L6: PATTERNS OF INHERITTANCE

Question 1

What are genes?

Answer 1

A segment of DNA within the chromosome.

Question 2

What is the basic unit of genetic info for a specific character?

Answer 2

Genes

Question 3

What is a genes fuction?

Answer 3

it is the code for proteins

Question 4

What is a chromosome?

Answer 4

A large strand of DNA

Question 5

How many chromosomes are in one of our cells? pairs?

Answer 5

46 chromosomes, 23 pairs

Question 6

T/F: most of our cells contain exactly the same set of genes

Answer 6

True.

Question 7

What is significant about our sperm and egg cells in regards to genes?

Answer 7

Sperm and egg cells contain only one of the two copies of gene

Question 8

Whats an alternative version of a gene called?

Answer 8

Alleles

Question 9

What is the basic unit of inheritance?

Answer 9

Gene

Question 10

Homozygote

Answer 10

an individual who carries two copies of the same allele

Question 11

Heterozygote

Answer 11

an individual that carries different alleles

Question 12

How did different alleles arise?

Answer 12

From mutation

Question 13

What is a mutation?

Answer 13

Change in DNA that makes up a gene

Question 14

Mutation can be three things:

Answer 14

1. harmful
2. benefical
3. neutral

Question 15

What is a genotype?

Answer 15

the genetic makeup of an organisim

Question 16

What is a phenotype?

Answer 16

the observable physical characteristics

Question 17

From the following, which is the phenotype vs the genotype… Short hair and LL homozygote :

Answer 17

Short hair = phenotype
LL homozygote = genotype

Question 18

Dominant alleles are represented by ….

Answer 18

capital letters

Question 19

Recessive alleles are represented by …

Answer 19

lowercases

Question 20

What is believed in the blending inheritance theory?

Answer 20

offspring should have a phenotype intermediate between those of their parents

Question 21

Whats a basic example proving the blending inheritance theory isn’t true?

Answer 21

-eye colour
- skips generations in humans

Question 22

Who disproved the theory of blended inheritance?

Answer 22

Gregor Mendel

Question 23

How did Mendel disprove the theory of blended inherritance?

Answer 23

• he used true-breeding pea plants
• crossed the pea plants - they were purple
• then self pollinated F1 plants to produce F2 plants

Question 24

What does true breeding mean?

Answer 24

When parents are self - pollinated the offspring are identical to the parents

Question 25

What happened when Mendel pollinated F1 plants to produce F2 plants ?

Answer 25

Some came out purple and some came out white

Question 26

What theory did Mendel come up with to conclude his experiment?

Answer 26

The particulate theory of inheritance

Question 27

What tool did Mendel use to support his findings ?

Answer 27

A Punnett square

Question 28

What 5 things did Mendel conclude about inheritance?

Answer 28

1. alleles cause variation 2. offspring inherit one copy of the gene from each parent 3. alleles separate into different gametes 4. gametes fuse without regard which allele they carry 5. alleles can be dominant or recessive

Question 29

What is Mendels 1st law?

Answer 29

- the law of segregation - state that two copies of each gene separate during meiosis, and end up in different gametes

Question 30

What is Mendel's 2nd law?

Answer 30

- independent assortment - states to form gametes alleles for one trait combine randomly with alleles for other traits

Question 31

How do you get 4 different types of gametes?

Answer 31

-meiosis 1 - anaphase - depends on the different combinations that the homologous pairs line up on the metaphase plate

Question 32

Incomplete dominance occurs when..

Answer 32

heterozygote phenotype that is intermediate between those of the two homozygotes

Question 33

Most characters are controlled by ...

Answer 33

multiple genes

Question 34

An example of characters being controlled by multiple genes:

Answer 34

- human skin colour - skin colour in humans is controlled by three genes that have equal effects