Plants Alternation of Generations
Ovules
haploid egg cells inside of a flower
Gametophyte example plants
spores, eggs or pollen of pine tree
Haploid cell examples
spores, sperm, egg
Plant in Sexual reproductive phase
will make sperm, pollen or eggs
Alternation of Generations in Mosses and Ferns
1. sexual gametophyte stage and an asexual sporophyte stage is present for both cycles. 2. In the gametophyte (1n), mitosis creates male and female gametes (1n) for sexual reproduction. 3. These gametes combine to make zygotes (2n) that grow into the sporophyte phase (2n) of the plant. 4. In the sporophyte stage, plants create haploid spores (1n) through the process of meiosis . 5. They disperse with wind, water, or in the fur of animals. When they land on fertile ground, they grow into the new gametophytes (1n).
Plant 1n example
1n = 12 for pollen or egg of pine tree
Haploid example plant
1n = 12 pine tree pollen or egg
Haploid example animal
1n = 23 in human egg or sperm
Plant 2n example
2n = 24 for pine tree
Alternation of Generations Gymnosperms
1. The adult sporophyte (2n) creates male and female cones (2n) on separate branches of the same plant. 2. These cones are not the gametophytes they contain the haploid spores . 3. The male and female gametophytes (1n) grow from the haploid spores (1n) hidden inside the cones. The male gametophytes (pollen ) disperse with the wind to the sticky female cones where the female gametophytes are enclosed. 4. A pollen tube grows from the pollen grain, allowing the male gametes to travel to the eggs 5. Once fertilization occurs, a seed (2n) forms that drops to the ground and grows into the sporophyte or adult gymnosperm tree
Moss sporophyte
1. The diploid (2n) sporophyte grows directly from the gametophyte as a capsule stalk 2. A spore capsule forms at the end of the capsule stalk 3.Meiosis creates haploid (1n) spores within the spore capsule 4. Spores disperse and grow into new gametophytes
Sporophyte of Fern
1. The diploid (2n) sporophyte grows from a zygote in ferns. 2. Sporangium form underneath fern fronds. 3. Meiosis creates haploid (1n) spores within the sporangium 4. Spores disperse and grow into new gametophytes
Alternation of Generations Angiosperms
1. The gametophytes (1n) grow directly from the sporophyte (2n) in the form of pollen grains and egg cells. 2. Wind, water, and animals bring the pollen and eggs together. 3. Fertilization takes place inside a flower 4. Eventually produces a 2n seed that can produce an adult plant (sporophyte)
Seedless watermelons
1. The ovules of a melon with 44 chromosomes are pollinated by a melon with 22 chromosomes in its diploid cells. 2. The result is a melon with 33 chromosomes that is incapable of producing seeds
Fertilization in a flower
1. pollen (1n) grain containing two haploid nuclei reaches the pistil, it sticks to the stigma 2. A pollen tube grows through the pistil into the ovary, and then into the ovules (1n). 3. The male gametes (two haploid sperm) join with the female gametes within the ovule. One sperm must fertilize the main egg, the other sperm joins the polar nuclei inside the embryo sac to make the endosperm 4. This creates a diploid zygote or seed (2n).
Animal 2n Example
2n = 46 humans
Seed
2n sporophyte that contains a plant embryo and its endosperm
Gametophyte of Fern
5. The gametophyte grows into a heart-shaped plant in ferns. 6. Mitosis produces flagellated male sperm and female egg cells in the gametophyte. 7. Flagellated sperm combine with female eggs cells (usually in moist areas) to form a diploid (2n) zygote.
Moss gametophytes
5. The gametophyte grows into separate male and female adult plants 6. In mosses, the male gametophyte makes the flagellated sperm and the female gametophyte makes the egg cells 7. Flagellated sperm combine with female eggs cells (usually in moist areas) to form a diploid (2n) zygote.
Haploid cell
A cell with half of the chromosomes, or 1n.
Gametophyte
A plant in its sexual reproduction phase
Sporophyte of Gymnosperm
Adult, diploid (2n) tree
2n
Diploid cells with 2 sets of chromosomes
Pistil
Female part of the flower and holds the female gametophytes
Sporophyte is the dominant stage in which plants?
Ferns, Gymnosperms , and angiosperms
Which plants DO NOT release spores?
Gymnosperms and Angiosperms
Which plants will the gametophyte grow within the sporophyte?
Gymnosperms and Angiosperms
Which plants do not have a flagellated male gamete?
Gymnosperms and angiosperms
Gametophyte of Gymnosperm
Haploid eggs and pollen made by the tree
Pollen
Haploid reproductive cell made by certain plants that contain sperm cells
Is Sporophyte 2n or 1n?
It is 2n or diploid
Vascular tissue
Tissues in plants that transport water and food up and down the plant
Angiosperm example
Maple tree, roses, corn, etc
Sporophyte is NOT dominant in which plants?
Mosses
Which plants release spores?
Mosses and Ferns
Which plants have a flagellated male gametes?
Mosses and ferns
Which plants will the gametophytes NOT grow within the sporophyte?
Mosses and ferns
Mosses
Non-vascular plants that do not produce seeds
Double Fertilization
Occurs in flowering plants when one sperm in the pollen fertilizes the egg and the other sperm in the pollen grain fertilzes the outside making the endosperm
Stamen
Part of flower that produces pollen or male gametophyte
Petals
Part of the flower that attracts pollenators like butterflies
Example of Gymnosperm
Pine tree
Sporophyte example plants
Pine tree is the sporophyte
Sporophyte
Plant asexual reproductive phase.
Haploid or 1n phase of plant reproduction
gametophyte
Endosperm
Substance inside of a seed that provides energy for the embryo plant
Ferns
Vascular plants that do not produce seeds
Gymnosperms
Vascular plants that produce seeds in cones
Angiosperms
Vascular plants with flowers that produce seeds with a seed coat
Germenation
When a seed begins growing and becomes a plant with roots and leaves
Pollenation
When pollen is taken from one flower to another for fertilization
egg
a haploid or 1n gamete in living things for reproduction
Spore
a haploid or 1n gamete of some plants such as mosses or fern
Example of Gymnosperm Sporophyte
adult pine tree
Sporophyte phase of Gymnosperm
adult pine tree
Alternation of generation
cycle between sporophyte and gametophyte generations
Animal n example
n = 23 for sperm and egg for humans
embryo sac
part of the ovule
anther
part of the stamen that contains the pollen
Gametophyte phase of Gymnosperm
pollen and eggs in the male and female cones