Bio 103 Exam 3 JMU

All Living things reproduce in one of two ways ____

asexually or sexually

Sexual reproduction involves what?

Gametes

What are the two ways of organis r’ reproduction?

cell division through Mitosis or meiosis

What do all eukaryotic cells possess 

a true nucleus, with a nuclear envelope

What are unorganized mass of DNA and Histone proteins that are seen within the nucleus?

Chromatin

When DNA and proteins fold/supercoil what are the structures that are formed?

Chromosomes

What are diploids 2n?

The characteristic number of Chromosomes

How many haploids do humans have?

23

How many diploids do humans have

46

What are the two processes of cell division in Eukaryotic cells?

Karyokinesis and Cytokinesis

What is Karyokinesis

the division of the nucleus

What is cytokinesis

the division of Cytoplasm 

what are sister chromatids?

they are genetically identical and are attached to the centromere

What does Mitosis produce?

daughter cells — identical to one another

what is the cell cycle

The process by which cells divide by mitosis and restore their DNA to the original level 

What is G1 phase 

the cell grows and the organelles double 

What is S phase

DNA replicates

What is G2 phase

Cell growth, production of enzymes and other proteins

What is mitosis

Karyokinesis and cytokinesis

What does interphase involve

G1, S, and G2

In Karyokinesis, what is prophase?

chromatin begins to condense- makes chromosomes

in animal cell: 2 pairs of centrioles can be seen outside the nucleus in centrosomes

what are centrosomes

microtubule-organizing centers

How are polar spindle fibers formed?

The centrosomes begin to move apart

What are polar spindle fibers made up of?

Microtubules

kinetochores

They have kinetochore fibers attached to the, in the centromere of each chromatid pair 

Metaphase:

The kinetochore and their fibers move the chromosomes to the equatorial plate and make a line 

Anaphase: 

the chromatids separate and move to opposite poles 

In anaphase what moves first the centromere or it’s arms?

Centromeres

What are they chromatids called what they are separated?

daughter chromasomes

What happens in telophase?

the spindle fibers break down and the Nuclear membranes, nucleoli, and chromatin reappear and new centrioles could appear 

When does cytokinesis occur

During telophase

What does cytokinesis look like in animals

With the formation of a cleavage furrow

How are cell plates formed in plants?

from the inside out

How is the cel plate formed?

From vesicles produced by the dictyosomes— and will eventually become the middle lamella

ASEXUL REPRODUCTION IN PLANTS

rhizomes

horizontal underground stems

examples of rhizomes (2)

grasses and stems

What are stolons?

Horizontal above ground stem 

Example of stolon

strawberries

What are plantlets?

formed at the margins of the leaves

Example of Plantlets?

air plan

Animals the reproduce asexually 

What is fragmentation?

a portion of an individual can break free and regenerate an entire organism.

makes a whole new organism 

Example of an animal using fragmentation?

Sponge- phylum Porifera

what does budding mean

a mini offspring forms and then breaks off

examples of budding (2)

Sea Anemone (phylum Cnidaria) and hydra (phylum Cnidaria)

What is fission

The separation of a parent into two or more individuals of roughly equal size.

Out of all three ways, which is the most advantageous?

Fission IN A STABLE ENVIRONMENT

Example of Fission?

Sea anemone, (phylum Cnidaria

What are the 4 advantages of asexual reproduction?

• create numerous offspring quickly

• quickly colonize a new habitat

• no need to find a mate (if an animal lives in isolation, it can still reproduce)

• perpetuates successful combinations of genes (sexual reproduction breaks them up)

What is the result of Mitosis? (2)

growth of multicellular organisms ]

Replacement of cells in multicellular organisms 

What is the main difference between prokaryotes and eukaryotes?

Most eurkaryotes sexually reproduce

What does sexual reproduction invlove?

meiosis- making a gamete

syngamy- fertilization 

What are ganetes

sperm and eggs 

In meiosis how many chromosomes are in each daughter cell?

the haploid number of chromosomes 

What happens when gametes fuse together?

they will make a diploid cell

What is meiosis known as

reduction division

what happens within meiosis

division where chromosomes goes from diploid number to haploid number

What is the production of meiosis and why/how

4 daughter cells (gametes) 

Happens because the diploids cell undergoes two divisions 

what happens after each cell division 

they contain ½ the number of chromosomes 

syngamy

fertilization

what is fertilization?

The process when two gametes fuse and form a diploid zygote

what happens in interphase

chromosomes are replicated—2 identical chromatids

What are the chromatids held together by?

a centromere

What happens in meiosis I

homologus chromosomes separate

What happens in meiosis II?

Chromatids separate 

Prophase I

Chromosomes become parid

the pairs synapse— tetrads

crossing over occurs 

metaphase I

homologous pairs line up at the equatorial plane of cell

Anaphase I

the homologues separate and move to opposite poles

Telophase I

they have reached the poles

The nuclear envelope may or may not happen and cytokinesis may or may not occur

interkinesis

Like interphase but NO DNA replication happens

Prophase II

the nuclear envelope (if present) breaks down again and the spindle fibers form

Metaphase II 

the chromosomes in each cell line up on the equatorial plane 

Anaphase II

The sister chromatids separate

which results in daughter chromosome moves toward one of the poles

Telophase II

Spindles disappear

nuclear envelope forms around each chromosomes

cytokinesis takes place

Why is meiosis good?

allows for genetic variability

In humans, how many different combinations of chromosomes are possible?

8,388,608

How many different combinations of chromosomes are possible?

64 trillion — not counting crossing over

UNIT 9!

coevolve 

Flowers and animals both evolve in order to their characteristics

Beetle Pollination

large flower

inflorescent 

its ovule is protected 

Bee Pollination

they are picky

white/yellow

NO RED 

collect pollen for babies and nectar for adults

they may even look like female bees

Fly pollination

mature or decaying smells

reddish/brown 

smells bad— then they lay their eggs 

moth pollination

white/pale color

smells good

pollinate at night 

butterfly pollination

white and yellow

humming bird pollination

red some yellow

lots of nectar

no smell 

Bat pollination

white/pale

tough flower

nectar heavy 

Wind pollination 

LOTS of pollen

no smell 

little to no nectar 

no color 

all by chance 

Example of a wind pollination

male catkins/Betular or paper birch 

Water pollination

Fruits and seeds

Aggregate Fruit

flower #, ovary and carpal, and ex

1 flower

1:1 ovary carpal 

Blackberry, raspberry, magnolia, and strawberry 

Multiple fruit

flower #, ovary and carpal, and ex

many flowers

1:1 

pineapple, osage, orange, fig, and sycamore

Simple Fruit

flower #, ovary and carpal

1 flower with one ovary 

1 carpal or many fused carpals

Fleshy fruit

fruit wall is fleshy

eaten during seed distribution process 

pericarp

fruit wall

examples of fleshy fruit (5)

berry, pome, pepo, hesperidium, drupe

Berry

flower #, ovary and carpal, and ex

compound ovary 

each carpal w/many seeds

leathery rind 

cucumber, squash, pumpkin, watermelon, and cantaloupe 

Hesperidium

flower #, ovary and carpal, and ex

compound ovary

each carpal with many seeds 

leathery rind with oil glands 

carpal segments lines with fleshy trichomes

 oranges, grapefruit, lemon, and limes 

Drupe

flower #, ovary and carpal, and ex

Simple/compound ovary 

carpal with one seed/pit

peach, cherry, olive, plum, and coconut