Key concepts in Biology

Question 1

What is a Cell?

Answer 1

The smallest, basic unit of life that is responsible for all life’s processes.

Question 2

What are Animal and Plant cells called?

Answer 2

Eukaryotic cells

Question 3

What is in a Eukaryotic cell?

Answer 3

Cell membrane, Cytoplasm and a Nucleus containing DNA.

Question 4

What are Bacterial cells called?

Answer 4

Prokaryotic cells.

Question 5

What is in a Prokaryotic cell?

Answer 5

Cell wall, Cell membrane, cytoplasm and Singular strand of DNA and Plasmids.

Question 6

What is the function of a Nucleus?

Answer 6

Contains genetic material that controls the activities of the cell.

Question 7

What is the function of the Cytoplasm?

Answer 7

Where most of the chemical reactions happen. It contains Enzymes which control these chemical reactions.

Question 8

What is the function of the Cell membrane?

Answer 8

Holds the cell together and controls what enters and exits the cell.

Question 9

What is the function of the Mitochondria?

Answer 9

These are where most of the reactions for respiration take place. Respiration transfers energy that the cell needs to work.

Question 10

What is the function of the Ribosomes?

Answer 10

Involved in translation of genetic material in the synthesis of proteins.

Question 11

What is the function of the Cell wall?

Answer 11

Made of cellulose, it supports the cell and strengthens it.

Question 12

What is the function of the Vacuole?

Answer 12

Contains cell sap, store food or any variety of nutrients a cell might need to survive.

Question 13

What is the function of the Chloroplasts?

Answer 13

Where photosynthesis occurs, contain a green substance called chlorophyll.

Question 14

What is the function of Chromosomal Dna (one long circular chromosome) in the Bacterial cell?

Answer 14

Controls cell’s activities and replication. Floats free in the cytoplasm.

Question 15

What is the function of the Plasmid DNA?

Answer 15

Small loops of extra DNA that aren’t part of the chromosome. contains genes for things like drug resistance.

Question 16

What is the function of the Flagellum?

Answer 16

Long, hair like structure that rotates to make the bacterium move, used to move bacteria away from harmful substances.

Question 17

What is a Specialised cell?

Answer 17

A cell which has a specific function.

Question 18

What are the 2 cells which are specialised for reproduction?

Answer 18

Egg cells and Sperm cells.

Question 19

What happens in sexual reproduction?

Answer 19

The nucleus of an egg cell fuses with the nucleus of a sperm cell to create a fertilised egg, which then develops into an embryo.

Question 20

What is the function of an Egg cell?

Answer 20

Contains nutrients in the cytoplasm to feed the embryo
has a haploid nucleus
after fertilisation, its membrane changes structure to stop any sperm getting in. This is to end up with the right amount of DNA.

Question 21

What are the functions of the Sperm cell?

Answer 21

To transport the males DNA to the female’s egg.

Question 22

Name the Key features of a Sperm cell.

Answer 22

Long tail so it can swim
lots of mitochondria to provide energy
an acrosome where it stores enzymes needed to digest its way through the membrane of the egg
contains a haploid nucleus.

Question 23

What is the function of the Ciliated Epithelial Cell?

Answer 23

To move substances in one direction, along the surface of the tissue.

Question 24

What is the function of the Enzyme?

Answer 24

Reduce the need for high temperatures and we only have enzymes to speed up the useful chemical reactions in the body.

Question 25

What is the Substrate?

Answer 25

The molecule changed in the reaction.

Question 26

What does every Enzyme have?

Answer 26

An active site, part where it joins on to its substrate to catalyse the reaction.

Question 27

What is needed for the enzyme to work?

Answer 27

The substrate has to fit into the active site.

Question 28

What affects the Rate of Reaction?

Answer 28

Temperature, pH and Substrate concentration.

Question 29

What happens if the temperature gets TOO hot?

Answer 29

Some of the bonds holding the enzyme together break.

Question 30

How does pH affect the Enzymes?

Answer 30

If too high or too low, it interferes with bonds holding Enzyme together. This changes the shape of the active site and denatures the enzyme.

Question 31

How does Substrate Concentration affect the Enzyme?

Answer 31

Once all active sites are full, adding more makes no difference.

Question 32

What do Enzymes called Carbohydrase do?

Answer 32

Convert carbohydrates into simple sugars.

Question 33

What do Enzymes called Proteases do?

Answer 33

Convert proteins into amino acids

Question 34

What do Enzymes called Lipases do?

Answer 34

Convert lipids into glycerol and fatty acids

Question 35

How can Carbohydrates be synthesised?

Answer 35

Joining together simple sugars

Question 36

How can Proteins be synthesised?

Answer 36

Joining amino acids together

Question 37

What do Microscopes do?

Answer 37

Uses lenses to magnify images. they also increase the resolution of an image.

Question 38

What is Resolution?

Answer 38

Means how well a microscope distinguishes between 2 points that are close together. Higher resolution = Image can be seen more clearly and in more detail.

Question 39

what is a light microscope?

Answer 39

A type of microscope that uses visible light and lenses to magnify the image of a specimen Lets us see things like nuclei and chloroplasts and we can also use them to study living cells.

Question 40

what is an electron microscope?

Answer 40

Use electrons rather than light. they have a higher magnification and resolution than light microscopes, so they let us see much smaller things in more detail like the internal structure of mitochondria and chloroplasts.

Question 41

How do you work out the total magnification of an image?

Answer 41

Total magnification = eyepiece lens x objective lens magnification

Question 42

What formula would you use to work out the magnification of an image if you didnt know which lenses were used?

Answer 42

Magnification = image size/real size

Question 43

What is diffusion?

Answer 43

The net (overall) movement of particles from an area of higher concentration to an area of lower concentration

Question 44

In what states of matter does diffusion occur?

Answer 44

Both liquids and gases because the particles in these substances are free to move about randomly.

Question 45

What is osmosis?

Answer 45

The net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.

Question 46

what is a partially permeable membrane?

Answer 46

One with very small holes in it. so small only tiny molecules can pass through them.

Question 47

What is Active Transport?

Answer 47

The movement of particles across a membrane against a concentration gradient using energy transferred during respiration