Chapter 16

Question 1

DNA

Answer 1

chemical of which genes are made (double helix, made of deoxyribose sugar, phosphates & four bases)

Question 2

Chromosomes

Answer 2

thread-like structure found in nucleus, DNA and protein, contains genes

Question 3

Gene

Answer 3

part of chromosome, length of DNA, controls organism characteristics by coding for certain protein

Question 4

Base

Answer 4

1 of 4 nitrogen-containing groups, form complimentary pairs in double helix

Question 5

Replication

Answer 5

copying of DNA, occurs before cell division

Question 6

Template strand

Answer 6

strand of DNA, codes for manufacture of proteins

Question 7

RNA

Answer 7

similar to DNA, single strand, ribose sugar & uracil, involved in protein synthesis

Question 8

mRNA

Answer 8

type of RNA, forms copy of template strand of DNA during transcription

Question 9

tRNA

Answer 9

type of RNA, carries amino acids to ribosomes during translation of mRNA

Question 10

Ribosomes

Answer 10

tiny structure in cytoplasm of cells, site of protein synthesis

Question 11

Transcription

Answer 11

process where information from base sequence in strand of DNA is copied into molecule of mRNA

Question 12

Translation

Answer 12

process where information in base sequence of mRNA used to produce sequence of amino acids in protein. Occurs at ribosomes

Question 13

Condon

Answer 13

triplet of bases on mRNA molecule, different triplets code for different amino acids

Question 14

Anticodon

Answer 14

group of 3 bases on tRNA molecule, complementary to codon on mRNA

Question 15

Mutation

Answer 15

change in structure of gene/chromosome

Question 16

Natural selection

Answer 16

process where certain individuals in a population survive because they are better adapted to their environment. Mechanism of evolution

Question 17

Mutagens

Answer 17

factors that increase rate of mutation (e.g. gamma radiation)

Question 18

Histones

Answer 18

protein associated with DNA in a chromosome

Question 19

Homologous pairs

Answer 19

pair of chromosomes, carry genes controlling same features in same position on each chromosome, same size/shape

Question 20

Diploid

Answer 20

number of chromosomes found in body cells, contain chromosomes of each homologous pair

Question 21

Sex chromosomes

Answer 21

pair of chromosomes, determine sex in humans, XX (f) XY (m)

Question 22

Meiosis

Answer 22

type of cell division, produces haploid cells (gametes)

Question 23

Haploid

Answer 23

number of chromosomes found in gametes, contain 1 chromosome from each homologous pair

Question 24

Fertilisation

Answer 24

fusion of male and female gametes to form a zygote

Question 25

Zygote

Answer 25

single cell resulting from fusion of male and female gamete

Question 26

Genome

Answer 26

entire DNA of an organism

Question 27

Alleles

Answer 27

different forms of a gene

Question 28

Dominant

Answer 28

allele of gene that is expressed in the heterozygote

Question 29

Recessive

Answer 29

allele that’s not expressed in phenotype when dominant allele of gene is present