B2 Biology Flashcards

Question

``` Definition of Environment Habitat Population Community Ecosystem ```

Answer 1

Environment-All the conditions that surround a living organism Habitat-The place where an organism lives Population-All the members of a single species that live in a habitat Community-All the populations of different organisms that live together in a habitat Ecosystem A community and the habitat in which it lives

Answer 2

is a line across a habitat or part of a habitat. It can be as simple as a string or rope placed in a line on the ground. The number of organisms of each species can be observed and recorded at regular intervals along the transect.

Answer 3

A quadrat is usually a square made of wire. It may contain further wires to mark off smaller areas inside, such as 5 x 5 or 10 x 10 squares. The organisms underneath, usually plants, can be identified and counted.

Answer 4

It is usually not possible to count the entire population of a particular organism in its habitat.

Answer 5

Proteins are made from long chains of smaller molecules called amino acids. These long chains are folded into particular shapes.

Answer 6

This is important in relation to how antibodies and enzymes work.

Answer 7

Enzymes are biological catalysts. There are optimum temperatures and pH values at which their activity is greatest. Enzymes are also proteins.

Answer 8

Denatured - May no longer work

Answer 9

They are built up in cells when monomers called amino acids join together end to end:

Answer 10

Lots of amino acid molecules → a protein molecule

Answer 11

Proteins act as: Structural components of tissues (such as muscles) Hormones (such as insulin) Antibodies (part of the body's immune system) Biological catalysts (enzymes)

Answer 12

Enzymes are proteins folded into complex shapes that allow smaller molecules to fit into them. The place where these substrate molecules fit is called the active site.

Answer 13

Enzymes can be denatured by high temperatures or extremes of pH.

Answer 14

The graph shows the typical change in an enzyme's activity with increasing temperature. The enzyme activity gradually increases with temperature up to around 37ºC, or body temperature. Then, as the temperature continues to rise, the rate of reaction falls rapidly as heat energy denatures the enzyme.

Answer 15

Changes in pH also alter an enzyme’s shape. Different enzymes work best at different pH values. The optimum pH for an enzyme depends on where it normally works. For example, intestinal enzymes have an optimum pH of about 7.5. Enzymes in the stomach have an optimum pH of about 2.

Answer 16

Amylase Starch → sugars Protease Proteins → amino acids LipaseLipids → fatty acids + glycerol

Answer 17

Amylase-Salivary glands, pancreas, small intestine Protease-Stomach, pancreas, small intestine Lipase-Pancreas, small intestine

Answer 18

Hydrochloric acids This helps to begin digestion, and it kills many harmful microorganisms that might have been swallowed along with the food.

Answer 19

lipase - breaks down fats protease - breaks down proteins carbohydrase - breaks down carbohydrates.

Answer 20

Protease Used to pre-digest proteins during the manufacture of baby foods Lipase Used - together with protease - in biological detergents to break down (digest) the substances in stains into smaller, water soluble substances

Answer 21

Carbohydrase Used to convert starch syrup, which is relatively cheap, into sugar syrup, which is more valuable - for example, as an ingredient in sports drinks Isomerase Used to convert glucose syrup into fructose syrup - fructose is sweeter than glucose, so it can be used in smaller amounts in slimming foods

Answer 22

Respiration releases energy for cells from glucose.

Answer 23

Aerobic respiration is the form of respiration which uses oxygen.

Answer 24

glucose + oxygen → carbon dioxide + water (+ energy)

Answer 25

Mitochondria

Answer 26

It may be used to build up larger molecules from smaller ones. For example: Plants make amino acids from sugars, nitrates and other nutrients These amino acids are then built up into larger molecules - proteins

Answer 27

Energy is used by animals to enable the muscles to contract so that the animals can move. Mammals and birds keep their body temperature steady. Energy from respiration is used to do this when their surroundings are colder than they are.

Answer 28

Oxygen and glucose must be delivered to them more quickly | Waste carbon dioxide must be removed more quickly

Answer 29

respiration releases energy, while breathing lets air into and out of our lungs.

Answer 30

Anaerobic respiration involves the incomplete breakdown of glucose.Not enough oxygen may reach the muscles during exercise.

Answer 31

glucose → lactic acid (+ little energy)

Answer 32

The waste product is lactic acid rather than carbon dioxide and water:

Answer 33

Muscle fatigue | Muscle stops contracting efficiently

Answer 34

The lactic acid is removed from the muscles by blood flowing through them.

Answer 35

Anaerobic respiration produces an oxygen debt. This is the amount of oxygen needed to oxidise lactic acid to carbon dioxide and water. The existence of an oxygen debt explains why we continue to breathe deeply and quickly for a while after exercise.

Answer 36

They you carry to genetic cold that determines the characteristics of living things

Answer 37

A gene is a short section of DNA. Each gene codes for a specific protein by specifying the order in which amino acids must be joined together.

Answer 38

The cell’s nucleus contains chromosomes made from long DNA molecules.

Answer 39

The genetic material is copied | The cell divides once to form two genetically identical body cells

Answer 40

Mitosis occurs during growth or to produce replacement cells.

