all Flashcards
(223 cards)
1
Q
What is a polymer?
A
Repeating units
Polymers are large molecules made up of smaller subunits called monomers.
2
Q
What are monomers?
A
Individual subunits
Monomers are the building blocks of polymers.
3
Q
What are the four macromolecules the body needs?
A
- Carbohydrates
- Lipids
- Proteins
- Nucleic acids
These macromolecules are essential nutrients that the body must consume.
4
Q
What is metabolism?
A
All the chemical processes carried out by cells
Metabolism includes reactions such as those catalyzed by enzymes.
5
Q
What are the three different structures of carbohydrates?
A
- Monosaccharides
- Disaccharides
- Polysaccharides
These structures define the complexity of carbohydrates.
6
Q
What are monosaccharides?
A
3-7 carbons with hydrogen and oxygen atoms
Monosaccharides are simple sugars like glucose.
7
Q
What is the function of carbohydrates?
A
- Provides materials to build cell membrane
- Provides quick energy for the cells
Carbohydrates are crucial for energy and structural purposes.
8
Q
Give an example of a monosaccharide.
A
Glucose
Glucose is a primary energy source for cells.
9
Q
What are lipids also known as?
A
Fats
Lipids include various molecules that are hydrophobic.
10
Q
What is the structure of lipids?
A
Doesn’t dissolve in water; glycerol attached to one or more fatty acids
Lipids form essential components of cell membranes.
11
Q
What is the primary function of lipids?
A
Good for long term energy
Lipids store more energy compared to carbohydrates.
12
Q
What are triglycerides?
A
3 glycerols bonded with 3 fatty acids
Triglycerides are a common form of fat storage in the body.
13
Q
What are proteins made of?
A
Peptides joined together by peptide bonds
Proteins are composed of amino acids, which are the building blocks.
14
Q
What is the function of proteins?
A
- Build and repair muscles and cell membranes
- Act as catalysts (enzymes)
- Fight infections
Proteins play a vital role in numerous biological processes.
15
Q
How many different amino acids exist?
A
20
These amino acids combine in various sequences to form different proteins.
16
Q
What are the two types of nucleic acids?
A
- Ribonucleic acid (RNA)
- Deoxyribonucleic acid (DNA)
These nucleic acids are essential for genetic information and protein synthesis.
17
Q
What is the function of nucleic acids?
A
Tell the cells what to do
Nucleic acids direct growth and development of all organisms.
18
Q
What do enzymes do?
A
Catalyze breakdown of macromolecules into smaller subunits
Enzymes are proteins that speed up chemical reactions.
19
Q
What are minerals?
A
Inorganic substances that enable chemical reactions and aid in tissue development, growth, and immunity
Minerals are essential for various bodily functions.
20
Q
What are vitamins?
A
Organic substances that enable chemical reactions and aid in tissue development, growth, and immunity
Some vitamins are water-soluble while others are fat-soluble.
21
Q
What is the digestive process called?
A
Metabolism
Metabolism includes breaking down macromolecules so cells can absorb nutrients.
22
Q
Fill in the blank: The alimentary canal extends from the mouth to the _______.
A
anus
The alimentary canal is a continuous tube that processes food.
23
Q
What is most of the blood made out of?
A
Most of the blood is made out of plasma
24
Q
What is the subunit of proteins and an example?
A
amino acids, example: some enzymes
25
What do lipids do, what is their subunit and an example?
Lipids store energy, fatty acid chain and glycerol, example: butters and oils
26
What is hydrolysis?
The process of water breaking down macromolecules into their monomers.
27
What is a polypeptide?
A chain of amino acids
28
What enzyme breaks down carbs, where is it from?
Carbohydrase, salivary amylase and pancreatic amylase
29
What do lipase break down, where is lipase from and an example?
Breaks down lipids into fatty acids and glycerol and its from the pancreas (pancreatic lipase)
30
What enzyme breaks down nucleic acids and from where + example, what do they produce?
Nuclease breaks down nucleic acids into nucleotides from the pancreas (nucleoslase)
31
What does the salivary glands do?
Produce saliva for chemical digestion and produced amylase to break down carbohydrates
32
Structure and function of the stomach
The stomach has rugae which allows it to contract to mechanically digest food. Chemical digestion is done by the gastric juices containing enzymes like pepsin and HCl which breaks down proteins.
33
What is in gastric juices and what is their role?
