Ch. 12 Mutagens and Gene Pools

Question 1

what are species

Answer 1

basic unit of biological classifications; members of a species are capable of interbreeding and producing fertile offspring

Question 2

what are alleles

Answer 2

alternate forms of genes

Question 3

define population

Answer 3

a group of organisms of the same species living together in a particular place at a particular time

Question 4

define gene pool

Answer 4

sum of all alleles carried by the members of a population

Question 5

Define mutation

Answer 5

a rapid change in a gene or chromosome leading to new characteristics of an organism

Question 6

what are the two main types of mutation

Answer 6

1. gene

2. chromosomal

Question 7

explain gene mutation

Answer 7

an alteration to a single gene (Traits normally produced by that gene= changed or destroyed)

Question 8

explain chromosome mutations

Answer 8

a change to the structure and/or # of chromosomes in an organism

Question 9

define mutagen

Answer 9

environmental agent that increases the rate of mutation

Question 10

where (what cells) can mutations occur

Answer 10

somatic or germline

Question 11

what is the difference between gremlin and somatic mutations

Answer 11

somatic= passed on

Question 12

define point mutation

Answer 12

change in one bases

Question 13

what are the three consequences of point mutation

Answer 13

o can alter a protein, no affect, or prevent protein from being produced
o // if DNA of particular gene altered= protein for which it codes may be missing/ abnormal

Question 14

define lethal recessive

Answer 14

recessive alleles that, inherited in a homozygous condition, result in death of the embryo, foetus, or child

Question 15

how do lethal recessives cause a change in the gene pool

Answer 15

o people who inherit two such alleles= die before alleles passed on to next generation // proportion of lethal recessive alleles in gene pool would gradually be reduced

Question 16

what are the 5 types of chromosomal mutation

Answer 16

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Deletion: part of chromosome lost
Duplication: a section of chromosome occurs twice (may happen if part of chromatid breaks off + joins on wrong chromatid)
Inversion: breaks occur in chromosome and broken piece joins back, but wrong way around= changes order of genes on chromosome + may disrupt pairing of homologous chromosomes during meiosis 
Translocation: part of a chromosome breaks off and is rejoined to wrong chromosome 
Non-disjunction: during meiosis, a chromosome pair does not separate and so one daughter cell has an extra chromosome and one daughter cell has one less than normal number  →	= aneuploidy( a change in chromosome number)

Question 17

what is monosomy and trisomy

Answer 17

m- missing

t- more