Unit 9 - Meiosis, Cell Cycle, Plants

Mrs. Essig

Why is interphase necessary for Meiosis?

It prepares the cell to split.

Meiosis I

pairs of homologous chromosomes are separated from each other

results in random chromosome combinations in gametes

Steps of Meiosis I

Prophase I; Metaphase I; Anaphase I; Telophase I

Prophase I

Homologous chromosomes cluster together

crossing over occurs

Crossing Over

segments of DNA exchanged between non-sister chromatids of homologous chromosomes

Metaphase I

homologous chromosomes line up in middle

attachment to spindle is random

Anaphase I

homologous chromosomes separated

move to opposite sides (poles) of cell

Telophase I

Spindle fibers dissolve

no form new nuclear envelope

will immediately divide again

no DNA replication between meiosis I and II

cell divides in cytokinesis

Meiosis II

sister chromatids separated; gametes generated; similar to mitosis

results in 4 genetically unique haploid daughter cells

sister chromatids

identical copies of chromatids

Prophase II

chromoesomes condense

Metaphase II

chromosomes line up on top of each other in middle of cell

spindle attached to centromere of each chromosome

Anaphase II

Sister chromatids separate

spindle shortens and moves to opposite ends of cell

Telophase II

nuclear envelope forms around chromosomes in all four cells

cytokinesis

How does Meiosis lead to variation in gametes, why is is important?

Gametes will have different DNA which is important for evolution

How does crossing over lead to more variation in gametes

It mixes parts of the chromosomes which allows for gametes to have different DNA

Gametogenesis

Development of Haploid cells into gametes

Male Gametes

Sperm

Female Gametes

Egg

Diploid Life Cycle

majority of life spend as diploid adults

meiosis produces haploid gametes

fertilization forms diploid zygote

mitosis and cytokinesis produce two diploid cells

Haploid Life Cycle

life cycle with majority of time spend as haploid organisms

fuse to form diploid zygote

meiosis produces more haploid gametes

Nondisjunction disorders

failure of replicated chromosomes to separate during anaphase II

Most human abnormal chromosome numbers result in death of developing embryo

Monosomy

when humans only have one autsome

Trisomy

When humans have an extra autosome

Chromosomal Abnormality

A mutation in the chromosome

Inversion

chromosome being flipped upside down

Deletion

removal of a part of a chromosome

Duplication

an addition of a chromosome

Translocation

a piece of a chomosome being transferred to another chromosome

Plant

Eukaryotic Organism that produces its own food

Why are Plants Essential for Humans?

* provide food
* produce oxygen
* material for manmade things

Why are Plants Important for Nature?

* provide food
* maintain atmosphere
* recycle matter
* provide materials for manmade things
* create habitats for many organisms

Alternation of Generations

Life cycle that alternates between haploid and diploid phases

Mosses (Bryophyte)

Non-Vascular plants with spores

Doesn’t have roots, vascular tissues, leaves, seeds, flowers

inefficient at absorbing water

Reproduce through moisture and spores

Ferns (and friends)

Vascular plants with spores

Has Xylem and Phloem

developed roots, stems, and sunlight

grew tall for sunlight

Conifers (Gymnosperm)

Cone bearing seed plants with an open ovule

seeds and reproductive structure in cones

male gametes carried by wind to fertilize femal egametes in seed cones

Flowering Plants

Seed bearing plants with a surrounded ovule

flowers contain reproductive organs

colors, designs, scents, nectars attract pollinators

How have plants responded to their Enviroment?

They have evolved overtime to adapt to their surroundings such as developing vascular tissues, flowers, and more.

xylem

vascular tissue that transports water and dissolved minerals from roots to stems and leaves

phloem

vascular tissue that transports food from photosynthetic cells to other parts of the plant for growth or storage

Roots

made of vascular tissues

anchor plants securely in the ground

Stems

made of vascular tissues and lignin

allows plants to grow higher and supply water to plant

Leaves

collect sunlight, CO2

reduce water loss

Flowers

Reproductive organs of flowering plants

Sepal

Protect developing flower while it is a bud

Petal

Attracts animals to the flower by being brightly colored

Stamen

Made of Anther and Filament

Male reproductive structure of a flower

helps pollen be more likely carried away

Carpel/Pistil

Made of Stigma, Style, Ovary, Ovule

Female reproductive structure of a flower

sticky to help catch pollen

Photosynthesis Formula

Light Energy + 6CO2 + 6H2O → C6H12O6+ 6O2

Photosynthesis reactants

Light Energy + Water + Carbon Dioxide

Photosynthesis Products

Oxygen + Glucose

Cellular Respiration Formula

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP

Cellular Respiration Reactants

Glucose + Oxygen

Cellular Respiration Products

Carbon Dioxide + Water + ATP

Chloroplast Structure

(only need to know Thylakoids and Stroma)

Stroma

Fluid-filled internal space of the chloroplasts which encricle the grana and thylakoids containing chloroplast DNA, starch, and ribosomes laong with the enzymes needed for the Calvin Cycle

Thylakoids

Flattened sac of membrane inside of a chloroplast where the first stage of photosynthesis occurs

Chlorophyll

A green pigment which absorbs light to provide energy for photosynthesis

Photosynthesis

Process of plants using light energy to create glucose as nutrients

Model of Photosynthesis

Light and water goes into Light reactions in the Thylakoid which produces O2, NADPH, ATP

NADPH, ATP, and CO2 go into the Calvin Cycle which Produces NADP+, ADP + Pi + sugar

NADP+ and ADP+Pi go into light reactions

Sugar is distributed to the plant as nutrients

Light Reactions

First part of Photosynthesis

Light energizes electrons in chlorophyll and these electrons are used to make ATP and are stored in a coenzyme (NADPH)

water is used to replace the electrons in chlorophyll and oxygen gas is released into the air

Calvin Cycle

Second Part of Photosynthesis

ATP and NADPH provide energy, hydrogen ion, and electrons

used to bind with CO2 to form sugar

Model of a Flower

Pistil

Stigma, Style, Pollen

Petal

(Stamen) Anther, Filament

Ovary, Ovule

Stem

Connection between Cellular Respiration and Photosynthesis Diagram

Light Energy, Chloroplast, Photosynthesis

O2, Glucose

Mitochondria, Cellular Respiration, ATP

CO2, Water

Photosynthesis Diagram

Light, H20

Light Reaction, Thylakoids

ATP, NADPH

C02

Calvin Cycle, Stroma

NADP+, ADP + P1

Sugars

Alternation of Generations Diagram

Meiosis, Spore, Mitosis, Gametes (Egg, Sperm)

Fertilization, Zygotes, Mitotsis

Diploid (2N Plant)

Haploid (IN Plant)