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REPRODUCTIVE ADAPTATTIONS

REPRODUCTIVE ADAPTATTIONS. WEEK 8. OBJECTIVES. extend your knowledge of the variety of reproductive strategies in animals and plants develop understanding of how various strategies assist successful reproduction in particular environments. LIFE CYCLES. DO YOU REMEMBER THESE TERMS?.

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REPRODUCTIVE ADAPTATTIONS

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  1. REPRODUCTIVE ADAPTATTIONS WEEK 8

  2. OBJECTIVES • extend your knowledge of the variety of reproductive strategies in animals and plants • develop understanding of how various strategies assist successful reproduction in particular environments.

  3. LIFE CYCLES DO YOU REMEMBER THESE TERMS? WHAT DOES THIS MEAN??? • Sequence of stages in the growth and development of sexually reproducing organisms; that is fertilisation alternating with meiosis. • This is an alternation of diploid and haploid stages known as the alternation of generations WHAT DOES THS INVOVE?

  4. DEVELOPMENT What is the purpose of the yolk??? • Indirect Development • Association between small amounts of yolk in the egg • Brief embryonic development so it can feed • Metamorphosis into their adult form • Direct Development • Large amounts of yolk in egg • Embryos develop for several weeks • Hatch in an essentially adult form Can you think of animals that under go indirect development???

  5. REPRODUCTIVE STRATEGIES • Sexual/Asexual • Gender • Separate genders, hermaphrodite, parthenogenesis • Mode of fertilisation • External, internal. • Mating system • Monogamy, polygamy, promiscuity. • Offspring • r/K selected. • Embryo development • Oviparity, viviparity. • Parental care • Nil, solo parent, both parents, family.

  6. Types of Reproduction CAN YOU REMEMBER WHAT THESE ARE? • Sexual • Combination of genetic material from two different organisms to create a new one • Asexual • Offspring arises from a single parent inheriting identical genetic material What are some advantages and disadvantages of these?

  7. Gender • Separate Genders • Sexes exist as separate male and female • Hermaphrodite • Ability to produce both eggs and sperm • Parthenogenesis • form of asexual reproduction where growth and development of embryos occur without fertilization

  8. Mode of fertilisation • When the sperm successfully penetrates the egg and the chemical interaction that occurs afterwards. • External • Occurs in aquatic species, as water is abundant and gametes are not subject to dehydration • chances of dispersal are high and many may not become fertilised • Internal • Occurs in terrestrial animals and ensures that: • Gametes and fertilised eggs are provided with a moist environment, removing the risk of dehydration • Zygote is also protected from environmental factors such as predation

  9. Mating Systems • Monogamy: single pair mating • one male mates with one female for or one or more breeding seasons or for life • seen in species where the survival of the young requires the care of both parents for tasks • Polygamy: multiple mating of individuals • When one male has multiple female partners during a breeding season, the situation is called polygyny • When one female has multiple male partners during a breeding season, the situation is termed polyandry • Harem Polygamy: one dominant male lives with many females • Serial Polygamy: male attracts many passing females • Promiscuity: • males and females within a social group engage in multiple and indiscriminate mating

  10. Number of Offspring • r-selection: the ‘quick-and-many’ strategy • produced in larger numbers but they have higher mortality rates so that few survive to adulthood • may put little or no parental care into their offspring • K-selection: the ‘slower-and-fewer’ strategy • mature slowly, breed later, produce fewer and larger offspring and may put extensive parental care into their offspring.

  11. Embryo Development • Oviparity: egg laying • eggs are released by the mother so that embryos develop outside the mother’s body with nutrients for the embryo coming from the egg yolk; • Viviparity: giving birth to live young • the eggs and embryos are protected within the female’s body and offspring are live-born • embryos are usually nourished by egg yolk or placenta.

  12. Parental Care • Nil • Offspring left the their own devices • Solo parent • One parents looks after young • Both parents • Both parents look after young • Family • Many siblings are brought up by parent/parents Attenborough: Grey kangaroo giving birth

  13. Patterns and times of breeding • Mating usually occurs just before fertilisation because sperm do not survive for long. • However, some animals can store sperm for a long period of time – honeybees. • Breeding season – when mature members have eggs and sperm ready for release. • This is called the spawning season for animals that live in an aquatic environment and have external fertilisation. • Called the mating season for animals with internal fertilisation.

