Chapter 27 - KauHelping · Oviduct Ovaries Follicles Corpus luteum Wall of uterus Uterus Endometrium (lining of uterus) Vagina Cervix (“neck” of uterus Front view of female reproductive

Chapter 27Chapter 27 Reproduction and Embryonic Development

Copyright © 2009 Pearson Education, Inc.

PowerPoint Lectures for

Biology: Concepts & Connections, Sixth Edition

Campbell, Reece, Taylor, Simon, and Dickey

Lecture by Richard L. MyersTranslated by Nabih A. Baeshen

ASEXUAL AND SEXUAL REPRODUCTION


27.1 Asexual reproduction results in the generation of genetically identical offspring

� Asexual reproduction

– One parent produces genetically identical offspring

– Very rapid reproduction


– Can proceed via

– Budding /

– Fission /

– Fragmentation/regeneration

Asexual reproduction of an aggregating sea anemone (Anthopleura elegantissima) by fission

27.2 Sexual reproduction results in the generation of genetically unique offspring

� Some animals exhibit hermaphroditism

– One individual with male and female reproductive systems

– Easier to find a mate for animals less mobile or solitary


Hermaphroditic earthworms mating

27.2 Sexual reproduction results in the generation of genetically unique offspring

� Sperm may be transferred to the female by

– External fertilization

–Many fish and amphibian species

– Eggs and sperm are discharged near each other

– Internal fertilization

– Some fish and amphibian species


– Some fish and amphibian species

– Nearly all terrestrial animals

– Sperm is deposited in or near the female reproductive tract

Frogs in an embrace that triggers the release of

eggs and sperm

HUMAN REPRODUCTION


27.3 Reproductive anatomy of the human female

� Both sexes in humans have

– A set of gonads where gametes are produced


– Ducts for gamete transport

– Structures for copulation

27.3 Reproductive anatomy of the human female

� Ovaries contain follicles that Nurture eggs and Produce sex hormones

� Oviducts convey eggs to the uterus where embryos develop

� The uterus opens into the vagina through the


� The uterus opens into the vagina through the

� The vagina

– Receives the penis during sexual intercourse

– Forms the birth canal

Oviduct Ovaries

Follicles

Corpus luteumWall of uterus UterusWall of uterus

Endometrium(lining of uterus)

Vagina

Cervix(“neck” of uterus

Front view of female reproductive anatomy (upper po rtion)

27.4 Reproductive anatomy of the human male

� Testes (singular testis) produce Sperm and Male hormones

� Epididymis stores sperm as they develop further

� Several glands contribute to semen


� Several glands contribute to semen

– Seminal vesicles

– Prostate

– Bulbourethral

UrinaryBladder

Prostate gland

Bulbourethral gland

SeminalVesicle(behindBladder)

Erectile tissue of penis

Vas deferens

Epididymis

Testis Glans ofPenis

Scrotum

Urethra

Front view of male reproductive anatomy

27.4 Reproductive anatomy of the human male

�� Sperm productionSperm production

– Regulated by a negative feedback system of hormones


– Involves the hypothalamus, pituitary, and testes

Hypothalamus

AnteriorPituitary

Stimuli from otherareas in the brain

ReleasingHormone

Neg

ativ

e fe

edba

ck

FSH LH

Testis

Androgenproduction

Sperm productionN

egat

ive

feed

back

Hormonal control of the testis

27.5 The formation of sperm and egg requires meiosis

�Spermatogenesis

– Occurs in seminiferous tubules

– Primary spermatocytes

– Formed by mitosis

– Divide by meiosis I to produce secondary


– Divide by meiosis I to produce secondary spermatocytes

– Secondary spermatocytes divide by meiosis II to produce spermatids

– Round spermatids differentiate into elongate sperm

– Mature sperm released into seminiferous tubule

Testis

Testis

Scrotum

Penis

Epididymis

Testis

SeminiferousTubule

Cross section ofseminiferous tubule

Secondary spermatocyte

(haploid; double chromatids)

Primary spermatocyte

(in prophase of Meiosis I)

Diploid cell

Sperm cells

(haploid)

Developing sperm cells(haploid; single chromatids)

Center of seminiferous tubule

2n

2n

n n Secondary spermatocyte

(haploid; double chromatids)

Primary spermatocyte

(in prophase of Meiosis I)

Meiosis I completed

Differentiation andonset of Meiosis I

Diploid cell

n n n n

nnnn

Differentiation

Sperm cells

(haploid)

Developing sperm cells(haploid; single chromatids)

Meiosis II

27.5 The formation of sperm and egg requires meiosis

� Oogenesis

– Begins before birth: diploid cells start meiosis and stop

– Each month about one primary oocyte resumes


– Each month about one primary oocyte resumes meiosis

– A secondary oocyte arrested at metaphase of meiosis II is ovulated

– Meiosis of the ovum is completed after fertilization

2n

2n

Differentiationand onset of

Meiosis I

Diploid cell in embryo

Firstn

Completionof Meiosis I

and onset of Corpusluteum

Ovary

(arrested in prophaseof Meiosis I; presentat birth)

