1/ intro, 2/ asexual cell cycle

Question 1

3 themes of genetics

Answer 1

• molecular/developmental genetics: transmitted from DNA
• Transmission genetics: transmitted from parent to offspring in families
• population/evolutionary genetics: transmitted over many generations within large pop

Question 2

structure of linear chromosomes - 4 things

Answer 2

• telomeres - end of chromosome, protect from degradation
• centromere - separates arms, binding site for kinetochore proteins, not always in middle
• p arm - petite arm. shorter arm
• 1 arm - longer arm

Question 3

euchromatin vs heterochromatin, how are they controlled

Answer 3

• euchromatin: loosely packed, readily transcribed
• hetero: condensed, tightly wrapped around histones, doesn’t allow expression of genes in that area
• epigenetics - addition of methyl and acetyl groups to histone proteins, heritable

Question 4

cytogenetics, g banding, karyotype

Answer 4

• study of chromosomes
• technique that uses a chemical to stain chromosomes - unique banding pattern
• all the chromosomes an organism has

Question 5

what is an exception to: cells in multicellular organisms contain the same genes

Answer 5

• deliberate rearrangement of DNA in cells that make immunoglobulins

Question 6

semidiscontinous DNA replication

Answer 6

• continuous replication of leading strand
• discontinuous replication of lagging strand

Question 7

binary fission in bacteria

Answer 7

• DNA duplicates, cell gets bigger, replicated chromosomes move apart
• FtsZ protein marks the middle
• 2 daughter cells

Question 8

cell cycle overview

Answer 8

• interphase:
• G1: increase cell size, RNA produced, prep for DNA synthesis
• s: DNA synthesised
• G2: checks for fidelity of dna, prep nuclear division
• Mitosis: prophase, prometaphase, metaphase, anaphase, telophase
• cytokinesis

Question 9

whats G0 phase

Answer 9

• cells inactive - quiescent
• can enter from G1

Question 9

prophase - what holds sister chromatids together

Answer 9

• sister chromatids held together by protein called cohesin

Question 9

prometaphase

Answer 9

• late prophase
• when nuclear memb breaks down

Question 9

what feature of spindle fibres contracting allows sister chromatids to speerate

Answer 9

• pulling equal strength both sides

Question 10

what defines centromeres

Answer 10

• specific epigenetic markers

Question 11

cytokinesis

Answer 11

• division of rest of cell - not nucleus
• cleavage furrow in animals or cell plate in plants forms between 2 poles
• constriction to give 2 daughter cells
• can be symmetrical or uneven

Question 12

mitosis goes wrong: bridge chromosome, acentric chromosome

Answer 12

• 2 centromeres, pulled towards both poles at once - broken
• lacking a centromere, can’t segregate properly