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)