an ________ cell from which the _____________ has been removed. The result is an
______ that now contains not 50%, but _________ of the genetic information from a
single parent.
Which statement concerning an organism produced by cloning is correct?
1. The clone is genetically identified to its parent.
2. The clone has the combined genes of both of its parents.
3. The genetic makeup of the clone will be somewhat different from each of its
4. The appearance of the clone will be entirely different from that of its parents.
Cell Division
_____________ is the orderly separation of one cell into two. Before a ______ divides, the
_____________ information in the ________ of the ________ is _______________ exactly.
The process, by which a cell’s genetic material divides, creating two complete sets of the
cell’s genetic material, known as _____________.
______________ provides two cells that each have a full set of identical __________ and
________________ (unless a mutation occurs somewhere along the way).
During _____________, one copy of ____________ information is distributed to each new
________. As a result, each new ______ has all the information it needs to ___________
properly. One-celled _______________ make use of ___________ for
_________________________. Multicellular organisms mainly use ______________ for
growth and for cell _____________________________.
A second type of cell division is ________________. This process ____________ the
genetic material in a way that results in the _______________ of __________ cells. Each
______________ has only __________ the genetic material needed for a cell to function
Organisms that produce asexually usually do so by a form of cell division called
1. meiosis
2. mitosis
3. gamete formation
4. sperm formation
Mitotic Division/Mitosis
During the process of ____________________________, the double-stranded
chromosomes that are visible during _____________ split into two identical single strands
and move apart to opposite ends of the cell.
In the space below, draw figure 4.3 on page 63
The process concludes when the _____________divides, resulting in two smaller, but
genetically ____________, cells.
The process of mitotic cell division normally results in the production of
1. four cells with half the number of chromosomes as the parent
2. two cells with the same number of chromosomes as the parent
3. two cells with only one chromosome from each parent
4. one cell with a replicated set of matched chromosomes
Meiotic Division/Meiosis
The ________________(sperm and egg) formed during ____________ cell division have
only one half of the organisms ____________________________—only one ____________
of each pair that is present in the body __________ of that organism. However, a full set
of _______________information is needed to produce a complete individual. When
__________ and _______ combine during ___________________, all of the newly paired
_________________ and all of the required genetic information are present in the
Meiotic _____________ begins with a body cell that has the _________________ of
chromosomes typical of the species. Depending on the species, the cell contains one or
more pairs of _______________ that determine the___________ of the organism.
During the first phase of _____________________, the double-stranded chromosomes line
up in pairs in the center of the cell. The two ________________of each pair (still doublestranded) then separate, moving to opposite ends of the cell. Following this separation,
the _____________________ physically to form_____________________.
The second phase involves the _______________ of each of these two new cells. This time,
however, the _________________ line up in a single file line in the center of each ______.
Each ________________ consists of two strands. The strands ____________ and move to
opposite ends of each of the ____________________.When the process is complete,
______________ are formed, each having _________ the number of __________________
of the organism’s body ________. Each contains only _____ member of each original
Meiotic division in females involves the ___________ number of _____________ and
____________ changes as in males. The division of _____________ is where the two differ.
The _____________ in a cell destined to become an _______ divides unequally, resulting
in one ________________ and three small nonfunctioning _____________.
Meiosis as a Source of Variation
The events that occur during _____________ do more than simply divide______________
into smaller sets and form smaller cells. ______________ is responsible for much of the
____________ variation among the ______________ of each individual. For example, the
two members of each pair of __________________ carry different ways of expressing many
of the ____________ traits, so the way the different pairs ______________ line up in
relation to other pairs leads to many possible ________________ in the ______________
that result.
Another way _____________ can arise is by the exchange of ________________ which
occurs as they pair up during the first ______________. This process is sometimes
called__________________. Each time a _________ and _________ combine, a unique
combination of ________________________ results.
Zygote Formation
During fertilization, the gametes unite (join together) to form a ____________—a cell that
contains all the genetic information needed by the offspring. This process is known as
_________________, since the genes from both parents recombine when ______________
occurs. Since a sex cell contains a unique combination of ______________ material, the
result of the random combination of any ________ and _______ explains the variation
found in ______________ produced by ______________________. This variation plays a
key role in the ________________ change and species__________________.
The ___________ contains all the information necessary for ___________, _____________,
and eventual _________________ of the organism. The zygote____________ by ________
to form a _______________ organism.
