DNA day 3 1B Part 2

Question 1

Chromosomes

Answer 1

DNa organized with proteins

Question 2

Chromatin (2)

Answer 2

a given region of DNA with its associated proteins in a chromosome

lower level of dna organization

Question 3

Chromosomes can either be

Answer 3

circular or linear

Question 4

Prokaryotes and their chromosomes: (3)

Answer 4

only have 1 chromosome

usually circular

there are also small independent circular DNA called plasmids in the cytoplasm

Question 5

Plasmids (3)

Answer 5

have genes that are not required for life but having it makes them advantageous.

For ex, some genes may include antibiotic resistance

Can be exchanged which grows concern for pests with antibiotic resistance

Question 6

How do you tell a chromosome is circular or linear?

Answer 6

Enzyme recognize specific sequence and cut it.

1 fragment= circular

2 fragment= linear

Question 7

Tell me about chromosomes and gene location etc.

Answer 7

For humans, all humans have same number of chromosomes and number of genes. All of us have gene on the same exact spot of chromosome 1 that codes for the same thing, just different allele.

Question 8

what has a haploid genome

Answer 8

sexually reprodouctive cells have this Sperms and egg

Question 9

Diploid+ vocab

Answer 9

majority of eukaryotic cells are this (2 copies of each chromosome= homologous chromosomes)

Question 10

why are some polyploid?

Answer 10

More copy of the same gene in polyploid then diploid to make more mRNA and protein to sustain such large size

Question 11

Origins of replication + who has this? (4)

Answer 11

DNA sequence along chromosome which initiate DNA replication/a particular sequence in a genome at which replication is initiated.

multiple in eukaryotes and only 1 in prokaryotes

mostly AT as opposed to CG

eukaryotes and prokaryotes has this

Question 12

Centromere + who has this? (2)

Answer 12

DNA sequences required for correct segregation of chromosomes by directing formation of the kinetochore in which the mitotic spindle attaches

only eukaryotes have this

Question 13

Telemeres + who has this? (2)

Answer 13

DNA sequences located at the ends of the chromosome that prevent degradation and allow proper replication of the chromosomal ends

only eukaryotes have this

Question 14

Eukaryote chromosomes (2)

Answer 14

linear and enclosed in the nucleus

Question 15

Kinetochore

Answer 15

large protein assemblies that connect chromosomes to microtubules of the mitotic and meiotic spindles in order to distribute the replicated genome from a mother cell to its daughters

Question 16

What do chromosome do to DNA

Answer 16

compact dna

Question 17

Histones

Answer 17

positively charged proteins that DNA wind around

Question 18

Nucleosome (3)

Answer 18

8 histones-2 copy of 4 types of histone

H2A H2B H3 H4

Question 19

Histone H1

Answer 19

Binds linker DNA to nucleosomes to form 30nm chromatin fibre

Question 20

Linker DNA are (2)

Answer 20

what H1 binds on to form the 30nm chromatin fibre.

It isnot around nucleosomes

Question 21

Histones in prokaryotes

Answer 21

None as prokaryotes only have positively charged proteins associated with DNA

Question 22

Dan packing and compaction along the chromosome is

Answer 22

not uniform

Question 23

Euchromatin (2)

Answer 23

regions have lower DNA compassion and genes are actively expressed

transcription occurs (ran produced)

Question 24

Heterochromatin

Answer 24

Chromosomal regions of high DNA compaction where gene expression is silenced bc to much compaction the enzymes for transcription can’t get in

Question 25

constitutive Heterochromatin+ex(2)

Answer 25

high DNA compaction that are permanent

centromeres and sib telomeric regions (no RNA produced)

Question 26

Facultative heterochromatin and why/how

Answer 26

can switch to euchromatin depending on cell type and during development

acetylation of histones=losen interaction between histone/DNA