Answer 41

Cells in the reproductive organs (testes and ovaries in humans) divide to form gametes. Gametes are sex cells:

Answer 42

Male gametes are sperm (produced in the testes) | Female gametes are eggs (produced in the ovaries)

Answer 43

Gametes contain one set of genetic information, while body cells contain two sets of genetic information. The type of cell division that produces gametes is called meiosis.

Answer 44

Fertilisation is the joining or fusion of a male gamete and a female gamete.

Answer 45

When a cell reproduces itself by splitting to form two identical offspring

Answer 46

For growth - replacement -

Answer 47

A catalyst is a substance which increases the speed of the reaction without being changed. In the reaction

Answer 48

PH and the right temperature

Answer 49

Pepsin is an enzyme used to break down protein in the stomach they works best at pH 3 which means it's well-suited to acidic conditions

Answer 50

Bile is produced in the stored in the gall bladder before it is released into the small intestine

Answer 51

The hydrochloric acid in the stomach makes the pH to acidic or enzyme in the small intestine to work properly by you is an alkali which neutralises stomach acid and makes conditions alkaline

Answer 52

The job of the large intestine is where excess water is absorbed from the food

Answer 53

To produce protease, analyse and lipase enzyme . It releases the into the small intestine

Answer 54

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

Answer 55

Stems cells are undifferentiated cells . They can develop into different type of cell depending on what instructions they are given

Answer 56

Human embryo a

Answer 57

They could be found in the bone marrow Disadvantage- they aren't as versatile as embryonic stem cells ... They can't turn into any cells type at all only certain ones

Answer 58

People with blood disease for examples sickle cell anaemia can be treated by bone marrow transplant bone marrow contains stem cells that can turn into new blood cells to replace the faulty old ones

Answer 59

human embryos shouldn't be used for experiment since Each one is a potential life Campaigners feel that scientists should concentrate more on finding and developing other sources of stem cell so people could be helped without having to use embryos In some countries stem cell research is banned but is allowed in the UK as long as it follows strict guidelines

Answer 60

What alleles you have and is actually presented physically

Answer 61

What alleles you have in your genes but are not shown

Answer 62

They are different versions of the same gene

Answer 63

Is a genetic disorder of the cell membrane which results in the body producing a lot of thick sticky mucus in the air passages and in the pancreas

Answer 64

Recessive allele

Answer 65

Is a genetic disorder where a baby is born with extra fingers or toes it doesn't usually cause any other problems so isn't life threatening

Answer 66

The disorders caused by a dominant allele and so can be inherited its just one parent carries the defective alleles

Answer 67

There might be a pain where everyone wants to screen their embryos headache and pick up the most desirable one eg: blond- haired The rejected embryos are destroyed -they could've been developed into humans It implies that the people with the genetic problems are undesirable this could increase prejudice Sreening is expensive

Answer 68

It will help to stop people suffering There are laws to stop it going too far for example parents cannot even select the sex of their baby unless it is for health reason During IVF most. Of the Embryos are destroyed anyways so screening just allows the selected to be healthy Treating disorders cost the government and Tax payers a lot of money

Answer 69

Fossils are Remains of organism from many years ago which can be found in rocks

Answer 70

From gradual replacement by minerals four example things like to have shells From casting &impressions: clay From perservation In places where no decays happens: Amber , glaciers , peat bogs

Answer 71

There is a lack of evidence because scientists believe many early organs were softbodied and soft tissue which tends to decay away completely so the fossil record is in complete Plus fossils that did form million of years ago may have been destroyed by geological activities for example the movement of tectonic plate might have crushed fossils already formed in the rock

Answer 72

Where species no longer exist

Answer 73

Environment changes to quickly e.g. a destruction of habitat The new predator kills them all They can't compete with another new species for food A new disease kills them all A catastrophic events happened that kills them e.g. a volcanic eruption all a collision with an astroid A new species develop(speciation)

Answer 74

It's the development of a new species

Answer 75

It's a group of similar organisms that can be reproduced to give fertile offspring

Answer 76

Speciation occurs when population of the same species become so different they can no longer breed together to produce fertile offspring

Answer 77

Isolation is where population of a species are separated Eventually in the variation from the different population has changed so much that they wont be able to breed with one another to produce fertile offspring. the two groups will have become separate species

Answer 78

this could be because of a physical barrier e.g. foulards or an earthquake can cause up barriered that geographically isolates some individuals from the main population conditions and in the side of the baryon will be slightly different and have different climates this is because the environment is different in each side different characteristics will become more common in each population Due tonatural selection Eventually in the variation from the different population has changed so much that they wont be able to breed with one another to produce fertile offspring. the two groups will have become separate species

Answer 79

Each population shows the variation because they have a wide range of alleles. In each population individuals with characteristic that makes them better adapted to the environment and have a better chance of survival as it makes it likely to breed successfully So the alleles that controls the beneficial characteristics are more likely to be passed on to the next generation

B2 Biology Flashcards

(104 cards)