1. Reproduction
Reproduction is the creation of new individuals from existing ones
ASEXUAL AND SEXUAL REPRODUCTION
Sexual and asexual reproduction are both common among animals

2. Asexual Reproduction Binary fission In asexual reproduction
One parent produces genetically identical offspring
Binary fission
Is the simplest type of asexual reproduction
Involves a single parent cell splitting through mitosis into two genetically identical offspring cells

3. Regeneration, is the re-growth of a whole animal from the pieces
Budding
Is the splitting off of new individuals from existing ones

4. Asexual reproduction has a number of advantages
It allows a species to perpetuate itself if its individual members are sessile or isolated from one another
It allows organisms to multiply quickly
One potential disadvantage of asexual reproduction is that it produces genetically uniform populations

5. Sexual Reproduction
Definition:
Process in which two cells, termed gametes, come together to form one fertilized cell that contains genetic information from both parental cells.
Production of offspring whose genetic constitution is a mixture of that of two potentially genetically different gametes.

6. Advantages of sexual reproduction
Increases genetic variation
Enhances reproductive success in changing environments
Disadvantage of sexual reproduction
Locating a mate

8. Meiosis 8

9. Quick Review -
Meiosis - division of cells which results in the production of gametes
Gametes - also known as sex cells, germ cells, or spores; cells of sexual reproduction, which contain only half the chromosomes of a normal cell
Chromosomes - Threadlike bodies found in the nucleus, or center part, of a cell that carry the information of heredity.

10. What is the point of meiosis?
To produce gametes
The usual purpose of meiosis is to form gametes- the sex cells that will fuse together to form a new diploid individual.

12. A sperm cell consists of: a head, which contains the nucleus
a midpiece, which contains energy-releasing mitochondria
a tail, which propels the cell forward
Head
Nucleus
Midpiece
Mitochondria
The sperm is the male gamete, or sex cell.
Tail

13. Male gametes Male gametes, very large numbers
100 million sperm per ejaculation
smallest cell in the human body
Motile (if they can propel themselves, mobile if they can be easily moved)

14. Sperm Production (Spermatogenesis)
Video

15. Female gametes (ova or eggs in animals, ovules in plants)
Fairly small numbers.
Human females for example release about 500 ova in a lifetime.
Larger
Stationary
They often contain food reserves (lipids, proteins, carbohydrates) to nourish the embryo after fertilization
Female gametes

17. Spermatogenesis Oogenesis Occurs in the testes Occurs in the ovaries
Produces 4 hapoid cells
Produces 4 viable
spermatozoa
Motile – swim with tail
Production begins at
puberty
Production continues for
entire life
Occurs in the ovaries
Produces 4 hapoid cells
Produces 1 Ovum & 3
polar bodies
Nonmotile – moved by
currents
All eggs present at birth
Eggs mature from
puberty to menopause
Oogenesis

18. Fertilization Fusion of gametes to produce zygote
In humans this takes place near the top of the oviduct. Hundreds of sperm reach the egg (shown in this photo). When a sperm reaches the ovum cell the two membranes fuse and the sperm nucleus enters the cytoplasm of the ovum. This triggers a series of reactions in the ovum that cause the jelly coat to thicken and harden, preventing any other sperm from entering the ovum. The sperm and egg nuclei then fuse, forming a diploid zygote.
In plants fertilisation takes place in the ovary at the base of the carpel. The haploid male nuclei travel down the pollen tube from the pollen grain on the stigma to the ovules in the ovary. In the ovule two fusions between male and female nuclei take place: one forms the zygote (which will become the embryo) while the other forms the endosperm (which will become the food store in the seed). This double fertilisation is unique to flowering plants

19.
fertilization

21. Basic lifecycle of sexually reproducing organisms
All sexually-reproducing species have the basic life cycle shown on the right, alternating between diploid and haploid forms. In addition, they will also use mitosis to grow into adult organisms, the details vary with different organisms
In the animal kingdom (including humans), and in flowering plants the dominant, long-lived adult form is diploid, and the haploid gamete cells are only formed briefly.

