1. Ch. 5 – Cell Growth and Reproduction

2. The Microscope & Cell Theory Robert Hooke first observed “cells” under a microscope in thin slices of cork. Anton van Leeuwenhoek first to observe living cells in samples of pond water and human blood. By the end of the 1800’s many biologists had discovered many of the structures in the cell, and the Cell Theory was developed.

3. Cell Theory All organisms are made up of one or more cells. All cells carry on life activities New cells arise only from other living cells by the process of cell division.

4. Microscopes

5. Anton Van Leeuwenhoek’s Microscope

6. Compound Microscope

7. Transmission Electron Microscope

8. Spider’s Silk Gland

9. Scanning Electron Microscope

11. Cells: The Basic Unit of Life Cells are the basic units of organisms – Cells can only be observed under microscope Two basic types of cells: Animal Cell Plant Cell On the following slides, all structures are found in both plant and animal cells unless stated otherwise.

12. Plant Cell – Made of cellulose which forms very thin fibres – Strong and rigid – In plant cells only Cell wall

13. –Protect and support the interior of the cell. –Give shape to the cell –A dead layer –Freely permeable Cell wall Plant Cell

14. –Lies immediately against the cell wall –Made of protein and lipid  Selectively permeable Cell membrane Plant Cell

15. –Can control the movement of materials into and out of the cell –A living layer –Found in plant & animal cells Cell membrane Plant Cell

16. –Jelly-like substance enclosed by cell membrane –Provide a medium for chemical reactions to take place Cytoplasm Plant Cell

17. –Found in all cells –Contains organelles and granules : e.g. chloroplast e.g. mitochondrion Cytoplasm Plant Cell

18. Organelles very small size – some can only be observed under electron microscope All organelles have specific functions Found in the cytoplasm

19. –Only in plant cells. –Contain the green pigment chlorophyll –Chlorophyll traps light energy, to make food by photosynthesis Plant Cell Chloroplast

20. –Contain starch grains (products of photosynthesis) Chloroplast Plant Cell

22. –Rod shape –For cellular respiration (provides energy for the cell) Plant Cell Mitochondrion ( mitochondria )

23. –Active cells ( eg. sperms, liver cells) have more mitochondria Plant Cell Mitochondrion ( mitochondria )

24. –Starch granules –Oil droplets –Crystals of insoluble wastes Plant Cell Non-living granules

25. –large central vacuole –Contains cell sap a solution of chemicals (sugars, proteins, mineral salts, wastes, pigments) –Larger in plant cells than animal cells Plant Cell Vacuole

26. –Control the normal activities of the cell –Bounded by a nuclear membrane –Contains the genetic material (DNA). –DNA is organized into threadlike structures called chromosomes. Plant Cell Nucleus

27. Nucleolus  Contains the information for the production of proteins in the cell.  Not bound by a membrane Nuclear Pore  Allows large molecules to move in and out of the nucleus

28. Different kinds of plant cells Onion Epidermal Cells Root Hair Cell root hair Guard Cells

29. Animal cell No cell wall or chloroplasts Stores glycogen granules and oil droplets in the cytoplasm

30. Animal Cell Endoplasmic Reticulum (E.R.) Found in plant & animal cells Transport of materials in cell Rough and smooth types Rough E.R. has ribosomes attached to the outside.

31. Endoplasmic Reticulum mitochondrion

32. Animal Cell Ribosomes Found in plant & animal cells. Sites of protein synthesis. Found on rough E.R. or in the cytoplasm.

33. Animal Cell Golgi Bodies Found in plant & animal cells. Serve as storage, packaging and processing centres for products released by the cell.

35. Animal Cell Microtubules “Skeleton” of the cell. Found in plant & animal cells. Gives cells shape and support. Found in centrioles, cilia, & flagella. Composed of Tubulin.

36. Animal Cell Lysosomes Small saclike structures that contain digestive enzymes. Found in most animal and some plant cells.

37. Rough E.R.

38. Different kinds of animal cells white blood cell red blood cell cheek cells sperm nerve cell muscle cell Amoeba Paramecium

39. Similarities between plant cells and animal cells  Both have a cell membrane surrounding the cytoplasm.  Both have a nucleus.  Both contain mitochondria, golgi bodies, E.R., ribosomes and microtubules.

