S4 - Biology Test (4)

Question 1

What is a gene?

Answer 1

The unit of inheritance & a section of DNA that codes for a specific protein

Question 2

What are alleles?

Answer 2

Different forms of the same gene

Question 3

What does it mean if a gene is dominant?

Answer 3

Hides the presence of a recessive gene

Question 4

What does it mean if a gene is recessive?

Answer 4

Hidden by dominant genes

Question 5

What is the genotype of an organism?

Answer 5

The genes an organism has

Question 6

What is the phenotype of an organism?

Answer 6

The physical appearance of genes

Question 7

What is the difference between homo and hetero zygous genes?

Answer 7

homo = contains 2 of the same type of allele of a gene

hetero = contains both a dominant and recessive allele of a gene

Question 8

What is a cause of variation within a species?

Answer 8

Combining genes from 2 parents

Question 9

Why does variation within a species occur?

Answer 9

Because fertilisation is a random process

Question 10

What is variation?

Answer 10

The differences that exist between and within populations

Question 11

What are the 2 types of variation?

Answer 11

• Continuous
• Discrete

Question 12

What is continuous variation?

Answer 12

A polygenic inheritance of characteristics showing continuous variation where there is a range of values between a max. and a min.

Question 13

What is discrete variation?

Answer 13

A single gene inheritance of characteristics showing discrete variation where measurements fall into distinct groups

Question 14

What are a plants organs?

Answer 14

• Roots
• Stems
• Leaves

Question 15

What is the function of the upper epidermis?

Answer 15

Has a waxy layer that reduces water loss

Question 16

What is the function of the palisade mesophyll layer?

Answer 16

Absorbs light for photosynthesis

Question 17

What is the function of the spongy mesophyll layer?

Answer 17

The air spaces allow gases to reach leaf cells for photosynthesis

Question 18

What is the function of the lower epidermis?

Answer 18

It contains pores called stomata which allow gases to diffuse in and out of the leaf

Question 19

What is the function of the stomata?

Answer 19

It allows water vapour to be released and is the site of gas exchange

Question 20

What is the function of guard cells?

Answer 20

Control the opening and closing of the stomata

Question 21

Why do plants need transport systems?

Answer 21

To make sure the essential materials can reach all cells and so that waste materials can be removed safely

Question 22

What are the essential materials plants need?

Answer 22

Sugar and water

Question 23

Name what each arrow is pointing to

Answer 23

Question 24

Name what each arrow is pointing to

Answer 24

Question 25

Why do plants need water and where is it needed?

Answer 25

- for photosynthesis & to help transport minerals (N, K, P) throughout the plant - the roots, stems and leaves

Question 26

Where does water enter a plant from?

Answer 26

The root hair cell

Question 27

What is the function of the root hair cell?

Answer 27

To absorb water from surrounding soil via osmosis

Question 28

How does the shape of a root hair cell help absorption?

Answer 28

It has a large surface area

Question 29

What transports water and minerals through a plant and what direction does it go?

Answer 29

Xylem cells, upwards

Question 30

What are xylem cells and why?

Answer 30

Dead. They don't have a nucleus

Question 31

What do xylem cells have and why?

Answer 31

Rings of lignin to help withstand pressure changes as water moves through the plant

Question 32

What is transpiration?

Answer 32

The process of water moving through a plant & its evaporation through the stomata

Question 33

What factors increase the rate of transpiration?

Answer 33

- Increase in temp. - Increase in wind speed - Decrease in humidity - Increase surface area

Question 34

What can transpiration be measured by and what does it do?

Answer 34

A potometer, measures the mass of water evaporated from the leaves over a set period of time

Question 35

What's transported through blood in mammals?

Answer 35

- nutrients (ie. glucose and amino acids) - O2 and CO2

Question 36

What does blood consist of?

Answer 36

Plasma, red blood cells & white blood cells

Question 37

What features does a red blood cell have?

Answer 37

- It's biconcave - Has no nucleus - Contains haemoglobin

Question 38

What does haemoglobin allow red blood cells to do?

Answer 38

Carry oxygen efficiently around the body in the form of oxyhaemoglobin

Question 39

What process do phagocytes carry out?

Answer 39

Phagocytosis

Question 40

What does phagocytosis involve?

Answer 40

Phagocytes engulfing pathogens that invade the body by digesting them

Question 41

What do lymphocytes produce?

Answer 41

Antibodies

Question 42

What do antibodies do?

Answer 42

Destroy pathogens

Question 43

What makes antibodies specific?

Answer 43

They are specific to a particular pathogen

Question 44

Where does the vena cava come from and lead?

Answer 44

The body to the right atrium

Question 45

Where does the pulmonary artery come from and lead?

Answer 45

The right ventricle to the lungs

Question 46

Where does the pulmonary vein come from and lead?

Answer 46

The lungs to the left atrium

Question 47

Where does the aorta come from and lead?

Answer 47

The left ventricle to the whole body

Question 48

What is the coronary artery?

Answer 48

The blood vessel which supplies the heart tissue with blood and oxygen

Question 49

What are the 3 types of blood vessels?

Answer 49

Arteries, veins, capillaries

Question 50

What do arteries, veins and capillaries have in common?

Answer 50

They're all types of blood vessels

Question 51

What do blood vessels do?

Answer 51

Carry blood to all cells in the body

Question 52

What do arteries do?

Answer 52

Carry blood away from the heart under high pressures

Question 53

What do veins do?

Answer 53

Carry blood to the heart

Question 54

What do capillaries do?

Answer 54

Form networks at tissues or organs for efficient gas exchange (O2) and materials (glucose)

Question 55

What factors make capillaries efficient at gas exchange?

Answer 55

- thin walls - large surface area - are in close contact with body cells

Question 56

Answer 56

Question 57

Answer 57

Question 58

Answer 58

Question 59

Answer 59

Question 60

Answer 60

Question 61

What must be delivered to cells, how and why?

Answer 61

O2 and nutrients, by being absorbed into the bloodstream, for respiration

Question 62

What must happen waste materials? What is an example?

Answer 62

Removed from cells and put into the bloodstream CO2

Question 63

What do tissues contain and why?

Answer 63

Capillary networks To allow the exchange of materials at cellular level

Question 64

What features do surfaces involved in absorption of materials have in common?

Answer 64

large surface area, thin walls, extensive blood supply

Question 65

What are lungs?

Answer 65

Gas exchange organs

Question 66

What do lungs consist a lot of?

Answer 66

Alveoli

Question 67

What happens in the alveoli?

Answer 67

O2 is absorbed into the blood capillaries and CO2 passes out of the blood capillaries

Question 68

What features do alveoli have?

Answer 68

large surface area, thin walls, an extensive blood supply

Question 69

Where are nutrients from food absorbed?

Answer 69

Into the villi in the small intestine

Question 70

What part of villi absorbed glucose and amino acids?

Answer 70

Networks of blood capillaries

Question 71

What part of villi absorbs fatty acids and glycerol?

Answer 71

The lacteals

Question 72

What features do villi have and why?

Answer 72

Large surface area, thin walls, extensive blood supply. To allow for efficient absorption of materials