Chapter 7- Plant reproduction

types of reproduction

Asexual and sexual

Advantages of Asexual Plants

-quicker, 1 parent, and involved

Advantages of Asexual plants

no genetic diversity

vegetative propagation

-form of asexual reproduction, involved parent plant producing runners that form buds & roots (ex. spire plants and strawberries)

advantage of sexual plants

-genetic diversity

disadvantages of sexual plants

-slower, 2 parents must be involved

nucleus

-DNA

-genetic material, protein-making instructions

three forms of nuclear DNA

-Chromatin

-Chromosomes

-Duplicated chromosome/ pair of sister chromatids

1st step of cell division

chromatin

chromatin

DNA & protien

2nd stage of cell division

chromosomes

chromosomes

formed when chromatin condenses

3rd step of cell division

duplicated chromosome or also known as pair of sister chromatids

duplicated chromosome/ pair of sister chromatids

-identical copies of chromosomes

diploid

(2n)=46 chromosomes

2 complete sets of chromosomes

-humans’s body cells

haploid

(n)=23 chromosomes

-1 complete set of chromosomes

men have it through sperm cells

women have it through egg cells

Cell cycle

Life cycle of a cell from one diction to the next

Consists of 3 steps: interphase, cell/ nuclear division, and cytokinesis

Interphase

-most of the time spent in this phase

-DNA in chromatin form

3 phases: G1, S, and G2

G1 (first Gap)

Cell growth, enzyme, and other proteins made, increase in number and size of organelles

S (synthesis) phase

DNA is copied

G2 phase (second gap)

Proteins are made, final preparation before division

Cell/ nuclear division

-division of the nucleus (DNA)

-mitosis or meiosis

Cytokinesis

-division of the cytoplasm

-separation nuclei into separate cells

-phragmoplast builds up across the diving cells to form a cell plate, which separates the newly formed daughter cells

Mitosis

-happens in body cells

-associated with asexual reproductive (producing clones)

-PMAT (prophase, metaphase, anaphase, telophase)

Prophase

-chromatin condenses so duplicated chromosomes/ pair of sister chromatids are seen

-the nucleus envelope and nucleolus break down

-the spindle, which is made of micro tubules, begins to form

Metaphase

-duplicated chromosomes/ pair of sister chromatids attach to the spindle & line up in the middle of the cell

Anaphase

-duplicated chromosomes/pairs of sister chromatids are pulled apart. They are called chromosomes.

telophase

-the chromosomes unravel back into chromatin

-the spindle breaks down

-the nuclear envelops and nucleoli reforms

Cytokinesis

-form 2 separate, identical daughter cells

meiosis

-happens in reproductive cells

-decrease the amount of DNA by half

-associated with sexual reproductive

-two parts Meiosis 1 and 2

-at the end of both parts of meiosis, 4 nuclei have been produced

meiosis 1

-separate homologous chromosomes

(pair of chromosomes with genes for some traits, same size & shape)

meiosis 2

separate chromatids

Meiosis 1: Prophase 1

-nuclear envelope & nucleolus break down

-the spindle begins to form

-chromatin condenses (homologous chromosomes can be seen)

-homologous chromosomes pair (synapsis)

-crossing-over (exchange of information between homologous chromosomes) occur

Meiosis 1: Metaphase 1

-homologous chromosomes attach to the spindle and line up in the middle of the cell

Meiosis 1: Anaphase 1

-homologous chromosomes are separated

-the amount of DNA has decreased by half

Meiosis 1: telophase 1

-the spindle breaks down

-DNA unravels into chromatin

-the nuclear envelops & nucleoli reform

Cytokinsis 1

-2 daughter cells with half the amount of DNA as the original cell

Meiosis 2: prophase 2

-the spindle begins to form

-DNA condenses so chromatids can be seen

-the nuclear envelops and nucleoli break down

Meiosis 2: metaphase 2

-the DNA attaches to the spindle & lines up in the middle of the cells

Meiosis 2: Anaphase 2

-the DNA (chromatids) separate & are called chromosomes

Meiosis 2: telophase 2

-the spindle breaks down

-the DNA unravels into chromatin

-the nuclear envelops & nucleoli re-form

cytokinesis 2

-4 cells, genetically different with half the amount of DNA that we began with earlier

what type of reproduction does mitosis go through

asexual reproduction

what type of reproduction does meiosis go through

sexual reproduction

how does the number of chromosomes change during mitosis

it copies and keeps the same number of chromosomes (start with 3 you end with 3)

how does the number of chromosomes change during meiosis

it cuts the number of chromosomes in half (start with 6 you get 3 in the end)

how many times does mitosis go through interphase

once

how many times does meiosis go through interphase

once

how many times does mitosis go through PMAT

once

how many times does meiosis go through PMAT

twice

how many daughter cells are there in mitosis

two

how many daughter cells are in meiosis

four

how do the daughter cells relate and differ in mitosis

they are genetically identical

how do the daughter cells relate and differ in meiosis

they are genetically different

what types of cells does mitosis include

body cells

what type if cells does meiosis include

reproductive cells/ sex cells

what process do animals go through for reproduction

animals form their sex cells (gametes) directly through meiosis

sporophyte

-diploid plant

-going to produce spores(haploids) through meiosis

gametophyte (haploids)

-develops form a haploid spore that went through mitosis, produces gametes/sex cells that are haploids

1st step of the process of alternation of generation

sporophyte (diploid) → spores(haploid)

-process goes through meiosis

2nd step of the process of alternation of generation

spores( haploid) →gametophyte (haploid)

-process goes through mitosis

3rd step of alternation of generations

gametophytes (haploid) → gametes (haploid)

-process goes through mitosis

4th step of alternation of generations

egg(haploid)+sperm(haploid) →zygote (diploid)

-process goes through fertilization

5th step of alternation of generations

zygote(diploid)→sporophyte(diploid)

-process goes through mitosis

double fertilization

-unique to angiosperms

-1 sperm fertilized egg

-1 sperm that joins with the 2 polar nuclei to produce triploid endosperm

-ex. wheat, rice, and corn