22.
Salmon spawning
Look for some disadvantages of this means of fertilization when watching this video
Types of fertilization: External

23. Types of fertilization: External

24. Human Reproduction 24

25. Are males & females all that different?
Battle of the sexes!!!
Are males & females all that different?
Well…….…..YES and NO 25

26. Same embryonic tissues becomes male or female reproductive organs.26

27. Male or Female??? All humans are female by default
DNA determines baby’s gender
XX = Female
XY = Male
All humans are female by default
At ~ 7 weeks the baby’s body may be “told” by DNA to become male
SRY gene located on the Y chromosome 27

28. Anatomy - similar
Fetus begins with “starter parts” that could develop into either gender.
Same tissue – Same function
Testicles & Ovaries
Glands responsible for the production of sex hormones and gametes
Start inside body (Testicles “descend” before birth)
Vas Deferens & Oviduct
Passageway of gametes
Penis & Clitoris
Contain thousands of nerve ending to aid in sexual stimulation 28

29. Physiology – VERY different!
Female
Very Complicated!
Born with ~ 400,000 eggs
Uses ~500
Ovulation
1 egg “ripens” and is released once a month
Careful coordination of hormones & body
Support life
Male
Uncomplicated
Produce sperm
2-4 MILLION every day 29

30. The Male Reproductive System

31. SPERM + SEMINAL FLUID = SEMAN
Males
Bladder
Seminal vesicle
Prostate gland
Urethra
Vas Deferens
Penis
Epididymis
Testes
Produce seminal fluid
Provides a medium for the sperms to swim
To activate and nourish the sperms
SPERM + SEMINAL FLUID = SEMAN
Prostate cancer – slow growing, surgical removal
Erected during copulation for insertion into vagina
Dilation of arterioles causes the erectile tissue of penis
become turgid
Semen is squeezed from the penis to the top of vagina
Produces male sex hormone
Produce 2-4 million sperm every day
Outside body – why?
Sperm like temps 1-2 cooler than body temp
Tube taking both urine and semen outside the body
Bulboureathral gland adds lubricant to aid travel of semen through the ureathra
Temporary storage of sperm
During copulation, muscle
contract to release sperm
Tube that carries sperm to the
seminial vesicle and prostate 31

32. Sperm Why a pH buffer? Why so many sperm? Semen contains
million sperm – 5%
Sperm food (fructose) – 30%
Alkaline fluid (pH buffer) – 65%
Why a pH buffer?
Why so many sperm? 32

33. What is sperm? Head Mitochondria Flagellum
Contains chemicals to dissolve egg goo
Dad’s genetic information – one each of 44 autosomal chromosomes and 1 sex chromosome
Mitochondria
Energy
Contains mitochondrial DNA
from mother
Flagellum
“tail” used for locomotion 33

35. The Female Reproductive Cycle
Human females have a reproductive cycle, a recurring series of events that produces gametes, makes them available for fertilization, and prepares the body for pregnancy

36. The Female Reproductive System
Fallopian tube
Ovary
Uterus
Cervix
Urinary bladder
Rectum
Pubic bone
The main function of the female reproductive system is to produce ova. The ovaries are the main organs of the female reproductive system.
Egg Development 
Each ovary contains about 400,000 primary follicles, which are clusters of cells surrounding a single egg.
The follicle helps an egg mature for release into the reproductive tract, where it can be fertilized.
Eggs develop within their follicles.
When a follicle has matured, its egg is released in a process called ovulation.
The follicle breaks open, and the egg is swept from the ovary into one of the two Fallopian tubes.
While in the Fallopian tube, an egg can be fertilized.
After a few days, the egg passes from the Fallopian tube into the uterus.
If the egg is not fertilized it passes through the cervix, and finally out of the vagina.
The vagina leads to the outside of the body.
Vagina
Urethra

