REVIEW: Sexual Reproduction

REVIEW: Sexual Reproduction

Sexual Reproduction:

GENES come from 2 PARENTS

Offspring are a COMBINATION of mom & dad’s GENES

Offspring

RESEMBLE their PARENTS

Not identical because of combination of genes.

Sexual Reproduction = MEIOSIS = production of sex cells

Homologous Pairs

CHROMOSOMES that CODE for the SAME TRAIT

Each PAIR has ONE from mom and ONE from dad

Genetic Recombination (“Crossing Over”)

SWAPPING of GENES

Results in genetic diversity

In the male…

MEIOSIS occurs in the testes

Makes sperm cells

Before MEIOSIS can occur DNA must REPLICATE

Each has ½ the diploid number of chromosomes

In the female…

MEIOSIS occurs in the ovaries

Makes egg cells

Some genes from the mother attach to the chromosome

of the father. Some genes from the father

attach to the chromosome of the mother.

http://www.google.com/url?sa=i&rct=j&q=egg+cell&source=images&cd=&cad=rja&docid=HkGbbX9SDX_2AM&tbnid=RZTBoaJl1mvxOM:&ved=0CAUQjRw&url=http://www.babymed.com/fertility-problems/good-eggs-and-bad-eggs&ei=CegbUZneHorW9QTM8oGgCw&bvm=bv.42261806,d.eWU&psig=AFQjCNFRJ3sMmVLQvyLSiu2aOem7cr6G4Q&ust=1360869699713847

After replication….

Cell SPLITS TWICE making 4 CELLS

Each has ½ of the GENETIC INFO.

Diploid Normal amount of chromosomes

Fertilization occurs cell now has normal number of chromosomes

Haploid HALF the number of normal

chromosomes

1st Division

2nd Division

http://www.google.com/url?sa=i&rct=j&q=fertilization+in+humans&source=images&cd=&cad=rja&docid=idbxVspDbSje6M&tbnid=4ZFCxghV3PF28M:&ved=0CAUQjRw&url=http://classes.biology.ucsd.edu/bimm110.SP07/lectures_WEB/L09.05_Gametogenesis.htm&ei=jO0bUcy8LYis9ASKxYDYAw&bvm=bv.42261806,d.eWU&psig=AFQjCNH75riHCXt_zjZ1rHrHkaxlz6R3qw&ust=1360871164676614

Non-Disjunction

Homologous chromosomes FAIL to SEPARATE

causes an ABNORMALITY ex: Down Syndrome (an extra copy of the 21st chromosome)

Male Reproductive System 1. Testes

where sperm are produced

2. Scrotum

Holds testes away from body

Keeps testes cooler than rest of body

TEMPERATURE very important to sperm production

3. Sperm

TRANSPORT genetic information

4. Vas Deferens

TUBE that transports sperm out of body

Vasectomy = cut vas deferens to prevent sperm from leaving the body

5. Prostate Gland

PREVENTS urine from mixing with sperm

http://www.google.com/url?sa=i&rct=j&q=sperm+cartoon&source=images&cd=&cad=rja&docid=-ZDMAj9JcNJ7CM&tbnid=YRuO0zyoflesNM:&ved=0CAUQjRw&url=http://www.shutterstock.com/cat.mhtml?safesearch=1&search_language=en&search_type=similar&similar_photo_id=13836211&tracking_id=70141244-7404-11E2-A3B5-4E089EA4A24C&ei=2hkdUdOuJ4fK9QS1x4GwCA&bvm=bv.42452523,d.eWU&psig=AFQjCNFEug1tQ4LIHZTUIaCrBTlNgA3JyQ&ust=1360948050504491

http://www.google.com/url?sa=i&rct=j&q=thermometer&source=images&cd=&cad=rja&docid=V25PZYmnIHiw1M&tbnid=xHDfOsoqBC3UTM:&ved=0CAUQjRw&url=http://sweetclipart.com/simple-red-thermometer-158&ei=GhodUYuCO5Co8gT8w4DgDg&bvm=bv.42452523,d.eWU&psig=AFQjCNGOloc8HHGOwa0E-OsA4UGXu43DAA&ust=1360948114559266

http://www.google.com/url?sa=i&rct=j&q=stop+sign&source=images&cd=&cad=rja&docid=hxC-xxCWh4-vzM&tbnid=myNcRcV47nrtZM:&ved=0CAUQjRw&url=http://www.bransonwestlaw.com/criminal-defense/traffic-violations/stop-sign-and-traffic-control-device-violations&ei=jBodUf2eEIqI8QSc7IBQ&bvm=bv.42452523,d.eWU&psig=AFQjCNEGdTorklFxYQT0mETKnKt17j2iTg&ust=1360948219294458

6. Urethra

Part of REPRODUCTIVE & EXCRETORY systems

Passage of semen and urine out of body

7. Penis

Allow for internal FERTILIZATION

Female Reproductive System

1. Ovary

Produces EGGS

2. Oviduct (Fallopian Tubes)

Site of internal FERTILIZATION

FERTILIZATION takes place in the OVIDUCT

3. Uterus

Embryo implants and develops

IMPLANTATION of the embryo takes place in the UTERUS

4. Cervix

Dilates to allow baby to pass through during labor

5. Vagina

Birth canal

Where baby passes out of body.

