A&P Ch 4

Question 1

nucleic acid structure

Answer 1

nitrogenous base (AGCUT), sugar (DNA=deoxyribose, RNA=ribose), phophate

Question 2

nitrogenous base

Answer 2

purines=AG, pyrimidines=CUT

Question 3

purines

Answer 3

A=adenine, G=guanine

Question 4

pyrimidines

Answer 4

C=cytodine, U=uracil, T=thymin

Question 5

dna structure

Answer 5

double stranded, twisted ladder, backbone is formed of sugar and phosphate, complementary base pairing A-T, C-G. held together with hydrogen bond

Question 6

dna function

Answer 6

dna-rna-protein, dna holds the instructions, proteins build the organism

Question 7

chromatin

Answer 7

dna+histones coiled together into nucleosomes and looped. to prepare for division, the chromatin loops again (condenses)

Question 8

rna structure and function

Answer 8

mrna-> protein. single stranded. mrna, rrna, trna

Question 9

mrna

Answer 9

only lasts a couple hours, carries messages from dna to ribosomes

Question 10

rrna

Answer 10

makes up ribosome along with proteins

Question 11

trna

Answer 11

carries amino acids to ribosome to make protein

Question 12

gene

Answer 12

unit of heredity contained on a chromosome. sequence of dna that can be transcribed to rna and usually translated to a protein

Question 13

human genome

Answer 13

all the dna sequences in one set of chromosomes. 23 pairs of chromosomes.

Question 14

genetic code

Answer 14

the 4 dna nucleotides are arranged in groups of 3=base triplet. base triplet -> codon (mrna) via transcription. codon->amino acid(protein) via translation. 64 possible codons. 60 code for 20 amino acids, 3 code for stop and 1 codes for start

Question 15

transcription

Answer 15

dna->pre-rna. rna polymerase. pre-rna->mrna. happens in nucleus

Question 16

translation

Answer 16

mrna->protein. ribosomes. happens in the ribosome. trna brings one amino acid at a time to growing polypeptide. polyribosomes speed the process.

Question 17

gene regulation

Answer 17

any one cell only uses a fraction of the genome. any one part of the genome may only be used at particular times

Question 18

dna replication

Answer 18

photocopying instruction book. cell replicates dna for growth, repair and maintenance. epithelial cells divide most. dna unwinds from histones, helicase opens helix, polymerase makes complementary strand, dna is rewound into chromatin

Question 19

cell cycle

Answer 19

g1, s, g2, m, cytokinesis, g0

Question 20

g1

Answer 20

first gap, growth and normal metabolic roles

Question 21

s

Answer 21

synthesis, dna replication, organelles double

Question 22

g2

Answer 22

2nd gap, growth and prep for mitosis

Question 23

m

Answer 23

division of dna

Question 24

cytokinesis

Answer 24

division of everything else

Question 25

g0

Answer 25

cells leave cell cycle

Question 26

mitosis

Answer 26

growth of the embryo and individual. replacement of cells. repair of injured tissue

Question 27

mitosis terminology

Answer 27

chromosome->2 sister chromatids, centromere, mitotic spindle, kinetochore, centriole, cytokinesis

Question 28

stages of mitosis

Answer 28

prophase, metaphase, anaphase, telophase

Question 29

prophase

Answer 29

nuclear membrane disintegrates, assemble mitotic spindle, chromosomes condense

Question 30

metaphase

Answer 30

sister chromatids align in the middle

Question 31

anaphase

Answer 31

separating

Question 32

telophase

Answer 32

chromosomes condense, reassemble mitotic spindle, nuclear membrane reappears

Question 33

karyotype

Answer 33

23 pairs of homologous chromosomes=22 pair of autosomes + 1 pair of sex chromosomes.

Question 34

homologous chromosomes

Answer 34

one pair of chromosomes, 1 maternal, 1 paternal, each member of the pair has the same genes, but may have different forms of the gene->different alleles.

Question 35

homozygous

Answer 35

same allele

Question 36

heterozygous

Answer 36

different allele

Question 37

phenotype

Answer 37

observable expression of a genotype

Question 38

punnet square

Answer 38

allows analysis of genetic make-up of offspring

Question 39

multiple alleles

Answer 39

more than 2 alleles of one gene are present in the gene pool

Question 40

codominance

Answer 40

expression of both alleles is observed in the phenotype

Question 41

incomplete dominance

Answer 41

phenotype is intermediate between 2 different alleles

Question 42

polygenic inheritance

Answer 42

many genes contribute to 1 phenotype

Question 43

pleiotropy

Answer 43

one gene contributes to many phenotypes

Question 44

sex linked traits

Answer 44

carried on the x chromosome. males are affected more than females. only mothers can pass these on to their sons.