40. Differences between plant cells and animal cells Animal cellsPlant cells Relatively smaller in size Irregular shape No cell wall Relatively larger in size Regular shape Cell wall present

41. Animal cellsPlant cells Vacuole small or absent No Chloroplasts Nucleus at the centre Large central vacuole Chloroplasts Present Nucleus near cell wall Differences between plant cells and animal cells

42. Assignment Read pages 140 – 143 Understanding Concepts & Making Connections pg. 141 – Questions 1-4 Understanding Concepts Pg. 143 – Questions 1-4

43. Cell Division

44. Cells multiply by the process of division. Cells divide into 2 identical cells half the size of the original cell and then grow & develop into full size cells. These new cells are called daughter cells

45. Functions of Cell Division 1.Healing and Tissue Repair Important part of cell division. You are continually replacing damaged or dying cells. You do not go through life with the same cells you are born with. If your cells did not reproduce then you would gradually shrink and die.

46. 2. Growth The growth of all living organisms depends on cell division. As the number of cells in an organism increase, so does it size. There are estimates of between 50 – 100 trillion cells in the human body. A blue whale is almost 2000X larger than a human so it would have about 1 sextillion cells 1000000000000000000000 cells

47. Why do cells divide? Most cells are small and a relatively constant size. Why don’t cells continually grow and increase in size instead of dividing? This is because the ratio between the surface area of the cell membrane and the volume of cytoplasm is very important.

48. As a cell grows, the volume of cytoplasm increases faster than the surface area of the cell. All essential materials for the cell exit and enter through the cell membrane. If a cell became too large, there would not be enough exchange with the cytoplasm to sustain the cell. Increasing distance from the nucleus would prevent effective communication within the cell since the nucleus controls all cellular activities.

50. 3. Reproduction of Organisms Cell division is vital to reproduction of any organism. You started off as a single cell in your mothers Fallopian Tube & Uterus. You are now made up of trillions of cells Single celled organisms can reproduce only through cell division.

51. Assignment Read Section 5.4 (pg. 148-149) Understanding Concepts & Making Connections Pg. 149 – Questions 1-5

52. The Cell Cycle All cells come from preexisting cells through cell division. Cells alternate between stages of dividing and not dividing. The sequence of events from one division to another is called the cell cycle (fig. 2 pg. 150) The actual process of cell division is only a small part of the cycle.

54. The Cell Cycle Most of the time, the cell is in a phase called interphase. In this phase, the cell is gathering sugar, proteins and other materials to allow the cell to divide. Just before division, the cell goes through a period of rapid growth and duplication of it’s chromosomes. Each new cell needs a copy of the chromosome.

55. What the heck is a chromosome? It is compacted DNA which contains all of the genetic information of the cell. Chromosomes contain all of the information for all cell functions.

56. Mitosis & Cytokinesis The process by which the nuclear material in the cell is divided is called mitosis. The process by which the rest of the cell (cytoplasm, organelles, etc.) are divided is called cytokinesis. Cytokinesis differs in plants and animals. In animal cells the cell membrane pinches together in the middle separating the cytoplasm into 2 equal parts and creating 2 new cells. In a plant cell, a new cell wall has to grow in between the new cells. These 2 processes work together to accomplish cell division.

57. The Phases of Mitosis I nterphase P rophase M etaphase A naphase T elophase I pee on the mat Remember this sentence

59. Interphase Cell is growing and preparing for cell division by duplicating it’s genetic material.

60. Prophase The DNA in the nucleus condense into chromosomes. The nuclear membrane begins to disappear.

61. Metaphase The double- stranded chromosomes line up along the middle of the cell.

62. Anaphase Each chromosome splits and each half is pulled to opposite ends of the cell (poles). If anaphase occurs properly each daughter cell have a complete set of genetic information.

63. Telophase Chromosomes reach the opposite poles and the nuclear membrane begins to reform. Cytokinesis begins and the cell divides into 2 daughter cells. After telophase, the cell then enters interphase to grow and prepare to divide again. Mitosis animation

64. Reproduction Asexual Reproduction: a single organism gives rise to offspring with identical genetic information. Sexual Reproduction: genetic information from 2 cells is combined to make a new organism. – Usually 2 specialized sex cells unite to form a fertilized egg called a zygote.

65. Assignment Read pages 150-153 & 159-161 Understanding Concepts & Making Connections pg. 153 – Questions 1-5, 7, 8. Make your own notes on the types of asexual reproduction (a-e) on page 160-161 Understanding Concepts & Making Connections pg. 161 – Questions 1-5 Omit sections 5.10 – 5.13 in chapter 5. You will not be required to know anything from these sections.

66. Chapter 6 A closer look at cell division

67. Some Fascinating Facts about DNA If all the DNA in the human body was put end to end it would reach to the sun and back over 600 times There are 3 billion letters in the DNA code in every cell in your body. The information would fill a stack of paperback books 200 ft (61m) high. If we recited the genome at one letter per second for 24 hours a day it would take a century to recite. Our DNA is 98% identical to chimpanzees and 75% identical to mice.

