Biology Unit 2: Topic 3 & 4

?
  • Created by: Lucy
  • Created on: 28-01-13 21:49
Describe the structure of the Nucleus (3)
*A large organelle surrounded by a nuclear envelope. *Which contains many pores *The nucleus contains chromatin and often a structure called the nucleolus.
1 of 105
What is the Nucleus' function? (3)
*Chromatin is made from proteins and DNA. * The pores allow sunstances (e.g RNA) to move between the nucleus and the cytoplasm. * The nucleolus makes ribosomes
2 of 105
Describe the structure of the Centriole (2)
*Hollow cylinders *Containing a ring of Microtubules
3 of 105
What is the Centriole's function? (1)
*It is involved in the separation of chromosomes during cell division
4 of 105
Describe the structure of the Golgi Apparatus (2)
*A group of fluid filled, curved flattened sacs. * Each sav is smaller than the previous one *Vesicles are often found at the edges of the sacs.
5 of 105
What is the Golgi Apparatus' function? (2)
*It processes and packages new lipids and proteins. *It also makes lysosomes
6 of 105
Describe the structure of the rough endoplasmic reticulum? (2)
*A system of membranes enclosing a fluid filled space. *Covered in ribosomes
7 of 105
What is the rough endoplasmic reticulum's function? (2)
*Folds and processes proteins *that have been made at the ribosomes.
8 of 105
Describe the structure of the smooth endoplasmic reticulum (1)
*A system of membranes enclosing a fluid filled space
9 of 105
What is the smooth endoplasmic reticulum's function? (1)
*It processes and synthesises lipids
10 of 105
Describe the structure of the lysosome (3)
*A round organelle *surrounded by a membrane *with no clear internal structure
11 of 105
What is the lysosome's function? (3)
*It contains digestive enzymes * Which are kept separate from the cytoplasm by the surrounding membrane *They can be used to digest invading cells or to break down worn out components of the cell.
12 of 105
Describe the structure of the ribosome (3)
*A small organelle *Which floats free in the cytoplasm *OR is attached to the rough endoplasmic reticulum
13 of 105
What is the Ribosome's function? (1)
*The site where proteins are made
14 of 105
Describe the structure of the vesicle (2)
*A small fluid filled sac in the cytoplasm *surrounded by a membrane
15 of 105
What is the vesicle's function? (4)
*They transport substances in and out of the cell *And between organelles. *Some are formed by the Golgi Apparatus or the Endoplasmic Reticulum *Others are formed at the cell surface
16 of 105
Describe the structure of the Mitochondria (5)
*Usually Oval shaped *They have a double membrane *The inner one is folded to form structures called Christae *Inside is the matrix, which contains enzymes involved in respiration *Floating in the matrix are: Ribosomes and DNA (as a loop)
17 of 105
What is the Mitochondria's function? (2)
*The site of aerobic respiration, where ATP is produced. *They're found in large numbers in cells that are very active and require a lot of energy.
18 of 105
Define : Species (3)
*A group of organisms with similar Physiology, Morphology, and Behaviour. *Which can interbreed to produce fertile offspring. *And which are reproductively isolated (In place, time or behaviour) from other species.
19 of 105
What factors influence height? (2)
*It's Polygenic. *Environmental factors such as Nutrition (as protein is required for growth)
20 of 105
What factors influence Monoamine Oxidase A (MAOA) Levels? (2)
*It's monogenic *However taking anti-depressants or smoking tobacco can reduce the amount produced.
21 of 105
What factors influence the chances of developing cancer?
*Risk of developing some cancers is affected by GENES. *Environmental factors such as Diet can influence the risk.
22 of 105
What factors influence animal hair colour?
*It's polygenic. *The environment plays a part in some animals (e.g those with dark hair in summer and white hair in winter) The environment TRIGGERS the change but the gene is needed to do so.
23 of 105
What is meant by locus?
Different alleles for the same gene are found in the same position on chromosomes. This position is called the locus.
24 of 105
What is Endemism?
This is when a species is unique to a single place (isn't naturally found anywhere else in the world)
25 of 105
What are the three ways organisms can be adapted to their Niche? (3)
Behaviourally, Physiologically, Anatomically. (3)
26 of 105
Describe behavioural adaptations
Ways an organism ACTS that increase its chance of survival and reproduction
27 of 105
Describe Physiological adaptations
PROCESSES inside an organism's body that increase its chance of survival.
28 of 105
Describe Anatomical adaptations
STRUCTURAL FEATURES of an organisms body that increases its chance of survival
29 of 105
Which type of cell, Eukaryote or Prokaryote, is larger, and what are the size (diameter) ranges of each? (3)
