 LABEL THE PARTS OF THE CHROMOSOME_______

 1.CHROMATID  2. CENTROMERE  3. SHORT ARM  4. LONG ARM  5. CHROMOSOME 5.

 Chromosomes are made up of 2 _____________ joined together at the ____________. Chromatids are made of ________ wrapped around a protein called _______.

 Chromosomes are made up of 2 chromatids joined together at the centromere. Chromatids are made of chromatin wrapped around a protein called histones.

 Label the parts of the cell cycle. Include the 5 parts from letter D.

 A. G1  B. S  C. G3  D. Mitosis  Prophase  Metaphase  Anaphase  Telophase  Cytokinesis

Sketch a nucleotide Monomer. Label the 3 Main parts.

 Of the four nitrogen bases in DNA, which two are purines and which two are pyrimidines?

Adenine Guanine  Purines are Adenine and Guanine Thymine Cytosine  Pyrimidines are Thymine and Cytosine

 Where is DNA located during interphase of Eukaryotic cells? Where in prokaryotic cells? When to chromosomes become visible?

 IN THE NUCLEUS  IN THE CYTOPLASM  DURING MITOSIS OF THE CELL CYCLE AFTER G2

 The complementary base pairing rule says that purines bond to pyrimidines. G always bonds to ____ with ___ hydrogen bonds. A bonds to ____ with ___hydrogen bonds?

 The complementary base pairing rule says that purines bond to pyrimidines. G always bonds to C with 3 hydrogen bonds. A bonds to T with 2 hydrogen bonds?

 In RNA molecules, adenine is complementary to___.

 uracil

List the 3 parts of interphase and tell what happens during each.

INTERPHASE – non-dividing phase G 1 - Grow bigger Cell is “doing its job” DNA is spread out as chromatin S - Synthesis (copy DNA) & chromosomal proteins G 2 - Grow bigger, make organelles & molecules needed for cell division

 List 2 reasons why cells begin mitosis and divide.

 Two reasons for cells to divide are 1.repair of tissues and 2.the growth and development of an organism.

 List two reasons surface area to volume ratio has to do with cell size?

 Surface Area to Volume Ratio: 1. As a cell grows larger, the volume inside the cell increases at a faster rate than the surface area (cell membrane). Therefore, the cell can't exchange nutrients and wastes as easily. 2. The nucleus capacity: The DNA in the nucleus can only control so much.

BIGGER CELLS NEED MORE FOOD and OXYGEN, but CAN’T TRANSPORT IT FAST ENOUGH or IN BIG ENOUGH QUANTITIES!

 Describe and draw the DNA in prokaryotes (ONLY BACTERIA).

 Bacterial DNA is circular.  Prokaryotes have one chromosomes.  No nucleus & attached to cell membrane  Bacteria divide by asexual binary fission

 What happens when an error is made in the replication process? Which kind of mutations are passed to offspring? Which kind of mutation is passed to offspring?

 Mutation  Only germ cell or sex cell mutations are passed to offspring, somatic cell or body cell mutations are typically not.  Examples of mutagens (cause mutations) are UV radiation and cigarette smoke.

 All sexually reproducing organisms have chromosomes that occur in _____. These pairs separate during meiosis and are called ___________ pairs.

 All sexually reproducing organisms have chromosomes that occur in pairs. These pairs separate during meiosis and are called homologous pairs.

 SAME SIZE  SAME SHAPE  CARRY GENES for the SAME TRAITS  BUT ______________! (Don’t have to have the SAME CHOICES) NOT IDENTICAL

What is a Karyotype?

A __________ is a picture of an organism’s chromosomes KARYOTYPE

 Which chromosomes determine the sex of the baby? All other chromosomes = _____. Humans have two sex chromosomes and _____ autosomes.

Chromosomes that determine the sex of an organism = _________________ All other chromosomes = _________________ Sex chromosomes autosomes Humans have two sex chromosomes and _____ autosomes X y 44

XX = Xy =

XX = Xy = female male femalemale

Mom can give X Dad can give X or y SO ____ determines sex of the baby. If dad gives X with mom’s X = girl If dad give y with mom’s X = boy X X X y X X y Dad

Homologous chromosomes ________________ during MEIOSIS = __________________. One cell gets 2 copies of the chromosome the other cell gets none. NONDISJUNCTION fail to separate

Since it happens to a sperm or egg, the new baby can end up with _____________ of a chromosome = __________________ OR only ___________ of a chromosome = __________.