68. More Fascinating Facts about DNA Scientists still don’t know what more than 50 percent of genes do. Also a lot of the DNA in our cells is "junk," that is, scientists don’t know exactly what the long stretches of repetitive DNA (usually long stretches of Gs and Cs) in our cells are for. The red blood cells are the only kind of cells in your body that don’t have DNA because they’re the only cells in your body that don’t have nuclei.

69. Deoxyribonucleic Acid (DNA) nucleotides DNA double helix. Made up of nucleotides (DNA molecule) in a DNA double helix. Nucleotide: Nucleotide: Phosphate group 1.Phosphate group 5-carbon sugar 2.5-carbon sugar Nitrogenous base 3.Nitrogenous base ~2 nm wide ~2 nm wide

70. DNA Double Helix Nitrogenous Base (A,T,G or C) “Rungs of ladder” “Legs of ladder” Phosphate & Sugar Backbone

71. DNA Nucleotide O O=P-O OPhosphate Group Group N Nitrogenous base (A, G, C, or T) (A, G, C, or T) CH2 O C1C1 C4C4 C3C3 C2C2 5 Sugar Sugar(deoxyribose)

72. DNA Double Helix P P P O O O 1 2 3 4 5 5 3 3 5 P P P O O O 1 2 3 4 5 5 3 5 3 G C TA

73. Nitrogenous Bases PURINES PURINES Adenine (A) 1.Adenine (A) Guanine (G) 2.Guanine (G) PYRIMIDINES PYRIMIDINES Thymine (T) 3.Thymine (T) Cytosine (C) 4.Cytosine (C)

74. BASE-PAIRINGS Base Purines PyrimidinesPairs Adenine (A)Thymine (T) Adenine (A) Thymine (T)A = T Guanine (G)Cytosine (C) Guanine (G) Cytosine (C)C G CG 3 H-bonds

75. Chargaff’s Rule Adenine Thymine Adenine must pair with Thymine GuanineCytosine Guanine must pair with Cytosine about the same Their amounts in a given DNA molecule will be about the same.

76. DNA: The Genetic Material This molecule can make perfect copies of itself in a process called replication. If DNA could not replicate itself then cell division could not occur. Remember, before the cell can divide it must duplicate its DNA so each of the new cells can have a complete set of genetic material.

77. DNA, Genes & Variation A dog has 70 chromosomes, a mouse 40 chromosomes and a human has ____ chromosomes arranged in __________. We all look different because of genes on those chromosomes. One chromosome in each pair comes from your mother and the other half comes from your father. You have two copies of every gene. For example you have 2 genes for hair colour, eye colour, etc.

78. DNA, Genes & Variation The DNA in your chromosomes is unique to you. Identical twins are the only people in the world with identical DNA. Fraternal twins, on the other hand, are formed when two different eggs are fertilized. Although identical twins have the same DNA, they do not always look identical. This is because the same DNA is expressed in different ways. Called a phenotype.

79. DNA, Genes & Variation Traits determined by physical phenotype, such as fingerprints and physical appearance, are the result of "the interaction of the individual’s genes and the developmental environment in the uterus." Thus, a DNA test can't determine the difference between identical twins, while a simple fingerprint can.

80. DNA Fingerprinting The chemical structure of everyone's DNA is the same. The only difference between people (or any animal) is the order of the base pairs. There are so many millions of base pairs in each person's DNA that every person has a different sequence. base pairs

81. DNA Fingerprinting Using these sequences, every person could be identified solely by the sequence of their base pairs. However, because there are so many millions of base pairs, the task would be very time- consuming. Instead, scientists are able to use a shorter method, because of repeating patterns in DNA.

82. DNA Fingerprinting These patterns do not, however, give an individual "fingerprint," but they are able to determine whether two DNA samples are from the same person, related people, or non-related people. Scientists use a small number of sequences of DNA that are known to vary among individuals a great deal, and analyze those to get a certain probability of a match.

83. How is it done?? All you need is a single cell from which to get some DNA. 1.The DNA is extracted from the nucleus of the cell. 2.Special chemicals are used to cut the DNA into segments. 3.These segments are placed on a gel and are pulled across the gel by an electric current. Short segments are drawn further creating bands.