Primary oocyte

Firstpolar bodyn

n

and onset ofMeiosis II

n

n

Entry of spermtriggers completion

of Meiosis II

Secondpolar body

Ovum(haploid) Sperm

Corpusluteum

Ovulation Ruptured follicle

Mature follicle

GrowingFollicle

Secondary oocyte(arrested at meta-phase of Meiosis II;released from ovary)

Oogenesis and the development of an ovarian follicl e

27.6 Hormones synchronize cyclic changes in the ovary and uterus

� Ovarian and menstrual cycles

– Occur about every 28 days

– Hypothalamus signals the anterior pituitary to secrete follicle-stimulating hormone (FSH) and


secrete follicle-stimulating hormone (FSH) and leuteinizing hormone (LH), which trigger

– Growth of a follicle

– Ovulation


� After ovulation, ovarian follicle becomes corpus luteum

� Corpus luteum secretes estrogen and progesterone, which

– Stimulate the endometrium to thicken


– Stimulate the endometrium to thicken

– Prepare the uterus for implantation of the embryo

– Inhibit hypothalamus, reducing FSH and LH secretion


�� If egg is fertilizedIf egg is fertilized

– Developing embryo releases hormones(human chorionic gonadotropin) that maintain the corpus luteum which continue to secrete progesterone and estrogen maintaining uterine lining to complete the pregnancy.

– Menstruation does not occur


– Menstruation does not occur

�� If egg is not fertilizedIf egg is not fertilized

– Drop in LH shuts down corpus luteum and stop secreting its hormones(progesterone and estrogen )

– Menstruation is triggered

– Hypothalamus and pituitary stimulate development of a new follicle

PRINCIPLES OF EMBRYONIC DEVELOPMENT


EMBRYONIC DEVELOPMENT

27.9 Fertilization results in a zygote and triggers embryonic development

� Embryonic development begins with fertilization

– The union of sperm and egg

– To form a diploid zygote

� Sperm are adapted to reach and fertilize an egg

Streamlined shape moves more easily through


� Streamlined shape moves more easily through fluids

� Many mitochondria provide ATP for tail movements

� Head contains a haploid nucleus Tipped with an acrosome containing penetrating enzymes

Tail

Plasma membraneMiddle piece

Neck

Head

Mitochondrion(spiral shape)

Nucleus

Acrosome

The structure of a human sperm cell

� Fertilization events

– Sperm squeeze past follicle cells

– Acrosomal enzymes pierce egg’s coat

– Sperm binds to vitelline layer

27.9 Fertilization results in a zygote and triggers embryonic development


– Sperm binds to vitelline layer

– Sperm and egg plasma membranes fuse

– Egg is stimulated to develop further

– Egg and sperm nuclei fuse(become diploid)

The sperm squeezesthrough cells leftover from the follicle

1 23

4

5

6

The sperm’sacrosomalenzymes digest theegg’s jelly coat

Proteins on thesperm head bind toegg receptors The plasma membranes

of sperm and egg fuse

The sperm nucleusenters the eggcytoplasm

A fertilizationenvelopeforms

Sperm

Nucleus

Acrosome

Plasmamembrane

Spermhead

Acrosomalenzymes

Spermnucleus

Receptor protein moleculesPlasmamembrane

Vitelline layerالطبقة المحيه

CytoplasmEggnucleus

Jelly coatالغ ف الھ مي

Egg cell

The nucleiof sperm and egg fuse

7

Zygote nucleus

27.10 Cleavage produces a ball of cells from the zygote

� Cleavage is a rapid series of cell divisions

–More cells


– Embryo does not get larger

– Thus new cells are smaller in size

8 cells4 cells

Zygote 2 cells

Blastula(hollow ball) Cross section

of blastula

BlastocoelMany cells(solid ball)

Cleavage in a sea urchin

27.11 Gastrulation produces a three-layered embryo

� Gastrulation

– Cells migrate

– The basic body plan of three layers is established

– Ectoderm outside—becomes skin and nervous systems


systems

– Endoderm inside—becomes digestive tract

– Mesoderm in middle—muscle and bone

– A rudimentary digestive cavity forms

Blastula(end of cleavage)

Blastocoel

Animal pole

Vegetal pole

Gastrulation(cell migration)

Blastocoel

Formation of asimple digestiveBlastocoel

shrinking

Blastopore

simple digestivecavity

EctodermMesoderm

EndodermSimpledigestivecavity

Gastrula(end of gastrulation)

