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Flashcards in Natural Selection/Genetics Deck (32)
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1
Q

Postulate definition

A

given truth that assembled together creates a complex understanding

2
Q

4 mechanisms of evolution

A
  1. individuals vary (variation)
  2. some of the variable traits among individuals are heritable
  3. there is a struggle for existence, not everyone survives
  4. individuals with favorable traits survive and reproduce
3
Q

Darwin’s logic

A

given enough resources, populations should be able to expand exponentially, yet they dont

this means that there is a struggle for existence

since traits vary and are heritable, the individuals with favorable traits will survive and reproduce

4
Q

Definition of evolution

A

inherited change in a group of organisms over time

5
Q

outcome of evolution by natural selection

A

a change in allele frequencies in a population over time

6
Q

fitness

A

the ability of an individual to produce, surviving offspring relative to that ability in other individuals in the population

7
Q

adaptation

A

a heritable trait that increases the fitness of an individual in a particular environment relative to individuals lacking the trait

8
Q

Common myths of natural selection

A
  1. natural selection does not change individuals
  2. acclimatization is not adaptation (acclimatization is a change of an individual’s phenotype due to natural condition)
  3. natural select is not goal oriented (mutations are chance, no higher/lower)
  4. natural select does not lead to perfection since there are trade-offs and vestigial traits
9
Q

Constraints on traits

A

genetically constrained

historically constrained (all traits evolve from previous traits)

environmentally constrained

= all 3 cause natural selection not to be perfect

10
Q

genetic correlation

A

can cause genetic constraint

a single gene affects multiple traits

11
Q

How to prevent antibiotic resistance?

A

Use a high concentration of antibiotics from the beginning and complete the course of antibiotics to prevent adaptations from occurring

12
Q

What does natural selection lead to?

A

adaptations

13
Q

What is more important reproduction or survival?

A

Both are equally important

14
Q

Abreu’s natural selection misconceptions

A
  1. Individuals do not change
  2. There is no goal
  3. There will never be a perfect organism
15
Q

What did Mendel want to answer?

A

Why offspring resemble their parents and how transmission of traits occurs

16
Q

Blending inheritance

A

The idea that parental traits blend

Offsprings have intermediate traits

17
Q

Inheritance of acquired characterisitics

A

Lamarckian understanding

Parental traits are modified and passed down

18
Q

Scientific name of Mendel’s peas

A

pisum sativum

19
Q

Why did Mendel use peas as model organisms?

A

Easy to grow

Short reproductive cycle

Traits are easily recognizable (discrete)

Produces large numbers of seeds

Matings are easy to control

20
Q

Model organism

A

a species that is widely studied because it is easy to maintain and breed in a lab setting

21
Q

How do peas reproduce?

A

They can be cross-pollinated or self-pollinated

22
Q

Phenotype

A

the observable appearance of a trait

23
Q

Genotype

A

the underlying genetic composition that makes up a trait

24
Q

Pure line

A

homozygous for a trait

also called true breeding

25
Q

Particulate inheritance

A

suggests that hereditary determinants maintain their integrity from generation to generation

genes are independently expressed without the blending of characteristics

26
Q

Gametes

A

haploid

contain one allele from either mom or dad

27
Q

Zygote

A

diploid

forms when two gametes are fused

contains one allele from both mom and dad

28
Q

Alleles

A

different versions of a gene

mendel says that each individual has two alleles

29
Q

Principle of segregation

A

two alleles of each gene must segregate into different gamete cells

Ex: Rr splits into R and r

30
Q

Law of Independent Assortment

A

the alleles of two or more different genes get sorted into gametes independently

the allele that one gamete receives does not influence the allele that another gamete receives

31
Q

Adaptations are often…

A

Compromises

Trade offs occur

32
Q

How to determine if a dominant phenotype is due to a heterozygous or homozygous dominant phenotype?

A

Cross with a homozygous recessive plant

This is called a test cross