84. How is it done?? 4.Bands of DNA can now be matched to known samples. This process is now widely used for solving crime and testing for paternity. http://www.pbs.org/wgbh/nova/sheppard/analyze.html

86. Assignment Read Section 6.1 on page 176- 178 Answer questions 1-5, 7 & 8. On page 178

87. DNA, Mutations & Cancer Changes in our genetic code are called mutations. Mutations can be beneficial, neutral or harmful. Things like chemicals, radiation, the sun, viruses, etc. may cause mutations to occur.

88. WHAT IS CANCER Normal body cells grow, divide and die in an orderly fashion. A cancer cell is a normal cell that has begun to grow fast and in an uncontrolled way Cancer cells are different because they do not die, just continue to divide and grow. Cancer cells form as a result of damaged DNA or DNA that has mistakes in its code.

89. WHAT IS CANCER? Many different types of cancer The cancer is usually named after the part of the body from which it came eg. Breast cancer from the breast Lymphoma from the lymph system Each person’s cancer is different

90. How cancer cells are made Cancer cell is a normal cell with many mistakes Three ways the mistakes are created: 1.Born with mistakes in all cells – genetic 2.Accident when cell divides - mutation 3.Substance causing cancer or mutations in the DNA - Carcinogens – Toxins, sunlight, viruses, fatty diet, cigarettes, other tobacco products, etc.

91. PROBLEMS WITH THE CELL’S INSTRUCTIONS A mutation in the DNA can effect the behavior of the cell: Normally the instructions read: “STOP dividing after coming in contact with more cells” is changed to “KEEP dividing after coming in contact with more cells” The cells won’t stop growing and dividing! Cancer cells will grow into normal tissue

92. Tumors A tumor is a collection of cancer cells A tumor starts as one cancer cell This 1 cell divides into 2 cells then 4 then 8 and so on. The tumor grows as long as more cells are made than dying. Tumors double in size in a few months. A 1 cm in size tumor has a billion cells.

93. Tumors There are two types of tumors: Malignant and Benign 1.Malignant tumors spread to other areas in the body. These are the dangerous ones. These cancer cells can get into the lymph and blood system to grow colonies in other parts of the body. This is how a cancer spreads. 2.Benign tumors stay in one place.

94. Causes of Cancer 80% of cancers are considered sporadic- meaning the cause is unknown. There are several risk factors that increase the chance of cancer: Age- risk increases >50. Diet- high fat, high cholesterol diets increase risk. Obesity- no clear link but research indicates it is a factor. Cigarettes- increases lung cancer, other tobacco products such as pipes and chewing tobacco increase cancers of the mouth. Long term exposure to chemicals- asbestos, radon and benzene.

95. Causes of Cancer Exposure to high levels of radiation Harmful ultraviolet rays from the sun. Some viruses- Hepatitis B, C, HPV Immune system diseases (HIV/AIDS) Heredity - Screenings are recommended for high risk families. You are considered high risk if : Several relatives have had cancer or if someone had cancer at a very early age.

96. Symptoms of Cancer Remember one word: CAUTION Changes in bowel or bladder habits. A sore that will not heal. Unusual bleeding or discharge Thickening or lump in breast or any part of the body. Indigestion or difficulty swallowing. Obvious change in any wart or mole Nagging cough or hoarseness.

97. Symptoms of Cancer Other early warning signs may include: – Unexplained weight loss – Fever – Fatigue – Pain – Skin changes These can also be symptoms of other problems also.

98. Diagnosis of Cancer Biopsy- small tissue sample is viewed under a microscope to look for cancerous cells. Endoscopy- a flexible plastic tube with a tiny camera is inserted into the body and the area is looked at by a doctor Diagnostic Imaging- x rays CAT scan- more precise than standard x-ray.

99. Diagnosis of Cancer MRI- uses a powerful magnetic field, very accurate but expensive. Blood Tests- some tumors release substances called tumor markers which can be found in the blood.

100. Treatment of Cancer Types of treatment: Surgery- 60% of all cancer pts. have some kind of surgery. Radiation Therapy Chemotherapy Immunotherapy

101. Cancer Prevention Be aware of your body, this is the best prevention against cancer. Early detection can be the difference between life and death! Five things you should remember about preventing cancer. 1.Eats lots of fruits, vegetables, and whole grains. 2.Discover the pleasure of physical activity.

102. Cancer Prevention 3.Stay tobacco free 4.Enjoy a low-fat diet 5.Protect yourself from the sun between 10:00 am and 4:00 pm.

112. End of Cancer

113. Regeneration This is the ability of an organism to regrow tissue, organs or parts of the body. Regeneration in humans is limited to the blood, bones (to repair a fracture) and the skin (healing wounds). Many organisms can reproduce asexually through fragmentation. Animals that have limited cell specialization are capable of regeneration.

