Genetic Variation

Question 1

Monohybrid

Answer 1

Is a trait expression that is controlled by a single gene

Question 2

Dihybrid:

Answer 2

Is a trait expression controlled by two genes and 4 alleles.

Question 3

Co-dominance

Answer 3

Co-dominance is when two alleles are equally dominant, so the physical expression of each allele can be seen in the individual

Question 4

Incomplete Dominace:

Answer 4

There are 3 possible genotypes and is the intermediate or blend of two alleles

Question 5

Multiple Allele

Answer 5

A gene that has 3 or more alleles that codes for a trait.

Question 6

Test Cross:

Answer 6

A test cross is used to find the unknown genotype and recessive genotype determining whether the individual is heterozygous or a homozygous trait

Question 7

Random Fertilization:

Answer 7

Fertilisation occurs when a male and female gamete fuse together to form a diploid cell called a zygote. As meiosis results in the formation of gametes that are all genetically unique, when two gamates fuse together there are millions of different combinations of chromosomes that a zygote can have

Question 8

Linked Genes:

Answer 8

Genes which are so close together on a chromosome that if one of them is switchedto the homologous chromosome in crossing over, it’s likely that the other one will go too

Question 9

Mutation:

Answer 9

A permanent change to the base sequence of a DNA. Causing variation and creating a new allele and this mutated allele will spread to others.

Question 10

Meiosis:

Answer 10

Cell division that creates female and male gametes. Humans get 46 chromosomes while gametes get half of the chromosomes which is 23 and is called an haploid cell. During meiosis when genes are shuffled, it increase variation within the population this is the reason why we look similar but not identical our siblings and parent.

Question 11

Migration

Answer 11

when a group/individual migrate from one population to another.

Question 12

Natural Selection

Answer 12

A Is a process when the beneficial phenotypes in a population tend to be persevered or survived while the unfavorable phenotype tends to be lost. Individuals with more advantageous traits pass on their advantageous trait to their offsprings and increasing FOA in their gene pool while non-favourable alleles would be lost from the population as they have less likihood of reproducing and increasing their survival rate

Question 13

Gene Pool:

Answer 13

Total of all genes that are present in a population

Question 14

Genetic Diversity:

Answer 14

different genetic combinations in a gene pool and the amount of genetic diversity can affect the population’s likelihood of survival, meaning less diversity will mean less likely to live.

Question 15

Population:

Answer 15

A group of individual that lives in one location.

Question 16

Genetic Drift:

Answer 16

Is when the frequency of alleles can change due to chance rather than selection pressure. eg; if the population is small their frequency of alleles is unstable as less people and can drift while large population are stable and has more people and losing people have too much of an effect. Overall genetic drifts tend to decrease within a population as it is mating with the same people and won’t have stronger genes in case and genetic drift tends to increase between population as it making new species with another populations - stronger genes.

Question 17

Bottleneck Effect:

Answer 17

Is when the population number is reduced due to human actions or destruction before when they weren’t struck by disaster they are genetically diverse meaning a lot of people but after disaster their numbers are reduced and then gather some people back but not as much as before meaning they are less genetically diverse.

Question 18

Founders Effect:

Answer 18

a small number of individuals emigrate from a population or become isolated from their original population

Question 19

Allele Frequency:

Answer 19

The number of times an allele occurs in a gene pool, compared to the total number of alleles in that pool for the same gene.

Question 20

Genetic Biodiversity:

Answer 20

Range of all the alleles present in the gene pool.

Question 21

Gene Flow

Answer 21

is the process in which individuals emigrate (leave) out of the population or immigrate (arrive) into the population

Question 22

Sexual Reproduction:

Answer 22

Reproduction in which one gamete (sex cell) from each of two individuals combine to form a new individual.

Question 23

Mutation in Gametic and Somatic

Answer 23

If a mutation occurs in somatic cells which is a body cells it cannot be passed if a mutation occurs in gametic cells (reproductive cells) it can be passed on to their offspring.

Question 24

Harmful Mutation

Answer 24

A random change to the gene DNA which can result in the protein not functionally properly or not functioning at all

Question 25

Benefical Mutation

Answer 25

have a positive effect on the organism in which they occur. They generally code for new versions of proteins that help organisms adapt to their environment.

Question 26

Silent Mutation

Answer 26

Silent mutations are when the mutation doesn’t actually affect the protein at all

Question 27

Mutagens

Answer 27

A mutagen is a chemical or physical agent capable of inducing changes in DNA called mutations. eg: regeants

Question 28

Mitosis

Answer 28

Cell division helps cells divide and repair damages and also makes cells cure.

Question 29

Prophase, Metaphase, Anaphase, Telophase ( MEIOSIS )

Answer 29

Pro - Spindles Starts to form

Meta - Chromosomes line up at the middle

Ana - chromotids are moved to opposite ends of the cell

Telo - The nuclei starts to form and create four new daughter cells each with different genetic variation.

Question 30

Allele

Answer 30

is a variation of an gene

Question 31

Gene

Answer 31

Is a section of DNA that codes fr a protein and genes are found on the same position in the homologous chromosome anddd are made up of long sequences of DNA nucleotides.

Question 32

Selection Pressure

Answer 32

Is an abiotic or biotic enviromental factor that affects the survival of an organism. it can affect the reproductive success rate of the organism and the influence the frequency of certain alleles in that gene pool

Question 33

Genotype

Answer 33

set of alleles that deterrmine a particular characteristics of a trait.

Question 34

Phenotype

Answer 34

is the obervable expression of characteristics of a trait for genotype.

Question 35

Lethal Allele

Answer 35

are the version of a gene that is mutated and can cause the death of an organism when it occurs a homozygous form and affect its survival rate.

Question 36

Crossing over

Answer 36

Crossing over is when the homologous pairs of chromosomes exchange sections of DNA with non- sister chromosomes. The homologous pairs of chromosomes exchange sections of DNA that code for the same trait Crossing over creates variation because each chromosome has different genetic information from either one parent or both parents ( Paternal or Maternal). Crossing over causes each chromosome to have different genetic information, this means that the chromosomes will each have different alleles which will mean that they will code for different genotypes and phenotypes.

Question 37

Law of Segregation

Answer 37

The law of segregation states that the placement of one allele in a gamete has no effect on the placement of any other allele although each gamete will only have one allele coding for a certain trait.
Segregation is the separation of alleles from a specific gene into different gametes. This means that both alleles will have an equal chance of being inherited, and that each parent will pass on an allele. Segregation creates variation as it ensures that the genetic material of both parents is contributed, meaning that the gametes will vary from one another and the parents. This process contributes to the overall level of variation found in the gametes in a big part, as without it, the gametes may only contain information from one parent.

Question 38

Independent Assortment

Answer 38

Independent assortment is when the homologous chromosomes line up in the middle of the cell. The order that the homologous chromosomes line up is random. The order that the chromosomes and homologous chromosomes line up at the centre determines what cell they get split into. Independent assortment creates variation as each of the gametes will have a random combination of the chromosomes making the genetic information random. Independent assortment leads to genetic variation as each chromosome which is unique in its genetic information due to crossing will randomly get split into the gametes increasing the genetic diversity in the gametes.

Question 39

Linked genes

Answer 39

Found on the same chromosomes and are inheerited together, don’t independently assort, less GV than unlinked genes

Question 40

Unlinked genes

Answer 40

Are found on two different chromosomes and have a ratio of 9:3;3;1 Unlinked genes can independently assort,herefore produce more genetic variation in
the gametes. unlinked genes can produce 4
different types of gametes.