In the space below, draw figure 4.10 on page 67
An exact duplication of the complete set of chromosomes of a cell, followed by the
separation of these duplicate sets into two new cells, is known as
1. mitotic cell division
2. zygote formation
3. meiotic cell division
4. Fertilization
New cells are produced within the uterus as a direct result
1. gamete formation
2. meiotic cell division
3. mitotic cell division
4. ecological succession
Early Development
During the early stages of development, the cells that are formed by __________________
begin to undergo __________________, which simple means that they become different
from one another. This leads to the ______________ of _____________________, which
form the _____________, and then the __________ of _________________ organisms.
In an _____________, an organism in an early stage of development, all the ____________
information in each cell starts out the same. However, different_________ are activated
and ______________ in certain cells, causing them to make only some of the many
_____________ they are capable of ________________. As a result, these _________
become different from others, and may develop into ____________, ____________, or any
of the other specialized cells of the organism. The _____________ or ______________ of
genes can be due to _______________________ from within the _______, from
surrounding _______, or from ___________ the organism.
When a gene is actively producing its protein, scientists say that the gene is
_______________. There is much evidence that ______________________, which is the
result of ____________________, can be modified through interaction with the
Provide two examples of an environmentally produced gene modification
Human Reproduction and Development
__________________ and _______________ are carried out by specialized organs. The
functions of these organs is regulated by ______________ from the ___________________.
In humans, as in nearly all mammals, _________________ and ________________ occur
internally—within the _____________ body. Reproductive ____________ in other
mammals are similar in appearance and function.
Female Reproductive System
The human female reproductive system is organized to produce______________, to
support internal ________________ and __________________, to exchange materials
through the _____________ and provide ___________ to the offspring.
In human females, the ____________ produce egg cells (female gametes) and the
hormones _____________ and ______________. The hormones are associated with sexual
______________ and the _________________ process. The ovaries are located near the
open ends of tubes called _______________ (egg ducts). The _______ cell can be fertilized
in the _____________ if ______________ are present. The oviducts lead to the __________,
where the _____________ develops into a _____________.
After the fertilized egg sinks into the thickened wall of the _____________, a
_______________ begins to form. The ______________ is the organ responsible for the
passage (by diffusion) of nutrients and oxygen from the mother’s blood to the fetus.
Wastes from the fetus also _____________ to the mother’s ________ through the placenta.
During birth, the muscular ______________ undergoes a series of contractions that
eventually push the ___________ out of the mother’s ____________.
Table 4.2 The Function of the Parts of the Human Female Reproductive System
Birth Canal (Vagina)
Male Reproductive System
The __________ of the male reproductive system are the organs that produce
__________________. The testes also produce the hormone_________________, which is
associated with male sexual development and ________________. Other structures
associated with the male reproductive ______________ produce _____________ and
______________ that are needed for the proper function and delivery of male
_____________ to the female _____________________.
Hormone Regulation
The male ______________________ and other male _________________, such as facial
hair and deep voice, that develop as sexual maturity is reached are influenced by several
________________, including ________________ from the testes. The development of
female reproductive system and female features, such as breast_____________ and
widening of the __________, also involves several important ______________, such as
________________ and __________________.
Once sexual maturity is reached, females begin a regular cycle of about _____ days,
during which an ________ is released on about day ______. The timing of the events of
this cycle is regulated by two hormones from the ____________, along with several others
from an ____________ gland in the __________.
Although the interactions of the hormone are quite complex,__________________ and
_________________ play important roles in the female_____________________________.
________________ from the ovaries influences sexual development of ______________.
Together, ________________ and ________________ influence the preparation of the
lining of the ______________ so that a fertilized _________ that embeds itself there can
develop normally. _________________ also maintains the uterine______________
throughout ________________. For this reason, _______________ is often called the
hormone of ________________. At the end of the cycle, if the _____ is not
_____________, the levels of_______________ and ________________ decrease, and the
lining of the _____________ breaks down. Then the ____________ begins again.
Human Development
As with most other mammals, embryonic development begins in the _________________.
During the first part of pregnancy, __________ continue to divide by _______________
division and begin to _______________, forming ______________ and _______________.
The _______________and a fluid sac that cushions and protects the developing
____________ both form at this time, too. After about _____________, when all the major
organs have begun to form, the embryo is called a ______________.