117. Regeneration As an animal becomes more complex, there is greater cell specialization in the organism. With increasing specialization, comes a loss of regenerative capability.

118. Cells that are specialized use different part of the genetic code (DNA). Stem cells are cells that have not yet become specialized and will actively divide and multiply. Amphibians and starfish cells have the ability for their cells to return to a stem cell and respecialize later after the body part is regenerated. Human skin and bone marrow contain stem cells in humans. This explains how we can grow new skin and replace dead red blood cells, but not nerve cells.

119. Producing Plants Without Seeds Artificial Vegetative Reproduction Common in horticultural production (fruits & vegetables). These techniques allow producers to grow plants with desirable traits.

120. 1. Cuttings (2 Types) a)Stem Cuttings – a branch, or slip, is cut from a plant and placed in water or moist sand. Usually the bottom of the clipping is dipped into hormones to promote root development. b)Common with geraniums, roses, ivy and grapevines.

121. b)Leaf Cutting – A leaf or part of a leaf is placed in water or moist soil. A new plant will arise from the base of the leaf. Common with African violet, snake plant and begonias.

122. 2. Layering A stem is bent over so that part of it is covered with soil. The covered part will develop roots and the cut from the parent plant and replanted as a new plant. Common with raspberries, roses and honeysuckle. This also occurs naturally.

123. Air Layering Trench Layering Tip Layering

124. 3. Grafting A stem or bud is removed from one plant and permanently joined to the stem of a closely related plant. The 2 parts are held together by tape, wax or commercial grafting compounds. The transplanted bud or stem will keep its characteristics on the new plant.

127. Cloning Cloning occurs everyday in nature. There are many different methods of natural cloning such as binary fission, budding, runners or fragmentation. Plants often respond well to cloning. This may be due to being able to delay specialization in the cells. Large parts of the DNA get turned off which allows the cell to specialize into a specific cell type.

128. What is cloning? What is cloning? Cloning is the process of making a genetically identical organism through nonsexual means. Taking an adult (fully differentiated) cell, and restarting its genetic program and protein synthesis (as if it were a fertilized egg)

129. It has been used for many years to produce plants (even growing a plant from a cutting is a type of cloning). Animal cloning has been the subject of scientific experiments for years, but garnered little attention until the birth of the first cloned mammal in 1997, a sheep named Dolly. Since Dolly, several scientists have cloned other animals, including cows, gaur (a large wild ox from India and southeast Asia) and mice. The recent success in cloning animals has sparked fierce debates among scientists, politicians and the general public about the use and morality of cloning plants, animals and possibly humans.

130. b In 1997 Dolly the sheep became the first vertebrate cloned from the cell of an adult animal. Not only was this a remarkable scientific breakthrough but it immediately gained interest and concern from around the world on the future of cloning technology as it would effect humans.

131. Cloning Dolly was cloned using the nuclear replacement method. The nucleus from an adult cell was inserted into an unfertilized egg cell that the nucleus had been removed. This embryo is then stimulated to divide and will eventually produce another individual with identical characteristics to the donor of the nucleus.

132. Cloning of Dolly

141. High Failure Rate in Animals 2% success rate Miscarriage frequent Animals often die after birth Some animals have developmental abnormalities Death of offspring is 10 times higher than normal before birth and 3 times higher after birth than naturally conceived animals

142. Why Clone? Reasons for cloning might include replacing lost or deceased family pets and repopulating endangered or even extinct species. Whatever the reasons, the new cloning technologies have sparked many ethical debates among scientists, politicians and the general public. Several governments have considered or enacted legislation to slow down, limit or ban cloning experiments outright. It is clear that cloning will be a part of our lives in the future, but the course of this technology has yet to be determined.

143. Chapter 7 Sexual Reproduction and the Diversity of Life

144. Sexual Reproduction in Flowering Plants Most plants reproduce sexually through flowers. Seeds are protected within the ovary of the flower which develops into a fruit.

145. Parts of the Flower The sepals are the green “leaves” that encase the flower before it blooms. All of the sepals form the calyx at the base of the flower. All of the petals of the flower make up the corolla.

146. Parts of the Flower The anther and the filament make up the stamen = male parts of the flower. The anther produces the sperm which is encased in the pollen for transport to the female flower parts.

147. Parts of the Flower The stigma, style and ovary make up the pistil = female flower parts. The stigma is where the pollen attaches; the style is the structure the pollen tube must grow through to reach the ovary which produces the egg. When the egg is fertilized it creates the seed and the ovary becomes the fruit to protect the seeds.