Gastric juices contain mucus, HCl and enzymes. Mucus lines the stomach, protecting it from the HCl which activates pepsinogens into pepsin to break down protein into polypeptides
34
What does the pancreas release and what do they do?
- releases pancreatic amylase which breaks down starches into glucose
- releases pancreatic lipase which breaks down triglycerides
- Releases trypsin which breaks down polypeptides
- Releases sodium bicarbonate which neutralizes the acidic chymes before it enters the duodenum
35
What is the structure and function of cilia?
Cilia are found all around the respiratory system and are used to filter out mucus and dirt from the airways
36
Why does the nasal passage contain capillaries?
The nasal passage contains capillaries to warm the air to body temperature as it passes through. This prevents that air from damaging the lungs
37
What controls breathing and how does it work?
The medulla oblongata controls breathing. When inhaling, the ribs flare out, the diaphragm contracts and pressure decreases while volume rises. When exhaling, the ribs come back on, the diaphragm relaxes and the volume decreases while pressure increases.
38
How does the alveoli's structure help its function?
Alveoli are one cell thick and surrounded by capillaries to allow for quick diffusion of gasses. There are also many alveoli which increases surface area.
39
What is the function of blood?
To deliver nutrients from the digestive system, deliver oxygen and regulate the body's temperature
40
What is the difference between systolic and diastolic pressure?
- Systolic pressure: maximum pressure in the arteries when the ventricle contracts
- Diastolic pressure: lowest pressure in the arteries when the ventricles relax
41
Describe COPD
A lung disease that causes airflow obstruction, making it hard to breathe. Most commonly caused by smoking, air pollution and exposure to chemicals. Treatments include Short-acting bronchodilator inhalers which widen the airways.
42
Describe asthma
Inflammation and narrowing of the airways causing coughing and wheezing. Causing by air pollution, physical activity, etc. Treatments include using inhalers to help with asthma attacks.
43
Describe Gastroesophageal Reflux Disease (GERD)
Caused by gastric acids flowing up the esophagus which leads to a burning sensation and sour taste in the throat. Treatments include antacid and other medications.
44
Describe peptic ulcers
The mucus in the stomach isn't enough and the gastric acids eat at the stomach lining causing pain in the upper abdomen. Treatments include antibiotics to kill the H. pylori.
45
Describe CAD
The reduction of blood flowing to the heart due the coronary artery's walls being thicken by fat causing chest pain or heart attacks. Treatments include lifestyle changes and aspirin to thin the blood.
46
Describe heart failure
When the heart doesn't pump enough blood causing fluid to build up in the lungs and legs and causing shortness of breath. Can be caused by coronary artery diseases and high blood pressure. Treatments include ACE inhibitors.
47
What is IRV?
Inspiratory Reserve Volume: used for physical activity like running since the tidal volume isn’t enough
48
What is ERV?
Expiratory Reserve Volume: the exhale after exhaling
49
What is an open circulatory system?
An open circulatory system is when the cells and tissues bathe in the fluid like in grasshoppers
50
What is the equation for cellular respiration?
C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy (ATP)
51
What is external respiration?
The exchange of oxygen and carbon dioxide between the inhaled air and the blood
52
What is the first and last part of the large intestine?
Cecum and sigmoid colon
53
What is internal respiration?
The process where oxygen diffuses from the blood into the body's tissues and carbon dioxide diffuses from the tissues into the blood.
54
What is diversity?
a measure of the variety and number of life forms on earth
55
What is a species?
a group who will mate and produce offspring that will also mate, also based on physical characteristics shared and morphology
56
What is taxonomy?
science of identifying and classifying all organisms.
before taxonomy, identification was based on DNA, location, behaviour and morphology
57
Who is Carl Linnaeus and contribution?
The father of taxonomy, introduced grouping species according to physical and morphology.
Developed Binomial Nomenclature (first name - genus, second name - species)
58
What is a Dichotomous Key?
helps identifying something based on a series of questions about their characteristic with two distinct answers for each question
59
What are taxonomic levels?
Levels going from broad to specific based on shared characteristics (each level called a taxon)
60
What is the saying for the taxonomic levels?
Dear King Philip Came Over For Good Soup
61
What are clades?
A taxonomic group that includes a single ancestor and it's descendants in a phylogenic tree
62
What is phylogeny?
Science of evolutionary relationships among species using taxonomy to trace back ancestry
63
What are the domains of life?
Carl Woese found all organisms fit into 3 domains (bacteria, Archaea, Eukarya)
- Bacteria and Archaea only have one kingdom by the same names (Eubacteria and Archae-bacteria)
- Eukarya has 4 kingdoms (fungi, plants, animals, protista)
64
What is modern taxonomy?
