comparative genomics + anatomy

Question 1

what are the 4 types of comparative genomics?

Answer 1

DNA
mitochondrial
proteins
retrovirus

Question 2

define comparative DNA studies

Answer 2

= comparing of DNA of different species to determine similarities and differences

Question 3

how can comparative DNA studies be used for evidence of evolution?

Answer 3

all living things use the same DNA code - so have evolved from a common ancestor

species more closer related have more similarities in their DNA

can identify genes preserved among species and organisms with unique characteristics

Question 4

how is mitochondrial DNA inherited?

Answer 4

after sperm has penetrated egg, mitochondria in sperm are rapidly destroyed, so mitochondrial DNA comes only from the egg

Question 5

how can mitochondrial DNA be used to provide evidence for evolution?

Answer 5

• allows tracking of a direct genetic line
• use similarity between mtDNA of individuals to provide estimate of closeness of relationship through maternal ancestors

Question 6

what is mitochondrial DNA?

Answer 6

DNA found in the mitochondria of the cells, rather than in the nucelus

Question 7

what is a retrovirus?

Answer 7

a virus that reproduces by inserting its genes into a cell’s DNA

Question 8

what is an endogenous retrovirus?

Answer 8

a retrovirus that has become part of an organism’s genome and exists in every cell of the body

Question 9

what is flanking DNA?

Answer 9

healthy DNA on either side of the retrovirus

Question 10

how are retroviruses passed on?

Answer 10

a gamete gets a retrovirus

offspring will have a copy of the ERV in the same place, the same chromosome in every one of their cells

all subsequent generations will have a copy of the ERV in the same location

Question 11

how do endogenous retroviruses provide evidence for evolution?

Answer 11

same virus in same location over many generations shows evidence for evolution

Question 12

what is junk DNA?

Answer 12

non-coding sequences of DNA with no function or purpose

Question 13

how can junk DNA be used as evidence for evolution?

Answer 13

similar to the comparison of other parts of DNA

more closely related species have more junk sequences in common - species have evolved from a common ancestor

Question 14

how can comparative protein studies be used for evidence for evolution?

Answer 14

amino acids are the same for all living things - evidence all organisms came from a common ancestor

closer related organisms have more similar amino acid sequences in their proteins
species with more distant ancestor will have more differences in amino acid sequence

Question 15

what are ubiquitous proteins?

Answer 15

proteins found in all organisms that are independent of the organism’s function or environment

they carry out the same function no matter where found

Question 16

how can ubiquitous proteins provide evidence for evolution?

Answer 16

can be compared for similarities and thus relatedness

Question 17

what are the 3 types of comparative anatomy?

Answer 17

• comparative embryology
• homologous structures
• vestigial structures

Question 18

what is embryology?

Answer 18

comparing very early stages of development in organisms

Question 19

how does comparative embryology provide evidence for evolution?

Answer 19

many vertebrae embryos are similar and have features not present in adults

similarities indicate common ancestors

common developmental pathway depends on the closeness of the relationship

providing evidence of common ancestors and evolution

Question 20

what are homologous structures?

Answer 20

structures similar in structure used in different ways

Question 21

how do homologous structures provide evidence for evolution?

Answer 21

similar structure, different function

shows they developed from a common ancestor and adapted to suit their environment

more similar structure and function = more closely related

Question 22

what are vestigial structures?

Answer 22

structures that may have once been important but lost or changed their function

remains of organs that were once functional

reduced in size to conserve energy

Question 23

how do vestigial structures provide evidence for evolution?

Answer 23

still have these structures even though we don’t use them

provide evidence of change over time

all have them - evolved from a common ancestor

Question 24

what are the 5 types of evidence of evolution?

Answer 24

fossils
comparative anatomy
- vestigial organs
- homologous structures
- comparative embryology
comparative genomics
- comparative protein studies
- comparative DNA studies
- mitochondrial DNA