Topic 1: The Natural And Variety Of Living Organisms

Question 1

Name the 8 Functions of living orgamisms.

Answer 1

· Movement
· Reproduction
· Sensitivity
· Control
· Growth
· Respiration
· Excretion
· Nutrition

Question 2

Movement

Answer 2

Can change position

Question 3

Reproduction

Answer 3

can have offspring either sexually or asexually

Question 4

Sensitivity

Answer 4

can detect stimuli, such as light, and then respond to them

Question 5

Control

Answer 5

Can control their internal environment (homeostasis)

Question 6

Growth

Answer 6

Can increase mass

Question 7

Respiration

Answer 7

Can produce energy either aerobically or anaerobically

Question 8

Excretion

Answer 8

Can remove toxic or waste produced by reactions in the body

Question 9

Nutrition

Answer 9

Can absorb nutrients in order to use them for growth and repair

Question 10

Eukaryotes

Answer 10

Eukaryotes are organisms that have a nucleus and organelles that are found within a plasma membrane

Question 11

Nucleus

Answer 11

· Subcellular structure found in plant and animal cells
· Contains the genetic material, which codes for a particular protein
· Enclosed in a nuclear membrane

Question 12

Cytoplasm

Answer 12

· Subcellular structure found in plant and animal cells
· Liquid substance in which chemical reactions occur
· Contains enzymes (biological catalysts, i.e. proteins that speed up the rate of reaction)
· Organelles are found in it

Question 13

Cell membrane

Answer 13

· Subcellular structure found in plant and animal cells
· contain receptor molecules to identify and selectively control what enters and leaves the cell

Question 14

Mitochondria

Answer 14

· Subcellular structure found in plant and animal cells
· Where aerobic respiration reactions occur, providing energy for the cell

Question 15

Ribosomes

Answer 15

· Subcellular structure found in plant and animal cells
· Where protein synthesis occurs
· Found on a structure called the rough endoplasmic reticulum

Question 16

Plants

Answer 16

· E.g. cereals (such as maize) or herbaceous legume (such as peas)
· Multicellular organisms
· Cells contain chloroplasts which is the site of photosynthesis: chlorophyll pigments within the chloroplast structure absorb light from the sun
· Cellulose cell walls which provide strength to the cell
· Contain a permanent vacuole, which stores cell sap and improves the cell’s rigidity
· Stores carbohydrates as starch or sucrose

Question 17

What does a Plant cell contain?

Answer 17

· Cell wall
· Cell membrane (inside cell wall)
· Vacuole
· Cytoplasm
· nucleus
· Mitochondria
· Chloroplast

Question 18

Animals

Answer 18

· E.g. mammals (such as humans) and insects (such as flies)
· Multicellular
· Cannot photosynthesise
· Do not have cell walls
· Have nervous systems in order to coordinate movement
· Store carbohydrates as glycogen

Question 19

What does a animal cell contain?

Answer 19

· Cell membrane
· Mitochondria
· Cytoplasm
· Nucleus

Question 20

Fungi

Answer 20

· Body is usually organised into a mycelium of thread-like structures called hyphae which have many nuclei but some are single-celled
· E.g. mucor has typical hyphal structure, yeast is single-celled
· Cell walls are made of chitin
· Feed by extracellular secretion of digestive enzymes which break it down into smaller pieces, which can then be absorbed (saprotrophic nutrition)
· May store carbohydrates as glycogen

Question 21

Protoctists

Answer 21

· Single-celled organisms
· Some have features like animals cells, such as Amoeba, that live in pnd water
· Others are more like plants and have chloroplasts, such as Chlorella

Question 22

Prokaryotes

Answer 22

Prokaryotes do not have a nucleus or membrane-bound organelles

Question 23

Bacteria

Answer 23

· E.g. lactobacillus bulgaris (rod-shaped bacterium used to make yoghurt), pneumococcus (spherical bacterium that causes pneumonia)
· Single-celled and very small
· Have a cell wall, cell membrane, cytoplasm and plasmids
· Lack a nucleus but have circular chromosomes of DNA
· Some can carry out photosynthesis but they mainly eat off of other organisms, either dead or alive

