TOPIC 10 & 11 Genetics

Question 1

What is a Genotype

Answer 1

The genetic makeup of an individual.

Eg. Eyes

Question 2

What is a Phenotype:

Answer 2

The observable traits or characteristics of an organism.

E.g Blue coloured eyes

Question 3

What is a Genome:

Answer 3

The complete set of an organism’s genes.

Question 4

What is an Allele:

Answer 4

Different versions of a gene.

Question 5

What is Recombination:

Answer 5

The reshuffling of genetic material during meiosis.

Question 6

What is an Autosome:

Answer 6

Non-sex chromosomes.

Question 7

What are Sex-linked genes:

Answer 7

Genes located on the sex chromosomes (X and Y).

Question 8

What is a Dominant allele:

Answer 8

An allele that masks the effect of the recessive allele.

Question 9

What is a Recessive allele:

Answer 9

An allele whose effect is masked by the dominant allele.

Question 10

What is a Heterozygous gene:

Answer 10

Having two different alleles for a particular gene.

Eg. Aa

Question 11

What is a Homozygous gene:

Answer 11

Having two identical alleles for a particular gene.

Eg. aa

Question 12

What are Homologous chromosomes:

Answer 12

Chromosomes that carry the same genes but may have different alleles.

Eg. a human arms and the wings of a bat

Question 13

Explain the significance of alleles in terms of heredity patterns

Answer 13

Alleles determine the specific traits an individual will inherit from their parents

Question 14

How does genetic recombination affect genetic diversity

Answer 14

It produces unique combinations of alleles and therefore diverse phenotypes

Question 15

What do dominant alles a required for a disease to manifest?

Answer 15

Dominant disorders require only one copy of the disease-causing allele to manifest

E.g Aa

Question 16

What do recessive alles are required for a disease to manifest?

Answer 16

recessive disorders require two copies (homozygous)

Eg. AA

Question 17

What happens in co-dominance

Answer 17

Co-dominance leads to both alleles expressing their traits in a heterozygote

eg red and blue fish = reds and blue on the fish

Question 18

What happens in incomplete dominance

Answer 18

Incomplete dominance results in a heterozygote with an intermediate phenotype.

Eg. red fish and blue fish = purple fish

Question 19

What is Sex-linked inheritance?

Answer 19

Sex-linked inheritance involves genes located on the X or Y chromosomes, leading to gender-specific inheritance patterns.

Question 20

What is a genetic mutation?

Answer 20

A mutation is a change in the DNA sequence

Question 21

How do mutations occur?

Answer 21

Errors in DNA replication, exposure to mutagens (e.g., radiation, chemicals), or spontaneous changes.

Question 22

What is a point mutation (substitutions):

Answer 22

Point mutations (substitutions): Single base changes that may or may not alter protein production

Question 23

What are insertion and deletion (indels) mutations:

Answer 23

Insertions and deletions (indels): Additions or removals of DNA bases, which can lead to frameshift mutations.

Question 24

What are Silent mutations:

Answer 24

Silent mutations: Point mutations that do not affect the resulting protein.

Question 25

What are Nonsense mutations:

Answer 25

Nonsense mutations: Create a premature stop codon, leading to a truncated, non-functional protein.

Question 26

What are Deleterious mutations :

Answer 26

Deleterious mutations are harmful and can reduce an organism’s fitness.

Question 27

What are Advantageous mutations :

Answer 27

Advantageous mutations provide an advantage, enhancing the organism’s chances of survival and reproduction, contributing to evolution.

Question 28

What is an A single nucleotide polymorphism (SNP) mutation?

Answer 28

A single nucleotide polymorphism (SNP) is a variation at a single DNA base, often with multiple alleles.

Question 29

What is a point mutation :

Answer 29

A point mutation refers to a single base change in the DNA sequence and can include both SNPs and other base changes.

Question 30

What are the Chromosomal rearrangements:

Answer 30

TID

Chromosomal rearrangements include translocations, inversions, and duplications.

Question 31

What is Karyotype analysis:

Answer 31

Karyotype analysis is a technique to examine an individual’s chromosomes.

Question 32

Aneuploidy is a condition where an individual has an abnormal number of chromosomes, which can result in genetic disorders.

Answer 32

Down syndrome, XXX syndrome, Edwards syndrome, Turner syndrome

Question 33

What is Nucleic acid analysis:

Answer 33

Nucleic acid analysis, such as sequencing, is used to identify specific genetic mutations.

Question 34

What are the advantages of genetic testing?

Answer 34

Advantages include early disease detection and informed decision-making.

Question 35

What are the disadvantages of genetic testing?

Answer 35

Disadvantages may involve ethical, psychological, and privacy issues.

Question 35

Why is mutation important in maintaining genetic diversity

Answer 35

Mutation introduces new genetic variation, which is essential for adaptation to changing environments and the evolution of species.

Question 35

What do genetic counsellors do?

Answer 35

Genetic counselors provide information and support to individuals and families facing genetic conditions.
They help people make informed decisions about genetic testing and its implications.

Question 35

What are the the ethical, legal and social issues involved with genetic testing:

Answer 35

These issues involve concerns about privacy, discrimination, consent, and the potential misuse of genetic information.

Question 35

Describe the principle of pre-implantation genetic diagnosis (PGD)

Answer 35

PGD is a genetic testing method used in assisted reproduction to screen embryos for specific genetic conditions before implantation.

Question 35

Describe the key concepts involved in the genetic engineering and the advantages/disadvantages to the methods described

Answer 35

Genetic engineering involves modifying an organism’s DNA. Advantages include creating disease-resistant crops, but ethical and ecological concerns exist.