1004 chapter 8_-_the_cellular_basis_of_reproductio

CHAPTER 8

The Cellular Basis of Reproduction and

Inheritance

8.1 Cell Division

___________ is a characteristic of life Organism level and cellular level

Cell division – production of 2 identical ‘________’ cells from ‘parent’ cell

Before division, cell needs to _________ chromosomes

8.1 Cell Division

_________ reproduction – creation of offspring by a single parent Double chromosomes, etc. and split Genetically ___________

___________Reproduction – creation of offspring by the fusion of a sperm and egg Not genetically identical Production of sperm/egg involves

specialdivision process, __________

8.1 Cell Division

Cell Division

_____________ reproduction

Multicellular reproduction

Sperm and egg __________

Development into multicellular organism

8.2 Prokaryote Reproduction

Prokaryotes Chromosome of ___________ DNA Plasma membrane Cell ________

Binary _________ - ‘dividing in half’

2 Identical daughter cells

8.2 Prokaryote Reproduction

8.3 Chromosomes Duplicate

In eukaryotes most genes found in _________ Exceptions?

Most of the time chromosomes diffuse mass ___________ – DNA and protein Too thin to see under microscope

As a cell prepares to divide, mass ___________ down Distinct ______________


Humans have _____ chromosomes 2 copies of each, 1 from each parent Dogs have 78 (36 from each parent) Cats have 38 (19 from each parent)

Chromatin – thin, long fibers of DNA wound around ____________ Proteins maintain ___________ and control activity of

genes


Before division chromosomes duplicate

Sister _________ – identical copies joined at ___________ 92 chromatids

Cell __________ Sister chromatids now called

chromosomes

8.4 Multiplying Cells

Cells divide at different _______

Cell cycle – ordered ____________ from formation to division

Interphase – ____________ stage

_________ phase - division


Interphase

90% of cell cycle (performs its ___________)

Creates ___________

Increases ____________

______________ duplicate


G1 – ‘first gap’ Cell grows

S – ‘_________ of DNA’ Cell continues to ________ Chromosomes duplicate

G2 – ‘second gap’ Cell continues to grow Prepares for __________


Mitotic phase

Cell divides

10% of cell cycle

Mitosis and ___________


Mitosis – _________ and contents divide

Cytokinesis – __________ divides

Yields 2 daughter cells, _________ to parent ‘daughter’ doesn’t have anything to do with ‘sex’

Cycle begins again

8.5 Cell Division

5 stages of mitosis – Figure 8.5 page 130-131

(Interphase)

Prophase

Prometaphase

Metaphase

Anaphase

Telophase

8.5 Cell Division - Interphase

Cell ________

DNA replicates but is __________ in the nucleus After replication, how many

chromatids? How many sister chromatids?

8.5 Cell Division - Prophase

In nucleus chromatin condense, coil into ___________

Duplicated chromosomes are sister chromatids, joined at _________

In cytoplasm ___________ move away from each other

___________ grow from centrosomes, form mitotic spindle

8.5 Cell Division - Prometaphase

Nuclear _________ breaks down

Spindle microtubules attach to each sister chromatid at _____________ (region on centromere)

‘Motor’ proteins move chromosomes toward center of cell

8.5 Cell Division - Metaphase

Mitotic _______ is fully formed

Chromosomes line up on imaginary ___________ plate

Kinetochores of each sister chromatids face __________

8.5 Cell Division - Anaphase

Centromeres separate, sister _____________ separate Apart: daughter chromosomes

Motor proteins ‘walk’ chromosomes along microtubules toward _____

Some spindles push, some pull

Cell _________

8.5 Cell Division - Telophase

__________ of prophaseCell continues to elongateNuclear _________forms

around 2 daughter nucleiChromatin uncoilsSpindle fibers disappear__________ furrow forms and 2

cell separate

Mitosis Animation

8.6 Cytokinesis

Different for plants and animals Why?

In ________ cells cleavage furrow Actin microfilaments cause myosin to

___________

8.6 Cytokinesis

In plants cell ________

___________ with cell wall material move to middle

Fuse to create cell plate

8.6 Cytokinesis

8.7 Factors Affecting Division

__________ of cell division is key for an organism

Influence by ________ and _________ factors Growth factors Density __________ to anchor

‘Cell culture’


Growth factors

Secreted _________

Cause other cells to divide

Blood __________ release ‘platelet-derived growth factors’


__________ dependence Cell must contact a solid surface

Density-dependent inhibition ___________ cells stop dividing Contact of cell-surface proteins

responsible

8.8 Control System

In an organism cells are __________, receive nutrients Growth factors signal ___________

