Cellular Control and Patterns of Inheritance Key Terms and Processes Flashcards

1
Q

Define the term :

Genotype

A

Alleles for a particular characteristic present in the cells of an organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define the term :

Phenotype

A

Observed characteristic of an organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define the term :

Homozygous

A

Organism with two identical alleles for a particular gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define the term :

Heterozygous

A

Organism with two different alleles for a particular gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define the term :

Dominant

A

Characteristic that is always expressed in the phenotype in an organism, even in those who are heterozygous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define the term :

Recessive

A

Characteristic only expressed in the phenotype when there is no dominant allele present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define the term :

Co-Dominant

A

A characteristic where both alleles contribute to the phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define the term :

Linkage

A

2 or more genes located on the same chromosomes and are normally inherited together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define the term :

Sex Linkage

A

Genes with a locus on one of the sex chromosomes (X or Y). Most are on the X chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define the term :

Epistasis

A

Interaction of genes concerned with the expression of one characteristic, one allele may mask or suppress the expression of another allele

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define the term :

Discontinuous Variation

A

No intermediate categories, phenotypic variation is clearly distinguishable categories, eg; blood group, attached ear lobes, etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define the term :

Continuous Variation

A

Phenotypic differences with a wide range of variation with no distinct categories, eg; height weight, etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define the term :

Allele

A

Alternative form of a gene found in a specific locus on a specific chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define the term :

Pure Breeding

A

Homozygous at both alleles, can both be dominant or recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define the term :

Multiple Alleles

A

Characteristic for which there are three or more alleles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define the term :

Dihybrid

A

Involving two gene loci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define the term :

Monogenic

A

Determined by a single gene

18
Q

Define the term :

Polygenic

A

Determined by multiple genes

19
Q

Define the term :

Mutation

A

A sudden, significant, random change in the sequence of nucleotides in DNA during DNA replication.

20
Q

Define the term :

Mutant

A

An organism affected by (a) mutations

21
Q

Define the term :

Somatic Mutation

A

Mutations in non-reproductive cells which cannot be inherited by offspring

22
Q

Define the term :

Germ-Line Mutation

A

Mutation in gametes, can be inherited by offspring

23
Q

Define the term :

Mutagens

A

Things like radiation or chemicals (eg in cigarette smoke) that increase the chance of mutations occurring

24
Q

What is a regulatory gene?

A
  • a gene that is present in DNA

- it has a role in the regulating the expression of structural genes

25
Define the term : | Point mutation
A mutation where one base pair is changed
26
Missense mutation
The first base pair of a triplet codon mutates (likely amino acid change)
27
Silent mutation
Mutation that occurs on the second/third base (unlikely amino acid change)
28
Point, Missense and Silent mutations are all types of _________ mutations
Substitution
29
Insertion and deletion is a type of _________ mutation
Frameshift
30
What are neutral mutations?
Mutations that have no effect on the survival of the organism
31
Define the term: | Reproductive Isolation
When two populations of the same species change sufficiently, they fail to interbreed successfully and are said to be reproductively isolated, they have become two separate species, which are genetically isolated
32
Define the term: | Prezygotic
Zygotes do not form because the gametes do not meet
33
Define the term: | Post Zygotic
Zygotes are formed, but they do not produce mature fertile offspring
34
Reasons for Pre-zygotic Isolation Mechanisms
• Geographical Isolation The populations never meet because they inhabit different areas • Ecological Isolation The populations never meet because all though they inhabit the same area, they live in the habitats within that area • Temporal Isolation The populations never meet although they inhabit the same area, they love in different habitats within that area
35
Deletion
When part of a chromosome containing genes and regulatory sequences is lost
36
Inversion
When a section of a chromosome may break off, turn through 180° and then rejoin, this results in genes being present but not be too far away from their regulatory sequence to be properly expressed in the phenotype
37
Translocation
A piece of chromosome beams off and attaches to different chromosomes, this can interfere with the regulation of genes on the chromosome with the new DNA
38
Duplication
A piece of chromosome may be copied, this can lead to over expression of genes which can be harmful, as TOL many proteins are produced which can affect the metabolism
39
Non Disjunction
When a pair of chromosomes or chromatids fail to separate in meiosis are lying in a gamete with an extra chromosome, when the gamete is fertilised, the zygote has an extra chromosome eg - Down syndrome, when individuals have three copies of chromosome 21
40
Define the term: | Operon
A sequence of DNA containing a cluster of genes under the control of a single promoter