1. Unit 13: Reproduction Ch. 23, 24, 25 Why do organisms reproduce? –to pass on genetic code & continue the species 200

2. What are the 2 Main Types of Reproduction? asexual –H–How many parents? 1 –I–In general, what happens to genetic material during asexual reproduction? genetic material is copied & cell(s) divide(s) –H–How do offspring compare genetically to each other & parent? identical

3. sexual –How many parents? 2 –In general, what happens to genetic material during sexual reproduction? genetic material combined when gametes (formed by meiosis) fuse during fertilization –How do offspring compare genetically to each other & parent? different –How does sexual reproduction speed up evolution? –increases genetic variety b/c mixing genes

4. Examples of Asexual Reproduction 1. What is binary fission? –DNA copied & organism divides in 2 Ex. of organisms that reproduce by binary fission? –bacteria –protists How is binary fission in protists different from in bacteria? Why? –protists undergo mitosis b/c eukaryotic (bacteria don’t b/c prokaryotic) Describe the offspring in relation to the parent.

5. 2.What is budding? –Offspring (bud) begins to develop on the parent’s body & then breaks off Ex. of organisms that reproduce by budding? –yeast –Hydra Examples of Asexual Reproduction Describe the offspring in relation to the parent.

6. 3. What is vegetative propagation? –Essentially budding… in plants Sends out runner/creeper… once rooted, separates from original plant & grows independently Ex. of organisms that reproduce by vegetative propagation? –strawberries –potatoes Examples of Asexual Reproduction tuber runners (creepers)

7. creeper

8. 4. What is fragmentation? –fragment (piece) grows into whole new organism Ex. of organisms that reproduce by fragmentation? –spongessponges –sea stars 1 leg  new organism Examples of Asexual Reproduction 1 leg growing whole new organism

9. 5. What is regeneration? –regrowth of missing body parts Ex. of organisms that reproduce by regeneration? –Planaria (flat worm) –sea stars leg cut off  grows new leg –salamander What process allows regeneration to occur? –mitosis Examples of Asexual Reproduction 1 leg growing back

10. 6. What is sporulation? –reproduction through spores which contain DNA, cytoplasm, & tough outer wall (coat) Ex. of organisms that reproduce by spores? –mushrooms –mold –mosses –ferns Examples of Asexual Reproduction fern sori What do you think the coat does? Why might some organisms produce a large number of spores?

11. Examples of Asexual Reproduction 7. What is parthenogenesis? –unfertilized egg develops into adult (drone) Ex. of organisms that reproduce by parthenogenesis? –Daphnia –aphids –honey bees

12. Sexual reproduction in plants… –What is alternation of generations? Some plants switch between a diploid (2n) sporophyte generation & a haploid (n) gametophyte generation We’re just going to focus mostly on the sporophyte generation… flowers…. Sexual Reproduction in Plants

14. The flower is the plant’s reproductive organ. Sexual Reproduction in Flowering Plants (pistil)

15. The flower is a plant’s reproductive organ. (pistil)

16. What are the female parts of a flower? –carpel (pistil) stigma –sticky tip to trap pollen style –long & narrow »sperm travels through ovary –swollen base that contains the ovules »ovules produce eggs Sexual Reproduction in Flowering Plants

17. What are the male parts of a flower? –stamen anther –produces pollen »contains sperm filament –“stalk” that supports anther Sexual Reproduction in Flowering Plants

18. What parts of the flower are neither female nor male? –sepals protect young flower bud –leaf-like structures at flower’s base »usually green (can be same color as petals) –petals attract pollinators –located in/above the sepals »can be large & colorful »can be scented »can produce nectar Sexual Reproduction in Flowering Plants

19. Let’s see if you got that… Sexual Reproduction in Flowering Plants What are 3 & 4 together called? What are 5, 6, & 7 together called? 8

20. Most flowers have both male & female parts. –What type(s) of pollination can they undergo? self- or cross-pollination Some flowers are only male or female. –What type(s) of pollination can they undergo? cross-pollination –Why is this beneficial? increases genetic variety Sexual Reproduction in Flowering Plants What is pollination? –transfer of pollen from anther to stigma

21. How many nuclei are in pollen? –3 nuclei 1 tube nucleus (forms pollen tube) 2 sperm nuclei How many nuclei are in an ovule? –3 nuclei 2 polar nuclei (become food/endosperm) 1 egg (becomes embryo) Sexual Reproduction in Flowering Plants

22. What is double fertilization? –1 sperm nucleus fertilizes egg & forms zygote (embryo) –1 sperm nucleus fertilizes the 2 polar nuclei & forms endosperm (food for embryo) Sexual Reproduction in Flowering Plants

23. 1. Pollen from anther lands on the stigma. Tube nucleus moves through style forming a pollen tube to the ovule. 2. Two sperm nuclei travel through the pollen tube made in the style to ovule. 3. In ovule: One sperm nucleus fertilizes the egg to form a zygote that develops into the embryo. One sperm nucleus fertilizes 2 polar nuclei to form endosperm/food for the embryo. Path of pollen to egg

