Biology Genetics

Front 1

Species Characteristics

Back 1

*characteristics that every member of a

species possesses

Front 2

Individual Characteristics

Back 2

*distinguishing features

*eyes, hair, skin color, body build,

intelligence,

*makes person unique

*inherited genes

*environment

*spiritual nature

Front 3

Genetics

Back 3

*the study of heredity

*the passing of characteristics from

parent to offspring

Front 4

Particulate Theory of Reproduction

Back 4

*Aristotle's theory

*particles of the parent's blood mix and then

join to form the offspring

Front 5

Preformationists

Back 5

*believed that there are tiny, completely

formed organisms in the father's sperm,

when planted in egg, they merely grow up

Front 6

Gregor Mendel

Back 6

*proposed that there are pairs of Factors

in organisms & that each parent gives a

single set of these factors to its offspring

*"Father of Genetics"

Front 7

Watson and Clark

Back 7

*described the structure of the DNA

molecule, opening the way to modern

genetics

Front 8

Gene

Back 8

*a section of DNA that produces a particular

polypeptide chain of amino acids(a protein)

that causes a particular trait

Front 9

Characteristics of a Gene

Back 9

*fundamentally identical in both type

and amount in the cells of an organism

*fundamentally identical in both type

and amount in the cells of each organism

of a species

*chemicals that can function as individual

units

Front 10

Characteristics of a Gene

card #2

Back 10

*able to carry information for the

formation of organic chemicals

*able to reproduce themselves

*can be passed on to the next generation

*found in the cell's nuclear material

Front 11

Chromosomes

Back 11

*a long strand of DNA with proteins attached

Front 12

Chromatin Material

Back 12

*chromosomes as they appear in an active

nondividing cell

*fuzzy, tangled mass

Front 13

Histones

Back 13

*help support and protect, thin strands of

DNA

Front 14

Chromatid

Back 14

*duplicated chromosome held together

to the other half by the Centromere

Front 15

What determines a species?

Back 15

*it is not the number of chromosomes

that determine a species, but rather

the Genes on the chromosomes

Front 16

Karyotype

Back 16

*a picture of the chromosome in the cell

*shows that chromosomes occur in pairs

*Humans have 23 pairs of chromosomes

*these pairs are called Homologous

Chromosomes

*each member of a homologous pair of

chromosomes is called a Homologue

Front 17

Diploid

Back 17

*when a cell has homologous pairs of

chromosomes

*abbreviated 2n

*most common organisms are this

*human ______ number is 46(2n=46)

Front 18

Haploid

Back 18

*cells that only have one set of chromosomes

*abbreviated n

Front 19

Cell Cycle

Back 19

*repeating cycle of events in the life of

a cell

*3 major phases: interphase, mitosis,

and cytokinesis

Front 20

Interphase

Back 20

*growth phase of the cell

*cell spends most of its time in this phase

*has 3 stages: G1, S, and G2

*G1--growth phase

*S--DNA replication phase

*G2--preparation for mitosis

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Mother Cell

Back 21

*cell that is ready to begin mitosis

Front 22

Mitosis

Back 22

*division of nuclear material, so that each

new nucleus has an identical copy of the

genetic info from the mother cell

*has 4 phases: Prophase, Metaphase,

Anaphase, Telophase

Front 23

Prophase

Back 23

*first phase of Mitosis

*centromeres migrate to poles in the

cytoplasm & chromosomes develop form

chromatin material in the nucleus

*chromosomes in the nucleus get short

and thick

*Mitotic Spindle forms: special microtubules

that will direct the movement of chromosomes

Front 24

Metaphase

Back 24

*2nd phase of mitosis

*chromosomes congregate along the

equatorial plane(an imaginary line bisecting

the spindle) of the cell

*this phase forms the familiar X shape

of a chromosome

Front 25

Anapahse

Back 25

*3rd phase of mitosis

*paired chromatids separate and begin

to migrate toward opposite poles of the

cell

*once the chromatids separate, they are

considered individual Daughter

Chromosomes

Front 26

Telophase

Back 26

*4th phase of mitosis

*chromosomes have reached opposite

poles of the cell and 2 distinct nuclei form

Front 27

Cytokinesis

Back 27

*the division of the cytoplasm in a

dividing cell

*forms 2 daughter cells

Front 28

Variations of Mitosis

Back 28

*plants vs. animals

*cytokinesis

*unicellular organisms

*sometimes no cytokinesis

*results in multiple nuclei

*all cells

*amount of time

*length of interphase and number of division

Front 29

Uses of Mitosis

Back 29

*growth

*repair

*and replacement of cells in multicellular

organisms

Front 30

Asexual Reproduction

Back 30

*any form of reproduction that involves

only mitotic cell divisions

*no genetic variety

*examples: fragmentation, budding, spores

Front 31

Meiosis

Back 31

*the reduction of a cell's chromosome

number from diploid to haploid by 2

consecutive cell divisions: meiosis 1

and meiosis 2

Front 32

Zygote

Back 32

*a diploid cell formed by the union of

2 haploid gametes

*n+n=2n

Front 33

Meisos Prophase

Back 33

*same as mitosis in that the chromosomes

tightly coil up & the mitotic spindles begin

to form

* different from mitosis in that the duplicated

homologous chromosomes pair up, forming

a structure called the Tetrad

Front 34

Meiosis Metaphase 1

Back 34

*the tetrads line up on the equatorial

plane

Front 35

Meiosis Anaphase 1

Back 35

*homologous chromosomes separate

(not the sister chromatids as in mitosis)

