fertilization & development homework: read pgs 67-68 in rb and answer questions 22- 31 on loose...

Fertilization & Development

Homework: Read pgs 67-68 in RB and answer questions 22-31 on loose leaf paper.

2015 Reproduction -SMP

https://www.youtube.com/watch?v=_5OvgQW6FG4

Types of Fertilization

1. External: gametes fuse outside the body of the female Occurs in animals that breed in the water (most

invertebrates- Fish/amphibian) The two parents release their eggs into the water, and

the sperm fertilizes the eggs.

2. Internal – gametes fuse inside the body of a female

Fertilization occurs inside the female body where it is moist

Occurs mostly in animals that reproduce on land and some aquatic animals like sharks, reptiles, and mammals


External Fertilization

COMPARISONCOMPARISON

PROS Large numbers of eggs

and sperm are released to increase chances of survival.

Gametes released at the same time

CONS Sperm may not find the eggs. Predators may find and eat

eggs or small offspring. Changes in temperature or

oxygen content of the water may cause death.


Fewer eggs need to be released.

Hormones and “mating signals” trigger the release of the eggs and sperm. Ex. Singing, special feathers, and pheromones.

Mating must take place within ~ 24 hours for fertilization to occur

EXTERNAL

INTERNAL

A. When sperm penetrates egg

1. Sperm releases special enzymes to do this

2. Forms a ZYGOTE

3. Recombination occurs:

a. Combining of genetic info from both parents

(n=23) (n=23) (2n=46)

Sperm + egg = zygote

C. Occurs in the oviduct (fallopian tube)

FERTILIZATION


D. Multiple births:

fraternal twins- 2 eggs identical twins- one egg

that splits in two, always the same

Conjoined (Siamese) twins are identical twins whose bodies

are joined in utero.

Abby & Brittany Hensel

2010 Reproduction -SMB

Occurs in the oviduct (fallopian tube) Zygote begins a series of mitotic divisions (cleavage) to undergo differentiation Division process is rapid - no increase in size, just the number of cells:

1 cell→ 2 cells→ 4→ 8→ 16→32→64→ 128 …etc

Implantation of zygote in uterus occurs around day 7

Early Development- The First WeekEarly Development- The First Week


EMBRYONIC DEVELOPMENT

Period of the zygote (silent video) http://www.bing.com/videos/search?q=Gastrulation+Animation&Form=VQFRVP#view=detail&mid=634F58C4C7A9487B3990634F58C4C7A9487B3990Follicle Development http://www.bing.com/videos/search?q=Ovarian+Cycle+Animation&Form=VQFRVP&adlt=strict&mid=59F979C28F731BF7FD6D59F979C28F731BF7FD6D%20-%20view=detail&mid=59F979C28F731BF7FD6D59F979C28F731BF7FD6D#view=detail&mid=AF57AA0A9AB206C6F4A4AF57AA0A9AB206C6F4A4

Embryonic Layers and FunctionsGASTRULATION

Cells in zygote form into 3 distinct layers

The cells within each layer The cells within each layer DIFFERENTIATE DIFFERENTIATE to formto form specialized cellsspecialized cells (muscle, liver, heart, etc) then tissue and (muscle, liver, heart, etc) then tissue and organs. organs. This is caused by This is caused by gene activationgene activation which can be which can be

influenced by the environment.influenced by the environment.


EctodermEctoderm

• skin and nervous system

EndodermEndoderm• lining of

digestive and Respiratory

tract (body organs)


MesodermMesoderm• Muscular,

circulatory skeletal, excretory and reproduction systems


These developing cells are now called an embryonic stems cells and can be used as for medical research and application

http://www.brainpop.com/science/cellularlifeandgenetics/stemcells/


HUMAN FETAL DEVELOPMENT

1. Placenta – Develops at 3 weeks Placenta is a fetal organ Connects mother and fetus

Food, gases and wastes DIFFUSE across blood vessels

watch

2. Umbilical cord- rope-like structure that connects the fetus to the placenta

3. Amnion- membrane surrounding the fetus

4. Amniotic fluid – fills the amnion, protects the fetus, and absorbs shock



Most critical time of development is the 1st trimester when organs are developing

Harmful environmental risk factors include drugs, rugs, alcoholalcohol tobaccotobacco medicinesmedicines poor dietpoor diet, , toxic substancestoxic substances infections infections

This can halt development or cause major developmental issues

Not taking care can result in miscarriage or can severely damage embryo/fetus

First and Second Trimester Dangers!!!!


