B11 Inheritance

Question 1

define inheritance

Answer 1

transmission of generic information form generation to generation

Question 2

define chromosomes

Answer 2

thread like structure of DNA, carrying generic information in the form of genes

Question 3

define genes

Answer 3

length of DNA that codes for protein

Question 4

define allele

Answer 4

versions of a gene

Question 5

define haploid nucleus

Answer 5

nucleus containing a single set of unpaired chromosomes

Question 6

define diploid nucleus

Answer 6

nucleus containing two sets of chromosomes

Question 7

in diploid cells, chromosomes are arranged in pairs of ..

Answer 7

23

so haploid - 23
diploid - 46

Question 8

define mitosis

Answer 8

nucleur division giving rise to genetically identical cells

Question 9

exact duplication of chromosomes occurs before/after mitosis

Answer 9

before

Question 10

state the role of mitosis (4)

Answer 10

1. growth
2. repair of tissues
3. replacement of cells
4. asexual reproduction

Question 11

define meiosis

Answer 11

reduction of division in which the chromosomes number if halved from diploid to haploid resulting in genetically different cells

Question 12

meiosis is involved in the production of …….

Answer 12

gametes, egg cells and sperm cells

Question 13

define genotype

Answer 13

genetic make up of an organism in term of the alleles present
eg. bb Bb BB

Question 14

define phenotype

Answer 14

observable features of an organism
eg. black hair blue eyes

Question 15

define homozygous

Answer 15

having two identical alleles of a particular gene
eg. BB bb

Question 16

define hetrozygous

Answer 16

having two different alleles of a particular gene
eg. Bb

not pure breeding

Question 17

define dominant

Answer 17

allele that is expressed if it is present

Question 18

define recessive

Answer 18

allele that is only expressed when there is no dominant allele of the gene present

Question 19

define variation

Answer 19

differences between individuals of the same species

Question 20

describe phenotype variation

Answer 20

the differences between features between individuals, cuased by both environment and genetic

Question 21

describe genetic variation

Answer 21

differences in genes between individuals
eg. blood types, gender

Question 22

define mutation

Answer 22

change in a gene or chromosome

Question 23

examples of things causing mutation

Answer 23

ionizing radiation
chemicals

Question 24

define evolution

Answer 24

change in adaptive features of a population overtime as the result of natural selection

Question 25

describe natural selection

Answer 25

• genetic variation
• overpopulation
• competition due to the struggle for existence
• survival for the fittest
• advantageous characteristics passed on to generation

Question 26

define adaptation

Answer 26

process, resulting from natural selection, by which populations become more suited to their environment over many generations

Question 27

describe selective breeding

Answer 27

• selection by humans of individuals with desirable features
• crossing these individuals to produce offspring
• selection of offspring with the desirable features

Question 28

example of selective breeding

Answer 28

improve crops and domesticated animals

Question 29

example of natural selection

Answer 29

antibiotic-resistant bacteria