B1 key concepts of biology

Question 1

What is the difference between a low resolution microscope and a high resolution microscope?

Answer 1

High resolution microscopes can have extra magnification, without the image become blurry.

Question 2

How do you find the total magnification of a lens?

Answer 2

Eyepiece lens (10) x objective lens magnification

SIZE OF REAL OBJECT

Question 3

What is the difference between multicellular organisms and unicellular organisms?

Answer 3

multicellular organisms are made up of organs, unicellular organisms are made up of one type of cell.

Question 4

What does the nucleus contain?

Answer 4

DNA

Question 5

What controls what goes in and out of cells in an animal cell?

Answer 5

Cell Membrane

Question 6

Where do the cells chemical reactions take place in an animal cell

Answer 6

Cytoplasm

Question 7

What occurs it Mitochondria?

Answer 7

Respiration

Question 8

what does chlorophyll allow plants to do?

Answer 8

Photosynthesise

Question 9

What does the cell wall do in a plant cell?

Answer 9

Supports the shape of the cell.

Question 10

What stores sugars in a plant cell, and keeps the plant cell swollen?

Answer 10

The vacuole

Question 11

How are red blood cells specialised?

Answer 11

they have no nucleus to carry more oxygen

Question 12

How are nerve cells specialised?

Answer 12

They have dendrites to carry out impulses.

Question 13

What do white blood cells do?

Answer 13

Enable us to fight infections

Question 14

Are plant cells prokaryotic or eukaryotic?

Answer 14

Eukaryotic

Question 14

What is the difference between Eukaryotic cells and Prokaryotic cells?

Answer 14

Prokaryotic cells are simpler, lacking a nucleus and membrane-bound organelles, while eukaryotic cells are more complex, possessing a nucleus and various membrane-bound organelles

Question 15

What is a ribosome?

Answer 15

Tiny structures where protein synthesis occurs.

Question 16

Why is a bacteria cell a Prokaryotic cell?

Answer 16

They don’t have a nucleus or any other structures surrounded by membranes

Question 17

Is a Eukaryotic cell bigger than a Prokaryotic cell?

Answer 17

yes
Eukaryotic(5μm-100μm)
PRO.(0.2μm-2μm)

Question 17

What is the difference between chromosomal DNA and plasmid DNA?

Answer 17

plasmid DNA can move from one bacterium to another giving variation.

Question 18

What are the three specialised plant cells?

Answer 18

Root cells
phloem cells
xylem cells

Question 19

What are the three specialised animal cells?

Answer 19

muscle cells
nerve cells
sperm cells

Question 20

What are the disadvantages of an electron microscope?

Answer 20

have to put metal coat on small specimens
hard to move around
are extremely expensive

Question 21

what tool aloud us to discover the most of living things work

Answer 21

the microscope

Question 22

what are the different parts of the microscope?

Answer 22

eyepiece
barrel
stage
lens
turret

Question 23

what are the steps when using a microscope?

Answer 23

1. place the slide on the stage and look through the eyepiece lens 2. use the focus wheel to obtain a clear image of the specimen. 3. start with lowest objective lens and gradually increase.

Question 24

what is the equation for magnification and actual size?

Answer 24

magnification = measured size / actual size actual size = measured size /magnification

Question 25

how do you prepare a specimen on a slide?

Answer 25

1. take a thin layer of cells and add chemical stain 2. apply cells to glass slide and carefully place a cover slip on avoiding bubbles.

Question 26

what are enzymes?

Answer 26

they are biological catalysts, only when the substrate has the right complementary fit.

Question 27

why does there need to be an optimum PH / temp when enzymes react?

Answer 27

as they could denature the shape of the active site.

Question 28

how can substrate concentration affect the rate of reaction?

Answer 28

it will increase, up to a point then it will remain the same as there are no enzymes left.

Question 29

explain the practical, effect of PH on enzyme activity.

Answer 29

combine amylase and starch with a PH buffer, keep adding to iodine solution which should turn blue black, time how long it takes to stay orange, do this for all different PH buffers to test which one is the most effective at breaking down the starch.

Question 30

what is the equation for rate?

Answer 30

rate = change (grams) / time (hours)

Question 31

what to carbohydrase turn carbohydrates into, protease turns proteins into, lipase turns lipids into?

Answer 31

1. simple sugars 2. amino acids 3. fatty acids and glycerol

Question 32

list the different food tests.

Answer 32

iodine solution turns starch blue/black warm benedicts solution turns reducing sugars brick red biuret solution turns proteins violet. ethanol and water produces a milky emulsion when lipids are present.

Question 33

explain calorimetry.

Answer 33

record temp of water, burn food under the tube and record temp change energy transferred = mass of water x 4.2 x temperature change this tells us the amount of energy in certain foods.

Question 34

explain diffusion, active transport and osmosis

Answer 34

diffusion is the movement of particles from high concentration to low concentration active transport is the movement of particles from low to high against the gradient. osmosis is in water with same principles of diffusion from a high to low concentration through a semi-permeable membrane.

Question 35

what is the experiment in percentage gain and loss of osmosis?

Answer 35

placing identical potato disks (that have been soaked in water) in sucrose solution with different concentration measuring the percentage change = (change in mass / start mass) x 100 this tests to see how much water has left the potato in different concentrations due to osmosis.

Question 36

what are independent, dependent and control variables?

Answer 36

independent - changing dependent - measuring control - what is kept the same