Unit 2 Flashcards
(151 cards)
1
Q
Name 3 plant organs
A
Roots
Stem
Leaves
2
Q
What main substances are transported by plant organs?
A
Water
Minerals
Sugar
3
Q
How are water and minerals taken from soil to plant leaves?
A
The roots absorb the water & minerals
The stems transport it
The leaves receive it
4
Q
What 2 main reasons is water needed for in plants?
A
- PHOTOSYNTHESIS - Plants making food from sunlight. Happens in leaves.
- TRANSPORTING DISSOLVED MATERIALS - For example minerals.
5
Q
How do plant roots absorb water?
A
Root Hair Cells
They have large surface area to be efficient.
6
Q
How do plant stems transport water and minerals?
A
Xylem tubes are:
Hollow
Made of dead cells
Lignified (strengthened with lignin)
This allows xylem to withstand water pressure changes in transport.
7
Q
Define transpiration.
A
The process of water moving through the plant and evaporating from the stomata on leaves.
8
Q
How does transpiration work?
A
Water is lost from stomata (pores). They can be open or closed.
Guard Cells control the opening and closing of stomata.
9
Q
What gases are absorbed from plant leaves by stomata?
A
Carbon Dioxide
10
Q
How does wind speed affect transpiration?
A
Wind speed INCREASES transpiration because the water released by transpiration is blown away from the plant quicker.
11
Q
How does humidity affect transpiration?
A
Humidity DECREASES transpiration because the water will evaporate slower in already wet conditions.
12
Q
How does temperature affect transpiration?
A
Increased temperature increases transpiration because higher temperatures cause water to evaporate faster.
13
Q
How does surface area affect transpiration?
A
Increased surface area increases transpiration because there are more stomata for water to leave from.
14
Q
How is the rate of transpiration measured?
A
With a potomer.
15
Q
Glucose is made in the leaves of a plant during __
A
Photosynthesis
16
Q
How is sugar transported through a plant?
A
Phloem
17
Q
What is phloem made from?
A
Living tissue
18
Q
What is the function of the UPPER EPIDERMIS?
A
A layer of transport cells.
They allow light to pass through to the next layer.
19
Q
Define fertilisation.
A
Fertilisation is the fusion of the nuclei of two haploid gametes to produce a diploid zygote which divides to form an embryo.
20
Q
How can transpiration rate be measured?
A
Using a potometer.
21
Q
State 4 facts about the heart.
A
- Has 4 chambers
- 4 valves to prevent backflow of blood
- 4 associated blood vessels
- Coronary arteries provide nutrients and oxygen
22
Q
State the 3 types of blood vessels.
A
Vein
Artery
Capillary
23
Q
State the structure and function of an artery.
A
Structure: Thick muscular wall, narrow central channel
Function: Carry blood at high pressure away from the heart
24
Q
State the structure and function of a human vein.
A
Structure: Thin muscular wall, wider central channel, contain valves
Function: Carry blood at low pressure back into the heart
25
State the structure and function of a capillary.
Structure: Thin walls, large surface area, form networks at organs and tissues
Function: Allows exchange of materials between blood and cells
26
What is blood in mammals made of?
Red blood cells
White blood cells (phagocytes, lymphocytes)
Plasma
27
State 2 facts about white blood cells.
- Part of the immune system
- Destroy pathogens
28
State 3 facts about the structure of red blood cells.
- Biconcave shape
- No nucleus
- Contains haemoglobin
29
State 2 types of white blood cell and their functions.
Phagocytes: carry out phagocytosis by engulfing and digesting pathogens.
Lymphocytes: Produce antibodies specific to just one type of pathogen.
30
What 2 materials must be absorbed into the bloodstream and why?
Oxygen
Nutrients from food
They must be delivered to cells for respiration.
31
What materials must be removed from the bloodstream?
Waste materials such as carbon dioxide.
32
What 3 features do surfaces involved in the absorption of materials have in common and why?
Large surface area
Thin walls
Extensive blood supply
These features all increase the efficiency of absorption.
33
What are the 3 food groups?
- Carbohydrates (starch)
- Proteins
- Fats
34
What are the 3 food groups broken down into by enzymes?
- Glucose (Carbs)
- Amino acids (Proteins)
- Fatty acids and glycerol (Fat)
35
How are nutrients from food absorbed?
By the Villi (villus) in the small intestine.
36
In a villus, what does the network of capillaries do?
Absorbs glucose and amino acids.
37
In a villus, what is the lacteal responsible for?
Absorbing fatty acids and glycerol.
38
How is oxygen absorbed in humans?
Into the alveoli in the lungs.
39
How does an alveolus give oxygen and remove carbon dioxide?
- Oxygen is absorbed from the thin alveolar walls into the capillaries.
- Carbon dioxide is absorbed into the thin alveolar walls from the capillaries.
40
What is the process of cell division called?
Mitosis
41
Why is mitosis important?
It provides new cells for the growth and repair of damaged cells and maintains the diploid chromosome complement.
42
How many chromosomes are in a human cell?
46 (2 pairs of 23)
43
What are the main stages of mitosis?
