Bio Honors Unit 9

Growth in multicellular organisms, Repair and regeneration of tissues/organs, Asexual repro in multicellular organisms , Asexual Reproduction of unicellular organisms

what is mitosis used for by organisms? (g,r,a,a)

prophase,metaphase, anaphase, telophase.

4 steps of mitosis? in order

interphase

which mitosis step: Nuclear membrane visible; no chromosomes present

prophase

which mitosis step:  Nuclear membrane disappears, chromosomes appear

mitotic spindle begins to appear; centrioles on animals appear and migrate

 towards poles of cell

metaphase

which mitosis step: Chromosomes in single line along equator of cell; mitotic spindle formed

anaphase

which mitosis step: Sister chromatids separate; migrate to poles of cell

telophase

Sister chromatids (now called individual chromosomes) clustered at poles

of cell; nuclear membrane begins to reform, mitotic spindle disappearing

cytokinesis

Cleavage furrow (animal) or cell plate (plant) visible; chromosomes 

disappearing or invisible; nuclear membrane reformed

energetically cheap, fast

advantage of asexual reproduction:

lack of genetic diversity

disadvantages of asexual reproduction → ?

Produces two clones of the original cell

mitosis produces:

2 diploid (2N) somatic cells

mitosis produces: 1 diploid (2N) somatic cell ----->?

identical, point mutations

the two clone cells mitosis produces should be ____ except for ______ _____

crossing over, random fertilization of gametes, independent assortment

3 main ways sexual reproduction causes genetic variation :

cleavage furrow

_____ occurs during animal cell division, pinching the membrane inward using a contractile ring,

cell plate

____ occurs in plant cells, forming a new cell wall from the inside out to separate cells

synapsis

“crossing over” occurs during ____

synapsis

The process where homologous chromosomes pair up.

tetrads

Comprised of four chromatids (two homologous chromosomes, each with two sister chromatids)

crossing over, genetic variation, chromosome separation

tetrads facilitate ____ to create ____ and ensures correct ______ ______

tetrads, metaphase I

the homologous pairs (____) line up, with each chromosome facing opposite poles. - process of _____

random arrangement

significance of metaphase I of meiosis - ______ (e.g., paternal on left or right) means each daughter cell receives a unique mixture of maternal and paternal chromosomes.

anaphase I

Homologous pairs separate; whole chromosomes migrate to poles, Random distribution of maternal/paternal chromosomes to poles  ensures “independent assortment” of genetic information

- ______ #_ of meiosis

telophase I

Chromosomes collected at poles; mitotic spindle disappears, Nuclear membrane reappears - ____ #_ of meiosis

cytokinesis I

  Cleavage furrow/cell plate appears, cell divides into two - _____ #_ of meiosis

interkinesis

brief interphase between meiosis 1 and meiosis 2 is known as _____

chromosomes disappear

what happens during interkinesis ?

interphase

what is this plant cell going through

prophase

what is this plant cell going through? - mitosis

metaphase

what is this plant cell going through?

anaphase

what is this plant cell going through?

anaphase

what is this plant cell going through?

telophase

what is this plant cell going through?

cytokinesis

what is this plant cell going through?

crossing over

 - Exchange of genetic information between homologous chromosomes during meiosis

Spermatogenesis

the biological process of producing mature sperm cells (spermatozoa) from stem cells in the male testes, starting at puberty

oogenesis

the biological process of creating, developing, and maturing female gametes, or egg cells (ova), within the ovaries

fertilization

union of an egg and sperm

zygote

- result of fertilization; full set of genetic information

cytokinesis

Cleavage furrow/cell plate appears, cell membrane/cytoplasm splits - occurs 2 times in meiosis and once in mitosis

2

homologous chromosomes can line up in __ ways during metaphase of meiosis

interphase

Chromosomes are not visible -

Interphase

Prophase

Metaphase

Anaphase

Telophase

telophase

Two separate groups of chromosomes visible; cell plate/cleavage furrow appears?

Interphase

Prophase

Metaphase

Anaphase

Telophase

prophase

Nuclear membrane disappears; chromosomes appear -

Interphase

Prophase

Metaphase

Anaphase

Telophase

anaphase

Sister chromatids separate and begin to migrate to the poles of the cell

Interphase

Prophase

Metaphase

Anaphase

Telophase

metaphase

A single line of chromosomes are visible along the equator of the cell

Interphase

Prophase

Metaphase

Anaphase

Telophase

prophase

Centrioles begin to migrate to opposite poles as spindle fibers appear

Interphase

Prophase

Metaphase

Anaphase

Telophase

telophase

Chromosomes begin to disappear as two, new nuclear membranes appear

Interphase

Prophase

Metaphase

Anaphase

Telophase

Prophase I

 Homologous chromosomes pair up (synapsis); tetrads observed

Telophase II

 Nuclei in 4 haploid cells begin to reform around single stranded chromosomes

Metaphase I

 Tetrads line up along the equator of the cell

Prophase I

 Crossing over occurs

Metaphase II

Double stranded chromosomes line up along the center of the cell

Anaphase I

 Homologous pairs of chromosomes are separated

Anaphase II

Chromatids of doubled chromosomes (sisters) are separated

telophase I

 Nuclei reform around a haploid number of doubled chromosomes in 

  two new cells

prophase I

A diploid number of doubled chromosomes first become visible.

F

put these steps in order : first one

B

put these steps in order: 2nd one

I

put these steps in order: last one

chromatin

The relaxed, thread-like form of DNA complexed with proteins that exists during interphase, allowing transcription and replication to occur.

interphase

Centrosomes (microtubule-organizing centers containing centriole pairs) replicate - what stage

interphase

Preparation for Division

Prophase

Mitosis Begins

prometaphase

: Spindle-Chromosome Connection

metaphase

Chromosome Alignment

anaphase

Separation of Sister Chromatids

telophase

Nuclear Re-formation

cytokinesis

Physical Cell Division (Animal Cells)

polar microtubules

Overlapping microtubules pushing poles apa

kinetochore

Protein complex on centromere for microtubule attachment

centromere

Region linking sister chromatids

synapsis

The intimate physical pairing of homologous chromosomes that enables genetic exchange between non-sister chromatids.

homologous pairs, sister chromatids

In metaphase I, _______ align, and ______ remain attached — unlike mitosis where individual chromosomes (each with two chromatids) align with bipolar attachment.