Eukaryotes are larger. (Eukaryotes: 2-200µm) (Prokaryotes: Less than 2µm)
30 of 105
What type of cell wall, if any, do Prokaryotes have? (1)
Cell wall made of a polysaccharide, but not cellulose or chitin.
31 of 105
What types of cell wall, if any, do Eukaryotes have? (3)
Animals: No cell wall. Plants: Cellulose cell wall. Fungi: Chitin cell wall.
32 of 105
Which type of cell, Eukaryote or Prokaryote has linear DNA, and which has Circular DNA? (2)
Eukaryotes have Linear DNA. Prokaryotes have Circular DNA.
33 of 105
Which type of cell, Eukaryote or Prokaryote, have mitochondria?
Eukaryotes
34 of 105
Which type of cell, Eukaryote or Prokaryote, has more organelles?
Eukaryotes
35 of 105
Which type of cell, Eukaryote or Prokaryote has a nucleus, and which does not?
Eukaryotes have a nucleus, where DNA is stored. In Prokaryotes there is no nucleus- the DNA lies free in the cytoplasm.
36 of 105
Which type of cell, Eukaryote or Prokaryote, has larger ribosomes?
Eukaryotes
37 of 105
Define: Niche
The role of a species in an ecosystem
38 of 105
Describe the structure of cellulose (3)
*Made of long, unbranched chains of beta glucose, joined by 1-4 glycosidic bonds by condensation reaction .* Between 50 and 80 cellulose chains are linked together by hydrogen bonds, forming microfibrils. *Inversion of alternate glucose molecules
39 of 105
What is the function of cellulose? (2)
*Microfibrils are strong threads that provide structural support for cells *e.g. they strengthen plant cell walls
40 of 105
What happens in Interphase? (4)
*Cell carries out normal functions but prepares to divide. *DNA is unravelled and replicated to double its genetic content *Organelles are replicated *ATP content is increased to provide energy for cell division
41 of 105
What happens in prophase? (4)
*The chromosomes condense *The centrioles start moving to opposite ends of the cell, forming the spindle *The nuclear envelope breaks down *Chromosomes lie free in the cytoplasm
42 of 105
What happens in Metaphase? (2)
*The chromosomes (each with two chromatids) line up along the middle of the cell *and become attached to the spindle by their centromere.
43 of 105
What happens in Anaphase? (2)
*The centromeres divide, separating each pair of sister chromatids * The spindles contract, pulling chromatids to opposite ends of the cell, centromere first.
44 of 105
What happens in telophase? (5)
*The chromatids reach the opposite poles on the spindle. *They uncoil and are re-known as chromosomes. *A nuclear envelope forms around each group of chromosomes, there are now 2 nuclei. *The cytoplasm divides. *There are now 2 identical cells.
45 of 105
Describe the Cell Wall (2)
*A rigid structure that surrounds plant cells. *It's made mainly of the carbohydrate cellulose.
46 of 105
What is the function of the cell wall? (1)
*It supports plant cells
47 of 105
Describe the Middle Lamella (1)
The outermost layer of the cell
48 of 105
What is the Middle Lamella's function? (2)
*The layer acts as an adhesive, sticking adjacent plant cells together. * It gives the plant stability
49 of 105
Describe the Plasmodesmata (1)
*Channels in the cell walls that link adjacent cells together.
50 of 105
What is the Plasmodemata's function? (2)
*Allows transport of substances between cells. *Allows communication between cells
51 of 105
Describe Pits (2)
*Regions of the cell wall where the wall is very thin. *They're arranged in pairs (the pit in one cell is lined up with the pit in the adjacent cell)
52 of 105
What is the function of Pits? (1)
*Allow transport of substances between cells
53 of 105
Describe the Chloroplast (5)
*A small, flattened structure. *Surrounded by a double membrane. *Also has membranes inside called thylakoid membranes. *These membranes are stacked up in some parts of the chloroplast to form grana. *Grana are linked together by lamellae.
54 of 105
What is the function of Chloroplasts? (3)
*The site where photosynthesis takes place. *Some parts of photosynthesis happen in the grana. *Other parts happen in the stroma.
55 of 105
Describe the Amyloplast (2)
*A small organelle enclosed by a membrane. *They contain starch granules.
56 of 105
What is the function of the amyloplast? (2)
*Storage of starch grains. *They also convert starch back to glucose for release when the plant requires it.
57 of 105
Describe the Vacuole and Tonoplast (2)
*The vacuole is a compartment *surrounded by a membrane called the Tonoplast.
58 of 105
What are the functions of the Vacuole and Tonoplast? (4)
*The vacuole contains cell sap. *Vacuoles keep the cells turgid- this stops plants wilting. *They're also involved in the breakdown and isolation of unwanted chemicals in the cell. *The tonoplast controls what enters and leaves the vacuole.
59 of 105
Define Pluripotency (1)
Pluripotent cells are able to give rise to many types of specialised cell. The cells that make up the inner mass of a blastocyst are known as pluripotent embryonic stem cells.
