Biology 101 Test 3 Chapter 8

Front 1

What is Cell reproduction

Back 1

Creation of new cells from already existing ones

Front 2

Chromatin

Back 2

All the DNA molecules plus their associated protein in the nucleus

Front 3

Chromosomes

Back 3

An individual DNA molecule plus its associated protein

Front 4

How many Chromosomes in a human and how many Pairs?

Back 4

46 Chromosomes in a human
23 pairs

Front 5

Homologous chromosomes:

Back 5

Two members of a pair of chromosomes that are similar in size and shape and that carry the same genes

Front 6

Karyotype

Back 6

A picture of your chromosomes

Front 7

What does The last pair of chromosomes do?

Back 7

Determines the sex

Front 8

What are genes?

Back 8

Unites of instructions that influence a partcular trait

Front 9

What is a Locus

Back 9

Location of a gene on a chromosome

Front 10

What are Alleles?

Back 10

Alternative forms of a gene

Front 11

What is a Dominant Allele

Back 11

One allele of a pair that suppresses the effect of the other allele in the pair

Front 12

What is a Recessive Allele

Back 12

The allele in the pair that is suppressed

Front 13

What is Homozygous

Back 13

If the two alleles are in a pair are the same

Front 14

What is heterozygous

Back 14

The two alleles are in a pair are different

Front 15

What is Genotype

Back 15

Genetic makeup of an individual

Front 16

What is Homozygous dominant individual

Back 16

has two dominant alleles for the trait being studied

Front 17

Homozygous recessive individual

Back 17

has two recessive alleles for the trait being studied

Front 18

Heterozygous individual

Back 18

has two different alleles

Front 19

What is Phenotype

Back 19

external manifestation (expression) of the gene

Front 20

Diploid Cells

Back 20

Has two chromosomes of each type

Front 21

What are haploid cells

Back 21

Have only one chromosome of each type

Front 22

Describe germ cells

Back 22

Cells that produce gametes (diploid) ovary cell – 46 and testis cell - 46

Front 23

What are Gametes

Back 23

egg and sperm (sex cells)

Front 24

What is chromatin made of?

Back 24

DNA + Proteins

Front 25

Nucleosomes

Back 25

are bead like structures formed of DNA wound around 8 proteins
----o-----o-----o-----o----

Front 26

DNA duplicates

Back 26

(46) -> (92)< (46) & (46)

Front 27

Sister Chromatids

Back 27

the two parts of a chromosome just before cell division. (Remain attached at the centromere)

Front 28

What is the cell cycle?

Back 28

Comprises all the events in the lifetime of a cell, from the time it is produced to the time it completes division itself.

Front 29

4 Main Events in the lifetime of a Cell

Back 29

Growth
Duplication of DNA
Nuclear Division
Cytoplasmic Division

Front 30

What can the cell cycle be divided into?

Back 30

Interphase and Mitosis

Front 31

Events in Interphase

Back 31

G1 phase, S phase and G2 phase
G1: The first gap (resting stage)
S phase: Synthesis phase (replication of DNA phase)
G2 phase: 2nd gap interval (resting stage)

Front 32

IPMATC

Back 32

Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis

Front 33

5 Events in Prophase

Back 33

In the nucleus
-Nucleolus disappears
-Nuclear membrane starts disintegrating
-chromosomes shorten and condenses
In the cytoplasm
-Spindle fibers are formed
-Centrioles duplicate

Front 34

Events in Metaphase?

Back 34

- Nuclear membrane completely disappears
- Spindle fibers attach to centromeres of chromosomes
- And they pull on them until they are oriented in the equatorial region of the cell

Front 35

Events in Anaphase?

Back 35

-Spindle fibers start pulling sis chromatids to the opposite poles
-Sister chromatids are pulled apart which they are then called chromosomes

Front 36

Events in Telophase?

Back 36

-Chromosomes arrive at poles
-Return to being thread-like
- Nuclear membrane and nucleolus reappear

Front 37

Cytokinesis?

Back 37

Cytoplasm divides after nucleuos

Front 38

Cytokinesis in Plant Cells

Back 38

Vesicles containing (come) from Golgi complex cell wall material get lined up at the equator combining to make a cell plate then a new cell wall is formed to parent cells.

Front 39

Cytokenis in Animal Cells

Back 39

The formation of cleavage furrow which (then divides the cell) which divides from the contracting ring of microfilaments at the equator that get aligned

Front 40

What happens in Meiosis?

Back 40

Leads to gamete formation (sperm and egg)
Diploid germ cells –meiosis Haploid gametes
*Reduced to half*
Germ cells undergo meiosis gets 4 daughter cells

Front 41

What does meisois have that mitosis does not have?

Back 41

Synapsis (they look for their partner and pair homologous chromosomes) and then crossing over take place (Non sister chromatids cross over and exchange genes and chromosomal segments in Propahse 1

Front 42

What is Mitosis for?

Back 42

Growth and repair and Asexual reproduction

Front 43

What is Meiosis for?

Back 43

Gamete formation

Front 44

End result: (# of daughter cells produced) in Mitosis

Back 44

2 diploid daughter cells

Front 45

End result: (# of daughter cells produced)

Back 45

4 haploid daughter cells

Front 46

Chromosome #: in Mitosis when finished

Back 46

Maintaining from generation to generation

Front 47

Chromosome #: in Meiosis when finished

Back 47

halved

Front 48

What is Variation in a species brought about by?

Back 48

a. Independent assortment of Chromosomes
b. Random Fertilization
c. Crossing over

Front 49

What is Independent assortment of Chromosomes

Back 49

random segregation (separation) and assortment (packaging) of chromosomes during gamete formation (gametogenesis) to produce unique gametes.

Front 50

What is random fertilization?

Back 50

-Any one of the 8 million eggs can unite with any one of the 8 million sperms out there
- Hence, you could get a zygote that could have any one of the 64 trillion possible combinations of chromosomes (8x10*6 X 8x10*6 = 64X10*24)

Front 51

What is Crossing Over?

Back 51

-The exchange of chromosomal segments between non sister chromatids of homologous chromosomes in Prophase 1
-Gametes formed get random mixes of paternal and maternal chromosomes
-This gametes formed are different (varied), resulting in variation in the population

Front 52

What are some errors in meiosis?

Back 52

Non-disjunction, Trisomy 21

Front 53

What is Non-disjunction?

Back 53

-Sis chromatids do not disjunct causing gametes formed to have one less or one more than the normal number of chromosomes it should have

Front 54

What is Trisomy 21

Back 54

When women produces (n+1) egg, the extra chromosome being chromosome #21
Thus zygote formed has 3 copies of #21 (47 chromosomess). This is also called Downs syndrome.

Front 55

What is Turner Syndrome

Back 55

-Females that are short, infertile because no functional ovaries
Lack One X chromosome (45 Chromosome)

Front 56

What is Klinefelter syndrome

Back 56

- XXY
-Taller than average
-Testes abnormally small and do not produce sperm
- Gynecomastia (partial breast development)

Front 57

What is XYY condition (Jacobs Syndrome)

Back 57

-Males
-Taller than average
- Mildly retarded
- Gets into a lot of trouble

Front 58

What is XXX condition?

Back 58

- Slightly lower IQ
-Females
-Emotional behavioral problems
- Females with triple X syndrome have normal sexual development and are to conceive children.