Lecture 3

Question 1

Prophase II

Answer 1

Chromosomes recondense

Question 2

Metaphase II

Answer 2

Individual chromosomes line up on the equatorial plate

Question 3

Anaphase II

Answer 3

Sister chromatids separate and move toward opposite poles

Question 4

Telophase II

Answer 4

Chromosomes arrive at the spindle poles and the cytoplasm divides

Question 5

Crossing Over

Answer 5

Exchange of genetic material between homologous chromosomes that results in shuffling of genes along the chromosome; can result in unequal exchange of genetic material producing chromosomes with deleted or duplicated regions; is independent across the centromere and is proportional to distance

Question 6

Cohesin

Answer 6

Protein complex that holds the chromatids together and is key to the behavior of chromosomes in mitosis and meiosis

Question 7

Spermatogenesis

Answer 7

Male gamete production

Question 8

Oogenesis

Answer 8

Female gamete production

Question 9

What is unique about meiosis in plants?

Answer 9

Plants alternate between diploid and haploid life stages

Question 10

Heredity

Answer 10

Passing on of physical or mental characteristics genetically from one generation to another

Question 11

Heritability

Answer 11

Proportion of total variation between individuals in a given population that is due to genetic variation

Question 12

MC1R Gene

Answer 12

Encodes the melanocortin 1 receptor; if it has AA variants that reduce receptor efficiency, the pathway shifts to pheomelanin production; if 2 copies are present, pheomelanin is the predominate pigment made which results in red hair

Question 13

Gene

Answer 13

Locus of DNA that encodes a functional RNA or protein product

Question 14

Allele

Answer 14

Alternative form of a gene that is located at a specific position on a specific chromosome

Question 15

Monohybrid Cross

Answer 15

Cross between two parents that differ in a single characteristic

Question 16

4 Conclusions made from a monohybrid cross

Answer 16

1: One character is encoded by 2 genetic factors
2: Two genetic factors (alleles) separate when gametes are formed
3: The concept of dominant and recessive traits
4: Two alleles separate with equal probability into the gametes

Question 17

Homozygous

Answer 17

True breeding; alleles are identical (FF, ff)

Question 18

Heterozygous

Answer 18

Alleles are different (Ff)

Question 19

Principle of Segregation (Mendel’s First Law)

Answer 19

Each individual diploid organism possesses two alleles for any particular characteristic and only one is passed to offspring

Question 20

Independent Assortment

Answer 20

Alleles segregate independently when gametes are formed

Question 21

Dominant

Answer 21

When two different alleles are present in a genotype, but the trait encoded by 1 of them, is the only phenotype observed

Question 22

Recessive

Answer 22

Both copies of the same allele have to be present for the phenotype to be observed

Question 23

Chromosomal Theory of Heredity

Answer 23

1902 by Sutton; proved genes are contained on chromosomes

Question 24

Chromosomal Theory of Heredity

Answer 24

1902 by Sutton; proved genes are contained on chromosomes

Question 25

Consequences of Meiosis and Genetic Variation

Answer 25

4 cells are produced from each original cell; chromosome number in each new cell is reduced by half (new cells are haploid); newly formed cells from meiosis are genetically different from one another and from the paternal cell; epigenetic modifications are erased and parent specific modifications are established