Nature of Variation

Question 1

Macro-evolution

Answer 1

• Is the evolution change over long periods of time and on a large scale
• Examples include the origins of new taxonimic groups, evolutionary treands, adaptive radiation and mass extinctions

Question 2

Micro-evolution

Answer 2

is the basis of natural selection when a population slowly adapts to its environment

Question 3

What is the difference between a homozygous and heterozygous chromosome?

Answer 3

• Homozygous chromosome contain the same allele
• Heterozygous chromosome contains different alleles

Question 4

Cells typically contain….

Answer 4

…3m of DNA

Question 5

What is Karotyping?

Answer 5

The ordering of the cells, involves pulling chromosomes apart and dying them with pseudo colours for easier identification

Question 6

What is Asexual reproduction?

Answer 6

• Daughter cells/offspring are clones
• Different types are Binary fission, Budding, Parthengenesis, vegetative reproduction, fragmentation.

Question 7

Binary fission

Answer 7

One cell divides into two

Question 8

Budding

Answer 8

New individuals split off from parent cell. Bud cell is a smaller clone

Question 9

Parthengenesis

Answer 9

This is the development of unfertilised eggs with no genetic input from males

Question 10

Vegetative reproduction

Answer 10

• New individuals from without production of seeds of spores.
• New plants form out of Rhizome or statons

Question 11

Fragmentation

Answer 11

• The organism splits into fragments and each continues to develop into the complete organism
• Occurs in animals and plants

Question 12

What causes genetic variation?

Answer 12

• Mutations
• Random seperation of chromosomes
• Crossing-over
• Random fertilisation

Question 13

What is an advantage of asexual reproduction?

Answer 13

• In a less stable environment, the best genotype is perpetuated.
• Uses up less energy and resources
• Able if no mate can be found?
  *

Question 14

What is an advantage of sexual reproduction?

Answer 14

Leads to more variation which promotes diversity and advantigous traits

Question 15

Lsit chromosome mutations

Answer 15

• Delection
• Duplication
• addition
• Inverstion
• Repiprocal translocation

Question 16

Polyploidy

Answer 16

• Multiple sets of chromosomes
• Usually found in plants
• Autopolyploidy is an error in meisosis or mitosis. The chromosome number increases from a diploid into a tetraploid
• Allopolyploidy is also an error in Meiosis or Mitosis. Caused by two different species interbreeding
• Highly uncommon
• Most offspring would be sterile but can produce asexually
• 70% all plants originated from poly ploidy