Since it happens to a sperm or egg, the new baby can end up with _____________ of a chromosome = __________________ OR only ___________ of a chromosome = __________. TRISOMY MONOSOMY 3 copies one copy

Down syndrome Klinefelter syndrome Turner syndrome

 LABEL interphase, cytokinesis, and the parts of Mitosis. Label CHROMATIN, SPINDLE FIBERS, CENTRIOLES, EQUATOR. WHICH CELLS DIVIDE BY MITOSIS? What does it mean to remain in G0? Which remain in G0?

centrioles chromatin Spindle fibers interphaseprophase metaphase anaphase cytokinesis telophase Somatic or body cells divide by mitosis. Cells that remain in G0 no longer divide by mitosis. Nerve cells are an example

 Briefly describe what happens during interphase.

In between divisions Cells are in this phase most of the time Can see nucleus DNA spread out as chromatin Can’t see chromosomes DNA gets copied (S) Cell gets ready to divide

 Briefly describe what happens during prophase of mitosis.

PROPHASE 1st dividing phase Spindle fibers form & attach to chromosomes Nuclear membrane & nucleolus disappear DNA scrunches into chromosomes Centrioles appear

 Briefly describe what happens during metaphase of mitosis.

METAPHASE Chromosomes line up in ___________ middle

 Briefly describe what happens during anaphase of mitosis.

ANAPHASE Centromeres split Centrioles pull chromatids_______ apart

 Briefly describe what happens during telophase of mitosis.

TELOPHASE (reverse prophase steps) See ______ nuclei Nuclear membrane & nucleolus return Chromosomes spread out as chromatin Centrioles disappear Spindle fibers disappear two

 Briefly describe what happens during cytokinesis.

CYTOKINESIS Cytoplasm splits into 2 cells ANIMAL CELLS pinch cytoplasm in two with a ______________________ CLEAVAGE FURROW

CYTOKINESIS Cytoplasm splits into 2 cells PLANT CELLS can’t pinch because they have a sturdy ____________ Plant cells separate cytoplasm by growing a _______________ down the middle. CELL PLATE CELL WALL

Define sexual reproduction.

Combines genetic material from 2 parents (sperm & egg) so offspring are genetically __________ from parents DIFFERENT + 

Define sexual reproduction.

Use the base pairing rules to correctly match the nitrogen bases together. ________________pairs with_______________ ________________pairs with ______________ What is the overall purpose of Meiosis?

to make cells with ½ the number of chromosomes for sexual reproduction

Use the base pairing rules to correctly match the nitrogen bases together. ________________pairs with_______________ ________________pairs with ______________ Most cells have 2 copies of each chromosome = ______________ All BODY (___________) cells are diploid HOMOLOGOUS CHROMOSOMES

Most cells have 2 copies of each chromosome = ______________ (one from mom; one from dad) All BODY (___________) cells are diploid DIPLOID2n HOMOLOGOUS CHROMOSOMES = SOMATIC

Some cells have only one copy of each chromosome = _____________ All sperm and egg cells are haploid

Some cells have only one copy of each chromosome = _____________ All sperm and egg cells are haploid HAPLOID or 1n

Makes ____ cells genetically different from parent cell & from each other Makes _____ cells Makes ______________ Used for ___________

Makes ____ cells genetically different from parent cell & from each other Makes _____ cells Makes ______________ Used for ___________ 4 1n Gametes (sperm & eggs) sexual reproduction

Label the steps of meiosis.

 Complete the table.

 How do your chromosomes appear in your body cells? (BE SPECIFIC!)

 How do your chromosomes appear in your body cells? (BE SPECIFIC!) ANSWER IN PAIRS

 If a diploid (body) cell in a buffalo has 60 chromosomes, how many chromosomes does its sex cells have?

ANSWER 30

 What type of cells are seen at letter D?

ANSWER HAPLOID OR SEX CELLS

 During which phase of Meiosis I does crossing over between maternal and paternal chromosomes take place?

ANSWER PROPHASE I

 What is the process of sperm coming into contact with an egg called?

ANSWER FERTILIZATION

 What is another name for gametes?

ANSWER SEX CELLS

 At the end of Meiosis, how many cells do you have?

ANSWER 4

 Human haploid (sex) cells contain 23 chromosomes. How many chromosomes do their diploid cells contain?

ANSWER 46

 What important process happens during Prophase I, that makes Meiosis different from Mitosis?

ANSWER Crossing Over

 How many chromosomes are in the cells created during Meiosis for humans?

ANSWER 23

 How many cells does the process of Meiosis I end with?

ANSWER 2

 Describe Independent Assortment. When does it occur?

Chromosomes separate independently of one another This is why you don’t look exactly like your brothers and sisters even though you share the same parents!

___________________= MAKING MATURE SPERM Mature & grow flagella

___________________= MAKING MATURE SPERM Mature & grow flagella SPERMATOGENESIS

POLAR BODIES Produces: 1 “good” egg 3 CYTOPLASM DIVIDES UNEVENLY __________________ = MAKING a MATURE EGG

POLAR BODIES Produces: 1 “good” egg 3 CYTOPLASM DIVIDES UNEVENLY __________________ = MAKING a MATURE EGG OOGENESIS