Question 24

Pathogens

Answer 24

Pathogens are disease-causing organisms and can be fungi, bacteria, protoctists or viruses

Question 25

Viruses in Pathogens

Answer 25

· E.g. tobacco mosaic virus which prevents chloroplast formation, influenza virus, HIV virus leading to AIDS · Viruses are smll particles (much smaller than bacteria) - not living organisms · Parasitic · can only reproduce within living cells · can infect every typle of living organisms · hijacks the cell mechanisms to create millions of copies of itself and then spreads within the host by cell bursting · They come in a wide variety of shapes and sizes · Do not have a cellular structure but have one type of nucleic acid (either DNA or RNA) and a protein coat

Question 26

Bacteria in pathogens

Answer 26

· E.g. Salmonella (food poisoning) · Can reproduce many times through binary fission · Produce toxins that can damage cells

Question 27

Protists in pathogens

Answer 27

· E.g. malaria · Parasitic - use animals as their hosts to live in

Question 28

Fungi in pathogens

Answer 28

· E.g. athlete's foot · Produce spored that can spread in the wind or between people · Can treat wth fungicides

Question 29

Amoeba

Answer 29

Protoctists that live in pond water and resemble animal cells

Question 30

Cell

Answer 30

The basic building block of all living organisms

Question 31

Cell membrane

Answer 31

A partially permeable barrier that surrounds the cell

Question 32

Cell wall

Answer 32

An outer, structural layer that surrounds some cells. In plant cells, it is made of cellulose. In fungi, it is made of chitin

Question 33

Chlorella

Answer 33

A protoctist that has features similar to plant cells e.g. chloroplasts

Question 34

Chloroplast

Answer 34

An organelle which is the site of photosynthesis

Question 35

DNA

Answer 35

A double-stranded polymer wound to form a bouble helix. It carries the genetic code

Question 36

Eukarotic cell

Answer 36

A type of cell found in plants and animals that contains a nucleus

Question 37

Human Immunodeficiency Virus (HIV)

Answer 37

An infectious virus that weakens the immune system and can lead to AIDS (acquired immunodeiciency syndrome)

Question 38

Hyphae

Answer 38

Long filaments of a fungus that contain many nuclei

Question 39

Influenza virus

Answer 39

An infiction virus that causes influenza (the flu)

Question 40

Lactobacillus bulgaricus

Answer 40

A rod-shaped species of bacterium used to produce yoghurt from milk

Question 41

Mucor

Answer 41

A multicellular fungus that has a hyphal structure

Question 42

Mycelium

Answer 42

A collection of thread-like hyphae in a fungus

Question 43

Pathogens

Answer 43

Microorganisms that cause infectious disease

Question 44

Photosynthesis

Answer 44

An endothermic reaction in which energy is transferred from the environment to the chloroplasts by light

Question 45

Plasmids

Answer 45

Loops of DNA found in the cytoplasm of prokaryotic cells

Question 46

Plasmodium

Answer 46

Pathogenic protoctists that cause malaria

Question 47

Pneumococcus

Answer 47

A spherical, pathogenic bacterium that causes pneumonia

Question 48

Prokaryotic cell

Answer 48

A type of cell found in bacteria that does not cntain a nucleus

Question 49

Protoctists

Answer 49

Microscopic single-celled organisms

Question 50

Saprotrophic nutrition

Answer 50

The mode of extracellular nutrition in which digestive enzymes are secreted onto the food outside the cell and the products of digestion are absorbed

Question 51

Tobacco Mosaic Virus (TMV)

Answer 51

A widespread plant pathogen affecting many species of plants which produces a mosaic pattern in the leaves. It infects chloroplasts and limits plant growth

Question 52

Virus

Answer 52

A non-living organism that can only reprodce inside host cells. Viruses have no cells, but possess a protein coat containing nucleic acids(DNA or RNA)

Question 53

Yeast

Answer 53

A single-celled fungus