1. The chromosomes replicate and become visible. Each chromosome is two chromatids joined together.
2. The nucleus breaks down.
3. The chromatids line up along the equator of the cell. Spindle fibres attach to the middle of the chromatids.
4. Spindle fibres pull the chromatids apart. The chromatids are pulled to opposite poles of the cell.
5. Separated chromatids are now called chromosomes and nuclear membranes form around them.
6. The cytoplasm splits. Two daughter cells are made.
44
How many chromatids does a chromosome contain?
2
45
Draw a diagram representing mitosis.
idk check notes
46
STEM CELLS in animals are ___ which can divide to make more stem cells.
UNSPECIALISED cells.
47
Stem cells are responsible for __
Growth and Repair.
48
Where can stem cells be extracted from?
Stem cells can be extraced from Embryo at a very early stage.
49
What is specialisation?
Specialisation is when a stem cell becomes a specific type of cell. It leads to the formation of a variety of cells, tissues and organs.
50
What are tissues?
A group of cells that carry out a similar function.
51
What are organs made of?
A collection of tissues.
52
What are systems?
A collection of organs.
53
Show the chain of cells to systems.
Cells > Tissues > Organs > Systems
54
What is the nervous system made up of?
Brain
Spinal Cord
Nerves
55
What is the Central Nervous System (CNS) made up of?
Brain
Spinal Cord
56
What are the main regions of the brain?
Cerebrum (top wrinkly part💀)
Medulla (weird stem...)
Cerebellum (lump thing beneath cerebrum)
57
What is the cerebrum responsible for?
Personality
Logic
Intelligence
Memories
58
What is the cerebellum responsible for?
Balance
Coordination
59
What is the medulla responsible for?
Breathing
Heart Rate
60
What is a neuron?
A nerve cell
61
What are the three types of neurons in the nervous system?
Sensory neurons
Inter neurons
Motor neurons
62
What are receptors?
Receptors are groups of specialised cells. They detect stimuli.
63
What are electrical impulses?
Messages travelling along neurons.
64
How do neurotransmitters transfer messages between neurons?
At synapses (the space between neurons).
65
Describe the Reflex Arc.
1. Receptors detect stimuli
2. Sensory neurons pass information to inter neurons in CNS.
3. CNS processes information.
4. Inter neuroms pass information to motor neurons.
5. Motor neurons enable a response to occur at an EFFECTOR (muscle or gland).
Messages travel along neurons as electrical impulses. Neurostransmitters transfer messages between neurons at synapses.
66
What are reflexes?
Rapid, automatic responses that protect the body from harm.
67
Provide examples of reflexes.
Sneezing
Coughing
Blinking
68
___ release hormones into the bloodstream.
Endocrine Glands
69
What are endocrine glands responsible for?
Releasing hormones into the bloodstream.
70
What are hormones?
Chemical messengers
71
What is a target tissue?
A target tissue is a tissue of cells. It is made with COMPLEMENTARY RECEPTOR PROTEINS for specific hormones, to ensure that only that tissue will be affected by those proteins.
72
What is blood glucose concentration regulated by?
Insulin
Glucagon
73
Where are insulin and glucagon released from?
The pancreas
74
What is released when blood glucose concentration rises?
Insulin
75
How does insulin affect the liver?
It instructs the liver to take up excess glucose and store it as glycogen.
76
When is glucagon released?
When blood glucose concentration falls.
77
How does glucagon affect the liver?
It instructs the liver to break down glycogen into glucose and put it back into the blood.
78
What is diabetes?
A condition caused when the body cannot regulate its blood glucose concentration.
79
What term is used to refer to a cell with two sets of chromosomes?
Diploid
80
What are the only type of cells that aren't diploid?
Gametes
81
What term is used to refer to cells with a singular set of chromosomes?
Haploid
82
What is the name of the MALE ANIMAL gamete?
Sperm
83
What is the name of the FEMALE ANIMAL gamete?
Egg
84
Where is the ANIMAL MALE gamete made?
Testes
85
Where is the ANIMAL FEMALE gamete made?
Ovary
86
What is the name of the MALE PLANT gamete?
Pollen
87
What is the name of the FEMALE PLANT gamete
Ovule
88
Where is the MALE PLANT gamete made?
Anther
89
Where is the FEMALE PLANT gamete made?
Ovary
90
Define fertilisation.
The fusion of the nuclei of two haploid gametes to produce a diploid zygote, which divides to form an embryo.
91
Define variation.
The differences that exist between the members of a species.
92
State the two types of variation.
- Discrete
- Continuous
93
What is discrete variation?
Discrete variation is variation that can split members of a population into discrete (complete) groups (due to limited possibilities).
eg. blood group, eye colour
94
What is continuous variation?
Continuous variation is variation which has a range of values ranging from a minimum to a maximum and can be measured.
95
What is the term used to describe characteristics which are controlled by multiple genes?
Polygenic
96
How can the inheritance of characteristics be predicted?
Using Family Trees or Monohybrid Crosses
97
What does the term "gene" refer to?
A unit of chromosome
98
What does the term "phenotype" refer to?
Description of Physical Appearance
99
What does the term "genotype" refer to?