Linnaeus only classified plants and animals and microscopes have helped to discover Archaea, eubacteria, fungi, protista
65
What are prokaryotes?
- Single celled organisms lacking membrane-bound organelles
- Can live in any environment
- Domains Bacteria and Archaea are prokaryotic
66
What are prokaryotes impact?
- Can do harm (pathogens which cause sicknesses)
- Can do good (help digest food, produce vitamins)
67
What is bacteria?
- Prokaryotic and has been around for 3.5 billion years (first domain)
- Sometimes includes plasmid (loop of DNA with additional genes)
- cell wall
- Escherichia Coli: present in the gut but can be harmful leading to food poisoning, abdominal infections
- Benefit: produces vitamins, digest food)
68
What are the shapes of bacteria?
- Coccus (round)
- Bacillus (rod-shaped)
- Spirochete (spiral)
- Diplococci (paired)
- Streptococci (train of circles)
- Staphilococcus (cluster)
69
What is Archaea
- Little known about it
- Cell walls and membrane have a unique chemical makeup + genetic code
Live in extreme environments
70
What are protists? how do they move?
- Eukaryotic and microscopic
- Over 200,00 known species, most diverse eukaryotic species
- Protist move via flagellum (tail), Cilium (hair), or extending their pseudopod
71
What can protist act like?
- Animals: lacking a cell wall, heterotrophs and motile (protosoan)
- Plan like: perform photosynthesis, contain chlorophyll, sessile (algae)
- Fungus like: reproduce with spores, found on decaying matter (mold)
72
What is Plasmodium?
- Parasites cause illness in humans, plants, and animals
- Singled celled protist leading to malaria
73
What is the importances of Protist?
- Help soil in terrestrial ecosystems through their presences
- Producers and consumers in aquatic ecosystems
74
What is the Origin of Protist?
- First eukaryotes, nucleus made form the internal folding of the cell membrane
75
Classification and charateristics of Protist
- Protista kingdom is a "catch-all" for species that don't fit into other kingdoms
- Don't have common characteristics because they are so diverse
76
What is Fungi?
- Heterotrophs and sessile
- Most of their structure is underground and found underground within another organism
77
What is the importance of Fungus?
- Decompose organic matter and cycle nutrients for growth of other organisms
- Mycellium (fungi found underground/not roots) breaks down raw materials
- Symbiotic relationship as fungi will benefit from obtaining the nutrients through
78
What are the uses of fungi?
- Yeast for bread rising/ beer fermenting
- Antibiotics like penicillin
79
Example of Fungus symbiotic relationship
- Lichens are green algae and fungus growing symbiotically
- Fungus provides CO2, O2, and support, Algae provides carbohydrates
Done through mycellium wrapping around the photosynthesis cells
80
Similarities and differences of plants and fungi?
Similarities:
- Multicellular Eukaryotic and sessile
Differences:
- Plants: have roots, autotrophs, cell wall made of cellulose
- Fungus: Heterotrophs, no roots, cell wall made of chitin
81
What is sexual reproduction in seedless plants?
- Uses spores (one male one female)
- In non-vascular plants, gametophytes are dominate while in vascular plants, sporophytes are dominate
82
When is asexual reproduction in seedless plants used?
- Used when plants can't find mate but leaves plant vulnerable
83
What is sexual reproduction in angiosperms?
- Male gametophytes develop into pollen grain and sperm
- Female gametophytes develop into egg cells
- Pollination occurs when sperm is transferred to female reproductive structure
84
What are mechanisms for pollination?
- Self pollination: plant pollinates itself
- Cross pollination: plant receives pollen from a different type of plant
- Animal pollination: insects move from one flower to another
- Wind pollination: large quantities of light pollen is made to land on a reproductive organ
85
What type of cells do plants have?
- Plants have meristemic cells that develop into specialized cells
- Specialized cells form tissue groups in roots, leaves, and stem
86
What does the vascular tissue do?
Vascular:
- transports water and nutrients through the plant
Xylem:
- cells are dead and consist of a cell wall to transport water and minerals up
Phloem:
- cells are alive but lack a nucleus and organelles, transports sugars up and down
87
What do epidermal tissues do?
- outside of the plant for protection
- allows for exchange of materials and gases
88
What do ground tissues do?