During the first few months, when essential organs are forming in the ___________,
things can go wrong. Problems associated with either the embryo's _______________
genes or the mother’s exposure to various harmful ___________________ factors can
affect the embryo. Harmful environmental factors woman should avoid at any time
during pregnancy include _____________, ___________, and ________________. Ise of
these can lead to the birth of a baby with ______________, ________________________,
and/or low ____________________ and problems associated with it. An embyo or
___________ may also be harmed if the mother has a poor _________, is exposed to
certain __________ substances, or gets certain _______________, such as German
______________ or ___________.
After birth, cell ________________ and body ____________ continue until adulthood.
During ____________, the structures of the ___________ slowly begin to age. Eventually,
the organism _____________ and ___________. The process of _________, ___________,
____________, __________, and ____________ is a predictable pattern that applies not
just to humans but to all _____________.
Application of Reproductive Technology
Recent discoveries by scientist have greatly changed the way we can deal with many
problems involving the _______________ of humans as well as plants and other
organisms. The knowledge we gained has a variety of ________________,
_______________, and __________________________.
In the field of agriculture, scientists have produced plants that are resistant to
___________, _________________, and even frost. Such altered plants can then be
__________ to produce thousands of genetically identical ______________. Using
______________________________, scientists can generate hundreds of offspring from
one farm animal.
In the field of ecology, ______________________ is being used to help build up
populations of ___________________________. Embryos from endangered species have
been __________________ into related species, who later give birth to offspring that are
no different than they would be if they developed in the ___________ of endangered
In the field of medicine, recent scientist discoveries have led to new ways of dealing with
__________________ problems in humans, other _______________ and _____________.
Some women cannot become _________________ because of problems with their
_________________, _______________, or other parts of their _______________________.
_____________________ have enabled doctors to help ____________ women
become________________ by using ____________________ to adjust their hormones to
normal levels.
List 3 more examples of Reproductive Technology discussed on pages 71-21.
Topic 4 Vocabulary
asexual reproduction- a method of reproduction in which all the genes passed on to the
offspring come from a single individual or parent
cloning- a technique used to make identical organisms
development- the process of change that occurs during an organism’s life to produce a
more complex organism
differentiation- the process that transforms developing cells into specialized cells with
different structures and functions
egg- a sex cell produced by a female
embryo- an organism in the early stages of development (prior to birth)
estrogen- a hormone (produced by the ovaries) that controls female and sexual
development and the reproductive process
expressed- the way that an unseen gene is seen in an organism as an actual physical trait
fertilization- the process that combines a sperm cell and an egg cell
fetus- the unborn, developing young of an animal during the later stages of development
gamete-an egg or sperm cell; a sex cell
gene expression- the result of activated genes
meiosis- the process that results in the production of sex cells (egg and sperm)
mitosis- the process that divides the cell’s nucleus into two, each with a complete set of
genetic material from the parent cell.
ovaries- the organ of the human female reproductive system that produces an egg cell,
the female gamete
placenta- the organ that enables nutrients and oxygen to pass from the mother’s blood to
the fetus, and waste products to pass from the fetus to the mother
progesterone- a human associated with sexual development and the reproductive
recombination- the additional mixing of genetic material from a sperm and egg which
results in a unique combination of genes
sex cell- an egg (female) or sperm (male)
sexual reproduction- a method of reproduction that involves two parents to produce
species- a group of organisms that share certain characteristics and can mate with one
another, producing fertile offspring
sperm- the male sex cell
testes- the male reproductive organ that produces sperm and the hormone testosterone
testosterone- a hormone associated with male asexual development and reproduction
uterus- the organ, in female animals, where the embryo develops into a fetus
Topic 4 Review Questions
1. Write one or more paragraphs that compare the two methods of
reproduction, asexual and sexual.
You must include at least:
One similarity between the two methods
One difference between the two methods
One example of an organism that reproduces by asexual reproduction
One example of an organism that reproduces by sexual reproduction
2. Which characteristic of sexual reproduction has specifically favored the
survival of animals that live on land?
