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

Postulate definition

given truth that assembled together creates a complex understanding

2

4 mechanisms of evolution

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

Darwin's logic

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

Definition of evolution

inherited change in a group of organisms over time

5

outcome of evolution by natural selection

a change in allele frequencies in a population over time

6

fitness

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

7

adaptation

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

8

Common myths of natural selection

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

Constraints on traits

genetically constrained

historically constrained (all traits evolve from previous traits)

environmentally constrained

= all 3 cause natural selection not to be perfect

10

genetic correlation

can cause genetic constraint

a single gene affects multiple traits

11

How to prevent antibiotic resistance?

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

12

What does natural selection lead to?

adaptations

13

What is more important reproduction or survival?

Both are equally important

14

Abreu's natural selection misconceptions

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

15

What did Mendel want to answer?

Why offspring resemble their parents and how transmission of traits occurs

16

Blending inheritance

The idea that parental traits blend

Offsprings have intermediate traits

17

Inheritance of acquired characterisitics

Lamarckian understanding

Parental traits are modified and passed down

18

Scientific name of Mendel's peas

pisum sativum

19

Why did Mendel use peas as model organisms?

Easy to grow

Short reproductive cycle

Traits are easily recognizable (discrete)

Produces large numbers of seeds

Matings are easy to control

20

Model organism

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

21

How do peas reproduce?

They can be cross-pollinated or self-pollinated

22

Phenotype

the observable appearance of a trait

23

Genotype

the underlying genetic composition that makes up a trait

24

Pure line

homozygous for a trait

also called true breeding

25

Particulate inheritance

suggests that hereditary determinants maintain their integrity from generation to generation

genes are independently expressed without the blending of characteristics

26

Gametes

haploid

contain one allele from either mom or dad

27

Zygote

diploid

forms when two gametes are fused

contains one allele from both mom and dad

28

Alleles

different versions of a gene

mendel says that each individual has two alleles

29

Principle of segregation

two alleles of each gene must segregate into different gamete cells

Ex: Rr splits into R and r

30

Law of Independent Assortment

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

Adaptations are often...

Compromises

Trade offs occur

32

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

Cross with a homozygous recessive plant

This is called a test cross