The Power of ReproductionThe Power of ReproductionReviewReview

CHAPTER 1CHAPTER 1

Cell TheoryCell Theory Over time scientists came have been able to Over time scientists came have been able to

use technological developments to assist in the use technological developments to assist in the creation of what we call today creation of what we call today Cell TheoryCell Theory..

Cell Theory States That:Cell Theory States That:1.1. All living organisms are composed of one or All living organisms are composed of one or

more cells.more cells.2.2. Cells are the basic units of structure and Cells are the basic units of structure and

function in all organisms.function in all organisms.3.3. All cells come from previously existing cells.All cells come from previously existing cells.4.4. The activity of an entire organism depends The activity of an entire organism depends

on the total activity of its independent cells.on the total activity of its independent cells.

A typical cell has numerous membrane-bound ORGANELLES, specialized structures that perform specific functions in the cell.

Animal CellAnimal Cell

Plant CellPlant Cell

YOU NEED TO KNOW THE YOU NEED TO KNOW THE FOLLOWING DEFINITIONS:FOLLOWING DEFINITIONS:

NucleusNucleus Nuclear MembraneNuclear Membrane DNA – DNA –

Deoxyribonucleic AcidDeoxyribonucleic Acid ChromatinChromatin NucleolusNucleolus RibosomeRibosome

Cell MembraneCell MembraneCytoplasmCytoplasmEndoplasmic Endoplasmic ReticulumReticulumMitochondriaMitochondriaGolgi BodiesGolgi BodiesVacuolesVacuolesLysosomesLysosomes

Animal and Plant CellsAnimal and Plant Cells

Plant cells have a Plant cells have a fibrous cell wallfibrous cell wall that that provides structure and support for the cell. provides structure and support for the cell. Plants need this cell wall to provide with Plants need this cell wall to provide with support. Example and sunflower.support. Example and sunflower.

Plant cells contain Plant cells contain chloroplasts. chloroplasts. They are They are organelles that enable the plant to make their organelles that enable the plant to make their own food through the process of own food through the process of photosynthesis.photosynthesis.

Animal and plant cells have many similarities. They do however have a few differences.

The Importance of Cell DivisionThe Importance of Cell Division

1.1. Repair tissue & healingRepair tissue & healing2.2. GrowthGrowth3.3. Reproduction of OrganismReproduction of Organism

MITOSISMITOSIS

Before mitosis can begin, the nucleus must Before mitosis can begin, the nucleus must make a copy, or replica of its chromatin, so make a copy, or replica of its chromatin, so that there are two complete sets of DNA. This that there are two complete sets of DNA. This is known as is known as replicationreplication. The replicated . The replicated chromatin coils up to form double-stranded chromatin coils up to form double-stranded chromosomes. The end result of mitosis is the chromosomes. The end result of mitosis is the separation of replicated DNA into two separation of replicated DNA into two complete sets of DNA, one for each new cell’s complete sets of DNA, one for each new cell’s nucleus.nucleus.

The Process that ensures each new cell has a nucleus with a complete set on instructions (DNA) is called MITOSIS.

Prophase Prophase The nucleolus and the nuclear membrane The nucleolus and the nuclear membrane

disappear. Spindle fibers form and stretch disappear. Spindle fibers form and stretch across the cell from centrioles that have moved across the cell from centrioles that have moved to opposite ends of the cell. The spindle fibers to opposite ends of the cell. The spindle fibers attach to one side of each centromere. attach to one side of each centromere.

Metaphase Metaphase The tugging action of the spindle fibers pulls The tugging action of the spindle fibers pulls

the double-stranded chromosomes into a line the double-stranded chromosomes into a line across the middle of the cell across the middle of the cell

Anaphase Anaphase The spindle fibers begin to contract and The spindle fibers begin to contract and

shorten which pulls the centromere apart. One shorten which pulls the centromere apart. One of each of the replicated strands to moves to of each of the replicated strands to moves to opposite ends (pole) of the cell.opposite ends (pole) of the cell.

Telophase Telophase The spindle fibers begin to disappear. And a The spindle fibers begin to disappear. And a

nuclear membrane forms around each set of nuclear membrane forms around each set of chromosomes. A nucleolus appears within chromosomes. A nucleolus appears within each new nucleus. The single stranded each new nucleus. The single stranded chromosomes start to uncoil into thin strands chromosomes start to uncoil into thin strands of chromatin.of chromatin.