- Makes up the majority of the plant
- In the root for food and water storage
- in the leaves for photosynthesis and stem for strength and support
89
What is the role of the root and leaves of a plant?
Root:
- Anchors the plant, absorbs water and materials, stores sugars, conducts water (make up of all 3 tissues)
Leaves:
- Photosynthesis (made up of all 3 tissues)
90
What is the role of the stem and types of stems?
- Supports leaves and fruits
- transports water and sugar throughout the plant
- Types of stems: Dicot, monocot, herbaceous, woody
- made of all 3 tissues
91
Where do plants come from?
Plants evolved from a protist group of green algae called charophytes
92
What is the cycle of alteration of generations?
- Sporophytes produce haploid spores via meiosis
- Spores divide via mitosis, producing gametophytes
- Gametophytes produce gametes
- Zygote is formed through fertilization of gametes
- Zygote divides via mitosis and creates sporophytes
93
What are bryophytes?
- Don't have a vascular system or roots (rhizoids instead)
- First to inhabit previously uninhabited places, die to enrich the soil for complex plants
- Diffusion and osmosis to obtain water
- No seeds so water is used to reproduce (haploid dominant)
94
What are tracheophytes?
- earliest vascular system in plants (ex. ferns)
- helps in evolution of ecosystems and grows in harsh conditions
- no seeds, water for reproduction
95
What are spermatophytes?
- vascular system, roots, stem, leaves
- Seeds contain embryo, no water needed for reproduction
96
What are gymnosperms?
- have cones containing seeds
- live in harsh conditions, protect their seeds
- needles help contain water, roots go deep underground
97
What are angiosperms?
- all have flowers or fruits for reproduction
98
What are some characteristics to describe animals?
- Radical symmetry
- Bilateral symmetry
- Cephalization: nervous system tissue in the head region
- Deuterostomes: first opening is the anus (complex organisms)
- Protostomes: First opening is the mouth (simple organism)
99
What are Annelida and Arthopods?
Annelida
- earthworms, bilateral symmetry, P, one way digest
Arthopods
- insects, P, sheds to grow, exoskeleton made of chitin
100
What are viruses?
- non-living structures, cannot reproduce by themselves
- have genetic material (DNA/RNA) force into host to reproduce
- diverse but all contain genetic material in capsule
101
What is the basic cycle of reproduction of viruses?
attachment, insertion, replication, assembly, release
102
What is the lytic cycle?
- virus attaches to the host cell and injects DNA
- tells cell to replicate the virus
- cell membrane explodes (lyses out)
- virus leaves cell to infect others
103
What is the lysogenic cycle?
- virus attaches to the host cell and injects DNA
- DNA stays hidden in the hosts DNA
- when cell replicates, so does the virus DNA
- when many cells have the virus DNA, cell enters stage 2 of lytic cycle
104
Benefits and disadvantages of viruses?
- HIV is a virus attacking immune cells leading to AIDS
- viruses help with gene therapy and are used to lower number of harmful bacteria
105
What are nucleotide made of?
A sugar- phosphate backbone and a nitrogenous base (A, T, G, C)
106
What are the nitrogenous base pairings?
Adenine matches with Thymine
Guanine matches with Cytosine
107
Who created the structural model of DNA?
James Watson and Francis Crick in 1952
108
What are histones?
Histones are the proteins wounded around DNA.
109
What is the importance of the base pairing in DNA?
The base pairing in DNA makes up the genetic code of an organism (genome is our whole genetic code).
110
What are Karyotypes?
A persons particular arrangement of chromosomes. Chromosomes can range in side (humans have 23 pairs and 46 in total)
111
What are autosomal chromosomes?
Regular chromosomes are autosomal (humans have 22 pairs of autosomal)
112
What are sex chromosomes?
Sex chromosomes tell the sex of the organism and is placed last in the chromosome picture line-up (XX for female, XY for male)
113
How do cells use DNA?
All DNA in the body has the same DNA but uses only a part of the DNA to do their job.
114
What is Asexual reproduction?
Asexual reproduction is done from a single-celled parent by cell division (mitosis). Offspring is genetically identical to parent
115
Advantages of asexual reproduction?
- Parents organisms do not need to seek out a mate to reproduce
- Specialized mating behaviours are not needed
- No specialized anatomy
116
What is Budding?
When an offspring develops from outside of the parent organism. When their offspring grows large enough, it detaches and lives on its own. Ex. Hydra
117
What is Fragmentation?
A piece of the parent organism breaks off and matures into its own. Ex. mushrooms grow spores that develop into mushrooms
118
What is the cell cycle?
