Diversity of Organisms and Karyotyping (SL)

Question 1

Organism

Answer 1

Any biological system that functions as an individual life form

Question 2

Population

Answer 2

A group of organisms of the same species in the same area; variation between individual organisms of the population

Question 3

Community

Answer 3

Populations of two or more different species occupying the same area at the same time; great variation between different species

Question 4

Variation

Answer 4

Defining feature of life; differences between members of a group

Question 5

Discrete variation

Answer 5

Traits that can be put into distinct qualitative categories; influenced by one or few genes; can be influenced by environment

Question 6

Continuous variation

Answer 6

Traits that vary along a quantitative continuum; most types of biological variation; caused by complex interaction between several genes (polygenic); phenotype expression influenced significantly by environment

Question 7

Variation between species

Answer 7

Amount of variation between individual organisms depends on how closely related they are to each other

Question 8

Binomial nomenclature benefits

Answer 8

1. Reflects evolutionary relationships between organisms
2. Enables scientists to talk to each other in the same language

Question 9

Biological species concept

Answer 9

A species is a group of organisms that can breed and produce fertile offspring

Over 30 definitions of species; has limitations (tiger and lion)

Question 10

Limitations of the biological species concept

Answer 10

1. Asexual organisms
2. Hybrids
3. Geographically inaccessible locations
4. Extinct populations
5. Chronospecies (entire species evolving over time)
6. Divergence during speciation (gray area)

Question 11

Divergence during speciation

Answer 11

Populations of the same species who do not interbreed build up genetic differences over time that can cause divergence to the point of becoming separate species

Makes distinguishing between different populations and species difficult

Question 12

Human and chimpanzee chromosomes

Answer 12

Humans: 46
Chimpanzees: 48

Question 13

Chromosomes

Answer 13

A distinguishing characteristic of a species

Different numbers of chromosomes mean that species cannot mix

Question 14

Even number of chromosomes in a diploid cell

Answer 14

One set from mother, one set from father

Question 15

Karyotyping and karyograms

Answer 15

Looking at/arranging by the size and number of chromosomes

Question 16

Karyotyping process

Answer 16

1. Cells are harvested
2. Cell division is induced and then chemically stopped (usually during metaphase)
3. Chromosomes are arranged into pairs according to size
4. Sex chromosomes are shown last

Question 17

Karyotyping purpose

Answer 17

1. Determine the gender of an unborn child using sex chromosomes
2. Test for chromosomal abnormalities

*Not the same as looking for genetic diseases

Question 18

Classifying chromosomes

Answer 18

1. Banding pattern created by stains (G-bands)
2. Length
3. Centromere position

*Banding does not represent genes/specific traits

Question 19

Human chromosome 2

Answer 19

Thought to have arisen from a fusion of chromosomes 12 and 13 in ancestor (chimps); evidence is similar banding patterns and centromere position

Question 20

Genome

Answer 20

All the genetic information of an organism

Question 21

Single-nucleotide polymorphisms

Answer 21

Variations in genomes of organisms of the same species

Question 22

Genomes vary in…

Answer 22

1. Overall size (determined by total amount of DNA)
2. Base sequence (including length of chromosome)

Variation between species is much larger than variation within a species

Question 23

Genome size

Answer 23

Can be measured in terms of number of base pairs or mass of DNA in the nucleus

Larger ≠ more complex

Question 24

Current and potential future uses of whole genome sequencing

Answer 24

Current: research into evolutionary relationships
Future: personalized medicine

Question 25

Speciation

Answer 25

Divergence into new species from a pre-existing species

Happens gradually rather than abruptly