NOW THERE ARE TWO NUCLEI NOW THERE ARE TWO NUCLEI IN ONE CELLIN ONE CELL

In animal cells, the cell membrane pinches in In animal cells, the cell membrane pinches in near the middle of the cell, dividing the near the middle of the cell, dividing the cytoplasm into two new cells.cytoplasm into two new cells.

In plant cells, a cell plate develops across the In plant cells, a cell plate develops across the center of the cell, forming a new cell wall center of the cell, forming a new cell wall between the two new cellsbetween the two new cells

Interphase Interphase During Interphase the cell grows, replicates its During Interphase the cell grows, replicates its

DNA, and becomes prepared for the first phase DNA, and becomes prepared for the first phase of mitosis of mitosis

AS A RESULT OF MITOSIS, THE NUMBER OF CHROMOSOMES IN THE

NUCLEUS OF EACH CELL IS IDENTICAL TO EACH OTHER AND TO THE NUMBER IN THE ORIGINAL CELL

CANCERCANCER --is the direct result of cells dividing is the direct result of cells dividing

uncontrollablyuncontrollably -the continue dividing and pile up on top of -the continue dividing and pile up on top of

one another, forming a tumor or lumpone another, forming a tumor or lump -these excess cells can stay contained in one -these excess cells can stay contained in one

area or, move to other parts of the organismarea or, move to other parts of the organism -the gobble up oxygen and nutrients for -the gobble up oxygen and nutrients for

themselves, crowding out other cells and themselves, crowding out other cells and robbing them of their foodrobbing them of their food

Asexual ReproductionAsexual Reproduction Mitosis and cell division are not only Mitosis and cell division are not only

important to human growth and tissue repair, important to human growth and tissue repair, but are also important in asexual reproduction.but are also important in asexual reproduction.

Asexual Reproduction is the formation of a Asexual Reproduction is the formation of a new individual that has identical genetic new individual that has identical genetic information to its parentinformation to its parent

BACTERIABACTERIA Are unicellular organisms that do not contain a Are unicellular organisms that do not contain a

true nucleustrue nucleus Reproduce asexually through a process known Reproduce asexually through a process known

as as binary fissionbinary fission In binary fission a parent cell divides so that In binary fission a parent cell divides so that

each new cell contains a single chromosome each new cell contains a single chromosome carrying a complete set of DNA identical to carrying a complete set of DNA identical to that of the parentthat of the parent

PROTISTSPROTISTS Are unicellular organisms that Are unicellular organisms that dodo contain a contain a

true nucleustrue nucleus Mitotic cell division results in the formation of Mitotic cell division results in the formation of

two identical offspringtwo identical offspring Protists are important because they form the Protists are important because they form the

basis of many food chains and are responsible basis of many food chains and are responsible for many diseases that affect humans.for many diseases that affect humans.

FUNGIFUNGI Fungi are composed of many filaments called hyphae which Fungi are composed of many filaments called hyphae which

grow over the surface of and into the bodies of other grow over the surface of and into the bodies of other organisms to obtain foodorganisms to obtain food

Can reproduce asexually three ways, fragmentation, budding Can reproduce asexually three ways, fragmentation, budding and spores.and spores.

In In fragmentationfragmentation, a small piece or fragment, breaks away , a small piece or fragment, breaks away from the main mass and grows into a new individual.from the main mass and grows into a new individual.

In In buddingbudding a copy of the nucleus is made, then a tiny bud a copy of the nucleus is made, then a tiny bud begins to form on the cell wall. This bud, containing the new begins to form on the cell wall. This bud, containing the new nucleus continues to grow and eventually breaks away.nucleus continues to grow and eventually breaks away.

A A sporespore is a reproductive cell that can grow into a new is a reproductive cell that can grow into a new individual through mitotic cell division. When mature, spores individual through mitotic cell division. When mature, spores can float about on air currents.can float about on air currents.

ANIMALSANIMALS Animals can be divided into two main groups, Animals can be divided into two main groups,

vertebrates (those with backbones) and vertebrates (those with backbones) and invertebrates (those without backbones)invertebrates (those without backbones)

Many invertebrates can reproduce asexually to Many invertebrates can reproduce asexually to form one or more identical offspring from a form one or more identical offspring from a single parentsingle parent

PLANTSPLANTS Unlike many animals, plants continue to grow Unlike many animals, plants continue to grow

throughout their lives.throughout their lives. The tips of their roots and stems contain The tips of their roots and stems contain

growing areas called meristem.growing areas called meristem. Meristem is made up of unspecialized cells Meristem is made up of unspecialized cells

that undergo mitosis and cell division that undergo mitosis and cell division repeatedly, producing new cells.repeatedly, producing new cells.

The Power of ReproductionThe Power of ReproductionReviewReview

CHAPTER 2CHAPTER 2

Sexual ReproductionSexual Reproduction Your body has specialized organs (Your body has specialized organs (GONADS GONADS

– testes and ovaries– testes and ovaries), that make specialized ), that make specialized cells (cells (GAMETES – sperm and eggsGAMETES – sperm and eggs), for ), for sexual reproduction. The gametes from two sexual reproduction. The gametes from two parents combine during a process called parents combine during a process called fertilization to form a new cell or fertilization to form a new cell or ZYGOTEZYGOTE. . This zygote is the first body cell of a new This zygote is the first body cell of a new organism.organism.

Sexual Reproduction Cont…Sexual Reproduction Cont… The total number of chromosomes in a human The total number of chromosomes in a human

body cell is 46 – this is referred to as body cell is 46 – this is referred to as diploiddiploid. . These 46 chromosomes can be arranged into These 46 chromosomes can be arranged into 23 pairs of chromosomes that resemble each 23 pairs of chromosomes that resemble each other in size and shape. These matching pairs other in size and shape. These matching pairs of chromosomes are known as of chromosomes are known as homologous homologous pairs. pairs. You receive one pair from your mother You receive one pair from your mother and on from your father.and on from your father.

Sexual Reproduction Cont…Sexual Reproduction Cont… Human gametes (sperm and eggs) have 23 Human gametes (sperm and eggs) have 23

chromosomes and are called chromosomes and are called haploidhaploid. Only haploid . Only haploid gametes can combine during fertilization to form a gametes can combine during fertilization to form a diploid zygote. Mitosis ensures that the chromosome diploid zygote. Mitosis ensures that the chromosome number does not change, while the process that number does not change, while the process that ensures each gamete contains only one-half set of ensures each gamete contains only one-half set of chromosomes is called chromosomes is called MEIOSIS. MEIOSIS. Meiosis ensures Meiosis ensures that each gamete has a different combination of the that each gamete has a different combination of the chromosomes that were present before meiosis.chromosomes that were present before meiosis.

Despite the differences among animals, the Despite the differences among animals, the fundamental sequence that allows them to reproduce fundamental sequence that allows them to reproduce

sexually is the same:sexually is the same: Meiosis produces gametesMeiosis produces gametes A male gamete combine with a female gameteA male gamete combine with a female gamete A zygote is produced and develops into an A zygote is produced and develops into an

embryoembryo The embryo develops through mitosis and cell The embryo develops through mitosis and cell

division into mature offspringdivision into mature offspring

For sexual reproduction to be successful, the For sexual reproduction to be successful, the following two requirements must be met:following two requirements must be met:

Both male and female gametes must arrive at Both male and female gametes must arrive at the same place and time for fertilizationthe same place and time for fertilization

The zygote must receive adequate food, The zygote must receive adequate food, moisture, warmth, and protection to developmoisture, warmth, and protection to develop

EXTERNAL FERTILIZATIONEXTERNAL FERTILIZATION The sperm and the egg meet outside the bodies The sperm and the egg meet outside the bodies

of both parents of both parents Most water-dwelling animals reproduce Most water-dwelling animals reproduce

through external fertilizationthrough external fertilization

INTERNAL FERTILIZATIONINTERNAL FERTILIZATION The sperm and the egg meet inside the body of The sperm and the egg meet inside the body of

the female. The sperm travel from the male’s the female. The sperm travel from the male’s body into the female’s body to meet the egg.body into the female’s body to meet the egg.

Most animals on land reproduce through Most animals on land reproduce through internal fertilization internal fertilization

HEMAPHRODITESHEMAPHRODITES Individuals that have both female and male Individuals that have both female and male

reproductive organsreproductive organs

Additional InformationAdditional Information You need to know all of the information from You need to know all of the information from

your cancer brochureyour cancer brochure

For Homework tomorrow, or Tuesday, write a For Homework tomorrow, or Tuesday, write a test (with answers). Test should include 20-30 test (with answers). Test should include 20-30 questionsquestions

Questions should be a combination of MC, Questions should be a combination of MC, matching, fill-in-the-blank, diagrams, and matching, fill-in-the-blank, diagrams, and short answershort answer