Lecture 1

Question 1

Who was the father of genetics

Answer 1

Mendel

Question 2

Who was genetics coined by and when

Answer 2

Bateson in 1905

Question 3

Who coined gene and when

Answer 3

Johannsen in 1909

Question 4

What did Gregor Mendel’s work with peas lead to

Answer 4

1. The discovery of dominant and recessive traits
2. The concept of the gene (‘heritable factor’)
3. The formulation of the basic laws of inheritance

Question 5

Character

Answer 5

A heritable feature of an individual

Question 6

Trait

Answer 6

A variant from a character

Question 7

Mendel’s Conclusion from monohybrid crosses

Answer 7

1. One trait is dominant (green pod) and the other is recessive (yellow pod)
2. The ‘heritable factor’ for the recessive had not been lost in the first generation but masked by the presence of a dominant trait

Question 8

Mendel’s Model (5 points)

Answer 8

1. Variation inherited characteristics are due to the existence of alternative versions of heritable factors called alleles
2. For each character, an organism inherits two alleles, one from each parent
3. If the two alleles differ, then the dominant allele determines the organism’s appearance (its phenotype)
4. The alleles do not bend when present in the same individual - they remain discrete
5. The two alleles segregate during gamete formation and end up in different gametes

Question 9

What is Mendel’s law of segregation

Answer 9

The two forms of a gene (alleles) present in each parent segregate independently

Question 10

What is the testcross

Answer 10

A method for determining the genotype of an individual with the dominant phenotype of a trait

Question 11

What is Mendel’s Law of Independent Assortment

Answer 11

Each pair of alleles (gene) assorts independently of each other pair of alleles (gene) during gamete formation

Question 12

Mitosis vs Meiosis

Answer 12

-Mitosis occurs in somatic cells and meiosis occurs in the germ line
-in mitosis there is only one cell division there is two in meiosis
-meiosis produces 4 (non-identical) haploid cells (gametes), mitosis produces 2 identical diploid cells.
-synapsis is unique to meiosis
-the role of mitosis is to drive growth and tissue repair; the role of meiosis is to produce haploid gametes and to introduce genetic variability

Question 13

Chromatid

Answer 13

One of the two identical strands of a newly replicated chromosome (not a pair homologous chromosomes)

Question 14

Sister chromatids

Answer 14

two identical chromatids help together by common centromere following replication

Question 15

Sutton made the link between the behaviour of chromosomes during meiosis and Mendel’s Law. What did he observe?

Answer 15

Chromosomes occur in pairs in somatic cells
Chromosome pairs segregate equally into gametes
Different chromosome pairs assort independently

Question 16

What does the Chromosome Theory of Inheritance state

Answer 16

-Mendel’s ‘inheritance factors’ are located at specific positions (loci) on chromosomes
-It is the chromosome that undergo segregation and independent assortment

Question 17

Genes

Answer 17

Units of heredity and determine traits. Each gene is located at a particular locus on chromosome

Question 18

How does the Law of Segregation link to chromosome behaviour in meiosis

Answer 18

Because each allele is on a different member of a chromosome pair and moves to opposite poles in anaphase I

Question 19

What links Law of independent assortment and chromosome behaviour during meiosis

Answer 19

Because the arrangement of chromosomes at metaphase I is random