biology basics

Question 1

describe the levels of organisation in organisms

Answer 1

organelles, cells, tissues, organs and systems

Question 2

describe cell structures

Answer 2

nucleus, cytoplasm, cell membrane, cell wall, mitochondria, chloroplasts, ribosomes and vacuole

Question 3

what are differences in the structure of plant and animal cells

Answer 3

plant cell has vacuole, cell wall, chloroplasts

Question 4

what is the role of enzymes

Answer 4

biological catalysts

Question 5

what are plant cell walls made of

Answer 5

cellulose

Question 6

what do plants store carbohydrates as

Answer 6

sucrose/starch

Question 7

what do humans store carbohydrates as

Answer 7

glycogen

Question 8

describe bacteria

Answer 8

microscopic single-celled organisms;
cell wall, cell membrane, cytoplasm and plasmids;
no nucleus but contain a circular chromosome of DNA; some carry out photosynthesis
most feed off other living or dead organisms.

Question 9

examples of bacteria

Answer 9

Examples include Lactobacillus bulgaricus, a
rod-shaped bacterium used in the production of yoghurt from milk, and
Pneumococcus, a spherical bacterium that acts as the pathogen causing pneumonia

Question 10

plants

Answer 10

multicellular organisms;
cells contain chloroplasts
carry out photosynthesis;
cellulose cell walls;
store carbohydrates as starch or sucrose.

Question 11

examples of plants

Answer 11

Examples include flowering plants, such as a
cereal (for example, maize), and a herbaceous legume (for example, peas or beans)

Question 12

animals

Answer 12

multicellular organisms;
cells do not contain chloroplasts and are not able to carry out photosynthesis;
they have no cell walls;
they usually have nervous co-ordination
can move from one place to another;
they often store carbohydrate as glycogen.

Question 13

fungi

Answer 13

no photosynthesis;
mycelium made from thread-like structures called hyphae, which contain many nuclei;
some are single-celled;
cell walls made of chitin;
feed by extracellular secretion of digestive enzymes onto food material and absorption of the organic products;
( saprotrophic nutrition);
they may store carbohydrate as glycogen.

Question 14

examples of fungi

Answer 14

Examples include Mucor, which
has the typical fungal hyphal structure, and yeast, which is single-celled.

Question 15

protoctists

Answer 15

microscopic single-celled organisms. Some, like Amoeba, have features like an animal cell, while others, like Chlorella, have chloroplasts and are more like plants.

Question 16

example of pathogenic protoctist

Answer 16

A pathogenic example is Plasmodium,
responsible for causing malaria.

Question 17

viruses

Answer 17

not living organisms. smaller than bacteria;
can reproduce only inside living cells;
they infect every type of living organism.
wide variety of shapes and sizes;
no cellular structure but have a protein coat and contain either DNA or RNA.

Question 18

examples of viruses

Answer 18

Examples include the tobacco mosaic virus that causes
discolouring of the leaves of tobacco plants by preventing the formation of
chloroplasts, the influenza virus that causes ‘flu’ and the HIV virus that causes AIDS.

Question 19

how do fungi decompose wood

Answer 19

1. hyphae / mycelium secrete enzymes onto wood
   2) they digest material, producing carbon dioxide / water
   (saprotrophyte example)

Question 20

define organelle

Answer 20

a specialized structure within a cell

Question 21

define tissue

Answer 21

a group of similar cells that work together to carry out a particular function

Question 22

define organ

Answer 22

group of different tissues tat work together to perform a function

Question 23

how does temperature affect enzymes

Answer 23

increase temp=increase activity
until they denature

Question 24

what happens when enzymes denature

Answer 24

the enzyme changes shape so the substrate no longer fits