60 of 105
Define Totipotency (1)
Totipotent cells can give rise to any type of specialised cell.
61 of 105
How are adult stem cells obtained? (3)
*They're obtained from the body tissue of an adult.E.g. the bone marrow. *It's a relatively simple, low-risk operation. *The adult is anaesthetised, a needle is inserted into the centre of a bone, and a small quantity of bone marrow is removed.
62 of 105
What is the difference between adult stem cells and embryonic stem cells?
Embryonic stem cells can develop into all types of specialised cells. Adult stem cells can only develop into a limited range of cells.
63 of 105
How are embryonic stem cells obtained? (4)
*Embryos are created in a laboratory using in vitro fertilisation. *Egg cells are fertilised by sperm outside the womb. *Once the embryos are approx. 4-5 days old, stem cells are removed from them. *The rest of the embryo is destroyed.
64 of 105
State two reasons why some people are against using embryonic stem cells (2)
*Some people believe that fertilised embryos have the right to life from the moment of fertilisation. *Some people believe it is wrong to destroy (viable) embryos.
65 of 105
Regulatory authorities regulate stem cell research. List 5 duties of these authorities.
*Allowing/disallowing proposals of research to go ahead *Licensing &monitoring centres involved in ESC research *Producing guidelines&codes of practise *Monitoring developments in scientific research *Providing info to governments and professionals
66 of 105
Name the seven taxonomic groups in order from largest to smallest.
Kingdom, Phylum, Class, Order, Family, Genus, Species
67 of 105
In the Latin binomial naming system (i.e. Human = Homo Sapiens) what do the first and second words correspond to?
First word: Genus name .Second word: Species name
68 of 105
What are the five kingdoms? Give an example of each.
Prokaryotae (e.g. bacteria), Protoctista (e.g. algae), Fungi (e.g. mushrooms), Pantae (e.g. flowering plants), Animalia (e.g. mammals)
69 of 105
What makes plant fibres strong? (2)
*The net-like arrangement of cellulose microfibrils in the cell wall *The secondary thickening of cell walls (the secondary cell wall between the cell wall and cell membrane is thicker than the normal cell wall and usually has more lignin.)
70 of 105
What are the advantages of using plant fibres rather than oil-based plastics to make rope? (3)
1) Using plant fibres is more sustainable than using oil- less fossil fuel is used up and crops can be regrown. 2) Plant fibres are biodegradable- unlike most oil-based plastics. 3) Plants are easy to grow- compared with extracting oil.
71 of 105
Why do plants need water? (4)
*Photosynthesis *Maintaining structural rigidity * Transporting minerals *Temperature regulation
72 of 105
Why do plants need magnesium ions? (1)
Magnesium ions are needed for the production of chlorophyll- the pigment needed for photosynthesis
73 of 105
Why do plants need nitrate ions? (6)
*DNA Production * Protein production *Chlorophyll production *Plant growth *Fruit poduction *Seed production
74 of 105
Why do plants need Calcium ions? (1)
*Sticking/holding adjacent plant cells together, component of Middle Lamella
75 of 105
What is Phenotype?
Phenotype describes the observable characteristics of an organism.
76 of 105
What is a seedbank?
A seedbank is a store of lots of seeds from lots of different species of plant.
77 of 105
What does the work of seedbanks involve? (2)
1) Creating the cool, dry conditions needed for storage (so seeds can be stored for a long time). 2) Testing seeds for viability. Seeds are planted, grown and new seeds are harvested and put back into storage.
78 of 105
What are the advantages of using seedbanks? (4)
1) Seeds are cheaper to store than plants. 2) Seeds require less storage space than plants. 3) Seeds require less labour than plants. 4) Seeds can be stored anywhere cool and dry. 5) Seeds are less likely to be damaged by disease,natural disaster etc
79 of 105
What are the disadvantages of using seedbanks? (3)
1) Testing the seeds for viability costs time and money. 2) It would be too expensive to store all types of seed and regularly test their viability. 3) It may be difficult to collect seeds from plants that grow in remote locations.
80 of 105
How do zoos and seedbanks help to educate people about conserving biodiversity? (2)
1) Zoos let people get close to organisms, increasing their enthusiasm for conservation work. 2) Seedbanks provide training and set up seedbanks all over the world.
81 of 105
Suggest four problems with the captive breeding and reintroduction of endangered species into the wild.
1) Animals can have problems breeding outside their natural habitat. 2) Some people think it's cruel to keep animals in captivity. 3) Reintroduced organisms can bring new diseases to wild habitats. 4) Reintroduced animals may behave differently
