1 Unit 14 - Reproduction How organisms make more of themselves

2 What is Reproduction? Definition - the life process by which living things produce other living things of the same kind - this is done so that the organism’s “genes” (DNA) are passed on

3 Two Types of Reproduction

4 Asexual Reproduction Binary fission - equal division of nuclear materials & cytoplasm resulting in 2 new organisms Ex. paramecium, amoeba, bacteria

5 Asexual Reproduction Budding - unequal division of cytoplasm Ex. yeast, hydra

6 Asexual Reproduction Sporulation - reproductive cells called spores develop into new individuals Ex. Bread mold, mushrooms

7 Asexual Reproduction Regeneration - the development of an entire new organism from part of the original organism Ex. starfish

For SEXUAL Reproduction… Both a male and female are needed Each system will make sex cells that will join together 8

9 Female Reproductive System oviduct (fallopian tube) uterus Ovary (female gonad) -tube that connects ovaries to uterus; place of fertilization -where embryonic development takes place -Stores the eggs and releases them

10 Female Reproductive System cervix vagina Egg (female gamete) -lower end of uterus -receives sperm; opening to outside; birth canal -produced in the ovaries; is fertilized & develops into the embryo

11 Female Reproductive System

12 The Female Reproductive System Females go through “menstruation” when the egg released by the ovary is not fertilized The menstrual cycle happens each month (approx. every 28 days) If an egg is not fertilized, it is flushed out with the uterine lining and a new lining is grown

13 Female Reproductive System Menstrual Cycle Day 1-4 Day 5-13 Day 14 Day Start over Menstruation; shedding of the uterus (period) Build up of the uterus (new lining) Ovulation - egg released from ovary Continual build up of the uterus Shedding of lining; menstruation

14 Female Reproductive System

15 Male Reproductive System penis scrotum urethra vas deferens -sex organ that allows for internal fertilization -Sac that protects the testes -tube that passes sperm & urine to outside -Tubes that carry sperm from the testes to urethra

16 Male Reproductive System Testes (male gonad) seminal vesicles bladder -make sperm; produce testosterone -produces seminal fluid -holds the urine

17 Male Reproductive System prostate Epididymis Sperm (male gamete) -produces fluids for semen -location where sperm form in the testes -Male sex cell containing male’s DNA

18 Male Reproductive System

19 Now… Sexual Reproduction Gametogenesis - Definition: the development of mature sex cells called gametes - male gamete = sperm - female gamete = egg *Sex cells are made in the gonads of an organism - male gonad = testes - female gonad = ovaries

20 Sexual Reproduction Gametogenesis cont… - testes make sperm; sperm swim in a liquid called semen - sperm can move - sperm are small in size

21 Sexual Reproduction Gametogenesis cont… - ovaries make eggs; the egg is fertilized by the sperm - eggs cannot move - the egg is larger than the sperm

22 Review: Meiosis Meiosis is the cell process where a diploid (2N-46 chromosomes) cell divides its contents in half so that two new monoploid (1N- 23 chromosomes) cells are created Cells have 1/2 the original #

23 Sexual Reproduction Fertilization - Definition: the joining of the egg and sperm - two monoploid (1N or 23 chromosome) cells join to form a diploid (2N or 46 chromosome) zygote - Two types of fertilization: external (outside female body) and internal (inside female body) zygote: fertilized egg

24 Sexual Reproduction Fertilization cont… - External fertilization - egg and sperm meet each other outside of the female - disadvantage: easily eaten - fertilization takes place in water, on a leaf, etc. - offspring number: many!! Ex. Fish, frogs

25 Sexual Reproduction Fertilization cont… - Internal fertilization - egg and sperm meet each other inside the female - advantage: protection - fertilization occurs in the oviduct (aka. fallopian tube) - offspring #: few (or less than external fert.) Ex. Humans, mice

26 Sexual Reproduction Internal Development - a zygote divides by “cleavage,” when one cell becomes two, then four, then eight, etc. - this is mitosis - for internal fertilization, the multicellular zygote leaves the oviduct and enters the uterus

27 Sexual Reproduction Internal Development cont… –The embryo (zygote that has left the oviduct) implants itself in the uterine lining –The embryo is fed by the placenta –The embryo develops in the uterus for the period of gestation (pregnancy) –Human gestation: 9 months

28 Sexual Reproduction - Internal Development

29 Sexual Reproduction External development - takes place in water or on land - adaptations for development outside the mother include a shell, membrane, and yolk sac - the yolk sac acts like a placenta; it provides food for the developing embryo

30 Sexual Reproduction - External Development

31 Embryonic Development Vocab. Placenta Umbilical cord Amnion Amnionic fluid -organ that passes materials betw. embryo and mother -Connection between placenta and fetus -Membrane that holds fluid around baby -Surrounds baby & provides protection

32 Embryonic Development Vocab. Fetus (embryo) Yolk sac Allantois chorion -9th week to birth; developing baby -Food source for externally developing embryo -Membrane that stores waste; site of gas exchange -Outer membrane; helps regulate what goes “in” and “out” of egg

33 Reproduction in Flowers Flowers reproduce sexually. The male reproductive organ in flowers is called the stamen. The female reproductive organ in flowers is called the pistil.

34 Reproduction in Flowers Male - “Stamen” - Stamen: male reproductive organ Parts:Anther (round top that produces pollen grains; male gamete ) Filament (stem-like structure that connects to anther)

35 Reproduction in Flowers Female - “Pistil” - Pistil: female reproductive organ in flowers Parts: Stigma (top part of pistil that captures pollen) Style (connects the stigma to the ovary; long stem-like part) Ovary (contains ovules which contain eggs & develop into seeds)

36 Reproduction in Flowers The anther is made of “diploid” cells (normal chromosome #) The anther makes pollen grains that are “monoploid” (1/2 the # of chromosomes) The ovary is made of “diploid” cells The ovary makes eggs which are “monoploid”

37 Reproduction in Flowers

38 Reproduction in Flowers Pollination - transfer of pollen from anther (male) to stigma (female) of plant; accomplished by birds, insects, and wind Self-pollination - transfer of pollen to stigma on the same plant Cross-pollination - transfer of pollen to stigma in a different plant

39 Reproduction in Flowers Fertilization and Development - when the male pollen and the female egg meet inside the ovule, a zygote seed (embryo) develops. 3 parts to the plant embryo: hypocotyl: develops into the roots epicotyl: develops into leaves cotylledons: food source