Patterns and Principles of Heredity

Question 1

What is meiosis?

Answer 1

Formation of gametes involving special type of nuclear division that halves the chromosomes number

Question 2

When does meiosis occur?

Answer 2

After S (synthesis) phase of the cell cycle

Question 3

What happens after the s phase?

Answer 3

• Division of pairs of chromosome types

- Division of sister chromatids

Question 4

How is meiosis accomplished?

Answer 4

Through meiosis I and meiosis II

Question 5

What is meiosis I?

Answer 5

Reproductive division (chromosome number is reduced)

Question 6

What is meiosis II?

Answer 6

Separation of sister chromatids

Question 7

Can mitosis do homologous recombination/crossing over?

Answer 7

No

Question 8

Can meiosis do homologous recombination/crossing over?

Answer 8

Yes

Question 9

Describe the mechanism of meiosis I:

Answer 9

• 2 chromosomes which each have two sister chromatids attached at the centromere
• Recombination occurs
• Prophase I occurs
• Then metaphase I
• Homolog segregation
• Then anaphase I
• Finally Telophase I

Question 10

Describe prophase I:

Answer 10

• Chromosome condence
• Homologous repair and form synaptonemal complex
• Crossing over durting pairing

Question 11

What is crossing over?

Answer 11

Exchange of genetic material between homologous chromosomes

Question 12

Describe metaphase I:

Answer 12

• Each pair of homologous line up at equator
• Centromeres don’t divide
• Orientation of pairs is random with respect to one another

Question 13

Do centromeres divide during mitosis?

Answer 13

Yes

Question 14

Do centromeres divide during meiosis?

Answer 14

No

Question 15

Describe anaphase I:

Answer 15

• Chromosomes move to separate poles

- Diploid mother cell

Question 16

How many chromatids do chromosomes have during anaphase I?

Answer 16

2

Question 17

Describe telophase I:

Answer 17

-Two daughter cells contain one of each chromosome

Question 18

How many chromatids are in the two daughter cells at the end of telophase I?

Answer 18

2 chromatids in each daughter cell

Question 19

What is the final product of meiosis I?

Answer 19

Haploid cell as consist of on chromosome in the cell

Question 20

Describe meiosis II:

Answer 20

• Metaphase II where individual chromosomes line up at metaphase plate
• Anaphase II centromeres split, chromatids separate to opposite poles
• Telophase II each daughter cell contains one chromosome of each types

Question 21

Do centromeres split during meiosis II?

Answer 21

Yes

Question 22

If a geneticist were to closely examine the sequence of a single autosomal chromosome from one of your cells, that chromosome would be found to be:

A) Derived entirely from sequences from just one of your grandparents
B) A mosaic of sequences derived from all four of your grandparents
C) A mosaic of sequences derived from just two of your grandparents – either your two grandfathers or your two grandmothers
D) A mosaic of sequences derived from just two of your grandparents – either your maternal grandparents or your paternal grandparents

Answer 22

D

Question 23

What is heredity?

Answer 23

How genetic material is transmitted from one generation to another

Question 24

How are traits transmitted?

Answer 24

• Alleles of genes are transmitted from parent to offspring according to particulate theory of inheritance
• Monohybrid cross reveal Mendel’s Law of Segregation
• Dihybrid crosses reveal Mendel’s Law of independent Assortment

Question 25

What is the particulate theory of inheritance?

Answer 25

- Characters are distinct and genes are particulate in nature - Each adult has two genes for each character - Members of gene pair-segregate equally into gametes - Fusion of gametes at fertilisation restoration pair of genes and is random - Different genes assort independently in gametes

Question 26

What is the word for different forms of genes?

Answer 26

Alleles

Question 27

What terms are used to describe transmission genetics?

Answer 27

``` Gene Allele Genotype Phenotype Homozygote Heterozygote F1 F2 ```

Question 28

Describe gene:

Answer 28

Basic unit of biological information, specific segment of DNA that encodes a protein

Question 29

Describe allele:

Answer 29

Alternative forms of a gene

Question 30

Describe genotype:

Answer 30

Alleles at a locus

Question 31

Describe phenotype:

Answer 31

Observable characteristics

Question 32

Describe homozygote:

Answer 32

Identical (YY) alleles at a locus

Question 33

Describe heterozygote:

Answer 33

Different (Yy) alleles at a locus

Question 34

Describe F1:

Answer 34

First filial (son or daughter) generation after a cross

Question 35

Describe F2:

Answer 35

Second generation after a cross

Question 36

What is monohybrid cross in relation to law of segregation?

Answer 36

- Crossing two heterozygote patterns - Meiosis results in formation of two types of gametes in equal numbers - Fertilisation resorts the two copies of gene to the offpring

Question 37

What is an offspring genotype?

Answer 37

Combination of specific alleles that they carry

Question 38

What are the word that are used to describe the hierarchy of genes

Answer 38

Dominate and recessive

Question 39

What is the probability of getting one allele over another during fertilisation?

Answer 39

1/2

Question 40

Why is the probability 1/2 of getting one allele over another during fertilisation?

Answer 40

As two alleles possible, each gamete can only carry one allele§

Question 41

A particular hypothetical human disease occurs with a probability of 0.1 in males and with a probability of 0.4 in females. Assuming that the frequency of males is 0.5 and females 0.5 (50:50) in a very large population, what is the probability that an individual will be male and have the disease? Hint: the problem is best solved with a tree diagram. A) 0.05 B) 0.1 C) 0.5 D) 0.6

Answer 41

A

Question 42

What are dihybrid cross?

Answer 42

The pattern of inheritance of two different traits at the same time.

Question 43

What do dihybrid crosses reveal?

Answer 43

Mendel's Law of Independent Assortment

Question 44

How do genes assort during formation of gametes?

Answer 44

Independently

Question 45

What ratio would mean that two traits are independent?

Answer 45

9:3:3:1

Question 46

What does 9:3:3:1 represent?

Answer 46

Random combination of two independent 3:1 ratios

Question 47

Wolves are sometimes observed to have black coats and blue eyes. Assume that each of these traits is controlled by a single locus gene and the genes are located on different chromosomes. Assume further that normal coat colour (N) is dominant to black (n) and brown eyes (B) are dominant to blue (b). Suppose the breeding male and female of a pack are black with blue eyes and normal coloured with brown eyes, respectively. The female is also heterozygous for both traits. What percentage of the offspring will be normal coloured with blue eyes? ``` Select one: A) 0% B) 25% C) 50% D) 75% ```

Answer 47

B

Question 48

What is the law of segregation?

Answer 48

Two alleles for each trait separate during gamete formation and then reunite at random, one from each parent, at fertilisation.

Question 49

What law does transmission of alleles follow?

Answer 49

Law of basic probability

Question 50

What can the laws of probably be used for?

Answer 50

Predict the occurrence of specific genotypes in the offspring of even complex crosses.

Question 51

In dogs solid coat colour (S) is dominant over spotted (s) and black coat colour (B) is dominant over tan (b). A female with a solid tan coat mates with a male with a solid blackcoat and produces a litter of 6 puppies. Using the informationfrom the puppies’ phenotypes, determine the genotypes of theparents. The phenotypes of the puppies are as follows: 2 solid tan 2 solid black 1 spotted tan 1 spotted black ``` Select one: A. mother = Ss bb, father = Ss BB B. mother = SS bb, father = Ss Bb C. mother = ss bb, father = SS BB D. mother = Ss bb, father = Ss Bb ```

Answer 51

D