38. Females Ovary Oviduct Uterus Cervix Vagina
Allows for placenta to attachment
During embryo development it protects the embryo and provides a constant environment for the embryo to develop
During birth of baby it pushes the baby out by muscular contraction
Carries the ovum forward by the beating action of the cilia on its inner surface and the contraction of muscles of oviduct
For production of female gametes (ova/eggs)
For production of female sex hormones
Birth canal
Opening between the uterus and vagina 38

40. Menstrual Cycle All about timing!!!
Uterus must be ready when egg gets there in case it was fertilized
If no fertilization, tear down lining of uterus and rebuild for next month 40

41. The Menstrual Cycle The Menstrual Cycle
The menstrual cycle is controlled by internal feedback mechanisms between the reproductive system and the endocrine system.
The cycle takes an average of 28 days.

42. http://www. abpischools. org. uk/page/modules/hormones/horm4. cfm
Menstrual cycle
Video (00:01:11)

43. The Menstrual Cycle Ovulation
The menstrual cycle is divided into four phases. Notice the changes in hormone levels in the blood, the development of the follicle, and the changes in the uterine lining during the menstrual cycle.

46. FSH causes the follicle to grow
Growing follicle releases estrogen
Estrogen ↑ the lining of the uterus
↑ levels of estrogen ↑production of LH
↑ LH causes the follicle to rupture releasing the egg (ovulation)

47. 6. Ruptured follicle (corpus luteum ) produces progesterone
7. Since follicle is gone:
- ↓ in estrogen which causes
- ↓ in LH which causes
- corpus luteum to break down which causes
- ↓ in progesterone

48. 8. Progesterone keeps the lining of the uterus from shedding, therefore ↓in progesterone = menstruation
**** if the egg does get fertilized, hormones will not drop and the uterine lining will be maintained for the entire pregnancy.

49. Hormones Estrogen Ovaries
Drop in levels causes shedding of uterine lining
Increase in levels causes uterine lining to thicken
Progesterone Corpus litheum (ruptured follicle)
LH (leuteinizing hormone) Pituitary gland & hypothalamus
Stimulates release of mature egg from ovary
FSH (follicle stimulating hormone) Pituitary gland
Acts on ovaries to mature the egg
HCG (Human Chorionic Gonadotropin) Corpus litheum (ruptured follicle)
Produced if fertilization occurs
Stimulates continued secretion of progesterone 49

50. Reproduction Hormones
Produced by
Function
Testosterone
Testicles
Male sex traits
FSH
Pituitary
Stimulates egg/sperm development
Stimulate estrogen LH
Stim. Testosterone
Release of egg, corpus luteum, progesterone
Estrogen
Ovaries
Female sex traits
Progesterone
Corpus luteum (Ovaries)
Maintains Uterus lining

51. Q: How many of you have more than one parent?
then, everyone in this room is a product of sexual reproduction

52. Characteristics of Sexual Reproduction
Requires a female and male parent (i.e. it takes two to tango)

53. Q: Why do we need more than 1 parent?
½ ½ = 1

54. Characteristics of Sexual Reproduction
Requires a female and male parent (i.e. it takes two to tango)
Each parent donates ½ of the Chromosomes/Genes/DNA

55. So, by what we’ve discussed, in sexual reproduction “mom” donates half, and “dad” donates half. How does this happen?

56. Characteristics of Sexual Reproduction
Requires a female and male parent
Each parent donates ½ of the Chromosomes/Genes/DNA
Requires fertilization - the combining of gametes

57. Now, nine months later, you come out kicking and screaming (and dancing).
To which parent do you look exactly alike?
How about your siblings? Do you look exactly alike one another?

58. Characteristics of Sexual Reproduction
Requires a female and male parent
Each parent donates ½ of the Chromosomes/Genes/DNA
Requires fertilization - the combining of gametes
Produces genetic diversity - variation among and within species that is attributable to differences in hereditary material.

59. So what can we conclude about Sexual Reproduction?
it produces diversity
diversity ensures survival of a species in an environment that changes