8 weeks = FETUS

Umbilical cord forms at 3 months

Body systems become more specialized

Fetus becomes bigger

BirthBirth (36 weeks (36 weeks)

Later Development



The end of the journey!

And you think 9 months of

Biology is hard!



REPRODUCTIVE TECHNOLOGYIn vitro Fertilization Process – assisted reproduction

Simulation http://www.sumanasinc.com/webcontent/animations/content/invitrofertilization.html


Directions: READ your review book pageS 71-72. Fill out the blank columns for each of the 4 technologies listed.

Technology Purpose

Agriculture 1.

2.

Ecology 1.

2.

Health Care 1.

2.

3.



Technology Purpose

Agriculture

GMO’s –genetically modified organisms

1. Alter plants so they are resistant

to insects, frost etc. 2. Artificial insemination of farm

animals allows desired traits

Ecology

Health Care



Technology Purpose

AgricultureGMO’s –genetically

modified organisms




Ecology 1. Build up of endangered populations 2. Use of hormones to regulate pest populations instead of harmful chemicals

Health Care


Technology Purpose

AgricultureGMO’s –genetically

modified organisms




Ecology 1. Build up of endangered populations 2. Use of hormones to regulate pest populations instead of harmful chemicals

Health Care 1. Hormone therapy Future of Infertility Treatment | Watch the video - Yahoo Finance

2. In Vitro Fertilization 3. Ultrasounds Video: Fetal ultrasound - Mayo Clinic

Answers for RB questions 32-52, pg 72-73

32) 2

33) 3

34) 2

35) 1

36) 1

37) 1

38) 3

39) 2


49) Sperm nucleus contains half the chromosomes needed to form a normal frog

50) hormones

51) An ovary

52) 2

40) 2

41) 3

42) 3

43) 2

44) 3

45) 1

46) 4

47) 1

48) 1

Practice ANSWERS from notes:1)C2)B3)A4)B5)B6)A7)A8)D9)D10)C11)B12)a) placenta b) ie. Drugs, alcohol (see pg 4 of notes for other responses) – FAS (fetal alcohol syndrome) or low birthweight or brain/organ damage13)Interfere with development or cause low birthweight or FAS or death to fetus14)A15)C

Human Reproductive Systems

Our species lives on…….

Human Reproduction Part II

MALE REPRODUCTIVE SYSTEM


Male Sexual DevelopmentTestosterone is the male reproductive hormoneSecreted in small amounts until puberty

Puberty begins when:Hypothalamus Pituitary increased

FSH and LH GONADS (TESTES)GONADS TESTOSTERONETestosterone produces male 2ndary sex

characteristics Ex. body hair, muscle development, deep

voice


Male Reproductive PartsA. Testes:

Male reproductive gland Sperm and testosterone produced

B. Scrotum: Protective sac around testes Keeps testes cool (this keeps the

sperm at an optimum temperature for development

C. Epididymus: Stores sperm while they mature

D. Vas Deferens: Tube that carries sperm from

epididymis to urethra

Diagram of Testicle


Male Reproductive PartsE. Prostate gland -- the largest of several glands which add lubricating and other fluids to the sperm

F. Urethra: tube through the penis

carrying sperm to the outside of the body

G. Other glands work together to produce seminal fluid.

Combination of sperm and seminal fluid = semen


H. Penis- adaptation for internal fertilization of the female

Semen travels from testes →vas deferens→ urethra→ penis → outside of the body through ejaculation (uncontrolled muscle contractions)

Female Reproductive SystemSide view


Female Sexual Development

A. Estrogen is the female reproductive hormone

B. Puberty begins when:Hypothalamus Pituitary increased FSH

AND LH GONADS (OVARIES)GONADS Estrogen and progesterone

C. Estrogen produces female 2ndary sex characteristics

(broadening of pelvis, breast development, and are involved in the menstrual cycle and pregnancy).


