cell biology 1

Question 1

what are the features of plasma membranes

Answer 1

• lipid bilayer
• selectivity permeable

Question 2

key features of the nucleus

Answer 2

• contains chromosomes
• one or more nucleoli
• nuclear envelope
• nuclear lamina
• nuclear pores

Question 3

what the the key features of ribosomes

Answer 3

• large protein/ RNA complex
• located in the cytosol
• read mRNA to produce proteins
• attached to the eukaryotic ER or prokaryotic PM

Question 4

what is the smooth ERs function

Answer 4

lipid processing and secretion

Question 5

what is the rough ERs function

Answer 5

• studded with ribosomes for protein production of:
• membrane proteins
• extracellular proteins
• secretory pathways

Question 6

what is the function of the Golgi

Answer 6

• exit route from ER in secretory pathway
• carbohydrate and polysaccharide synthesis
• protein glycosylation and sorting
• glycosaminoglycans synthesis

Question 7

what is the structure and function of lysosomes

Answer 7

• membrane bound organelles
• contain soluble hydrolytic enzymes
• regulate intercellular macromolecule digestion

Question 8

what are peroxisomes functions

Answer 8

• membrane bound organelles
• perform oxidation reactions using hydrogen peroxide and oxygen

Question 9

what is the structure of mitochondria

Answer 9

• contains inner and outer membrane
• have their own DNA
• have their own ribosomes

Question 10

what are the functions of mitochondria

Answer 10

• ATP production
• inner membrane for electron transport chain
• fatty acid beta oxidation
• Ca2+ regulation

Question 11

what is a tight junction

Answer 11

• seals gaps between epithelial cells

Question 12

what is a adherens junction

Answer 12

• connects actin filament bundles in one cell with that in the next cell

Question 13

what is a desmosome

Answer 13

connects intermediate filaments in one cell to those in another

Question 14

what is a gap junction

Answer 14

allows the passage of small water soluble molecules from cell to cell

Question 15

what is an actin-linked cell-matrix junction

Answer 15

anchors actin filaments in a cell to extracellular matrix

Question 16

what is a hemidesmosome

Answer 16

anchors intermediate filaments in a cell to extracellular junction

Question 17

what are the key features of bacteria cells

Answer 17

• no nucleus - single circular DNA in cytoplasm
• cytoplasm lacks membrane bound organelles
• smaller ribosomes - 70S
• outer membrane -ve
• thick peptidoglycan cell wall +ve
• plasmid DNA
• capsule
• flagella
• surface layer

Question 18

where did archaea originate from

Answer 18

originally isolated from extreme environments “extremophiles”

Question 19

what are the features of archaea

Answer 19

• no nucleus - single circular DNA
• cytoplasm lacks membrane bound organelles
• smaller 70S ribosomes
• cell wall contains pseudopeptidoglycan or pseudomurein
• genome is larger and more complex than bacteria

Question 20

what are viruses and what are their features

Answer 20

• non living particles
• DNA or RNA surrounded by protein or lipid and protein capsid
• replicate in living cells

Question 21

what are the stages of the cell cycle

Answer 21

• M phase
• G1 phase
• S phase
  -G2 phase

Question 22

what happens in prophase of mitosis

Answer 22

• sister chromatids condense
• mitotic spindle assemble between two centrosomes

Question 23

what happens in prometapahse

Answer 23

• breakdown of nuclear envelope
• chromosomes attach to spindle microtubules via kinetochores

Question 24

what happens in metaphase

Answer 24

• chromosomes aligned at equator of the spindle
• kinetochore microtubules attach sister chromatids to opposite spindle poles

Question 25

what happens in anaphase

Answer 25

• sister chromatids separate to form two daughter chromosomes
• they are pulled towards spindle poles
• kinetochore microfibrils get shorter and spindle poles move apart

Question 26

what happens in telophase

Answer 26

• daughter chromosomes arrive at poles and decondense
• nuclear envelope reassembles around each set
• end of mitosis
• contractile ring starts to contract

Question 27

what happens in cytokinesis

Answer 27

• cytoplasm is divided into two by a contractile ring of actin and myosin
• two daughter cells are created

Question 28

what are the stages of meiosis

Answer 28

1) prophase
2) prometaphase
3) metaphase
4) anaphase
5) telophase
6) metaphase 2
7) anaphase 2
8) telophase 2

Question 29

what Is a diploid cell

Answer 29

have chromosome pairs

Question 30

what is a somatic cell

Answer 30

genetic information not passed onto offspring

Question 31

what is a germ-line cell

Answer 31

genetic information passed onto offspring

Question 32

what is a haploid cell

Answer 32

has one set of chromosomes

Question 33

what is a totipotent cell

Answer 33

able to produce any type of body cell aswell as the placenta

Question 34

what is a pluripotent cell

Answer 34

able to produce nearly every body cell apart from placenta

Question 35

what is a multipotent cell

Answer 35

can differentiate into many different body cells

Question 36

what is a oligopotent cell

Answer 36

can only differentiate into a few different body cells

Question 37

what is a unipotent cell

Answer 37

can only differentiate into one type of body cell