1. The genetic Basis of Life

Question 1

what is evolution

Answer 1

is the change in one or more heritable traits found in a population of individuals over time

Question 2

what are acquired characteristics?

Answer 2

(eg. muscle gain/loss resulting from exercise) not heritable characteristics

Question 3

What is the germ plasm theory?

Answer 3

we are made out 2 fundamentally different material: germ plasm and somato plasm

only characteristics in the germ line are passed on

Question 4

Where are genes located?

Answer 4

on chromosomes

Question 5

What is natural selection?

Answer 5

emergence of characteristics (phenotype) that confer to reproductive advantage will more likely be passed onto the next generation

Question 6

What were Mendel’s interpretations of his results?

Answer 6

1. inheritance of characteristic trait is predictable
2. each form of a character is controlled by a certain heritable characteristic
3. obtained results are best explained by the existence of such factors in pairs
4. each parent only passes to its progeny one of its two factors for the character

Question 7

what is a gene

Answer 7

is a heritable characteristic

Question 8

what is an allele

Answer 8

is a version of a gene

Question 9

Who was the first one to observe chromosomes and thier segregation during cell division

Answer 9

Flemming

Question 10

What is the chromosome theory of inheritance

Answer 10

1. chromosomes show specific forms and sizes
2. nr. of chromosomes is characteristic of each species
3. chromosomes segregate equally between daughter cells during cell division
4. in most plants and animal cells chromosomes were present in pairs

Question 11

How did Thomas Hunt Morgan proof that genes were passed on through chromosomes?

Answer 11

He did cross breeding of genes that were located on the sex chromosome

Question 12

What was Morgan able to say after causing other mutant gene alles in addition to WHITE that were similarly transmitted by the X chromosomes

Answer 12

more than one gene could be associated/transmitted (proved theory of inheritance)

Question 13

What is a diploid cell

Answer 13

two copies of each chromosome in the nucleus, hence two copies of each gene

Question 14

What is a pair of homologous chromosomes

Answer 14

(one chromosomes from dad and one from mum) have the same genes on the same locus but different alleles

Question 15

Do the proteins expressed by 2 different alleles of the same gene function differently?

Answer 15

No the perform the same function

Question 16

What occurs during somatic cell division?

Answer 16

• each homologous chomosome pair is replicated
• sister chromatids are separated into daughter cells during mitosis
• genetic information is not mixed

Question 17

are progeny cells from somatic cell division, the same as parental cells?

Answer 17

Yes they are genetically the same

Question 18

Are progeny cells from germ cell division differnt parental cells?

Answer 18

Yes. Progeny cells are recombined and are haploid

Question 19

What occurs during meiosis?

Answer 19

1. recombination of homologous chromosomes leads to mixing of the genetic material (cross over)
2. after completion of meiosis, the resulting haploid gametes are genetically distinct from each other and their parental cells

Question 20

What was Griffth able to conclude after he injected harmless R bacteria and harmless heat killed S bacteria, and the mouse died?

Answer 20

R strain bacteria must have taken up the transformation principle from the S bacteria.

This caused R bacteria to transform to S bacteria

Question 21

What is the agent that causes genetic transformation? Protein, RNA or DNA?

Answer 21

DNA is the agent causing genetic transformation of the passive R form to virulen S form.
- no DNA, no transformation

Question 22

What did Hershey and Chase do to test whether DNA or protein carried genetic instructions?

Answer 22

they radioactively labelled DNA’s phosphorus and protein’s sulfur

Question 23

Are radioactively labelled protein coats of phages able to inject radioactivity into the cell?

Answer 23

No. Only DNA is passed on