GCE BIOLOGY BY2 Reproductive Strategies GCE BIOLOGY BY2 Reproductive Strategies

GCE BIOLOGY BY2 Reproductive Strategies Which Came First? ChickenEgg The Chicken?The Egg? Place your vote by clicking the ‘Chicken’ or ‘Egg’ button Be prepared to justify your choice Which came first? OR

GCE BIOLOGY BY2 Reproductive Strategies Reproduction What type of reproduction does this animation represent? Hint: Mitosis is involved. Identical offspring to the parent is produced. Simple unicellular organism Next: What type of reproduction?

GCE BIOLOGY BY2 Reproductive Strategies Sexual Occurs when unicellular organisms, such as amoeba reproduce Produces offspring showing variation from the parent Only involves mitosis Involves the production of haploid gametes (n) (sex cells with one copy of each of the parents’ chromosomes) What Type of Reproduction? Drag the corresponding numbers to the appropriate circle to determine if the statement relates to sexual or asexual reproduction: Asexual

GCE BIOLOGY BY2 Reproductive Strategies Outline of Mitosis Diploid parental cell (2n) Duplication of a Chromosome is Followed by nuclear division Diploid daughter cells (2n) Next: Outline of meiosis

GCE BIOLOGY BY2 Reproductive Strategies Outline of Meiosis maternal chromosome paternal chromosome Diploid parent cell (2n) Each chromosome duplicates to form two Pairs of chromatids 2 chromatids centromere Meiosis I Meiosis II Haploid gametes (n) Next: Comparison of mitosis and meiosis

GCE BIOLOGY BY2 Reproductive Strategies Comparison of Mitosis and Meiosis Diploid parental cell 2n First division Diploid daughter cells 2n Haploid gametes nnnn 1st meiotic division (meiosis I) 2nd meiotic division (meiosis I)

GCE BIOLOGY BY2 Reproductive Strategies The Human Life Cycle 2n meiosis mitosis 2n zygote 2n fertilisation n n This is an example of a diploid life cycle

GCE BIOLOGY BY2 Reproductive Strategies The Human Life Cycle Drag the labels provided to create the Human life cycle Human fertilisation sex organs zygote gametes adult

GCE BIOLOGY BY2 Reproductive Strategies Plant Reproduction sporophyte spores gametophyte mitosisfertilisation zygote male gamete female gamete diploid haploid mitosis

GCE BIOLOGY BY2 Reproductive Strategies Reproduction Task: Compare the life cycle shown below.

GCE BIOLOGY BY2 Reproductive Strategies Fertilisation Human Fish Compare fertilisation in a fish and humans A strong possibility that many of the eggs will not encounter sperm A lot of waste with both sexes producing a large number of gametes Fertilisation happens inside the body An intromittent organ required to transfer sperm into the female’s body

GCE BIOLOGY BY2 Reproductive Strategies The Life Cycle of a Fish Fish eggs spawning Larval fish fry juvenile adult

GCE BIOLOGY BY2 Reproductive Strategies Metamorphosis: Frog Drag the images provided to create the life cycle of a frog The Frog

GCE BIOLOGY BY2 Reproductive Strategies The Insect Life Cycle Many insects change form during their lifetime - this is called metamorphosis. They do this in one of two ways: a) Complete metamorphosisb) Incomplete metamorphosis Click on the images above for a larger version of the life cycles Next: The fly life cycle

GCE BIOLOGY BY2 Reproductive Strategies The Insect Life Cycle The Butterfly eggspupa larva butterfly (adult) NextBack

GCE BIOLOGY BY2 Reproductive Strategies The Insect Life Cycle The locust eggs nymph (showing rudiment of wings) locust (adult) instars (showing first wings) Back

GCE BIOLOGY BY2 Reproductive Strategies The Insect Life Cycle The Fly Eggs 1st larval stage 2nd larval stage 3rd larval stage Pupa Adult Fly

GCE BIOLOGY BY2 Reproductive Strategies Metamorphosis metamorphosis insect Choose an insect and drag it to the ‘insect’ box below. Decide what type of metamorphosis it has, then complete its life cycle by dragging the appropriate labels into the correct position on the diagram: complete metamorphosis incomplete metamorphosis egg larva nymph pupa chrysalis adult