GENETICS Flashcards
1
Q
- GENETICS
A
a branch of biology study the heredity and variation of organism
2
Q
- genome
A
- the genetic material of an organism
3
Q
- how much genes in the human genome ?
A
- the human genome consists of approximately 20,000 GENES .
4
Q
- what do genes make ?
A
- each of these genes is an instruction to build a single protein
5
Q
- trait ?
A
- it is any characteristic that can be passed from parent to offspring .
6
Q
- gene ?
A
- its a unit of heredity that controls the development of one trait ,
- Each chromosome carries many genes ,
- Most genes are composed of two alleles .
7
Q
- alleles ?
A
- two forms of a gene ,
- Each one comes from each parent ,
- One allele is dominant and the other is recessive,
- each one is represented by a single letter .
8
Q
- locus ?
A
- its the position in a chromosome of a particular gene or allele .
9
Q
- who is the father of GENETIC ?
A
- Gregor Johann Mendel , Father of modern genetics born in July 20, 1822 - January 6, 1884 .
10
Q
- do the recessive alleles are expressed when dominant alleles are present ?
A
- NO , Recessive alleles are only expressed when no dominant allele is present .
11
Q
- when can the recessive alleles be expressed ?
A
- it can be expressed when all the recessive alleles are located in the homologous chromosomes .
12
Q
- ¨ TT ¨ or ¨ tt ¨ ?
A
- are homologues alleles .
13
Q
- ¨ Tt ¨ ¨ tT ¨ ?
A
- are heterologous alleles .
14
Q
- F1 generation ?
A
- first-generation offspring are bred among themselves
( self-fertilized ) , to produce the second generation .
15
Q
- F2 generation ?
A
- mendelian ratios are based on this generation results .