Where sperm is deposited

Hormones REGULATE Reproduction

Male Hormones Female Hormones

Testosterone Estrogen & Progesterone (stimulates development) (thickens uterus lining)

Menstruation occurs when NO FERTILIZATION has occurred Shedding of the uterine wall

Fertilization

when SPERM meets the EGG to form a ZYGOTE

Takes place in the OVIDUCT

Called the UNION

http://www.google.com/url?sa=i&rct=j&q=fertilization+in+humans&source=images&cd=&cad=rja&docid=idbxVspDbSje6M&tbnid=4ZFCxghV3PF28M:&ved=0CAUQjRw&url=http://classes.biology.ucsd.edu/bimm110.SP07/lectures_WEB/L09.05_Gametogenesis.htm&ei=jO0bUcy8LYis9ASKxYDYAw&bvm=bv.42261806,d.eWU&psig=AFQjCNH75riHCXt_zjZ1rHrHkaxlz6R3qw&ust=1360871164676614

Fraternal Twins

from 2 ZYGOTES

2 EGGS & 2 SPERM External Fertilization

OUTSIDE the body

in aquatic animals Internal Fertilization

INSIDE the body

in mammals

Identical Twins

From 1 EGG

Zygote SPLITS

Exactly the SAME DNA

http://www.google.com/url?sa=i&rct=j&q=twins&source=images&cd=&cad=rja&docid=DQPFHw9pxOgCnM&tbnid=tqjtF-hi0mRguM:&ved=0CAUQjRw&url=http://christinabaglivitinglof.com/&ei=VqYvUfTbJYLU9ASNoYHoCQ&bvm=bv.43148975,d.eWU&psig=AFQjCNF7vErg5hyeLjEQYdU1CAuCiF7RMg&ust=1362163658633861

http://www.google.com/url?sa=i&rct=j&q=external+fertilization+++fish&source=images&cd=&cad=rja&docid=jd6DEWS3mTvyQM&tbnid=WyWRach9E2cQVM:&ved=0CAUQjRw&url=http://friendsseminarystephan.pbworks.com/w/page/25760188/Fishes%20%D0%AF%20us%206S&ei=GqsvUYm0KJDc8wTeqIDIAw&bvm=bv.43148975,d.eWU&psig=AFQjCNF2VpsSby5YPnkJI9beQJwuJqMNdw&ust=1362164878493078

Marsupials

offspring born in IMMATURE state

get nutrients from mother’s MILK

KANGAROOS

ZYGOTE grows into an EMBRYO by MITOSIS (cleavage)

Differentiation

cells become SPECIALIZED TISSUE

controlled by HORMONES, GENES, CELL LOCATION

GENETIC CODES are TURNED-ON. development of

Differentiation Body Systems

results in

http://www.google.com/url?sa=i&rct=j&q=kangaroo+and+baby&source=images&cd=&cad=rja&docid=npE0k1n2hh906M&tbnid=B4YBP0hAgv_NBM:&ved=0CAUQjRw&url=http://wallpapers.stillmaza.com/2011/09/kangaroo-high-resolution-wallpapers.html&ei=1awvUcaTF4nK9gSv3oG4AQ&bvm=bv.43148975,d.eWU&psig=AFQjCNFaMB5VyMNxuRrCdmtm7jRvpynPjA&ust=1362165324561851

http://www.google.com/url?sa=i&rct=j&q=kangaroo+cartoon&source=images&cd=&cad=rja&docid=gCHD36ERfzyc0M&tbnid=VTu-s48pNYFQIM:&ved=0CAUQjRw&url=http://sherrirodell.blogspot.com/2012/03/tie-me-kangaroo-down-sport.html&ei=F60vUbPxH5DQ8wTdlIGgCg&bvm=bv.43148975,d.eWU&psig=AFQjCNFguTPuHrG4HvSgIEqhBSi2hoHmow&ust=1362165392970003

Placenta

Allows EXCHANGE of materials between MOTHER and FETUS

No blood mixes Umbilical Cord

CONNECTS placenta to embryo Amnion

Membrane that surrounds embryo

PROTECTS embryo Amniocentesis

Fluid taken out

Detects genetic mutations

REVIEW: Sexual Reproduction

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