Sexual Reproduction

Chapter 38

I1.Sexual/Asexual Reproduction

Asexual• Exact copy• Mitosis• One parent• Constant

conditions

Sexual• Genetic variety• Meiosis = eggs &

sperm• Two parents• Changing

conditions

Asexual examples: Hydra

Budding

of polyps

Regen-erationOf cut pieces

Amoeba asexual division

2nd amoebaNucleus

Asexual Reproduction:

Runners in strawberries

Spores in Puffball Mushrooms

Sexual Reproduction

“Joey” develops in a Pouch

Flowering Plants Sexual Reproduction

Dry PollenFor sperm

Ferns Sexual & Asexual Reproduction

Sexual & Asexual

Comparison of Egg & Sperm

Egg• Round• Floats• Food reserves• One• Ovaries• 1N haploid

Sperm• Oval• Flagella• No food reserves• Many secrete enzyme to

penetrate egg membrane• Testicles• 1N haploid

Sperm• 1/600th inch• Survives in Temperature of 93o – 97o

• 3 Parts:– Head or Cap – holds Genetic Information of Father– Body – filled with mitochondria & supplies energy– Tail – flagellum to propel and move

• 200 million sperm made every 24 hours• 750 feet of twisted tubules which contain

specialized cells that each care for about 150 sperm• Testosterone & Estrogen made exactly balanced to

develop specific sexual characteristics

February 23, 2010

• Draw a sperm and label its parts

• Review Vocab #2• Notes 38.1• Inside Story page 1033

Meiosis in the Gonads

Sperm

Meiotic celldivision Egg

Gonads make gametes!

Testes makesperm

Male Reproduction • Scrotum – sac surrounding testes that

maintain temperature – muscles contract/relax– Temperature must be 3o below body for sperm

• Testes – produces sperm cells haploid (1n) produce 4

• Sperm – male gamete– Enzymes in cap or head allow sperm to penetrate

egg– Nucleus contains genetic material– Mitochondria – lots for energy to move– Flagellum – for movement

• Epidiymis – stores sperm from testes until mature• Vas Deferens – duct that carries sperm to

ejaculatory glands and urethra• Semen - fluid• Seminal Vesicles - at base of bladder that secretes

mucous like fluid to increase fructose energy• Prostate glands – underneath bladder secretes

alkaline fluid to help sperm survive & move• Bulburethral Glands – secrete clear sticky alkaline

fluid protecting sperm by neutralizing acidic environment of vagina

• Uretha – tube running from the bladder that carries urine out through the penis.

• Semen enters the urethra after a muscle closes it off from the bladder.

• Semen is ejaculated through this tube that runs the length of the penis.

Chromosomes

Sex Chromosome Y determines a Male

February 24, 2010

• List the hormones and their actions for the male and female reproductive system.

• Trace the pathway of sperm from the testes

• Notes cont….

Reproduction Hormones - PubertyHormone Produced by Function

Testosterone Testicles Male sex traits

FSH Pituitary Stimulates LH

LH Pituitary Release of egg

Estrogen Ovaries Female sex traits

Progesterone Corpus luteum Maintains Uterus lining

Gonads make gametes!

Ovaries make eggs

Female Reproductive System• Ovary – size of an almond, where eggs are

produced approximately 400/life – Egg production is before birth, goes through meiosis –

prophase 1 then rests till sexual maturity

• Oviduct – tube that transports the egg to the uterus, fertilization occurs here

• Ovulation – oocytes finish meiosis the egg ruptures the ovary & released into oviduct (1n) 1 egg, 3 polar bodies dissolve

• Fertilized egg remains in oviduct for 7 days then divides and embeds in the lining of uterus–9 months

• Unfertilized - the egg and lining of the uterus will shed called the…

• Phases of Menstrual Cycle:• 1. Flow Phase - Discard of egg & uterine lining –

lasts approximately 5 days• 2. Follicular Phase – FSH increases & another

follicle goes through meiosis II, lasts from day 6-14, LH released & Ovulation occurs around day 14 by rupturing ovary

• 3. Luteal phase – 15-28 days the corpus luteum releases progesterone & some estrogen to increase blood supply (lipids) preparing for pregnancy by thickening the endometrium lining of the uterus

February 25

• Draw the negative feedback cycle… Then describe it in words.

• PS Lab 38.1• Finish up Notes

Negative Feedback Cycle

Menstrual Cycle

Tracking Hormone LevelsDay 2 4 6 8 10 12 14 16 18 20 22 24 26 28

LH 17 17 17 17 17 46 35 20 19 18 17 16 14 13

FSH 14 14 14 13 10 8 15 8 7 7 6 6 6 7

Estrogen

4 4 5 6 10 13 13 10 9 10 11 11 11 8

Progesterone

1 1 1 1 1 1 2 4 7 12 14 14 9 3

1. Make a graph showing the changes in amounts of LH & FSH throughout the menstrual cycle. Use 2 different colors & label please.

2. Make another graph showing the levels of estrogen and progesterone.

Tracking Hormone Levels (cont)

• Analysis:• 1. Describe the pattern of each

hormone.• 2. Indicate with a dashed line how

progesterone level would look if pregnancy occurred.

Tubal ligation