Topic 1 - Introduction to Cell Biology

Question 1

3 domains of life

Answer 1

1. Bacteria
2. Archaea
3. Eukaryotes

Question 2

what is the one exception to the three key points about cells?

Answer 2

viruses

Question 3

T or F… there are gene families that are common to all 3 domains of life?

Answer 3

TRUE!!

Question 4

what are the 4 basic features of all cell?

Answer 4

1. plasma membrane
2. DNA
3. ribosomes
4. cytosol

Question 5

what metabolic pathway do plants use?

Answer 5

photoautotrophic

Question 6

what metabolic path do humans use?

Answer 6

chemoheterotrophic

Question 7

what are the two methods used to identify bacteria?

Answer 7

1. DNA sequencing

2. grow and culture

Question 8

what features are unique to animal cells

Answer 8

1. centrosome with pair of centrioles (plants have centrosomes without pair)
2. lysosomes

Question 9

what features are unique to plant cells

Answer 9

1. central vacuole
2. cell wall
3. plasmodesmata
4. chloroplast

Question 10

flow for regulatory DNA

Answer 10

• signal molecule from outside of cell binds to receptor protein embedded within the plasma membrane of the target cell
• signal activates cascade in cells
• proteins respond and change behaviour of cell

Question 11

Which cells have hybrid genomes and what does that mean?

Answer 11

Eukaryotes. This means they have DNA in the nucleus and extranuclear DNA

Question 12

What do bacteria and mitochondria have in common?

Answer 12

Both have ribosomes with their own DNA

Question 13

Is there a correlation between genome size and level of organization?

Answer 13

Yes, between eukaryotes and prokaryotes. But no correlation within eukaryotes exclusively

Question 14

Why do plants, algae, and protozoans have large ranges in genome size?

Answer 14

Because they are polyploids

Question 15

What is a complete set of human chromosomes called?

Answer 15

Karyotype

Question 16

Does the number of chromosomes correlate with the level of organization?

Answer 16

No. In some cases during evolution chromosomes fused together, so similar species can have varying chromosome amounts

Question 17

What is the difference between orthologs and paralogs?

Answer 17

Orthologs = same function, different species

Paralogs = different function, same species

Question 18

composition of human genome

Answer 18

50% repeated sequences: transposons, simple sequence repeats, and segmental duplications
50% unique sequences: introns, etc.
quite a few pseudogenes: look like genes but never expressed

Question 19

how can human genomes differ?

Answer 19

• SNPs
• duplication and deletion
• gene copy numbers