Genetics and Inheritance

Question 1

what is DNA

Answer 1

the genetic material found in the chromosomes in the nuclei of cells

Question 2

where is DNA found

Answer 2

nucleus

Question 3

what is a chromosome

Answer 3

a string of genes/DNA

Question 4

what is the shape of DNA

Answer 4

double helix

Question 5

what are the 4 bases

Answer 5

Adenine
Cytosine
Guanine
Thymine

Question 6

what are the complementary bases

Answer 6

AT
CG

Question 7

what holds the DNA strands together

Answer 7

weak hydrogen bonds

Question 8

DNA is a _________ made up of __________

Answer 8

polymers monomer

Question 9

what is a DNA monomer called

Answer 9

a nucleotide

Question 10

what is a nucleotide made up of

Answer 10

phosphate
sugar
base

Question 11

what is the biggest molecule in nucleotide

Answer 11

sugar

Question 12

what are the 3 steps to extracting DNA from fruit

Answer 12

1. grind fruit to separate cells
2. add detergent to break open the cell membranes
3. add ice-code alcohol so that the DNA precipitates out

Question 13

who discovered inheritance

Answer 13

Gregor Mendel

Question 14

describe Mendels experiment

Answer 14

1. Mendel created pure bread pees that would always produce the same offspring when bred
2. he bred tall peas with dwarf spread and discovered that all the offspring were tall
3. he discovered that the tall gene was dominant and the short gene was recessive

Question 15

what is a game

Answer 15

a sex cell

Question 16

what is made when 2 gametes fuse

Answer 16

a diploid zygote

Question 17

what is a gene in terms of genetics

Answer 17

it codes for a particular characteristic

Question 18

what is an allele

Answer 18

a different version of a gene

Question 19

what does homozygous mean

Answer 19

when the person has the same allele for a particular characteristic on both chromosomes

Question 20

what does heterozygous mean

Answer 20

when the person has different alleles for a particular characteristic on the chromosomes

Question 21

what is the genotype

Answer 21

shows the alleles in the individual

Question 22

what is the phenotype

Answer 22

means the characteristics that are produced

Question 23

how many chromosomes do humans have

Answer 23

23 pairs or 46 chromosomes

Question 24

what is the genotype of a male

Answer 24

XY

Question 25

what is the genotype of a female

Answer 25

XX

Question 26

what is the chance of your child being a male

Answer 26

50%

Question 27

what 3 alleles are used to determine blood group and if they are recessive or dominant

Answer 27

A - dominant B - dominant O - recessive

Question 28

what are the four blood groups

Answer 28

A B AB O

Question 29

how is the blood group AB possible

Answer 29

codominant, this occurs when the heterozygous individual shows the effects of both alleles that they carry for the gene

Question 30

name 2 sex-linked disorders

Answer 30

colour blindness haemophilia

Question 31

what is meant by a sex-linked disorder

Answer 31

when a disease is more likely to affect males as they carry only one X chromosome a recessive allele on this chromosome will affect the phenotype as an allele on the Y chromosome will not match it

Question 32

what 2 factors cause variation

Answer 32

genes and environment

Question 33

what is a mutation

Answer 33

when the sequence of bases in a gene is changed

Question 34

what was the human genome project

Answer 34

a collaboration between scientists to decode the human genome (the order of bases on all human chromosomes).

Question 35

what are 3 advantages of the human genome project

Answer 35

- it can be used to alert people of any particular disease that they are at risk for so that they can change their lifestyle and prevent it - can be used to distinguish between similar diseases - allows doctors to tailor treatments, where specific alleles affect how a person will respond to a treatment

Question 36

what are 2 disadvantages of the human genome project

Answer 36

people who are at risk of certain diseases may have to pay more for life insurance it may not be helpful to tell someone they have an incurable disease