82 of 105
When preparing onion root tip cells to observe mitosis: Name the process which must occur in the genetic material before the chromosomes become visible.
DNA replication
83 of 105
When preparing onion root tip cells to observe mitosis: Explain why the cells are warmed in acid during the preparation of the slide.
To separate the cells.
84 of 105
Explain the meaning of the term tissue (2)
*(One/ few/ similar) Cell types *working together for the same function.
85 of 105
Explain why it is important that the sperm has a nucleus that is haploid (2)
*It has 23/half the required chromosome complement *So at fertilisation full complement is restored. * Allows for genetic variation/ mixing of alleles.
86 of 105
Name the three domains of organisms (3)
*Bacteria *Archaea *Eukarya
87 of 105
In an plant cell, which structure other trhan the nucleus contains DNA?
Chloroplast
88 of 105
What is genetic diversity? (2)
*The number of different alleles *In a population/gene pool
89 of 105
Why do seedbanks store seeds at a low temperature? (4)
*To prevent germination *Stops enzymes from working (stops growth) *Prevents bacteria growing *Prevents decomposure
90 of 105
Explain the meaning of the term stem cell (1)
This is an undifferentiated cell that has the ability to give rise to other types of cell. There is no limit to division.
91 of 105
Suggest two reasons why there are regulating authorities for human embryo research (2)
1) Can decide on max age of embryo allowed for research 2) Can set/consider ethical/legal aspects 3)Example of what is/not acceptable 4) Checking the source of stem cells is acceptable 5) Stopping of human cloning 6) To prevent unnecessary repeating
92 of 105
Describe the structure of a plant cell wall. (4)
*Cellulose *as microfibrils *Cellulose molecules held together by hydrogen bonds. *Correct reference to arrangement of microfibrils (in primary cell wall) *Reference to primary and secondary cell walls
93 of 105
Starch is a polymer of one monosaccharide. Name this monosaccharide.
(Alpha) glucose
94 of 105
Suggest why it is better to store seeds from several individual plants of one species rather than seeds from one individual plant
*To maintain genetic diversity *Less chance of inbreeding *Reduced chance of storing seeds with low viability/disease *Less chance of all being susceptible to disease *More chance of having beneficial allele
95 of 105
Describe how the acrosin is released from the acrosome.
*Stimulus: contact with zona pellucida *Acrosome swells *Vesicle/acrosome fuses *With sperm cell surface membrane
96 of 105
Mitosis is a part of the cell cycle. Give two roles of the cell cycle.
*Growth *Asexual reproduction
97 of 105
How do zoos use captive breeding programmes to conserve rare species?
*Increase population size *Maintain genetic diversity by inter-zoo animal movement *Protect from predators/poachers *Selection of mates/records kept of breeding programme *May use surrogates/IVF
98 of 105
How do zoos use reintroduction programmes to conserve rare species? (3)
*Prepare animals: reinforce wild behaviour, encourage hunting etc. *Select habitats/reserves *Encourage education amongst local population
99 of 105
Name the type of cell division required for asexual reproduction.
Mitosis
100 of 105
Describe and explain why asexual reproduction results in low genetic diversity. (2)
*Asexual reproduction leads to all offspring being genetically identical. Llow genetic diversity is low number of different alleles in the gene pool. *no meiosis/ no recombination of genetic material *variation only possible as a result of mutation
101 of 105
What happens in Cytokenesis? (3)
*Organelles become equally arranged at opposite sides of the cell *Cytoplasm divides *Cell divides to form two daughter cells
102 of 105
What is polygenic inheritance? (1)
The inheritance of a character controlled by a number of genes. (Each gene in a polygenic system will have a small, but significant effect on the phenotype. Environmental factors may also influence the expression of polygenic characteristics)
103 of 105
What is species diversity? (1)
The number of different species and the abundance of each species in an area.
104 of 105
What is species richness? (1)
This is the number of different species in an area. (It gives no indication of the abundance of each species)
105 of 105

Other cards in this set

Card 2

Front

What is the Nucleus' function? (3)

Back

*Chromatin is made from proteins and DNA. * The pores allow sunstances (e.g RNA) to move between the nucleus and the cytoplasm. * The nucleolus makes ribosomes

Card 3

Front

Describe the structure of the Centriole (2)

Back

Preview of the front of card 3

Card 4

Front

What is the Centriole's function? (1)

Back

Preview of the front of card 4

Card 5

Front

Describe the structure of the Golgi Apparatus (2)

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »