Bio Exam 4

Front 1

cell cycle

Back 1

activities from one cell division to the next- acquire and digest nutrients, synthesis and growth, replication and division of DNA

Front 2

gametes

Back 2

haploid sex cell formed in sexually reproducing organisms

Front 3

interphase

Back 3

stage of cell cycle between cell divisions, chromosomes are replicated, other cell fxns occur such as growth, movement, and acquisition of nutrients

Front 4

mitosis

Back 4

production of gametes in plants and haploid organisms, growth and repair, and asexual reproduction; parent cell divides into two identical diploid daughter cells

Front 5

meiosis

Back 5

2 successive cell divisions with 1 interphase, produces 4 different haploid cells, reduces chromosome number from 2n to n, source of variability

Front 6

haploid

Back 6

1 set of chromosomes (n)

Front 7

diploid

Back 7

2 sets of parental chromosomes, 1 from each parent (2n)

Front 8

gametogenesis

Back 8

spermatogenesis (production of sperm)
oogenesis (production of egg or ovum)

Front 9

monoecious

Back 9

pertains to organisms where male and female gametes are produced in same individual

Front 10

dioecious

Back 10

pertains to organisms where male and female gametes are produced by separate individuals

Front 11

sexual reproduction

Back 11

reproduction in which genetic material from two parent organisms is combined in the offspring

Front 12

asexual reproduction

Back 12

single parent, genetically identical offspring (the parent body may divide and new parts regenerate, or a new smaller individual may form as an attachment to the parent to drop off when complete)

Front 13

genetic diversity

Back 13

-new gene combination, genotypes
- may result in new phenotypes
- may increase survival and reproduction rates

Front 14

rH factor

Back 14

protein on the red blood cells of some people (rH-positive), but not others (Rh negative); exposure of Rh-negative individuals to Rh-positive blood triggers production of antibodies to Rh-positive blood cells

Front 15

allele

Back 15

one of several alternative forms of a particular gene

Front 16

crossing over

Back 16

discovered by Morgan 1910, exchange of genetic material between homologous chromosomes during Meiosis 1, used to map chromosomes and locate genes

Front 17

nondisjunction

Back 17

error in meiosis where chromosomes fail to segregate properly into daughter cells

Front 18

parthenogenesis

Back 18

specialization of sexual reproduction, in which haploid egg undergoes development without fertilization

Front 19

conjugation

Back 19

-transfer of DNA between 2 temporarily joined cells
- cell donating DNA extends an external appendage, pilus
- cytoplasmic bridge forms and DNA, plasmid, is transferred
- pilus is withdrawn

Front 20

transduction

Back 20

discovered by Lederberg, Zindler, Lively in 1952, temperate virus carries portion of bacterial DNA from one host to another bacterium

Front 21

transformation

Back 21

AVery, Macleod, and McCarty in 1944, bacterium binds to and takes up DNA released into environment by dead bacteria

Front 22

chromosomes

Back 22

single DNA helix together with proteins that help organize DNA

Front 23

plasmids

Back 23

discovered in E. Coli, small accessory rings of DNA, can replicate independently of bacterial chromosome

Front 24

blastula

Back 24

embryonic stage attained at end of cleavage, embryo consists of hollow ball with a wall one or several cell layers thick, 7 days in humans

Front 25

morula

Back 25

embryonic stage during cleavage, embryo consists of solid ball of small cells, same size as zygote

Front 26

cleavage

Back 26

division of fertilized egg with no increase in size

Front 27

gastrula

Back 27

in animal development, a 3-layered embryo with ectoderm, mesoderm, and endoderm cell layers, 14 days in humans

Front 28

genotype

Back 28

actual combination of alleles carried by organism, ex- Pp

Front 29

phenotype

Back 29

organism's traits

Front 30

homozygous

Back 30

homologous chromosome has the same allele at a given gene locus

Front 31

heterozygous

Back 31

if two homologous chromosomes have different alleles at a locus

Front 32

dominant

Back 32

an allele that can determine the phenotype of heterozygotes completely

Front 33

recessive

Back 33

allele expressed only in homozygotes and completely masked in heterozygotes

Front 34

transposons

Back 34

described in Zea mays by McClintock 1940s, 1983 nobel prize, DNA sequences that change their chromosome location

Front 35

karyotype

Back 35

preparation showing number, sizes, and shapes of all chromosomes within a cell, therefore the individual the cells came from

Front 36

jacobs condition

Back 36

XYY, 1/1000 males, high testosterone, acne, tall, color blind, maternal uncle is color blind

Front 37

klinfelter's condition

Back 37

XXY, 1/1000, some show mixed secondary sexual characteristics, infertile but not impotent

Front 38

turner's condition

Back 38

XO, 1/3000, hormone deficiencies prevent menstruation or development of sexual characteristics, treatment with estrogen promotes physical development, can't bear children, suggests inactivation of 1 X chromosome in XX females is not complete b/c they would have identical features

Front 39

super female

Back 39

XXX or XXXX, 1/1000 women, no detectable defects, tendency to be tall and below normal intelligence, most are fertile and bear normal children

Front 40

trisomy 21

Back 40

1/900 births, ex chromosome 21, Down syndrome (weak muscle tone, small mouth, distinctive eyelids, low resistance, varying degrees of mental retardation) frequently increases with maternal age

Front 41

trisomy 18

Back 41

1/3000 births, extra material from chromosome 18, interferes with normal development

Front 42

trisomy 13

Back 42

1/10,000 births, extra chromosome 13, cleft lip, extra digits, mental retardation

Front 43

trisomy 13

Back 43

1/10,000 births, extra chromosome 13, cleft lip, extra digits, mental retardation

Front 44

prophase

Back 44

1st phase of mitosis
- duplicated chromosomes condense
-spindle microtubules form
-chromosomes are captured by the spindle

Front 45

metaphase

Back 45

middle stage, two kinetochores on a duplicated chromosome engage in tug of war, microtubules either lengthen or shorten, each chromosome lines up along equator of the cell, with one kinetochore facing each pole

Front 46

anaphase

Back 46

sister chromatids separate, allows motor proteins in kinetochores to pull chromosomes poleward along spindle microtubules, unattached spindle microtubules interact and lengthen to push poles of cell apart, forms oval shape

Front 47

telophase

Back 47

when chromosomes reach the poles, the spindle microtubules disintegrate, nuclear envelope forms around each group of chromosomes, they revert to extended state, nucleoli reappear, cytokinesis occurs

Front 48

codominance

Back 48

relationship between 2 alleles of a gene, both are phenotypically expressed in heterozygous individuals

Front 49

multiple alleles

Back 49

many alleles of a single gene, result of mutations