4: Seeds, Seedlings, & Angiosperm Life Cycles Flashcards
Define coleoptile
a protective sheath that protects leaves as they push through the soil
Define coleorhiza
coating around root tissue that protects t he root to push through the seed coating
Define cotyledon
the embryo leaves or seed leaves that store nutrients for the immature seed
Primary root vs. adventitious roots
Primary root is the main root that comes out of the seed into the soil
Adventitious roots are roots that grow off the stem
Primary root vs. adventitious roots
Primary root is the main root that comes out of the seed into the soil
Adventitious roots are roots that grow off the stem
Primary (radicle) root vs. adventitious roots
Primary root is the main root that comes out of the seed into the soil
Adventitious roots are roots that grow off the stem
What kind of cell division is meiosis and how many of what kind of cell does it create?
Meiosis is the cell division involved with sexual reproduction. Meiosis produces 4 genetically unique haploid cells called gametes
T or F: Meiosis produces haploid cells from a diploid cell? why/why not?
TRUE. One mother diploid cell undergoes meiosis to produce 4 genetically unique haploid cells (gametes)
Explain how meiosis relates to genetic diversity? What are the two main processes involved in meiosis that account for this?
Meiosis is the cell division type that is involved with sexual reproduction and sexual reproduction is responsible for genetic diversity. This is because meiosis produces 4 genetically unique haploid daughter cells from a diploid mother cell.
Within meiosis, the processes of independent assortment and crossing over occur and these are the reasons for the genetic uniqueness of the daughter cells
Describe independent assortment and which cell division type is it involved in?
This step occurs in meiosis when the duplicated pairs of chromosomes align in the centre in any order, they will then separate to the poles of the cell and it will change the combination of mother/father chromosomes before division.
Describe crossing over and which cell type is it involved in?
This step occurs in meiosis when the chromosomes twist together and wrap around, breaking some genes off the mother and father chromosomes to exchange them onto the other
How many full divisions occurs on meiosis?
two divisions including the prophase, metaphase, anaphase and telophase
How many full divisions occurs on meiosis?
two divisions including the prophase, metaphase, anaphase and telophase
What does “n” refer to?
the number of chromosomes
Define diploid cells
2n. Has the full 46 chromosomes (half from mom and half from dad). These are SOMATIC CELLS
Define haploid (1n or n) cells
They have one set of chromosomes per cell = total 23 chromosomes
Sex cells
What kind of cell division is mitosis and how many of what kind of cells does it produce?
Mitosis is a cell division of somatic cells that produces two genetically identical diploid cells to BUILD TISSUES
What is the purpose of mitotic cell division?
Mitosis copies body/somatic cells to function in the growth and development and the maintenance of body tissues.
Which phase of mitosis occupies 90% of the cell’s existence? What occurs in this phase?
Interphase - in between divisions. This is when the cell performs their functions
Define megaspores
SEEDS. Female plants produce these
Define microspores
POLLEN GRAINS. Male plants produce these
Where does meiosis occur in a female plant?
in the ovule of the pistil
Where does meiosis occur in a male plant?
In the anther of the stamen
What does alternation of generations mean?
An angiosperm plant lifecycle goes through two unique stages. 1 is the diploid stage and the 2nd is the haploid stages.
Which stage of the lifecycle does the suffix ‘-cyte’ refer to?
DIPLOID STAGE (somatic)
Which stage of the lifecycle does the suffix ‘-spore’ refer to?
HAPLOID STAGE (gametes)
What is an egg? Is it haploid or diploid?
It is a haploid female gamete (sex cell)
What is an embryo? is it haploid or diploid?
Diploid.
An immature sporophyte that develops from a zygote within an ovule after fertilization
What is an embryo sac? is it haploid or diploid? What does it contain?
The female gametophyte (haploid) that contains:
- the egg
- polar nuclei
- antipodals
What is the endosperm? How is it formed? Is it haploid or diploid?
TRIPLOID. A food storage tissue that is formed from the 2nd fertilization between the female polar nuclei and the second sperm produced by the male generative cell.
What is the epicotyl?
The portion of the stem above the cotyledons
Describe the process of fertilization?
When the female egg and male sperm (gametes) fuse together to form a diploid zygote.
Define gametes. Are they haploid or diploid?
Gametes are the egg and sperm cells (sex cells) that will fuse during fertilization to form a zygote. They are haploid.
Define gametophyte. Is this haploid or diploid?
The haploid gamete-producing phase of the life cycle
Describe the process of germination
the beginning or resumption of seed growth
What is the generative cell/nucleus? Where is it produced? What is its function?
a pollen grain nucleus that divides by mitosis to produce 2 sperm cells for double fertilization
Define hilum
The mark on a seed where the ovary was once attached to the ovary wall
Define hypocotyl
The portion of stem that is below the cotyledons
Define integument. What do the integuments become?
The outermost layer of an ovule that usually develops into a seed coat
What is a megasporocyte? Are they haploid or diploid?
Female diploid cell that undergoes meiosis to produce 4 megaspores
What are megaspores? Are they haploid or diploid?
Female haploid cells produced when the megasporocyte undergoes meiosis and one will develop into a female gametophyte
What does the megasporocyte become after meiosis?
The diploid megasporocyte will undergo meiosis to form 4 unique haploid MEGASPORES
what is a microsporocyte? Are they haploid or diploid?
A male diploid cell that undergoes meiosis to produce 4 haploid microspores
What are microspores? Are they haploid or diploid?
Male haploid cells that were produced through meiosis that will develop into the male gametophyte
What is the micropyle?
an opening in the integuments of an ovule through which a pollen tube will enter to reach an embryo sac
describe a sporophyte. Is it haploid or diploid?
diploid
Describe a zygote. Is it haploid or diploid?
Diploid
What is a plumule?
The tiny undeveloped leaves inside the embryo
What is the radicle/primary root?
The tip that will develop into a root
What is a pollen grain? Are they haploid or diploid?
A haploid structure that formed from the microspore and will develop into the male gametophyte
What are pollen sacs?
Where the microsporocytes are held in the anther
Describe the process of pollination
The transfer of pollen from an anther to a receptive stigma
What is a plumule?
The tiny undeveloped leaves inside the embryo. The terminal bud of the embryo of a seed
What is the radicle/primary root?
The part of an embryo that will develop into a root
What is the seed coat? Which parts of the ovule becomes the seed coat?
the outer part of a seed. The integuments become the seed coat.
Describe a seed
A mature ovule containing an embryo and covered in a protective seed coat
What is sperm? is it haploid or diploid?
The male haploid gamete
Define sporophyte. Is it haploid or diploid?
The diploid spore-producing phase of the life cycle
What is the true leaf?
the first leaves to grow above the cotyledons
Describe a zygote. Is it haploid or diploid?
The diploid product of fertilization (female and male gametes fusing)
