Chapter 38: angiosperm reproduction Flashcards
Complete flower
A flower which has all four organs found in flowers
Incomplete flower
Does not have all flower organs
Inflorescence
A flower that is actually a bunch of flowers together in one
What is the dominant generation in an angiosperm?
Sporophyte
What are all the parts of a flower
Sepal: the green part on a flower
Petal: the petal, usually colorful
Stamen: The male part, sticks out and contains pollen
Carpel: the female part, contains the egg
What is the development of a male gametophyte
Microsporocyte: undergoes meiosis —>
Microspores: creates four of them, which then undergo mitosis —>
Each of them create a pollen grain with two sperm cells inside
What cell types are present in the mature pollen grain?
Tube cell, and generative cell
What is a pollen tube? What cell does it develop from and what is its function?
It develops from the Tube cell, its sole purpose is to deliver the male gametophytes to the female gametophyte
What is the development of a female gametophyte
Megasporangium: undergoes meiosis —>
Megaspore: four are created, only one survives, undergoes mitosis three time–>
Creates 8 haploid nuclei which become the female gametophyte and the embryo sac
What process is responsible for converting the microsporocyte to a microspore?
Meiosis
What is the primary difference between a microsporocyte and a microspore?
The microsporocyte is diploid, and the microspore is haploid
What process is responsible for converting the megasporocyte to a megaspore?
Meiosis
What is the primary difference between a megasporocyte and a megaspore?
The megasporocyte is diploid, whereas the megaspore is haploid
How many mitotic divisions are required for conversion of the megaspore to the female gametophyte?
Three
How many mitotic divisions are required to convert the microspore to the male gametophyte?
Two
Generative cell
The cell which divides into the two sperm in the pollen
Tube cell
The cell which becomes the tube which brings the sperm to the egg
Egg cell
The female gametophyte, becomes the actual seed
Antipodal cells
Has no known purpose
Polar cells
Become the endosperm in the fruit
Synergids
Attract and guide the pollen tube
What is meant by the term double fertilization? What does double fertilization ensure?
Double fertilization is the process which angiosperms use to ensure they do not go through the trouble of creating a fruit for a seed which has been not fertilized, the pollen carries two male gametophytes, one fertilizes the polar nuclei of the seed, which signals to the plant that therefore a sperm has also fertilized the egg itself.
What part of the female gametophyte gives rise to the endosperm? What part gives rise to the fruit?
The polar nuclei, the ovary
What is the function of fruit?
The fruit provides something for the fruit to consume while it is still young, it is a bunch of sucrose and other things the seed will need to grow until it is big enough to sustain itself
What are the advantages and disadvantages of asexual versus sexual reproduction?
Advantages:
More resistant
Passing on all of its genes
Does not rely on other species for spreading its babies
Disadvantages:
Bad at adapting to different environments
Missing out on good ways of dispersing its kids
What are the mechanisms utilized by plants to discourage self-fertilization?
Plants can be dioecious, which is when they will only have male/ female for one plant at a time, instead of both at the same time
They can also have their anther and carpels arranged in such a way which makes it very hard for self-fertilization to happen
Lastly they can just be self-incompatible, which is when at the atomic level the egg will reject the sperm from itself