Front 36

Meiosis Telophase 1 and cytokinesis

Back 36

*chromosomes arrive at the poles of the

cell

*usually do not uncoil

*cell undergoes cytokinesis and 2 new

cells enter directly into the second division

of meiosis

Front 37

Meiosis 2

The Second Division

Back 37

*will produce 4 daughter cells, each with

one unduplicated chromosome of each

pair

Front 38

Meiosis 2

Prophase 2

Back 38

*a mitotic spindle re-forms and the spindle

fibers begin to move the chromosomes

toward the equatorial plane of the cell

Front 39

Meiosis 2

Metaphase 2

Back 39

*chromosomes are aligned on the equatorial

plane

*now there is only one member of the

homologous chromosomes pair on the

equatorial plane

Front 40

Meiosis 2

Anaphase 2

Back 40

sister chromatids separate, and the

resulting daughter chromosomes move

toward opposite poles

Front 41

Meiosis 2

Telophase 2

Back 41

*nuclei are reformed and each of the four

new cells has a haploid chromosome

number

Front 42

Gametes

Back 42

*haploid cells that, when they unite,

form a diploid cell called a zygote(the

first cell of a new individual)

Front 43

Fertilization

Back 43

*the process of forming a zygote, the union

of gametes

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isogametes

Back 44

*gametes that are all alike

*move by cilia or flagella

*many algae and fungi produce isogametes

Front 45

heterogametes

Back 45

*is usually either a sperm formed by a male

or an ovum formed by a female

*humans, all animals, many plants, and few

other organisms produce heterogametes

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spermatogenesis

Back 46

*forming of sperm

*produces 4 functional gametes

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oogenesis

Back 47

*forming of an ovum

Front 48

sexual reproduction

Back 48

*the union of haploid gametes, resulting

in a diploid zygote

*offspring are not genetically identical to

either parent

*the offspring have one chromosome of every

pair from each parent

Front 49

Gregor Mendel

Back 49

*born in 1822 on a farm in Austria

*Father of Genetics

*Mendelian Genetics:he used peas to study

genetics

*he started with self-pollinating, purebred

plants

*used self-pollination and cross-pollination

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Self-pollination

Back 50

*the process by which a plant's structure

allows its own pollen to provide the sperm

for fertilization of ova

Front 51

Cross-pollinaiton

Back 51

*to fertilize a flower with the pollen from

another flower

Front 52

dominant trait

Back 52

*Mendel called a trait that is expressed

when factors for two opposing traits are

present the ______trait. Caused by a

_______gene.

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recessive trait

Back 53

*Mendel called a trait that is masked(hidden)

when 2 genes for opposing traits are

present the _________trait. Caused by a

_________gene.

Front 54

Concept of Segregation

Back 54

*Mendel reasoned that when a cell forms

gametes, the genes segregate(separate)

so that there is only one gene for each

characteristic in each gamete.

Front 55

Phenotype

Back 55

*the physical expression of an organism's

genes----what an organism is like(tall, green,

constricted).

*not all genes result in a visible trait

example:every person inherits digestive

enzymes that must work for him, but are

not seen

Front 56

Genotype

Back 56

*the specific genes that an organism contains

its genetic makeup

*often expressed by letters such as TT, Tt

tt and so forth

Front 57

Locus

Back 57

*the specific site on a chromosome where

a particular gene is located

Front 58

Allele

Back 58

*an alternate form of a gene that occupies

the same locus on homologous chromosomes

*they are often expressed by letter: T or t

Front 59

Homozygous

Back 59

*the condition where both alleles in an

organism are the same

*TT or tt

Front 60

Heterozygous

Back 60

*the condition in which both alleles in an organism are not the same

*Tt

Front 61

Monohybrid Cross

Back 61

*a cross between individuals that deals

with only one set of alleles, that is, with

one set of opposing characteristics.

Example: the cross between short & tall

pea plants is a monohybrid cross

Front 62

Punnett Square

Back 62

*a diagram used to depict genetic crosses

and to determine the probability of the

offspring's particular genotype & phenotype

Front 63

Test Cross

Back 63

*mating an organism that has the dominant

phenotype but an unknown genotype

with another plant that has the homozygous

recessive phenotype

Front 64

Pedigree

Back 64

*chart that geneticists use to trace the

presence or absence of a trait in a

number of generations

Front 65

Difference is Mitosis and Meiosis

Back 65

*alike because they both involve cell

division

*different in that meiosis involves 2

cell divisions and produces haploid cells,

mitosis involves only 1 cell division