24. What happens after fertilization in flowering plants? –ovule matures into seed seed contains embryo & food –ripened ovary becomes the fruitripened ovary becomes the fruit Seed coat embryo Sexual Reproduction in Flowering Plants

25. Sexual reproduction in animals… –no alternation of generations –gametes produced in ovaries & testes –can have external fertilization (spawning) or internal fertilization –can have external development or internal development Sexual Reproduction in Animals

26. What is external fertilization? –fertilization occurs in aquatic environment (not in mother) Why in water? –so sperm can swim to egg –How many gametes are produced & released? large #s –Why? »chances of fertilization & survival low, but increased by synchronized release of gametes (ensured by mating behaviors) Sexual Reproduction in Animals Do animals that use external fertilization exhibit parental care?

27. What is internal fertilization? –fertilization takes place inside mother How is internal fertilization an adaptation to life on land? –moist, protective environment –How many gametes are produced & released? male  many, female  few –Why is it better than external fertilization? »chances of fertilization & survival are higher b/c sperm only exposed for short time Sexual Reproduction in Animals

28. Sexual reproduction in humans… Sexual Reproduction in Animals

29. *Accessory glands seminal vesicle, prostate, bulbourethral (Cowper’s) gland penis Male Reproductive System Anatomy—Side View

30. 1. Sperm cells are produced by the testes in the seminiferous tubules. 2. Sperm are stored in the epididymis (& mature). 3. Sperm pass through the vas deferens. 4. Accessory glands along the vas deferens add seminal fluids (water, buffers, & nutrients) to sperm. –combo of sperm & fluid together is called semen 5. Semen passes through the urethra –& out of the penis during ejaculation Male Reproductive System Anatomy: What Path Does Sperm Follow from Production to Ejaculation? ***Sperm do NOT pass through accessory glands!!!

31. Let’s Review G A B C D E F

32. Male Reproductive System Anatomy— Front View

33. Let’s Review A B C F E D G

34. Structure of Male Sperm

35. Female Reproductive System Anatomy— Side View (fallopian tube)

36. What path does sperm follow until fertilization occurs? 1.sperm enters vagina 2.passes through cervix 3.enters uterus 4.travels into oviduct (fallopian tube) where fertilization normally occurs What happens after egg is fertilized in the oviduct (f.t.)? 1.fertilized egg (zygote) travels to uterus 2.implants in lining of uterine wall (endometrium) Where does the development of the embryo/fetus occur? 1.normally occurs in uterus Female Reproductive System Anatomy: What Path Does Sperm Follow Until Fertilization Occurs? Where Does Fertilization Occur? Where Does the Development of the Embryo/Fetus Occur?

37. Let’s Review Female Reproductive System Anatomy—Side View A B C D (oval object in back) E

38. (fallopian tube) Female Reproductive System Anatomy—Front View

39. Where does: fertilization take place? implantation take place? the fetus develop? Female Reproductive System Anatomy— Front View What is the pathway that sperm follows prior to fertilization? A B C D E

40. Formation of Eggs Where do eggs form? –In follicles in the ovaries. What is ovulation? –the release of an egg from follicle

41. What controls the menstrual cycle? –hormones What is the role of the menstrual cycle? –prepares uterus for possible pregnancy How often does the menstrual cycle occur? –usually monthly (~28 days) What are the 4 phases of the menstrual cycle? 1.thickening of uterine lining 2.ovulation egg matures & is released 3.passage of egg into uterus (if not fertilized) ~day 14 4.loss of unfertilized egg & lining (menstruation) Human Menstrual Cycle

42. Fertilization The Miracle Begins What is the pathway that sperm follows prior to fertilization?

43. Fertilization & Development

44. (below) Embryo & Fetal Development Animation Developmental Timeline

46. Labor & Delivery The big day! –3 stages 1.dilation of cervix 2.delivery of newborn –contractions of uterus push baby out head first 3.delivery of placenta –also by contractions of uterus

47. Comparing Asexual vs. Sexual Reproduction AsexualSexual # of parents gametes produced? genetic variety? time needed to produce offspring rate of population growth Domains/Kingdoms 1 Fast No Short No All 2 Slow Yes Long Yes All

48. Asexual Reproduction Sexual Reproduction vs. 2 parents  increases genetic variation long generation times  small # of offspring & pop. grows slowly parents often care for offspring  low death rate survival of individuals “fit” for environment more difficult, slow long generation times  small # of offspring & pop. grows slowly requires a lot of energy to find mate & carryout parental care of offspring requires a lot of energy easy, fast short generation times  can produce large # of offspring & pop. grows quickly requires little energy well adapted individuals spread quickly offspring are genetically identical to parent  no variation no parental care of offspring  high death rate poorly adapted individuals die easily