148. Fertilization of a Flower

149. Self – Pollination of Flowers Pollen is transferred from the anther to the stigma on the same plant. This is not ideal because the inbreeding limits them genetically. There are three common advantages: 1.A species may be particularly adapted to an environment. Self-pollination helps keep this trait. 2.Self-pollinating plants are not dependent on pollination agents. 3.Self-pollination is an advantage when the number of individuals is small or widely spaced.

150. Cross Pollination of Flowers This process is by which a flower is fertilized by the pollen from another plant of the same species. The advantages of cross-pollination are genetic in nature. This creates genetic diversity in the plant population and reduces inbreeding. Mechanisms of cross pollination are insects, wind, chemical suppressants, separate male and female flowers or plants, animals and genetic incompatibility

151. Types of Fruit 1.Simple Fruit – Fruit that develops from a single ovary.

152. 2. Aggregate Fruit Fruit is produced from a single flower that has many ovaries.

153. 3. Multiple Fruit Simple fruits of many flowers fuse together. A – Jackfruit B – Pineapple C - Breadfruit

154. Assignment Read pages 208-209 Answer questions 1-7 page 209.

155. THE MALE & FEMALE REPRODUCTIVE SYSTEMS Pages 214-218

156. Male Reproductive system includes: Gonads (testes) Ducts Accessory glands and organs External genitalia

157. Males and Females Males – Testes produce sperm Expelled from body in semen during ejaculation Females – Ovaries produce oocytes (eggs) Immature ovum – Travels along uterine tube toward uterus Vagina connects uterus with exterior of body

158. Male Reproductive System Pathway of sperm – Epididymus – Vas deferens – Ejaculatory duct Accessory organs – Seminal vesicles – Prostate gland – Bulbourethral (Cowper’s) glands – Scrotal sac encloses testes – Penis

159. Male Reproductive System Figure 28.1

160. Figure 28.3 Male Reproductive System in Anterior View

161. Sperm production occurs in seminiferous tubules – Seminiferous tubules are lined with reproductive cells that produce the sperm. – Normal cells contain 46 chromosomes (23 pairs) – Sperm cells contain only 23 chromosomes. – This allows for the zygote that is produced when the egg is fertilized to have a total of 46 chromosomes. – The tubules also secrete sex hormones. Testosterone Sperm production

162. Each sperm has: – Head Nucleus and densely packed chromosomes – Middle piece Mitochondria that produce the energy needed to move the tail – Tail The only flagellum in the human body Anatomy of Sperm

163. Figure 28.8 Sperm Structure and Development

164. Testes produce mature sperm. Sperm enters the epididymus from the testes. The epididymus: – Monitors and adjusts fluid in seminiferous tubules – Stores and protects sperm – Sperm mature here after production in the testes. Male Reproductive Tract

165. Male Reproductive System Figure 28.1

166. It is a tube that carries the sperm from the epididymus to the ejaculatory duct The ejaculatory duct empties into the urethra. Vas deferens

167. Male Reproductive System Figure 28.1

168. Seminal vesicles – Active secretory gland – Contributes ~60% total volume of semen – Secretions contain fructose (sugar), hormones, fibrinogen Accessory glands

169. Prostate gland – Secretes slightly acidic prostate fluid Bulbourethral (Cowper’s) glands – Secrete alkaline mucus with lubricating properties Accessory glands

170. Typical ejaculate = 2-5 ml fluid – Contains between 20 – 100 million sperm per ml Seminal fluid – A distinct glandular secretion that contains nutrients and ions. Contents of Semen

171. Male external genitalia consist of the scrotum and the penis Scrotum – Function is to keep the testicles at a point slightly lower than body temperature. – This is necessary for production of sperm. External genitalia

172. Figure 28.11 The Penis

173. The Female Reproductive System

174. Principle organs of the female reproductive system Ovaries Uterine tubes Uterus Vagina

175. Figure 28.13 Female Reproductive System

176. Organ that produces the oocytes (eggs). The eggs are produced in small groups of cells called follicles. The follicles contain 2 types of cells: – Reproductive cell – produces the egg – Nutrient producing cell – provide energy-rich chemicals to the developing egg. The ovary has a finite number of follicles that gradually declines over time and stops producing eggs at menopause. The Ovaries

177. Ovulation Release of the egg from the follicle is called ovulation. After ovulation, the nutrient cells transform into a structure called the corpus luteum. The corpus luteum secretes hormones essential for pregnancy. If fertilization and pregnancy does not occur, the corpus luteum degenerates and allows for another ovulation cycle.

