section d- biology

Question 1

the two helical strands of DNA are held together by covalent bonds

Answer 1

false

Question 2

DNA polymerase is involved in the formation of mRNA

Answer 2

false

Question 3

translation of the genetic code takes place on the ribosome

Answer 3

true

Question 4

transfer RNA is double stranded throughout its length

Answer 4

false

Question 5

in both mitosis and meiosis, the replication of DNA and the chromosomes occur at the same stage

Answer 5

false

Question 6

crossing over is accompanied by chromosome breakage

Answer 6

true

Question 7

the existence of a range of differences for certain traits, rather than two discrete classes probably due to the fact that a number of genes are involved in the trait (polygenic inheritance)

Answer 7

true

Question 8

where multiple allele exist for a trait any one individual will have more than two alleles for that trait

Answer 8

false

Question 9

sex linked traits may defined as those traits that affect the development of sex organs

Answer 9

false

Question 10

a normal women who is a carrier for haemophilia could expect to have half of her sons suffer from the disease

Answer 10

false

Question 11

enzymes necessary for nuclear functions are actually made in the cytoplasm of eukaryotes

Answer 11

true

Question 12

the nerve tube derives from the ectoderm

Answer 12

true

Question 13

the human thorax has 12 pairs of ribs

Answer 13

true

Question 14

gametes are usually produced in specialized structures knowns as gonads

Answer 14

true

Question 15

cell- mediated immunity involves only the b-lymphocytes

Answer 15

false

Question 16

the vocal cords are found in the larynx

Answer 16

true

Question 17

involuntary muscles have no myosin or actin, since it lacks striations

Answer 17

false

Question 18

convergent structures are described as homologues

Answer 18

false

Question 19

a universality of the genetic code suggests that all organisms have had a common origin

Answer 19

true

Question 20

the mitochondria in a eukaryotic cell serves as the cell’s power plant

Answer 20

true