Development of the frog gastrula

You should now be able to

1. Explain how fertility drugs have affected multiple births in the United States

2. 2. Compare the types of asexual and sexual reproduction

3. Describe the structures and functions of the male and female human reproductive tracts

4. Describe and compare spermatogenesis and oogenesis

5. Describe the events of the menstrual cycle

6. Describe the nature of the most common STDs

7. Describe the most common forms of birth control7. Describe the most common forms of birth control

8. Relate the structure of sperm to its roles in fertilization

9. Describe the processes of cleavage and gastrulation

10. Describe the functions of the four extraembryonic membranes

11 Describe the main changes that occur during each trimester of human development

12. Describe the most common reproductive technologies


Reproduction

المصطلــــــــح تعــريف المصطـــلحAngiosperms كاسيات البذورSporophyte : The Diploid Generation. .الجيل ثنائي العدد الكروموزومي :النابت البوغيGametophyte: The Haploid Generation. .لكروموزومياالجيل أحادي العدد :النابت الجاميطيPollen Grain: The Male Gametophyte. .النابت الجاميطي المذكر :حبه لقاحEmbryo Sac: The Female Gametophyte. .النابت الجاميطي ا0نثوي:الكيس الجنينيEndosperm: Central Cell Within The Embryo Sac Has Two Nuclei.

خلية واحدة مركزية داخل الكيس الجنيني :ا2ندوسبيرم.لھا نواتان

Pollination :Transfer Of Pollen From Anther Pollination :Transfer Of Pollen From Anther To Stigma.

.نقل حبوب اللقاح من الُمتك إلى الميسم: عملية التلقيح

Double Fertilization: One Sperm Fertilizes The Egg To Produce A Zygote, The Other Fuses With The Central Cell Nuclei To Produce 3n Endosperm.

Cتقوم إحدى الخليتين المنويتين : خصاب المزدوجاو تقوم ا0خرى باCندماج , بتخصيب البيضة 2نتاج الIقحة

مع النواة الخلية المركزية لتنتج نسيج ا2ندوسبيرم ثIثي .(3n)العدد الكروموزومي

Seed Dormancy: Embryo Growth And Development Are Suspended.

.توقف نمو و تكوين الجنين: كمون البذرة

Two Cotyledons = Eudicot Seeds فلقتانSingle Cotyledon = Monocot Seeds فلقة واحدة

Reproduction

Fruit: Developed Ovary. .مبيض مكتمل النمو: الثمرةGermination ا2نباتAsexual Reproduction: One Parent Produces Genetically Identical Offspring.

.ينتج أحد الوالدين ذرية متماثلة وراثياً : الIجنسيالتكاثر

Hermaphroditism: One Individual With Male And Female Reproductive Systems.

.فرد واحد بأجھزة تكاثر ذكرية وأنثوية :الخنوثة

External Fertilization: Eggs And Sperm Are Discharged Near Each Other.

يتم إطIق البيض والحيوانات المنوية : ا2خصاب الخارجي.بالقرب من بعضھا البعض

المصطلــــــــح تعــريف المصطـــلح

Discharged Near Each Other. .بالقرب من بعضھا البعضInternal Fertilization: Sperm Is Deposited In Or Near The Female Reproductive Tract.

يتم إيداع الحيوانات المنوية في أو : ا2خصاب الداخلي. لWنثيقريباً من القناة التناسلية

Gonads: Where Gametes Are Produced. .حيث يتم انتاج الجاميطات: المناسلOvaries: Contain Follicles That Nurture Eggs And Produce Sex Hormones.

تحتوي على حويصIت والتي تقوم بــ تغذية : المبايض.البيض وانتاج ھرمونات الجنس

Testes (Singular Testis): Produce Sperm And Male Hormones.

تنتج الحيوانات المنوية ): مفردھا خصية(الخصي .ھرمونات الذكورة

Epididymis: Stores Sperm As They Develop Further

.يتم فيه تخزين الحيوانات المنوية وإنضاجھا: البربخ

Reproduction

المصطلــــــــح تعــريف المصطـــلح

Spermatogenesis: Formation Of Sperms. عملية تكوين الحيوانات المنويةOogenesis: Formation Of Ovum. عملية تكوين البيض Menstrual Cycle الدورة الشھريةMenstruation الحيضCorpus Luteum الجسم ا0صفرEndometrium Endometriumبطانة الرحم بطانة الرحمCleavage: Rapid Series Of Cell Divisions. .ھو سلسلة سريعة من اCنقسامات الخلوية: التفلجGastrulation: Cells Migrate And Basic Body Plan Of Three Layers Is Established.

يتم تأسيس الخطة ا0ساسية وھجرة الخIيا : التبطن.للجسم ذو الثIث طبقات

Documents

Chapter 27 - KauHelping · Oviduct Ovaries Follicles Corpus luteum Wall of uterus Uterus Endometrium (lining of uterus) Vagina Cervix (“neck” of uterus Front view of female reproductive