Cell cycle ________ system Like a washing machine Triggers/coordinates key

events

8.8 Control System

3 major checkpoints, what is the cell checking for? __________ of stage Environmental conditions Presence of ____________

molecules

G1 is most important G0 is a _______________ state

8.9 Cancer Cells

_________ is a disease of cell cycle

Transformed cells usually killed by ___________ system

__________ – abnormally growing mass; a cancer cell that proliferates

8.9 Cancer Cells

Benign tumor – abnormal cells remain at __________ site

Malignant tumors – __________ to other parts of the body

8.9 Cancer Cells

___________ – spread of cancer cells from their original site Circulatory system Lymphatic system

8.9 Cancer Cells

Named for original location

Carcinoma – internal or external ___________ of the body

___________ – tissue that supports the body

Leukemia / Lymphoma – blood-forming tissue and ________ nodes

8.9 Cancer Cells

Treatments

Surgical ___________

Radiation – damages _________ Cancer cells often lose ability to repair

______________ – disrupts cell cycle

8.10 Mitosis Review

Growth, cell replacement and asexual reproduction of multicellular organisms

Yields same chromosome _________ and ______

8.11 Homologous Pairs

___________ cells (all cells in your body except sperm/egg cells) - 46 chromosomes

22 pairs of ___________ chromosomes (autosomes) 1 homolog from mom, 1 from dad – carry genes controlling

same characteristics

1 pair of sex chromosomes

Other species typically have __________ homologs


Example of chromosome 1 during metaphase

Genes at the same ______ (location) May be different

types

__________ at the same location


_____ chromosomes – determine individual’s sex Autosomes – other 22 pairs

X and Y chromosomes are exceptions Females carry ____ Males carry ____

Not truly homologous

8.12 Gametes

_________ cell – any cell with 2 homologous chromosomes (2n=46) _________ cells

_________ cell – a cell with 1 set of chromosomes Gametes (sperm/egg cells) – 22 autosomes + 1 sex

chromosome Sex chromosome is either X or Y

8.12 Gametes

___________ – sperm and egg fuse Zygote is diploid

Mitosis takes over

How are gametes made? …_________

8.13 From Diploid to Haploid

Meiosis – cell division that _________ the number of chromosomes Single __________ of DNA followed by 2 divisions Meiosis I and Meiosis II Yields 4 daughter cells, each with _______ the number

of chromosomes as parent cell


8 stages of meiosis Prophase I Metaphase I Anaphase I Telophase I and Cytokinesis Prophase II Metaphase II Anaphase II Telophase II and Cytokinesis

Meiosis I

Meiosis II


Chromosomes _________DNA is a loose mass


Chromatin _______________________ – homologous

chromosomes (each 2 sister chromatids) pair up Results in a ___________ Crossing over – chromatids __________

segments of DNA

Centrosomes move, spindle forms


Tetrads align at imaginary __________ plate

________ microtubules attach to kinetochores at the centromeres


Tetrad is ________Sister chromatids stay _______

at centromere and move toward opposite poles together


2 daughter cells are ________, each chromosome consists of 2 sister chromatids

Meiosis II is the same as _________ just beginning with haploid cells

TYPO!!

Meiosis Animation

8.14 Mitosis vs Meiosis

8.15 Varied Offspring

Genetically __________ from parents and siblings

_____________ assortment/orientation

Red for maternal, blue for paternal

2n Combinations

223 for humans

about 8 million

8.16 Different Versions of Genes

Chromosomes each contain many ________ Homologous chromosomes have genes for same

_________ at same __________

8.17 Crossing Over

An exchange of ____________ segments of DNA between two homologous chromosomes

__________ – where 2 homologous, non-sister chromatids cross over

8.17 Crossing Over

1. ________ at the same place2. Rejoin the ________

chromatid3. ‘Untwist’ and homologs

separate4. Sister chromatids

_________

Yields 4 different chromosomes

8.19 Altering Chromosome Number

______________ – a pair of chromosomes fail to separate

8.19 Altering Chromosome Number

Trisomy – having ____ copies 13, 18 and 21 (Down syndrome)

Monosomy – having ____ copy

8.23 Chromosome Structure

Chromosome structure can be __________

Inversions less likely to have _________ effects than deletion or duplication

You should now be able to…

1. Compare the parent-offspring relationship in asexual and sexual reproduction.

2. Explain why cell division is essential for prokaryotic and eukaryotic life.

3. Explain how daughter prokaryotic chromosomes are separated from each other during binary fission.

4. Compare the structure of prokaryotic and eukaryotic chromosomes.

5. Describe the stages of the cell cycle.

6. List the phases of mitosis and describe the events characteristic of each phase.

7. Compare cytokinesis in animal and plant cells.


8. Explain how anchorage, cell density, and chemical growth factors control cell division.

9. Explain how cancerous cells are different from healthy cells.

10. Describe the functions of mitosis.

11. Explain how chromosomes are paired.

12. Distinguish between somatic cells and gametes and between diploid cells and haploid cells.

13. Explain why sexual reproduction requires meiosis.

14. List the phases of meiosis I and meiosis II and describe the events characteristic of each phase.


15. Compare mitosis and meiosis noting similarities and differences.

16. Explain how genetic variation is produced in sexually reproducing organisms.

17. Describe the causes and symptoms of Down syndrome.

1004 chapter 8_-_the_cellular_basis_of_reproductio

Career

dna cell

cell plate

contact of cell

cell division prophase

cell division telophase

center of cell

dependence cell

cell culture