Chapter 4 (21)

Question 1

replication

Answer 1

when DNA is copied before every cell division

Question 2

transcription to RNA

Answer 2

when DNA is copied for instructions to be activated

Question 3

DNA replication steps

Answer 3

1. enzyme “unzips” H-bonds, separating strands
2. new nucleotides are added by a second enzyme
3. complementary base pairing ( A&T, C&G)
4. proofreading & error correction
5. Final enzyme seals breaks in backbone
6. mutation if any change in sequence between original and final

Question 4

what are the 4 categories of RNA

Answer 4

messenger, ribosomal, transfer, small RNAs

Question 5

messenger RNA

Answer 5

carries copy of DNA template for translation into protein

Question 6

ribosomal RNA

Answer 6

combines with proteins to make ribosomes

Question 7

transfer RNA

Answer 7

transfers amino acids to ribosomes

Question 8

small RNA

Answer 8

assist with making mRNA and rRNA

Question 9

Transcription

Answer 9

making of mRNA in nucleus

Question 10

steps of transcription

Answer 10

1. enzyme unzips section of DNA
2. complementary base pairing (but with U) from just one strand
3. joining of nucleotides along P backbone
4. Processing to mature
   removing non-coding parts (introns) & leave only coding parts (exons)
   add cap and tail to ends

Question 11

Translation

Answer 11

turning mRNA into amino acid sequence in cytoplasm

Question 12

translation steps

Answer 12

1. mRNA has code-3 nucleotides are CODON for one amino acid.
2. tRNA has anticodon to complement codon and carries one amino acid
3. tRNA has anticodon to complement codon and carries one amino acid
4. ribosome reads mRNA and has binding sites where codons and anticodons match up
   p-site holds tRNA with polypeptide chain, A-site holds tRNA with next amino acid, peptide bond forms, P-site tRNA detaches, A-site tRNA moves over to P-site, repeat until termination signal

Question 13

one mRNA can have many

Answer 13

ribosomes reading it at once

Question 14

polypeptide chains must go through

Answer 14

further processing & folding to make working enzymes

Question 15

what are the 4 types of tissues

Answer 15

connective, muscle, nervous, epithelial

Question 16

connective tissue

Answer 16

“glue” of body
cells mixed with extracellular matrix of proteins and ground substances
protein fibers: collagen, elastic, reticular
ground substances: solid, fluid, semi-like

Question 17

three types of connective tissue

Answer 17

fibrous, supportive, fluid

Question 18

fibrous connective tissue

Answer 18

gelatinous matrix
loose fibrous- supports and covers many internal organs
dense fibrous- mostly collagen; tendons & ligaments
adipose-fat storage; beneath skin & around kidneys and heart

Question 19

supportive connective tissue

Answer 19

solid matrix

cartilage: flexible; many fibers; joins, nose & ears
bone: rigid bc of inorganic salts; compact or spongy

Question 20

fluid connective tissue

Answer 20

liquid matrix
blood-plasma & formed elements (red & white blood cells, platelets)
lymph: excess tissue fluid & white blood cells

Question 21

muscle tissue

Answer 21

special fiber cells, contract when stimulated

Question 22

three kinds of muscle cells

Answer 22

skeletal, smooth cardiac

Question 23

nervous tissue

Answer 23

signaling and communication, neurons, neuroglia

Question 24

neurons

Answer 24

conduct signals, dendrites, body, axon

Question 25

neuroglia

Answer 25

support, insulate, protect, may speed signal

Question 26

epithelial tissues

Answer 26

membranous or glandular

Question 27

membranous epithelial tissue

Answer 27

simple or stratified (single/layered) | squamous, cuboidal or columnar (squashed/cubed collumn)

Question 28

glandular epithelial tissue

Answer 28

exocrine, endocrine

Question 29

endocrine glands have

Answer 29

no ducts, products are transported by bloodstream

Question 30

skin is an organ system.. also a

Answer 30

integumentary system

Question 31

functions of the skin

Answer 31

protects, regulates body temperature, and excretes

Question 32

two layers of the skin

Answer 32

epidermis, dermis

Question 33

what layer of the skin anchors

Answer 33

subcutaneous

Question 34

epidermis

Answer 34

``` stratifies squamous epithelium hardened by waterproof keratin surface layers are dead new layers derived from basal cells also in deeper layers -langerhans cells: white blood cells that eat infectious agents -melanocytes-produce melanin -formation of vitamin D in UV light ```

Question 35

dermis

Answer 35

``` beneath epidermis dense fibrous connective tissue -fibers give elasticity -blood vessels -sensory receptors ```

Question 36

subcutaneous layer

Answer 36

anchors skin loose connective & adipose tissue -insulation -excess fat storage

Question 37

accessory organs of skin

Answer 37

nails, hair, sweat glands

Question 38

nails

Answer 38

hardened with keratin, protect and sense for tips of digits, , grow from nail root

Question 39

hair

Answer 39

dead cells filled with keratin, function in protection and sensing, grow from follicles in dermus-contain oil glands that make sebum, sebum lubricates & waterproofs, and inhibits some bacteria

Question 40

sweat glands

Answer 40

make sweat, primary function to help cool body, also start in dermis, open to surface of skin, sometime into hair follicle

Question 41

tanning occurs from

Answer 41

increase melanin production stimulated by sunlight

Question 42

sunburn is due to

Answer 42

heat damage to skin cells

Question 43

most organs are housed in _________ that are lined with ________

Answer 43

body cavities; membranes

Question 44

homeostasis is maintained by

Answer 44

negative feedback mechanisms