section 1- the nature and variety of organisms

Question 1

characteristics of living organisms

Answer 1

movement, respiration, sensitivity, growth, reproduction, excretion, nutrition, respond

Question 2

two types of cells

Answer 2

prokaryotic
eukaryotic

Question 3

eukaryotic

Answer 3

plants animal fungi protoctists

Question 4

prokaryotic

Answer 4

bacteria

Question 5

what is an organelle

Answer 5

tiny structures within cells

Question 6

plant cells

Answer 6

• plants are multicellular organisms
• cells contains chloroplasts and are able to carry out photosynthesis, it contains chlorophyll which is used in photosynthesis
• they have cellulose cell walls that surrounds the cell membrane, it supports and strengthens the cell
• the cell stores carbohydrates such as sucrose and starch

Question 7

animal cells

Answer 7

• multicellular organisms
• do not contain chloroplasts and aren’t able to carry out photosynthesis
• no cell wall, usually have nervous co ordination and are able to move from one place to another
• often store carbohydrates as glycogen
• contains nucleus, contains genetic info that controls cell activity
• has cell membrane, controls what goes in and out of cell
• cytoplasm, gel like substance where most of cells chemical reactions happen
• ribosomes which are small organelles where proteins r made in cell
• contains mitochondria where most of the reactions for aerobic respiration takes place
• respiration transfers energy that the cell needs to work.

Question 8

what do animal cells CONTAIN

Answer 8

cell membrane
nucleus
ribosomes
mitochondria
cytoplasm

Question 9

what does a plant cell contain

Answer 9

vacuole
nucleus
cell wall
cytoplasm
ribosomes
chloroplasts
mitochondria
cell membrane

Question 10

fungi

Answer 10

• some fungi are single-celled
• others have a body called mycelium, which is made up of hyphae ( threadlike structures)
• they can’t photosynthesise
• their cell walls are made of chitin
• most feed by saprotrophic nutrition
• they secrete extracellular enzymes into the area outside their body to dissolve their food, so they can then absorb the nutrients
• they can store carbohydrates as glycogen

Question 11

protocists

Answer 11

• single celled and microscopic
• some have chloroplasts and are similar to plant cells
• others are more like animal cells

Question 12

bacteria

Answer 12

• there are also single celled and microscopic
• dont have a nucleus
  have a circular chromosome of DNA
• some can photosynthesis
• most bacteria feed off other organisms - both living and dead

Question 13

viruses

Answer 13

• these are particles, rather than cells and are smaller than bacteria
• they can only reproduce inside living cells. A virus is an example of a parasite - it depends on another organism to grow and reproduce
• they infect all types of organisms
• they come in loads of different shapes and sizes
• they dont have a cellular structure - they have a protein coat around some genetic material (either DNA or RNA)

Question 14

levels of organisation

Answer 14

SIMILAR CELLS –> TISSUES –> organs –> organ system

Question 15

state –> cells are specialised to carry out a particular function

Question 16

what is a tissue

Answer 16

• tissue is a group of similar cells that work to carry out a specific function
• a tissue can contain more than one cell type

Question 17

whats an organ

Answer 17

• an organ is a group of different tissues that work together to perform a function

Question 18

what are organ systems made of?

Answer 18

organs work together to form an organ system, each system does a different job

Question 19

What Are Stem Cells?

Answer 19

-Stem cells are unspecialized cells that have the ability to:
- Divide and produce more stem cells (self-renewal).
- Differentiate into specialized cells (e.g., nerve cells, muscle cells, or blood cells).

Question 20

types of stem cells

Answer 20

• embryonic
• adult stem cells

Question 21

whats cell differentiation

Answer 21

the process by which a cell changes to become specialised for its job

Question 22

what do undifferentiated cells do

Answer 22

they divide to produce lots more undifferentiated cells

Question 23

where are stem cells found

Answer 23

in early human embryos

Question 24

where are adult stem cells found

Answer 24

bone marrow

Question 25

can adult stem cells turn into any cell type

Answer 25

no

Question 26

what cell types can adult stem cells turn into to

Answer 26

only certain ones like blood cells

Question 27

where can stem cells from embryos and bone marrow be grown and why

Answer 27

they can be grown in a lab to produce clones (genetically identical cells) and made to differentiate into specialised cells to use in medicine or research

Question 28

what does medicine use to cure disease

Answer 28

adult stem cells

Question 29

whats an example of adult stem cells being used to cure disease

Answer 29

stem cells transferred from the bone marrow of a healthy person can replace faulty blood cells in the patient who receives them

Question 30

what stem cells can also be used to replace faulty cells in sick people

Answer 30

embryonic stem cells

Question 31

whats an example of embryonic stem cells being used to replace faulty cells in sick people

Answer 31

you could make insulin-producing cells for people with diabetes, or nerve cells for people paralysed by spinal injuries

Question 32

whats a risk involved in using stem cells in medicine

Answer 32

stem cells being grown in the lab may become contaminated with a virus which could be passed on to the patient and so make them sicker

Question 33

why would some people be against stem cell research

Answer 33

- they feel as though human embryos shouldnt be used for experiments bcs each one has the potential of becoming a human life