Meiosis

Question 1

Diploid

Answer 1

contain two sets of chromosomes

Question 2

Haploid

Answer 2

have half the number of chromosomes as diploid, one complete set

Question 3

Prophase 1

Answer 3

• chromosome condensation and the pairing of and physical connection of homologous chromosomes along their length
• facilitated by synaptonemal complex that forms between homologous chromosomes which holds them together during synapsis
• rearrangement of genetic info occurs between sister chromatids
• crossing over occurs at chiasma
• crossing over results in physical breakage and reunion between non-sister chromatids
• nuclear envelope breaks down
• centrosomes are duplicated
• spindle formation

Question 4

Metaphase 1

Answer 4

• pairs of homologous chromosome bivalent will become randomly arranged relative to each other at the metaphase plate
• this done by the microtubules of the spindle apparatus

Question 5

Anaphase 1

Answer 5

• proteins that hold the homologous chromosome pairs together will break down
• this allows the separation of the homologues that make up each bivalent
• they are separated to opposite poles of the cell

Question 6

Telophase 1

Answer 6

• each half of the cell has a complete haploid set of duplicated chromosomes with each chromosome consisting of a pair of recombinant sister chromatids
• chromosomes slightly uncoil and nuclear envelope reforms
• cytokinesis follows this

Question 7

Prophase 2

Answer 7

• nuclear envelope breaks down
• spindle apparatus forms
• chromosomes condense

Question 8

Metaphase 2

Answer 8

-chromosomes are positioned at metaphase plate

Question 9

Anaphase 2

Answer 9

• proteins that hold sister chromatids together at the centromere are broken down
• allows chromatids to separate
• move to opposite poles of the cell as individual chromosomes

Question 10

Telophase 2

Answer 10

• reforming of the nuclear envelope
• chromosomal decondensing
• followed by cytokinesis

Question 11

Non-disjunction

Answer 11

when pairs of homologous or sister chromatids fail to separate resulting in some gametes having extra chromosomes and some having missing chromosomes, this can lead detrimental in the generated offspring

Question 12

Mendel One trait

Answer 12

homozygous plants would carry two identical alleles for that specific trait

Question 13

P generation

Answer 13

parents

Question 14

F1

Answer 14

produced offspring

Question 15

Mendel two traits

Answer 15

performed crosses between plants that were homozygous for the two traits, colour and shape

Question 16

Law of Segregation

Answer 16

two alleles of a gene segregate into different gametes during gamete formation in both parents

Question 17

Punnett Square

Answer 17

• one can use the outcome of meiosis to predict the expected genotype and phenotypes ratios of the offspring of different crosses
• 1:2:1 genotypic ration

Question 18

Law of Independent Assortment

Answer 18

• Mendel wanted to identify the characteristic segregation pattern of one set of alleles of a gene pair compared to another set of alleles of a different gene pair
• if the genes are located on the same chromosome they will not show independent assortment

Question 19

Development of pea seeds

Answer 19

sugar is converted into starch by a key enzyme that is coded for by the B gene
-in wrinkled peas this gene is interrupted, not allowing the conversion sugar to starch