Mid-Semester Exam

Question 1

Levels of Explanation

Answer 1

• Proximate: How something works within lifetime of the organism
• Ultimate: How did the trait/ characteristic evolve?

Question 2

Definition of Natural Selection

Answer 2

Change in the frequency of genotypes (alleles in the end) over generations due to differences of their phenotype to reproduce

Question 3

Requirements for Natural Selection

Answer 3

1. Variation
   
   • No basis for selection without this
   • Sexual reproduction increases it
2. Heritability
   
   • Proportion of all variation thats due to alleles from parents
3. Competition
   
   • Gives advantage to resources
4. Differential Reproduction
   
   • Some better able to reproduce

Question 4

An Adaptation

Answer 4

• A trait that in some way increases survival and reproduction
• It is an outcome of the process of adaptation, which takes generations

Question 5

Adaptation (Verb)

Answer 5

• Process takes many generations
• It is the result of interaction of phenotype with the environment
• When look at specific traits need to see how it functions in fitness sense - must increase phenotype’s overall reproduction through more efficient use of environment than is true of an alternative

Question 6

Reproductive Success

Answer 6

Number of viable fertile offspring produced by an individual

Question 7

Definition of Trade- Off

Answer 7

Negative relationship between 2 traits

Question 8

Definition of Genotype

Answer 8

Genetic constitution of an individual

Question 9

Allele

Answer 9

Alternative form of a gene at a specific locus

Question 10

Phenotype

Answer 10

Trait determined by genotype +/- environment

Question 11

DNA Structure

Answer 11

• DNA is composed of units called nucleotides
• Nucleotides consists of:
  
  • Nitrogenous base
    
    • Thymine (pyrimidine) – 1 ringed basis
    • Cytosine (pyrimidine) – 1 ringed basis
    • Guanine (purine) – 2 ringed basis
    • Adenine (purine) – 2 ringed basis
  • Deoxyribose (sugar)
  • Phosphate
• Carries information via the base sequence
• Back bone of each strand is comprised of sugar phosphate sequence
• A + T – make a bond as they have 2 hydrogen bonds
• C + G – make a bond as they have 3 hydrogen bonds

Question 12

Gene

Answer 12

• Basic physical and functional unit of heredity
• Specific sequence of nucleotides at a given position on a chromosome
• Codes specific protein
• 2 copies of a gene in each cell

BASIC STRUCTURE

• Promoter – specifies where transcription begins
• Exon – contains coding info – specify a sequence of amino acid - make polyproteins/ proteins contribute to different phenotypes
• Intron – non coding region which do not specific amino acid

Question 13

Androgen Effects

Answer 13

• Organisational: Affects structural develoments during physical + physiological developments
• Activational: response of tissues to later androgen/ estrogen exposure

Question 14

Carrying Capacity

Answer 14

Number of individuals that a given environment can support given its technology to access the resources