Chapters 8-10

Question 1

Mitosis

Answer 1

somatic cells; asexual vs. multi-celled eukaryotes: increase in body size in growth; replacement of dead cells; repair of damaged tissues

Question 2

Chromosome #

Answer 2

sum of chromosomes in cells of a given type (human haploid: 46)

Question 3

nucleosome

Answer 3

each histone-DNA spool

Question 4

cell cycle (mitosis)

Answer 4

P,M,A,T,G1,S,G2 Early P: DNA condenses Late P: chromosomes continue to condense; new microtubules assemble; nuclear envelope breaks Transition to M: microtubules penetrate nuclear region; bipolar spindle apparatus M: chromosomes lined up at spindle equator A: microtubules move to opp. spindle poles T: patches of new membrane fuse to form a nuclear envelope

Question 5

spindle apparatus

Answer 5

moves chromosomes during mitosis

Question 6

cytokinesis

Answer 6

cytoplasmic division: plants (vesicles form cell plate at spindle equator) animals (ring of microfilaments attached to plasma membrane contracts; cleavage furrow)

Question 7

Allele

Answer 7

each unique molecular form of the same gene

Question 8

PMA1 vs mitosis

Answer 8

homologous chromosomes align upon metaphase plate; sister chromatids aren’t divided

Question 9

crossing over in prophase I

Answer 9

interaction between 2 nonsister chromatids of a pair of homologous chromosomes; genetic recombination a chromosome and a homologous partner trade segments to produce a genetic variation, yielding an infinite variation of cells

Question 10

Meiosis I vs. meiosis II

Answer 10

I: duplicated chromosomes align w/ partner (homologue to homologue) II: two sister chromatids of each chromosome separate

Question 11

metaphase I alignments

Answer 11

random attachment and subsequent positioning

Question 12

spores

Answer 12

haploid resting cells; resist adverse environmental conditions

Question 13

sperm & oocyte

Answer 13

4 spermatoids vs. 3 polar bodies + 1 ovum

Question 14

fertilization

Answer 14

female & male gametes unite and their haploid fuse

Question 15

only clones

Answer 15

mitotic cell division

Question 16

meiosis variation

Answer 16

1. crossing over 2. random assignment 3. diff. combos during fertilization

Question 17

sexual reproduction requirements

Answer 17

meiosis, gamete formation, & fertilization

Question 18

homologous chromosomes

Answer 18

carry same genes, same length/shape, interact at meiosis

Question 19

gene

Answer 19

unit of info about specific traits; has specific locus on a chromosome

Question 20

diploid chromosome #

Answer 20

cell has pairs of genes on pais of homologous chromosomes

Question 21

true breeding lineage vs. hybrid offspring

Answer 21

true-breeding: inherit pair of identical alleles generationally hybrid: inherit a pair of nonidentical alleles for a trait

Question 22

AA vs. aa vs. Aa

Answer 22

homozygous dominant vs. homozygous recessive vs. heterozygous

Question 23

genotype vs. phenotype

Answer 23

genotype: particular alleles phenotype: individual’s observable traits

Question 24

testcross

Answer 24

organism shows dominance for a specified trait but its genotype is unknown; crossed with known homozygous recessive allele

Question 25

Mendel's theory of segregation

Answer 25

Diploid cells have pairs of genes on pairs of homologous chromosomes Genes of each pair are separated from each other during meiosis, ending in diff. gametes

Question 26

Mendel's theory of independent assortment

Answer 26

By the end of meiosis, genes on pairs of homologous chromosomes have been sorted for distribution into gametes independent of how other pairs were sorted

Question 27

incomplete dominance

Answer 27

one allele pair isn't fully dominant over its partner; heterozygous phenotype somewhere between 2 homozygous (red, pink, white; 1:2:1)

Question 28

codominance

Answer 28

a pair of nonidentical alleles specify 2 phenotypes (expressed in heterozygous) e.g. 3 alleles I\_A, I\_B, i: A, AB, B, O multiple allele system

Question 29

pleiotrophy

Answer 29

phenotypic outcome of a single gene's activity

Question 30

epistasis

Answer 30

interactions between the product of pairs of genes

Question 31

continuation variation

Answer 31

outcome of the # of genes affecting a trait & the # of environmental factors influencing their expression

Question 32

polygenic

Answer 32

describes how several genes result in a single trait; graph ppl of a polygenic trait to create a bell curve (e.g. eye color, height)