Ch 6 - Genes & Heredity Flashcards Preview

Bio 30 > Ch 6 - Genes & Heredity > Flashcards

Flashcards in Ch 6 - Genes & Heredity Deck (43):
0

The passing of traits from parent to offspring is called?

Heredity

1

Genes

Segment of DNA that controls a trait

2

Hybrids

Offspring that differ from their parents in one or more traits

3

Gregor Mendel

-father of genetics
- experiments with garden peas.

4

Mendel choose the garden pea because...

Had a number of different characteristics
Could both self fertilize and cross fertilize

5

True-breeding

- Mendel tryed to use
-exhibit the same traits as their parents, same as in every following generation

6

Dominant

Strong
Determines the expressed gene

7

Recessive

Weak
Overruled by dominant genes

8

F1 generation

The first generation
Filial generation

9

Genotype

Tt, TT, tt

Dominant- capital
Recessive-lowercase

Always use same letter.

10

Phenotype

Observable traits

11

Homozygous

Both genes are the same

12

Heterozygous

Genotype that are different

13

Alleles

2 or more alternate forms of a gens

Red white

14

Single - trait inheritance

Mono hybrid cross

15

Punnnet square, is used to find.....

Genotype and phenotype

16

Test cross

-determine the genotype of dominant phenotype

-preformed between the unknown genotype and homozygous recessive genotype

17

Multiple alleles..

Most traits have more then two alleles (or options)

18

Incomplete dominance

-when two genes are equally dominant and interact to produce a new phenotype

19

Different types of incomplete dominance

-Intermediate inheritance
-Codominance

20

Intermediate inheritance

When a totally different phenotype is expressed

21

Codominance

When both genes are expressed at the same time.

22

Dihybrid crosses

-use foil
-ratio 9:3:3:1 --both heterozygous for both and complete dominant

23

Probability

Number of chances for an event / number of possible combinations

24

When determining probabilities
2 rules must be followed

1. The rule of independent events -pervious events don't effect future events

2. The product rule- multiply probabilities

25

Selective breeding

The crossing of desired traits to produce offspring with these desired traits

26

Gene interaction
(Test cross)

Polygenetic traits
Epistatic genes
Pleiotropic genes

27

Polygenetic traits

Inherited characteristics that are affected by more then one gene.

-one gene doing more then one thing

28

Epistaxis genes

Mask the expression of other genes

29

Pleiotropic genes

Genes that affect many characteristics

30

Thomas hunt Morgan

Provided a deeper understanding of gender and the inheritance of some characteristics

31

Morgan observed...

Drosophila had 8 chromosomes
-females had 4 homologous pairs
-males had 3 homologous pairs
And the 4th set (the sex chromosomes) were not homologous

32

Morgan reasoned that..

Eye color of this fruit fly was a sex-linked trait

-carried on the X or Y chromosomes

33

Sex-linked traits are also found in humans

-Red-green color blindness
-male pattern baldness
-hemophilia :blood loss

X-linked (more common)
Y-linked (less common)

34

The first 22 pairs are called.....

The last pair is...

Autosomes

Sex-chromosomes & determine gender

35

Linked genes

-Genes located on the same chromosome
-tend to be transmitted together

36

Crossing over

-during meiosis
-come in contact with each other
-genetic material is exchanged

37

Mapping chromosomes

-map distance

-The distance between two genes along the same chromosome

Written as map units (separation) or cross-over frequencies

The further apart the higher frequency of cross-overs

38

Genome

Is the complete set of DNA in a person

39

Gene therapy

Gene insertion
Gene modification
Gene surgery

40

Gene insertion

The normal gene from Another cell is inserted into position on the diseased cell

41

Gene modification

The defective gene is modified chemically -to recode the genetic message

42

Gene surgery

Most ambitious
The defective gene is extracted and replaced with a normal gene