B11 Inheritance

Question 1

inheritance

Answer 1

the transmission of genetic information from generation to generation

Question 2

Chromosome

Answer 2

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

Question 3

Gene

Answer 3

a length of DNA that codes for a protein

Question 4

XX and XY

Answer 4

XX=girl and XY=boy

Question 5

Haploid nucleus

Answer 5

a nucleus containing a single set of unpaired chromosomes e.g. sperm and egg cells

Question 6

Diploid nucleus

Answer 6

a nucleus containing two sets of chromosomes e.g. body cells

Question 7

mitosis

Answer 7

a nuclear division giving rise to genetically identical cells (two of them with 46 chromosomes each) their role is repair tissue, growth, asexual reproduction and replacement of cells

Question 8

meiosis

Answer 8

reduction division in which the chromosomes number is halved (4 different ones with 23 chromosomes each) from diploid to haploid resulting in genetically different cells

Question 9

genotype

Answer 9

the genetic make-up of an organism in terms of alleles present

Question 10

phenotype

Answer 10

the observable feature of an organism

Question 11

homozygous

Answer 11

having two identical alleles of a particular gene

Question 12

heterozygous

Answer 12

having two different alleles of a particular gene

Question 13

dominant allele

Answer 13

an allele that is expressed if it is present

Question 14

recessive allele

Answer 14

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

Question 15

Punnett squares

Answer 15

diagram to show what the possible genotypes are with the parents genotypes

Question 16

variation

Answer 16

difference between individuals of the same species

Question 17

continuous variation

Answer 17

results in a range of phenotypes between to extremes e.g. height

Question 18

discontinuous variation

Answer 18

results in limited number of phenotypes with no intermediated e.g. tongue rolling

Question 19

phenotypic variation

Answer 19

it’s caused by both genetic and environmental factors

Question 20

mutation

Answer 20

a change in a gene or chromosome

Question 21

natural selection

Answer 21

when organism struggle for survival because of the environment or competition for resources and a certain characteristics helps them survive and then it gets passed onto multiple generations

Question 22

selective breeding

Answer 22

when humans select 2 organisms with desirable characteristics and breed them throughout a few generations