A. Fusion of gametes in the outside environment
B. Male gametes that may be carried by the wind
C. Fertilization within the body of the female
D. Female gametes that develop within ovaries
3. The nucleus is removed from a body cell of one organism and is placed in an
egg that has had its nucleus removed. This process, which results in the
production of organisms that are genetically alike, is known as
A. Cloning
B. Fertilization
C. Biological adaptation
D. DNA production
4. “Dolly” is a sheep developed from an egg cell of her mother that had its
nucleus replaced by a nucleus from a body cell of her mother. As a result of
this technique, Dolly is
A. No longer available to reproduce
B. Genetically identical to her mother
C. Able to have a longer lifespan
D. Unable to mate
5. Which phase does not describe cells cloned from a carrot?
They are genetically identical
They are produced sexually
They have the same DNA codes
They have identical chromosomes
6. Compare asexual reproduction to sexual reproduction. In your comparison,
be sure to include:
A. Which type of reproduction results in offspring that are usually genetically
identical to the previous generation and explain why this occurs
B. One other way these methods of reproduction differ
Cloning an individual usually produces organisms that
Contain dangerous mutations
Contain identical genes
Are identical in appearance and behavior
Produce enzymes different from the parent
8. A variation causes the production of an improved variety of apple. What is
the best method to use to obtain additional apple trees of this variety in the
shortest period of time?
A. Selective breeding
B. Natural selection
C. Asexual reproduction
D. Hormone therapy
9. Kangaroos are mammals that lack a placenta. Therefore, they must have an
alternate way of supplying the developing embryo with
A. Nutrients
B. Enzymes
C. Carbon dioxide
D. Genetic information
10. Which statement best explains the significance of meiosis in the evolution
of a species?
A. Meiosis produces egg and sperm that are alike
B. Meiosis provides form chromosomal variation in the gametes produced by the
C. Equal numbers of eggs are sperm are produced by meiosis
D. The gametes produced by meiosis ensure the continuation of any particular
species by asexual reproduction
11. Most cells in the body of a fruit fly contain eight chromosomes. In some
cells, only four chromosomes are present, a condition which is a direct
result of
A. Mitotic cell division
B. Meiotic cell division
C. Embryonic differentiation
D. Internal fertilization
12. Meiosis and fertilization are important processes because they may most
immediately result in
A. Many body
B. Genetic variation
C. Immune responses
D. Natural selection
13. The great variety of possible gene combinations in a sexually reproducing
species is due part to the
A. Sorting of genes as a result of gene replication
B. Pairing of genes as a result of mitosis
C. Pairing of genes as a result of differentiation
D. Sorting of genes as a result of meiosis
14. Compared to human cells resulting from mitotic cell division, human cells
resulting from meiotic cell division would have
A. Twice as many chromosomes
B. The same number of chromosomes
C. One half the number of chromosomes
D. One-quarter as many chromosomes
15. Which statement is true of both mitosis and meiosis?
A. Both are involved in asexual reproduction
B. Both occur only in reproductive cells
C. The number of chromosomes is reduced by half
D. DNA replication occurs before the division of the nucleus
16. Down syndrome is a genetic disorder caused by the presence of an extra
chromosome in the body cells of humans. This extra chromosome occurs in
a gamete as a result of
A. An error in the process of cloning
B. An error in meiotic cell division
C. A gene mutation
D. Replication of a single chromosome during mitosis
17. Most mammals have adaptions for
A. Internal fertilization and internal development of the fetus
B. Internal fertilization and external development of the fetus
C. External fertilization and external development of the fetus
D. External fertilization and internal development of the fetus
18. A human zygote is produced from gametes that are usually identified as
A. The expression of encoded information
B. The number of altered genes
C. Chromosome number
D. Cell size
19. The human brain, kidney, and liver all develop from the same zygote. This
fact indicates that cells formed by divisions of the zygote are able to
A. Differentiate
B. Undergo cloning
C. Mutate
D. Be fertilized
20. As certain species has little genetic variation. The rapid extinction of this
species would most likely result from the effect of
A. Successful cloning
B. Gene manipulation
C. Environmental change
D. Genetic recombination
21. Sexual reproduction in a species usually results in
A. An increase in the chromosome number in the offspring
B. Offspring genetically identically to the parent
C. Recombination of genes
D. A decrease in biodiversity
22. Which hormone does not directly regulate human reproductive cycles
A. Testosterone
B. Insulin
C. Estrogen
D. Progesterone
23. Which structure is correctly paired with its function
A. Ovary—provides milk for newborns
B. Testis—development of sperm
C. Placenta—storage of released eggs
D. Uterus—produces estrogen
24. Which process normally occurs at the placenta
A. Oxygen diffuses from fetal blood to material blood
B. Materials are exchanged between fetal and maternal blood
C. Maternal blood is converted into fetal blood
D. Digestive enzymes pass from maternal blood into fetal blood