Artificial Selection (2/12)

Question 1

Biological Species Concept

Answer 1

a group of inter-breeding natural populations that are reproductively isolated from other such groups

Question 2

What does it take for a hybrid to be successful?

Answer 2

1. ) It is capable of producing viable (fertile) offspring

2. ) It exploits niche that differs it from its parents

Question 3

Three Reasons Darwin Focused on Artificial Selection

Answer 3

1. ) Natural selection is often too slow for us to observe in a life time
2. ) Artificial Selection has resulted in dramatic changes
3. ) Artificial Selection demonstrates inheritance

** ARTIFICIAL SELECTION IS
WHEN PEOPLE DO THE SELECTING **

Question 4

Darwin’s Dillema

Answer 4

1. ) What is the source of this variability?

2. ) How does variability work?

Question 5

Gregor Mendel

Answer 5

• pea plant experiments

- applied statistical principle to biology and recognized the value of large scale experiments

Question 6

Blending Hypothesis

Answer 6

predicts that each hereditary factor is permanently diluted in a hybrid

** proved to be incorrect by Mendel through “discrete units”

Question 7

Chromatids

Answer 7

each of the two threadlike strands which a chromosome divides longitudinally during a cell division

• humans have 46

Question 8

Chromosomes

Answer 8

a pair of chromatids make up a chromosome; threadlike structure of nucleic acids and proteins found in the nucleus of most living cells

• carries the genetic information in the form of genes
• huamans have 23 pairs

Question 9

Mitosis

Answer 9

normal cell division;

in the parent cell, each chromosome is copied and 2 daughter cells are produced

Question 10

Meiosis

Answer 10

reproductive cell division;

in the parent cell, each chromosome is copied and 4 egg or sperm are produced (unpaired chromosome)

Question 11

Locus

Answer 11

a fixed position on a chromosome

• i.e. the position of a gene or a marker

Question 12

Homozygous

Answer 12

the 2 alleles are identical

Question 13

Heterozygous

Answer 13

the 2 alleles are different

Question 14

Dominant Allele

Answer 14

expressed even when heterozygous

Question 15

Recessive Allele

Answer 15

only expressed when homozygous

Question 16

Five Tenents of Mendelian Genetics

Answer 16

1. ) Phenotypic traits are determined by units of heredity called genes
2. ) One gene codes for one trait
3. ) Some alleles are dominant and others are recessive
4. ) Each parent contributes one randomly chosen allele of gene to each offspring
5. ) Each pair of alleles (genes) behaves independently of other allele pairs

Question 17

Principle of Segregation

Answer 17

each parent contributes one randomly chosen allele of gene to each offspring

Question 18

Principle of Independent Assortment

Answer 18

each pair of alleles (gene) behaves independently of other allele pairs

Question 19

Which Tenents of Mendelian Genetics Are Often Broken?

Answer 19

1. ) One gene codes for one trait

2. ) Some Alleles are dominant and others are recessive