178. Figure 28.14a, b Ovaries, Uterine Tube and Uterus

179. Uterine tubes (Fallopian tubes or oviducts) Each uterine tube opens directly into uterine cavity Fertilization occurs in uterine tube – 12-24 hours after ovulation – During passage from ovary to uterus The Uterine tubes

180. Figure 28.18c The Female Reproductive System

181. Major functions – Passageway for elimination of menstrual fluids – Receives the penis during sexual intercourse – Forms the bottom portion of the birth canal External Genetalia - Vulva The Vagina

182. Female Hormones Follicle stimulating hormone (FSH) and Luteinizing hormone (LH) are released by the pituitary gland in the brain at puberty. These hormones stimulate the changes that take place in the female body at puberty. Both internal and external reproductive organs mature and the development of follicles begin.

183. Estrogen FSH triggers the development of follicle cells in the ovary. As the follicles develop, estrogen is released into the blood which triggers the endometrium to thicken and prepare for the zygote (fertilized egg).

184. Progesterone Once the follicle cells begin to develop, LH is released into the blood. LH causes ovulation and the formation of the corpus luteum. The corpus luteum secretes estrogen and progesterone. Progesterone continues to stimulate the development of the endometrium and prepares the uterus for the zygote. If there is no pregnancy, the corpus luteum breaks down, no estrogen or progesterone is produced and menstruation starts.

187. Read pages 214 – 218. Answer questions 1-6 page 215. and 1-7 page 218. Assignment

188. Ch. 8 Zygotes and Development

189. Survival and development of organisms Key strategies for survival of offspring Some organisms produce a zygote that remains in suspended animation and does not develop until conditions are favorable. Some organisms wrap their developing zygote (called an embryo) in a food package that supports the development of the embryo.

190. Survival and development of organisms In some organisms the embryo develops within the adult where it is protected from the environment. The adults of some organisms nourish and protect their young after birth.

191. Spores A spore is a reproductive body encased within a protective shell. If conditions are unfavorable the spores can lie dormant for long periods of time until conditions are favorable for growth. The shell is often resistant to drying out, heat, boiling and radiation. When conditions are favorable the spores germinate and a new organism grows. Spores are often dispersed by the wind or water.

192. Seeds Seeds contain the plant embryo along with a food source for the developing embryo. Unlike spores, seeds do not have to wait until conditions are favorable, they have a head start on development with the food source in the seed. Needle producing trees produce exposed seeds on the scales of a cone. These seeds are described as naked seeds. Flowering plant seeds are enclosed and protected inside a fruit.

194. radicle epicotyl

195. Eggs The vast majority of animals lay eggs. An egg includes a zygote, a food source and some mechanism for protection. Some organisms fertilize their eggs internally (birds, insects, etc.) before the tough shell is secreted. This is called internal fertilization. Other animals, usually aquatic animals (fish, frogs, etc.) fertilize their eggs outside of the female body after they are laid. This is called external fertilization.

196. Eggs There are 2 strategies for survival of a species that lay eggs. 1.Produce thousands of eggs in the hope that a few will hatch and survive to adulthood. Eg. _________________. 2.Produce a few eggs and care for the young or the young are well developed for survival when they hatch. Eg. _______________

197. The Amniotic Egg This is the main adaptation that allowed animals to successfully colonize land and not be reliant on water for reproduction. The egg provides a self contained environment for the developing embryo. It provides protection, food, and a moist environment for development.

198. Parts of the Egg Albumen (egg white): Its primary purpose is to protect the egg yolk and provide additional nutrition for the growth of the embryo. It contains many proteins. Air space: Gives air for the embryo to breathe just prior to hatching. Chorion: Membrane that surrounds the embryo and yolk sac. Amnion: Fluid filled sac that cushions the embryo. Yolk Sac: Contains stored food for the embryo. Allantois: Holds wastes produced by the embryo.

199. – The spiny anteater (Echidna) and the duckbilled platypus are unique mammals that lay eggs. – Mammary glands but no nipples – Live in Australia

201. Marsupial Mammals Pouched mammals Give birth very early and the young animal climbs from the mother's birth canal to the pouch. The young embryo attaches to a nipple and finishes development in the pouch. Very common in Australia and the surrounding islands. The only marsupial outside of Australia is the American Opossum.

205. Placental Mammals Diverse group, with nearly 4000 described species in 15 different orders mostly rodents and bats. All bear live young, which are nourished before birth in the mother's uterus through a specialized embryonic organ attached to the uterus wall, the placenta. The gestation (pregnancy) period varies from 16 days for a hamster to 624 days for an Indian Elephant The embryo is nourished from the blood of the mother. Offspring in placental mammals often develop slower and require greater long term care. The mother provides the young with milk and protects them from danger.

