Genetic Change

Question 1

What is genetic variation?

Answer 1

Variation relates to different forms of genes within a population

Question 2

Examples of genetic variable

Answer 2

Small and tall gene for height

Question 2

What does genetic variability refer to?

Answer 2

All different possible alleles for characteristics within a population

Question 2

What cause genetic variation?

Answer 2

Meiosis, Fertilisation and Mutation cause genetic variation

Question 3

What is meiosis?

Answer 3

The process of having sex cell which is caused by 3 factors during meiosis which includes crossing over, random segretation and independent assortment

Question 4

What is Fertilisation?

Answer 4

2 haploid cell fuse to form a diploid zygote with 50% of genetic material from the mother and 50% from father

Question 5

What does variation arises

Answer 5

Genetic materials from different parents are combined and also the unique genetic material in spem and egg

Question 6

What is mutation?

Answer 6

The change in DNA sequences in a cell, it arise due to the mistake being made during DNA replication or brought by environment factor

Question 7

What did Gregor Mendel predict?

Answer 7

The ratio and patterns of inheritane and develop law on genetic inheritance

Question 8

What is mendel 1st law of dominance and segregation?

Answer 8

The characteristic of an organism is determined by factors (genes) that occur in pairs, only one member of a pair of factors can be represented in any gamete due to segregation

Question 9

What is Mendel 2nd law of independent assortment?

Answer 9

When individuals with 2 or more pairs of unrelated, contrsting characteristics are crossed, the different pairs of factors separate out independently of each other

Question 10

What does the 2nd law assumes?

Answer 10

The genes are located on different chromosomes. The further apart genes are, the greater the probability that they will be separated by crossing over

Question 11

What is sex determination

Answer 11

It determined by the way sex segregate during meiosis and then recombine during fertilisation

Question 12

What is female gametes?

Answer 12

In the ovaries and have 22 autosomes + 1X chromosome

Answer 13

Half male sperms during meiosis have Y sex while other have has X chromosome

Answer 14

Sperm determine whether the offspring is male or female

Question 14

What is in the male sperm?

Answer 14

22 autosomal + Y chromosome

Question 15

What is in female sperm?

Answer 15

22 autosomal + X chromosome

Question 15

What is punnett squares?

Answer 15

A model used to represent inheritance patterns and can be used to predict possible outcome when individuals is cross breed

Question 16

What is pedigree Charts

Answer 16

• Across generations
• At least 3 generations are needed
• Used to study inheritance of a particular trait and make predicatio about future offspring

Question 17

Types of inhertiance

Answer 17

• Autosomal recessive
• Autosomal dominant
• Sex linked
• Incomplete domainance
• Co-dominance
• Determined by multiple alleles

Question 18

Autosomal Recessive - Pedigree charts

Answer 18

• Only expressed when individual has 2 copies of the recessive allele
• trait will skip generation
• Parents of individual with recessive must be both be heterozygous OR one be homozygous recessive and the other heterozygous
• Gene can be passed on to both male and female equally
• The affected individual must carry at least ONE of the affect alleles
• Trait can be passed on both maes and females equally

Question 19

Autosomal (Punnet squares)

Answer 19

• Results for autosomal recessive trait to follow typical Mendel ratios
• heterozygous offspring will be carriers and only homozygous for the recessive trait will express the disease
• Both heterozygous and homozygous recessive genotypes will express the trait

Question 20

What is codominance?

Answer 20

Both alleles behave as dominant alleles, with both forms of the gene being expressed to create new phenotype

Question 21

What is gene

Answer 21

A section of DNA that contains the information to encode for a particular trait

Question 21

Example of codominance

Answer 21

Homozygous white cow x with homozygous red bull = roan calf with both red adn white patches

Question 22

What is chromosome

Answer 22

The package DNA is arranged into inside the nucleus. The chromosomes carry the DNA

Question 22

What is allele

Answer 22

A form of gene that you inherit one allele from your father and one from mother for every gene

Question 23

What is genotype?

Answer 23

The genetic combination of alleles for each gene

Question 23

What is diploid?

Answer 23

Those body cells that contain the full set of DNA

Question 24

What is haploid?

Answer 24

Gamete or sex cells that contain half the genetic material

Question 25

What is phenotype?

Answer 25

The expression of the genes or sum of the gene products

Question 26

What is homologous chromosomes?

Answer 26

Similar chromosomes that carry genes for the same trait

Question 27

What sister chromatids?

Answer 27

When a chromosome undergoes DNA replication for meiosis

Question 28

What is homozygous?

Answer 28

A particular gene tha has identical alleles on both homologous chromosome

Question 29

What is heterozygous?

Answer 29

A particular genes contains different alleles on homologous chromosomes

Question 30

What is recessive?

Answer 30

The allel that is masked or hidden by the presence of a dominant allele and only expressed when person inherits both recessive alleles from their parents

Question 31

What is dominant?

Answer 31

The allele that is expressed is teh domiinant allele. THe dominant allele mask the recessive allele in herozygous genes

Question 32

What does multiple alleles?

Answer 32

One gene has 3 or more allels present in the population (ABO blood group system has 3 alleles = A,B and O)

Question 33

What is human blood types are determined by?

Answer 33

Genes that follow the CODOINANCE patterns of inheritance, there are 2 dominant alleles and one recessive

Question 34

What is sex linked inheritance?

Answer 34

The inheritance of genes carried on the X and Y chromosomes

Question 35

Who has the smaller chromosome?

Answer 35

Y chromosome is smaller than X chromosome

Question 36

What happens if a gene for a condition is carried on the X chromosome?

Answer 36

Male will express higher rate as female will have no corresponding allele on their Y chromosome

Question 37

What happens if gene is carried on the X chromosome and is recessive?

Answer 37

Females will only express the disease if inherits 2 chromosome, however it can be passed on

Question 38

What happens if gene is carried on the X chromosome and is dominant?

Answer 38

Females will only need to inherit one X chromosome with teh affected allele to express the disease

Question 39

What happens if X chromosome trait is dominant or recessive

Answer 39

Males only need to inherit the one affected X chromosome to express the disease

Question 40

In Punnet Square what does it predict?

Answer 40

Sex linkef inheritance always show the chromosome the trait is on by using the symbol X or Y

Question 40

What does sex linked pedigree chart include?

Answer 40

Sex linked recessive and dominant

Question 40

Sex linked recessive features

Answer 40

- traits are more common in male - Females may not express the disease but could be carriers - Trait is never passed from father to son becase carriers the allel on his X chromosome but always passes his Y chromosome on to any son

Question 41

Sex linked dominant features

Answer 41

- trait affects both males and females equally and doesn't skip generations - All affected males and have an affected mother - All affected females have an affected father or mother - All female progeny of an affected male is affected

Question 42

Autosomal recessive features

Answer 42

- individual recieve TWO copies of affected allele - Two unaffected parents can be carriers and have an affected child - Affects males and females equally

Question 42

Features in Autosomal dominant

Answer 42

- Individual can be homozygous dominant or heterozygous - Trait doesn't skip a generation - One of the parents of all affected children must have the disease - Affects males and females equally

Question 43

Features in Sex linked recessive

Answer 43

- Affects males more than females - Females may not express the disease but could be carriers having affect sons - Never passed from father to son becuase a father carriers the allele on his X chromosome but always passes his Y chromosome on to any sons