1 - nature and variety of living organisms

Question 1

what characteristics do all organisms share?

Answer 1

they require nutrition
they respire
they excrete their waste
they respond to their surroundings (sensitivity)
they move
they control their internal conditions
they reproduce
they grow and develop
(MRS H GREN)

Question 2

label/ name what would (not) be in a typical animal cell

Answer 2

nucleus, cell membrane, mitochondria, and cytoplasm.
they don’t have any chloroplast - therefore can’t photosynthesise. they have no cell walls.

Question 3

label/ name what would (not) be in a typical plant cell

Answer 3

cell wall, cell membrane (inside cell wall), vacuole, cytoplasm, mitochondria, chloroplasts (for photosynthesis), nucelus

Question 4

what is an organelle

Answer 4

a structure in the cytoplasm

Question 5

what is the largest organelle? what does it do?

Answer 5

Nucleus - controls activities of the cell. Contains chromosomes (in human cells) which carry genetic material, or genes.

Question 6

what do genes do? how does this happen?

Answer 6

controls the activity in the cell by determining which proteins the cell can make. The DNA remains in the nucleus but the instructions for making the proteins are carried out of the nucelus to the cytoplasm, where proteins are assembled on ribosomes

Question 7

what do enzymes do in the cell?

Answer 7

control the chemical reactions that take place in the cytoplasm

Question 8

what does the mitochondria do?

Answer 8

site of respiration (releases energy)

Question 9

what is the cell wall of a plant made out of?

Answer 9

cellulose

Question 10

how do plants store carbohydrates? where does it go?

Answer 10

as starch or sucrose
starch is often found inside of the plant and sucrose is transported around the plant and is sometimes stored in fruits and other plant organs

Question 11

what are examples of plants?

Answer 11

flowering plants like maize
herbaceous legume like peas or beans

Question 12

what are examples of animals?

Answer 12

mammals like humans
insects like horsefly and mosquito

Question 13

what are examples of fungi?

Answer 13

Mucor (which has the typical hyphal structure)
yeast - unicellular

Question 14

what are examples of protoctists?

Answer 14

Amoeba (lives in pond water and has features of an animal cell), Chlorella (more like plant cells with chloroplasts), Plasmodium (pathogen causing malaria)

Question 15

and plants and animals multicellular?

Answer 15

yes

Question 16

how do animlas often store carbs?

Answer 16

glycogen

Question 17

what does photosynthesis do?

Answer 17

the process uses light and energy to convert simple inorganic molecules such as water and carbon dioxide into complex organic compounds

Question 18

what do most animals have?

Answer 18

nervous coordination to be able to move from one place to another

Question 19

what does vertebrate/invertebrate mean

Answer 19

they have a vertebral column, invertabrates lack this feature

Question 20

are fungi multicellular or unicellular?

Answer 20

both
e.g., mushrooms are multicellular but yeast is unicellular

Question 21

what is in a fungi cell? What is not in a fungi cell?

Answer 21

cell wall (made of chitin), cell membrane surface, cytoplasm, vacuole, nucleus
there are never chloroplasts and cant carry out photosynthesis

Question 22

what is the cell wall of fungi made of?

Answer 22

chitin

Question 23

what is the structure of fungi?

Answer 23

their body is organised into a mycelium made from thread-like structures called hyphae which can contain multiple nuclei. their cell wall is made of chitin

Question 24

what is hyphae?

Answer 24

thread like fillaments

Question 25

what is mycelium

Answer 25

a network of hyphae

Question 26

how do fungi eat/feed?

Answer 26

they feed by extracellular secretion of digestive enzymes onto food material and ab]sor[tion of organic products; this is known as saprotrophic nutrition
e.g., when a spore of Mucor lands on food, hyphae grows out from them. the hypha grows and branches again and again, until the mycelium covers the surface of the food. the hyphae secrete digestive enzymes onto the food, breaking it down into soluble substances such as sugars which are then absorbed by mould. Eventually, the food is used up and the mould must infect another source of food by producing more spores.

Question 27

how does fungi store carbs?

Answer 27

as glycogen

Question 28

are protoctists multicellular?

Answer 28

no - they are microscopic unicellular organisms

Question 29

what is the difference between eukaryotic and prokaryotic cells

Answer 29

eukaryotic cells have a nucleus along with other membrane-bound organelles such as mitochondria and chloroplasts whereas prokaryotic cells don’t

Question 30

name the eukaryotes

Answer 30

plants, animals, fungi, protoctists

Question 31

name a prokaryotic organism

Answer 31

bacteria

Question 32

is bacteria multicellular?

Answer 32

no they are unicellular

Question 33

describe the structure of a bacteria cell

Answer 33

cell wall, cell membrane, cytoplasm, and plasmids(circular rings fo DNA carrying some of the bacterium’s genes- most bacterium have this) , they lack a nucleus but contain a circular chromosome of DNA (loose in cytoplasm)
(+capsule (slime layer), flagellum)

Question 34

what are some different bacterial shapes?

Answer 34

spheres (can be in singles, pairs, chains, groups), rods (singles, chains, with/without flagellum), spirals

Question 35

what are bacterial cell walls made out of?

Answer 35

complex compound of sugars and proteins called peptidoglycan

Question 36

what is an example of bacteria?

Answer 36

lactobacillus bulgaricus - rod-shaped bacterium used in the production of yoghurt from milk
pneumococcus - spherical bacterium that acts as the pathogen causing pneumonia

Question 37

how does bacteria feed?

Answer 37

some carry out photosynthesis but most feed off other living or dead organisms. In fact, they, like fungi, are important decomposers, recycling dead organisms and waste products in the soil and elsewhere

Question 38

can bacteria respond to stimuli?

Answer 38

yes- e.g., going towards food or away from harmful chemicals

Question 39

what are viruses?

Answer 39

parasites which can only reproduce inside living cells

Question 40

what is the cell in which a virus lives in called?

Answer 40

host cell

Question 41

what are virus’ made up of?

Answer 41

they are not made up of cells. thye are small particles and there is no nucleus, or cytoplasm. it is made up of a core of genetic material surrounded by a protein coat. this genetic material can either be DNA or a similar chemical called RNA. It has a cell membrane AKA envelope which can surround the virus particle bus it doesn’t make this (it’s stolen from the surface membrane of the host cell).
thye have a variet of shapes and sizes

Question 42

are virus’ living?

Answer 42

no- thye can’t carry out MRS H GREN
they are small particles (smaller than bacteria)

Question 43

how does a virus reproduce?

Answer 43

by entering the host cell and taking over the host’s genetic machinery to make more virus particles. After many virus particles have been made, the host cell dies and the particles are released to infect more cells. (usually, the host body system destroys the virus however sometimes it can lead to death)

Question 44

examples of virus’

Answer 44

colds, measles, mumps, polio, rubella, INFLUENZA, HIV (which leads to aids because the virus attacks the cells of the immune system) in human cells
tobacco mosaic virus in plant cells which interferes with the ability of the tobacco plant to make chloroplasts making mottled patches to develop on leaves

Question 45

label a virus cell

Question 46

can virus’ infect every type of living organism?

Answer 46

yes

Question 47

what can be a pathogen?

Answer 47

fungi, bacteria, protoctists, viruses

Question 48

how big are viruses, animal, and bacteria cells?

Answer 48

virus - 0.01-01µm diameter
animal - 10-50 µm diameter
bacterium - 1-5 µm diameter