Angiosperms & Reproductive Development Notes

Achaefructus are extinct and they are the oldest angiosperms known

There is two major classes of angiospeerms

    Edudiots - tress, shrubs

  • pollicated by wind and animals

    Monocots - grasses, grains

  • pollinated wind

Meiosis and mitosis

Ploidy- the # of compelte sets of chromosomes in a cell

haploid- one set

diploid - two sets

Mitosis- chromosomes seperate into two identical sets creating two diploid cells

this creates photocopied cells

Meiosis chromosomes are ‘halved into four sets, clalled daugter cells

one cell replicated and splits into 2 daughtere cells then into 4

Animal life cycle meiosis for sperm and egg 1n)

feretillication happens then mitosis happens to create a diploid 2n

Plant life cycle

mitosis to sperm and egg then fertilizzation occurs leading to growth and delevelopment 2n then meiosis to create an adult plant

Flower morhology

gametophye phase takes placde in the flower

flowers consit of 4 whorls

  • sepals protects reproductive organs

  • petals are often brightly colored to attract pollinators and facilitate the process of fertilization.

  • stamens is the male reproductive organ, consisting of anthers that produce pollen and filaments that support the anthers.

  • Carpels are the female reproducive organ , composed of the ovary, style, and stigma, playing a crucial role in the development of seeds after fertilization.

An incomplete flower lacksone or more whorls

Monoecious plants have seperate female and male flowers on the same plant like black walnut

Dioecious plants have seperate female and male flowers on separate pants

Stamen is the male reproductive structioin with anthers that cotail pllen and filamen which holds the anther

carpel isi the female pricductive struction with stigma where pollen lands and a style which connects the stigma and ovary

ovary develops into a fruit and the ovule develops into a seed

pistaal is the stigma, style and ovary

simple pistil contains a single carpel and a compound pistil consist of several

receptcale is the base of the flower that holds is all and the

pedicel is the stalk

Perefect flowers have the stamens and pstils

imperfect folwers lack one

Emvryo ac develops in the ovule which is wherea diploid is mafe and cell devides by meiosis into 4

Female gametophyte and embryo sac only a megaspores survives and undergoes 3 mitotic division to produce the embryo ac or megagametophyte

Polle grains deveop in the anther

the anther containas 4 pollens sacs 2n

each pollen grain has generative cell and tube cell

the tube cell develops into a pollen tube

Angiosperm life cycle

Mitiosis heppens which pollen goes to pollen tub 1n in the style

then double fertilization occurs and mitotsis happens to create endosperm and embryo 2n)

then germiination happens to create a young sporophyte 2n which will develop into an adult with flower 2n and the cycle continuyes

Hypogynous flower and epigynous flowers

Hypogynous flowers have their ovaries above the other floral parts

Epigynous flowers have the ovaries below other floral parts

There is two serperate fused floral parts

fused petals and or fused stamens and pistils

primitive fowers tend to have radially symmeetrical petals

while advance flowers have bikaterally symmetrical petals

Moonocot flowers have 3 or multple of 3 petals while

eudicot flowers hae 4,5, or multples of thatt

Cluster of flowers are called inflorescence

Primitive flowers have

  • many parts

  • 4 whorls

  • non fused parts

  • superior ovary

  • radial symmerty

More advance

  • few parts

  • less 4 whorls

  • fused parts

  • inferior ovary

  • bilateral symmerty