Female Reproductive PartsA. Ovaries:

Female Reproductive Gland Egg (ova) produced here Also contain follicles:

Place where eggs mature

B. Fallopian tubes (Oviduct): Tubes that carry an egg from

ovary to uterus Place of fertilization Egg Travel: From the

ovaries → fallopian tubes/oviducts → uterus



C. Uterus:• Mostly muscle• implantation and

development of the embryo and fetus before birth occurs here

D. Vagina • Vagina (or birth canal)

entry point for sperm from the male and exit tube for the baby when it is born


HUMAN REPRODUCTIVE SYSTEMS Diagrams….

Your turn

COMPLETE QUESTIONS ON: pages 3-4 of your notesPage 8 (use the diagram given)


Answers for pages 3-4

1) B

2) A

3) A

4)D

5)C

6)B

7)C

8)D

9)C

10)A

11)D


12) ADD LUBRICATION/NUTRIENTS FOR THE SPERM TO SWIM/TRAVEL IN

13) B

14) B

15) ESTROGEN OR PROGESTERONE OR FSH OR LH

16) D

17) A

The HORMONES-& Cycles

• Uses a negative feedback mechanism to maintain homeostasis

• Permanent cessation of the cycle is called Menopause

Add this to notes

The HormonesThe HormonesA. Secreted by the Pituitary gland:

FSH (Follicle Stimulating Hormone)Stimulates follicle to cause egg to mature

LH (Luteinizing Hormone)Causes release of mature ovum

(ovulation)Prepares uterus for implantation of

fertilized egg

B. Secreted by Ovaries: Estrogen

• Causes uterine lining to thicken Progesterone:

Works with estrogen to finish uterine lining thickening2015 Reproduction -SMP

Female Reproductive Cycle

Female Reproductive Cycle Video: 5:00 min

Menstruation Cycle of Female Reproductive Systemhttp://www.bing.com/videos/search?q=Ovarian+Cycle+Animation&Form=VQFRVP&adlt=strict&mid=59F979C28F731BF7FD6D59F979C28F731BF7FD6D#view=detail&mid=59F979C28F731BF7FD6D59F979C28F731BF7FD6D


The CyclesThe Cycles1. Ovarian Cycle:

Occurs over 28 days in the ovaries

Process during which an ovum matures in a follicle and is released during ovulation

After ovulation, a corpus luteum (yellow body) is left behind

Ovarian Cycle (1:17) http://www.bing.com/videos/search?q=Ovarian+Cycle+Animation&Form=VQFRVP&adlt=strict#view=detail&mid=59F979C28F731BF7FD6D59F979C28F731BF7FD6D


2. Menstrual (Uterine) Cycle:Occurs over 28 days

Process during which uterine lining is preparing for fertilized ovum

If fertilization occurs, this cycle stops until after birth

If not fertilized, lining sheds (menstruation!) and cycle begins again

THESE TWO CYCLES ARE GOING AT THE SAME TIME!!!!!!!!!!!

I REPEAT: THESE TWO CYCLES ARE GOING AT THE SAME TIME!!!!!!!!!!!

The Beginning to the end: The Beginning to the end: Phase 1-Menstruation• Occurs if egg is not

fertilized• Days 1- 5 • Corpus luteum

(yellow body) breaks down• This causes drop in

estrogen and progesterone

• Uterine lining sheds• FSH increases during


Phase 2: Follicular PhaseDays 5 –13Low estrogen = FSH to be releasedThis stimulates growth of follicleEgg begins to

matureFollicle matures causing estrogen levels upUterine lining

begins to thicken again 2015 Reproduction -SMP

Phase 3: Ovulation http://www.bing.com/videos/search?q=Ovarian+Cycle+Animation&Form=VQFRVP&adlt=strict#view=detail&mid=59F979C28F731BF7FD6D59F979C28F731BF7FD6DDays 13-15Sudden rush of FSHMajor SPIKE of LHThis causes follicle

to break and release egg into fallopian tube

FERTILIZATION MOST LIKELY TO OCCUR AT END OF OVULATION!

Phase 4: Luteal PhaseDays 15-28LH and FSH levels crashCorpus luteum forms from broken follicleCorpus luteum secretes estrogen and progesterone This thickens uterine

lining to prepare for egg


What is going on all at once?

Phase

1 Phase 2

Phase

3

Phase

4

Complete practice questions on pg 7

Let’s look at diagram on page 8


fertilization & development homework: read pgs 67-68 in rb and answer questions 22- 31 on loose...

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