Chapter 6: Meiosis Is The Basis For Sexual Reproduction

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Pages 170-175

6.1 Meiosis

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6.01 Illustrate and describe the basic processes of cell divisionMeiosis

gametes are produced

with half the

chromosomes numbers

as body cells

Occurs in the sex

cells3

6.01.1 State and briefly describe the eight phases of meiosisDNA replication occurs

only once during the process of meiosis.

Meiosis I: the result is two daughter cells.

Meiosis II: the result is four haploid cells, each with half the number of chromosomes.

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6.01.1 Meiosis IProphase I Double stranded

chromosomes and

spindle fibers appear.

Chromosomes come

together in matching

pairs.5

Meiosis IMetaphase IThe pairs of

chromosomes line up in the center of the cell.

Their centromeres become attached to the spindle fibers.

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Meiosis IAnaphase IEach double-stranded

chromosome separates Chromosomes pulled

to opposite ends of the cell.

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Meiosis ITelophase I The cytoplasm

divides and two cells form.

Each chromosome is still double-stranded and pulled to each pole of the cell.

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Meiosis II beginsProphase II The double-stranded

chromosomes and spindle fibers reappear in each cell.

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Meiosis IIMetaphase II The double-stranded

chromosomes move to the center of the cell.

The centromeres attach to spindle fibers.

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Meiosis IIAnaphase II The centromere

divides, and the chromosome separate.

Sister chromatids move to opposite poles of the cell.

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Meiosis IITelophase II A nuclear membrane

forms around the

Chromosomes. Each nucleus contains

only half the number of

chromosomes

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Vidoes…Meiosis http://www.youtube.com/watch?v=D1_-mQS_FZ0&feature=Pla

yList&p=08E14413B4A2B8B2&index=2 http://www.youtube.com/watch?v=uh7c8YbYGqo&NR=1 http://www.youtube.com/watch?v=jdQeKjEsj0U&feature=PlayLi

st&p=08E14413B4A2B8B2&index=3 http://www.youtube.com/watch?v=3xtD8uUZBhM&feature=relat

ed

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6.01.1 Meiosis Summary

Give hand-out with summary of meiosis

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6.01.2 Define haploid

Half the genetic content (n)

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6.01.3 Define DiploidGenetic

material is equal to the parent

Full genetic content (2n)

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6.02 Compare and contrast mitosis and meiosis.

Mitosis In body cellsTwo daughter cellsSame number of

chromosomes as parent cell

Asexual reproduction

Meiosis In sex organs to produce

sex cells Four daughter cells Half number of

chromosomes as parent cell

Sexual reproduction

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6.02 Compare and contrast mitosis and meiosis.

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6.03 Organize data using format that is appropriate to the experiment

Comparing Mitosis and Meiosis

Core Lab Activity

6-1B (pages 176-177)

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6.04 Compile and display data using a variety of formats

Comparing Mitosis and Meiosis

Core Lab Activity

6-1B (pages 176-177)

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6.05 Receive, understand, and act on the ideas of others

Comparing Mitosis and Meiosis

Core Lab Activity

6-1B (pages 176-177)

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6.06 Work cooperatively members to carry out a planned activity

Comparing Mitosis and Meiosis

Core Lab Activity

6-1B (pages 176-177)

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Pages 180-194

6.2 Sexual Reproduction

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6.07 Distinguish between sexual and asexual reproduction in organisms.

Asexual Reproduction

BacteriaVirsusPlantsRarely animals

Sexual ReproductionPlants (seeds)Most Land Animals Internal FertilizationMost Aquatic

AnimalsExternal Fertilization

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6.08 Explain how various organisms reproduce sexuallyMosses

External fertilizationWater allows the

egg and sperm cells to meet

Reproduces both sexually and asexually

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6.08 continued…Flowering Plants

PollinationTransfer of male

gametes in structures

called pollen to the

female structure of the

plant.

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Pollination1.Bees and other insects2.Fruit bats3.Wind4.Water

After fertilization, seeds are often protected in fruit or cones.

Seeds contain the fertilized eggs or plant embryos

6.08 continued…Insects

Internal FertilizationIn many insects, the

male deposits a

package of sperm

inside the female.

Insects often change between hatching and adulthood

This change in form is called metamorphosis.

Metamorphosis can be incomplete or complete.28

6.09 Compare and contrast complete and incomplete metamorphosis

Incomplete metamorphosis

Three stages The adult, egg and the

nymph The adult and nymph

resemble one another

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6.09 Compare and contrast complete and incomplete metamorphosis

Complete Metamorphosis

Four stagesThe adult, egg, pupa

and larva Adult and larva look

completely different

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http://www.youtube.com/watch?v=OpCQaTRe7VU&feature=related

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6.10 Compare and contrast sexual and asexual reproduction

Asexual Reproduction One parent cell Cell divides Very little variation in

offspring Very little energy required Little or no parental care

Sexual Reproduction

Two parent cells 2 sex cells unite to form

zygote Greater variation in

offspring Large amount of energy

required Lot of parental care

involved in raising offspring

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Pages 196-203

6.3 Human Reproductive Systems

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6.11 Compare the structure and function of the human reproductive system.

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6.11.1 Identify the major parts of the male reproductive system

Penis…male external sex organ

Vas Deferens…two tubes that sperm travel through from testicles to urethra

Scrotum…supports and regulates temperature of testicles during sperm production

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6.11.1 continued…

Testicles…gland which produces male hormone (testosterone) and male sex cell (sperm)

Epididymis…comma-shaped structure located on testicles where sperm are stored and transported to vas deferens36

6.11.2 Identify the major parts of the female reproductive system.

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Vagina…muscular tube which expands to fit penis and birth of baby

Cervix…narrow inner part of vagina which leads to uterus

Uterus…muscular tube which nourishes and holds the fetus

6.11.2 Identify the major parts of the female reproductive system.

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Ovary…produces female hormones (estrogen and progesterone) and female sex cell (egg)

Oviduct…two tubes which allow eggs to travel from ovaries to the uterus. Site of fertilization.

6.12 Describe major stages of development from conception to early infancy.

1. Fertilization

2. First Trimester

3. Second trimester

4. Third Trimester

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1. Fertilization

Occurs in fallopian tube

Egg and sperm unite to form zygote

Zygote moves to implant in uterine lining

Embryo is term used for first 8 weeks40

2. First Trimester

At 8 weeks, embryo is called fetus

Organ systems begin to develop

Zygote is now called embryo

All major organs are formed by end of 12 weeks.41

3. Second Trimester

Rapid growth Skelton forms Mother will feel

movement by 20 weeks.

Growth slows between 20 and 24 weeks.

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4. Third Trimester

Growth in preparation for birth

Significant changes in the brain.

Immune system develops

Fat is deposited under the skin.

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6.13 Identify visible signs of pregnancy.

I. Menstruation stops

II. Hips will become slightly larger

III. Breast become larger

IV. Weight gain and abdomen will bulge

V. Nausea and dizziness

VI. Cravings

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Pages 204-213

6.4 Studying Genetic Changes

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6.14 Identify major shifts in scientific understanding of genetics.

Four major works that caused a shift in our

understanding of genetics:

1. Gregor Mendel

2. Watson and Crick

3. Human Genome Project

4. Genetic Engineering

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1. Gregor Mendel

Gregor Mendel Mid-1800s Experimented with

inherited traits in pea plants.

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Mendel’s work with pea plants

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2. Watson and Crick

1953 Described the

structure of DNA and how it replicates.

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Watson and Crick

3. Human Genome Project

1986-2003 Genome: consists of the full set of genetic

material that makes up an organism. Made a map to identify genes This information may be used to check for

particular diseases.

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4. Genetic Engineering

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Videos…

http://www.youtube.com/watch?v=sf0YXnAFBs8&feature=related

http://www.youtube.com/watch?v=GWpoBUi06xM&feature=related

http://www.youtube.com/watch?v=Zzh5TVXaAr4&feature=PlayList&p=6A2E4CCA5B231363&index=2

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6.15 Provide examples of genetic conditions that cannot be cured using present knowledge.

Three examples of diseases that cannot be

cured at present:

1. Down’s Syndrome

2. Cystic Fibrosis

3. Alderdice Syndrome

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1. Down’s Syndrome

Karyotypes can help

identify certain if there

are abnormalities in

the chromosomes Karyotypes can identify

syndromes such as

Down’s Syndrome

(extra 21st chromosome)55

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1. Down’s Syndrome

2. Cystic Fibrosis

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2. Cystic Fibrosis

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3. Alderdice Syndrome

Allderdice syndrome where part of one chromosome is reversed.

Trait is passed from the mother to offspring (31%)

Individuals have low

birth weights, hand and

facial abnormalities and

both mental and physical

challenges Identified in Sandy

Point NL by Dr. Penny

Allderdice59

http://www.youtube.com/watch?v=bEVkbuooXo4&feature=channel

http://www.youtube.com/watch?v=l0dDhKFk2HU&feature=related

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6.16 Provide examples of knowledge of cellular functions that resulted in the development of technologies.

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6.17 Provide examples of Canadian contributions to science and technology related to genetic engineering

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6.18 Evaluate information and evidence gathered on the topic of genetics and genetic engineering.

Can be used to save the genetic information from endangered plants and animals

To mass-produce an organism with a desired trait.

Human-assisted Cloning

Two types:

1. Reproductive cloning

2. Therapeutic cloning63

1. Reproductive Cloning

Also called DNA cloning

Purpose is to produce a genetic duplicate of an existing organism with desirable qualities.

Reproductive cloning of sheep64

1. Reproductive Cloning

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2. Therapeutic Cloning

Used to correct

health problems. Stem cells and

embryonic stem cells

are able to become

many different types

of cells.

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Cloning Videos

http://www.youtube.com/watch?v=7tbxN5uwaqA

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