Inheritance

Question 1

Genome

Answer 1

Entire DNA of an organism

Question 2

Gene

Answer 2

section of DNA that codes for a specific protein

Question 3

Nucleus

Answer 3

contains chromosomes in which genes are located

Question 4

Allele

Answer 4

Different forms of the same gene

Question 5

Dominant

Answer 5

the allele that is expressed in a phenotype of a heterozygote

Question 6

Recessive

Answer 6

the allele that is not expressed in a phenotype of a heterozygote

Question 7

Homozygous

Answer 7

When someone has 2 identical alleles of a gene

Question 8

Heterozygous

Answer 8

When someone has 2 different alleles of a gene

Question 9

Phenotype

Answer 9

The physical features as a result from a genotyp

Question 10

Genotype

Answer 10

the alleles each gene has for a certain feature

Question 11

Monohybrid Inheritance

Answer 11

The inheritance of a single characteristic

Question 12

Sex chromosomes in a female

Answer 12

XX

Question 13

Sex chromosomes in a male

Answer 13

XY

Question 14

What is sex determination based on?

Answer 14

Sperm - if an X sperm or Y sperm fertilises the egg

Question 15

Human diploid number

Answer 15

46

Question 16

Human haploid number

Answer 16

23

Question 17

What is a DNA molecule made up of?

Answer 17

2 strands coiled together to form a double helix
Complementary bases: A, T. C,G

Question 18

Bases in DNA

Answer 18

Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)

Question 19

What is an RNA made up of?

Answer 19

Single stranded
Thymine replaced by Uracil

Question 20

Codominance

Answer 20

When both alleles in a genotype are expressed in the phenotype

Question 21

Polygenic Inheritance

Answer 21

Characteristics that are controlled by multiple genes

Question 22

Types of cell division

Answer 22

Mitosis
Meiosis

Question 23

Mitosis

Answer 23

Cell division in body cells to produce 2 genetically identical daughter cells (dipoid)

Question 24

When does mitosis occur?

Answer 24

growth, repair, cloning and asexual reproduction

Question 25

Stages of Mitosis

Answer 25

1. Chromatids duplicate = chromosomes 2. Line up at centre of cell and form spindle fibres 3. Seperate arms of chromosome 4. Divide

Question 26

Meiosis

Answer 26

Cell division in gametes to produce 4 non-genetically identical daughter cells (haploid)

Question 27

When does meiosis occur?

Answer 27

Gametes Sexual reproduction

Question 28

Stages of Meiosis

Answer 28

1. Chromatids duplicate = chromosomes 2. Line up in pairs at centre of cells 3. Divide = 2 cells 4. Line up at centre and form spindle fibres 5. Seperate arms of chromosomes 6. Divide 7. 4 daughter cells

Question 29

What can variation within a species be?

Answer 29

Genetic Environmental Both

Question 30

Mutation

Answer 30

rare, random change in genetic material can be inherited Have no effect on the phenotype

Question 31

What can a change in DNA cause?

Answer 31

affect the phenotype by altering the sequence of amino acids in a protein

Question 32

Types of Mutations

Answer 32

substitutions, deletions and insertions

Question 33

How can the chance of mutations be increased?

Answer 33

* exposure to ionising radiation (for example, gamma rays, x-rays and ultraviolet rays) * chemical mutagens (for example, chemicals in tobacco)

Question 34

Darwin's Theory of evolution through natural selection

Answer 34

Life begins at simple organisms from which more complex organisms evolved

Question 35

Natural Selection

Answer 35

The process where certain individuals in a population survive due to being better adapted to the environment

Question 36

Process of Natural Selection

Answer 36

1. There is variation in the characteristics of organisms within a species 2. Changing conditions in the environment favour one particular characteristic. 3. The frequency of the gene for this characteristic increases as it is best adapted to the environment. These survive + reproduce = survival of the fittest 4. The frequency of the less adapted gene decreases. 5. Over time, the gene that increases survival becomes more common in the population

Question 37

Survival of the Fittest

Answer 37

Survival of the individuals that will leave the most offspring (reproduce) in later generations