The set of genes present
100
What does the term "allele" refer to?
Forms of a gene (eg. L or l)
101
What does the term "dominant" refer to?
The allele that shows up in the phenotype
102
What does the term "recessive" refer to?
The allele that is masked by the dominant allele.
103
What does the term "homozygous/true-breeding" refer to?
Alleles in genotype are the same (eg. BB or bb)
104
What does the term "Heterozygous" refer to?
Alleles in genotype are different (eg. Bb)
105
What does the term "P" refer to?
The parent generation
106
What does the term "F1" refer to?
The first generation
107
What does the term "F2" refer to?
The second generation
108
Why is the predicted ratio of phenotypes not always achieved?
Because fertilisation is a RANDOM PROCESS and involves an ELEMENT OF CHANCE.
109
What do plant roots have lots of?
Root hairs
110
Water moves from a higher water concentration in the soil to a lower water concentration in the root hairs. The water then moves into the xylem.
What is this called?
Osmosis
111
What does xylem do?
Xylem transports water up from the roots of the plant.
112
What are the characteristics of xylem?
- Made up of dead cells
- Have hollow tubes
- Lignin is present — withstands pressure changes as water moves through the plant.
113
During transport of water in plants, where does water move after reaching the xylem?
Into the leaf
114
State all the structures of a leaf.
Upper Epidermis
Palisade Mesophyll
Spongy Mesophyll
Vein
Lower Epidermis
Guard Cells
Stomata
115
What is the function of a leaf's UPPER EPIDERMIS?
The upper epidermis is made of transport cells.
This allows light to shine through to the next layer.
116
What is the function of the Palisade Mesophyll?
The palisade mesophyll contains chlorophyll to photosynthesise. It is the PRIMARY site of photosynthesis.
117
What is the function of the Spongy Mesophyll?
The function of the spongy mesophyll is to serve as the SECONDARY site of photosynthesis. It contains chlorophyll.
118
What is the function of a plant vein?
The function of a plant vein is to contain the xylem and phloem.
119
What is the function of the Lower Epidermis?
The function of the lower epidermis is to contain stomata.
120
What is the function of Guard Cells?
The function of guard cells is to control the opening and closing of stomata.
121
What is the function of stomata?
The main functions of stomata are to regulate gas exchange and water loss.
They are pores that allow CO2 in and O2 out.
122
What is the function of phloem?
The function of phloem is to transport sugar all over the plant.
123
What are the characteristics of phloem?
- Made up of living tissue
- Companion cells which provide energy for the sieve cells.
- Sieve cells which allow the movement of water and other substances throughout the plant with low resistance.
124
What is a pathogen?
A disease-causing microorganism.
125
What is a pathogen?
A disease-causing microorganism.
126
Why is the haemoglobin in red blood cells useful?
It allows the cells to transport oxygen efficiently in the form of oxyhaemoglobin.
127
How many chambers does the heart have?
4 — 2 atria, 2 ventricles
128
Go look at a heart diagram.... girl it'll be useful i swear
129
Name the blood vessels of the heart.
Vena Cava (Vein)
Pulmonary Artery
Aorta (Artery)
Pulmonary Vein
130
What is the function of the vena cava?
To carry deoxygenated blood from the body to the heart.
131
What is the function of the pulmonary artery?
To carry deoxygenated blood from the heart to the lungs.
132
What is the function of the pulmonary vein?
To carry oxygenated blood from the lungs to the heart.
133
What is the function of the aorta?
To carry oxygenated blood from the heart to the body.
134
What structure within the heart prevents the backflow of blood?
Valves
135
Which side of the heart is thicker and why?
The left side of the heart is thicker because it pumps blood to the entire body.
136
Which side of the heart is thinner and why?
The right side of the heart is thinner because it pumps blood only to the lungs.
137
What structure provides blood rich in oxygen to the heart?
The coronary artery
138
What type of organs are lungs?
Gas exchange organs.
139
What do lungs consist of to allow a large surface area?
A large number of alveoli
140
What do lungs consist of to allow a large surface area?
A large number of alveoli
141
State the characteristics of alveoli that allow them to efficiently exchange gas.
- Thin walls
- Large surface area (lots of them)
142
What system is food broken down in?
The digestive system
143
What is the purpose of the small intestine?
To absorb nutrients from food.
144
How does the small intestine absorb nutrients from food?
Due to villi.
145
What are villi?
Small structures within the small intestine that work to absorb the nutrients from food.
146
How do villi efficiently absorb the nutrients from food?
- Thin walls
- Large surface area
- Lots of them
147
What structure within a villus is responsible for absorbing glucose and amino acids?
A NETWORK of CAPILLARIES.
148
Which structure within a villus is responsible for absorbing fatty acids and glycerol?
Lacteal
149
Tissues contain ____ to allow the exchange of materials at a ____ level
Capillary Networks
Cellular
150
What three features do surfaces involving the absorption of materials have in common?
- Large Surface Area
- Thin Walls
- Extensive Blood Supply
These increase the efficiency of absorption.
151
Give two examples of where absorption of materials occurs.
Small Intestine
Lungs