  14. Oestrous Cycle • Time between release of eggs. • Humans = 28 days • Cows and horses = 21 days • Mice and rats = 4-6 days • Wolves, foxes, bears = one per year • Deer, sheep, goats = several in a short time period (autumn). • Hamsters and horses = several in a short time period (spring). Why?

  15. ACITIVITY • Fill in the table • Description of the terms • Move around room and find at least one example of an animal for each different strategy listed

  16. INTERESTING REPRODUCTIVE BEHVAVIOURS

  17. Most gigantic sperm: Drosophila bifurea • This fruit fly is only 3mm long from the top of its head to the end of its abdomen, yet it produces sperm that are 58mm long. If a human male made a sperm on a similar scale they would be as long as a Blue Whale

  18. Attenborough: saltwater crocodile American Alligator • The male American Alligator looks tough with his rough skin and jagged teeth. Really he’s more like a reptilian Casanova, stroking the female, rumbling gently and even blowing bubbles against her cheek. Their courtship is slow and quiet.

  19. Banana Slug • Like people, Banana slugs like cuddling under a blanket. Their blanket is not a cosy quilt, it’s made out of slime! They have been known to inter twine in their slime blanket for several hours.

  20. Hanging Fly • Male Hanging Flies give a gift that’s better than jewellery – the corpse of a dead insect! During the height of the mating season, females no longer bother to catch their own prey, they get free handouts instead.

  21. False Map Turtles • A False Map Turtle views his mate as both bongo drum and lover. Before mating, the smaller male swims above the female, faces her and drums her snout with his long toenails and fore claws. They also include head bobbing, butting and biting.

  22. Mantids • The female mantid takes the act of nibbling on her mates head to a whole new level. To her, a mate is simply a piece of food!

  23. Western Diamondback Rattlesnake • Sex is an all – day event for this poisonous snake. It might last for up to 25 hours and they can intertwine many couples. They also have a bizarre penis. It has two heads and contains hooks and spurs that engage when it is enlarged!

  24. Moose • Moose go through a lot of trouble to mate, travelling great distances, marking a territory and fighting for their lovers. When it is time to mate, it is over in about 5 seconds, roughly how long it takes to tie a shoelace!

  25. Northern Goshawks • Birds, unlike mammals, have no external sex organs. They simply keep them tucked away until they are needed and that can be quite often. These birds have been known to mate for up to 10 times a day for the six to eight week breeding period.

  26. Panda • Each spring, barks, bleats and roars resonate through China’s bamboo forests as Panda males call for mates. Once a female finds a mate, she crouches on the ground with her head tightly tucked in and her rear raised in a “come and get me pose”.

  27. Most Explosive Lover: Male Honeybee • When the male Honeybee ejaculates, he explodes and his genitals tear from his body with an audible snap. His body falls the ground, but his genitals remain inside the female – preventing her from mating again.

  28. Worst Dad: Japanese Cardinal Fish • Contenders for the worst parent are many, however, the champion must be the Japanese Cardinal Fish. All child care is done by the male, who looks after the babies in his mouth. If however, he sees a better looking mate, he quickly eats his babies and tries to seduce her.

  29. VIDEOS • Elephant mating, reproduction + pregnancy • Golden Frog: Fighting & Mating • Lemon Shark Gives Birth • Embryonic cannibalism • Attenborough: Anaconda giving birth • Attenborough: Coral Spawning • Demersal eggs: Finding Nemo

  30. PLANTS BRAINSTORM: What are some adaptations that plants have that help with reproduction??? WHATS GOING ON IN THE FOLLOWING PICTURES?

  31. Pansies with yellow and blue patterns, UV reflective markings.

  32. Greenhood orchid lures gnat with female scent and then traps it until it is covered with pollen.

  33. Bird pollinating plants that have tubular flowers.

  34. Video clips • Attenborough: orchids and wasps • Attenborough: hoverfly pollinators • Attenborough: Amorphophallustitanum

  35. Seeds within fruit

  36. Wind dispersal of seeds. Attenborough: dandelions

  37. External and internal hitchhikers Attenborough: burdock Attenborough: bird cage plant

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