206. Assignment Read pages 232 – 235. Answer understanding concepts questions 1-4 on page 235.

209. Human Conception and Pregnancy The process by which a sperm fertilizes the egg is called conception. This is when the head of the sperm penetrates the wall of the egg. Only one sperm will fertilize the egg. The chromosomes from the egg will combine with the chromosomes of the egg to form a zygote.

210. Within hours of fertilization the fertilized egg begins to move from the oviduct to the uterus. This is about a 4 day trip. As it moves it undergoes mitosis. When it reaches about the 100 cell size (about 1 week), it is called an embryo and attaches to the uterine wall. The uterine wall then transforms and forms the placenta around the embryo. The placenta allows for movement of oxygen, nutrients and wastes between the embryo and the mother without their blood mixing. Human Conception and Pregnancy

212. After about 3 months, the placenta begins to produce progesterone and estrogen. High levels of progesterone first from the corpus luteum and later from the placenta prevent further ovulation. This means that once a woman is pregnant she can not conceive again until after birth. Human Conception and Pregnancy

213. The Human Embryo After the embryo implants into the endometrium of the uterus it grows rapidly. A membrane called the amnion develops into a fluid filled sac that protects the embryo from infection, dehydration, impacts and temperature changes. The umbilical cord also develops which connects the embryo to the placenta. Human pregnancy can be divided into three parts called trimesters, or 3 month stages.

214. The first trimester This period begins with fertilization to the end of the third month. By the end of the first month, the heart has formed, parts of the brain, limb buds with fingers and toes are visible. A tail and gill arches, characteristics of all vertebrates can be seen. By the end of the second month, the cartilage of the skeleton begins to be replaced by bone and the embryo is now called a fetus.

215. By the end of the third month, most of the body parts have formed, facial features continue to develop, arms and legs begin to move and the fetus enters into a growth phase. The fetus also has developed a sucking reflex which it uses to nurse when it is born. The first trimester

216. Five-Week-Old Embryo

217. Seven-Week-Old Embryo

218. 9.5-Week-Old Embryo

219. Three-to-Four Month-Old Fetus

220. The second trimester By the second trimester the fetus is about 57 mm long and moves enough to be felt by the mother. All of the organs and facial features are present but not all the organs will be functional. The fetus is covered entirely by soft hair like all mammals. Early in the fourth month, the fetus begins to swallow amniotic fluid and hiccup

221. In the fifth month it may start to suck its thumb. By the sixth month, eyelids and eyelashes form and almost all of the cartilage in the skeleton has turned to bone. A fetus born prematurely at the end of the sixth month has a chance to survive. The second trimester

222. 5 month old fetus

223. Six-Month-Old-Fetus

224. The third trimester The fetus grows very rapidly in the final 3 months. Organ systems begin to function properly. The only thing left for the fetus is to gain body mass. Toward the end of the ninth month, the baby turns head facing down to prepare for birth.

225. The Birth Process Prior to labour, the hormone relaxin is produced by the placenta which causes the ligaments of the pelvis to loosen and provide a more flexible passageway for birth. Onset of labour – Uterine muscles begin to make rhythmic contractions – Contractions gradually become stronger and closer together. Oxytocin is a hormone secreted by the pituitary gland that causes strong uterine contractions

226. The Birth Process Dilation of cervix allow the head of the fetus to pass through Uterine contractions causes amnion to break and amniotic fluid to escape out of the vagina Muscular contractions push the fetus head first through the vagina, and the umbilical cord is cut and tied Further contractions push the placenta out of the body “After birth” “After birth”

227. Hormones and Lactation Lactation is the process by which a mother produces milk. Through out pregnancy, the breasts of the mother have been enlarging and preparing for lactation. At birth, the mother’s pituitary gland in the brain secretes the hormone prolactin which stimulates the glands in the breasts to produce milk. The first milk that the mother produces is called colostrum. It gives the baby protection from disease early in its life and provides a large amount of sugar.

228. Milk production is stimulated by the baby’s sucking action and the removal of milk. Prolactin and oxytocin are involved in lactation, and may prevent the mother from ovulating while breastfeeding. (Fig. 4 pg. 255) Human milk is high in fat and sugar. About twice the amount found in cow’s milk. The world average for breast feeding is 4-5 years. The North American average is about 6-9 months when the baby develops teeth. Hormones and Lactation

230. Assignment Read pages 242- 243, 250-251, 254- 255. Omit pages 244-249 & 252-253. Answer questions 1-3 on page 243,ques. 1-6 page 251 and ques.1-4 on page 255.