The cells cycle of life. Starts in the growth stage (Interphase) then the division stage which is much shorter and split into to parts: Mitosis (prophase, metaphase, anaphase, and telophase) and cytokinesis.
119
What happens in Prophase?
- Chromatin (DNA) condenses into
chromosomes
- Centrioles move to opposite ends of the cell
- Spindle fibers form from the centrioles
- Nuclear membrane dissolves
120
What happens in Metaphase?
- Spindle fibers attach to centromeres
- Chromosomes align along the equatorial plate
121
What happens in Anaphase?
- Spindle fibers shorten
- Centromere splits and pulls chromatids to opposite ends of the cell
122
What happens in Telophase?
- Chromosomes relax into chromatin
- Nuclear membrane reappears
- Two new nuclei are formed
- Spindle fibers disappear
123
What happens in Cytokinesis?
- the cytoplasm divides
- In animal cells, cleavage furrows are formed
- In plant cells, cell plates are formed
124
Disadvantages of sexual reproduction?
- Specialized organs are needed to produce the sex cells
- Need courtship techniques to mate like bright colours but that could also attract predators
- May require the lost of a resource such as nectar in flowers
- The offspring may be weak or unable to survive when combining the genetic information
125
Advantages of sexual reproduction?
- Allows for evolution due to the genetic variability
- Can support the long term survival of a species
126
What is sexual reproduction in humans?
Sexual reproduction is the fusion of 2 sex cells which makes a genetically unique offspring. This is done in 2 steps:
- The 2 sex cells joining to form a zygote, the first cell of a genetically unique individual through fertilization
- The formation of a haploid cell or gamete which contains genetic information from both parents
127
What are some modes of sexual reproduction with examples?
- External fertilization: parrot fish have egg cells that are layed and sperm cells fall on it
- Internal fertilization: Humans (most mammals)
128
How many chromosomes is in the cell during Meiosis 1 Prophase 1?
46. Diploid cell containing 23 pairs of homologous chromosomes
129
What is meiosis?
A special type of cell division similar to mitosis. Present in organism that sexually reproduce and is the process that makes the gametes (sperm and egg cells) for sexual reproduction.
130
Difference between Mitosis and Meiosis?
- Mitosis has the same number of chromosomes in each generation (from parent cell to daughter cell)
- Meiosis starts with a diploid cell and ends with 4 haploid cells (chromosomes reduce by half by the end)
131
How does genetic variation occur in Meiosis
- The combination of two gamete cells each containing a complete set of DNA (one from each parent which contains one version of each gene) creating homologous chromosomes
- Genetic variation occurs during prophase 1 when homologous pairs crossover
- In metaphase 1 and 2 when chromosomes randomly pick which side to go to
132
Recite Meiosis for human sperm and egg cells
133
What is the production of sex cells?
The production of sex cells is called gametogenesis whcih is done through meiosis. In humans there are 2 types: spermatogenesis (1 diploid cell to 4 sperm cells) and oogenesis (1 diploid cell to 1 ovum and 3 polar bodies).
134
What term describes the improper chromosome separation in meiosis?
Nondisjunction
135
What term describes the process of traits being passed from parent to offspring?
Heredity
136
What is the chemical composition of DNA?
Discovered by Phoebus Levene, DNA is made of a pentose sugar (5 carbon sugars), a phosphate group, and a nitrogenous base. All together this is a nucleotide.
137
What are the 2 types of nitrogenous bases?
Pyrimdines (cytosine, thymine) and Purines (guanine and adenine)
138
What happens when a sequence of nucleotides is translated by the ribosome?
The sequence of nucleotides will produce a certain protein when going through the ribosome. 3 nucleotides is called a codon.
139
What is the key relationship between nitrogenous bases?
Erwin Chargaff discovered that the amount of Adenine is equal to the amount of thymine and the amount of guanine is equal to the amount of cytosine.
140
What is multiple births?
More than one egg can get released and fertilized separately (leading to fraternal twins) or the zygote splits early and becomes two cells (identical twins).
141
What is independent assortment in meiosis?
During Metaphase 1, the homologous chromosome pairs are randomly oriented when lining up at the poles.
142
What is crossing over in meiosis?
During prophase 1, genetic material is exchanged between maternal and paternal chromosomes in multiple sections. However, errors can occur causing errors in the chromosome sequence.
143
What are errors in chromosome number?
Euploidy: when a human has the correct number of chromosomes
Aneuploidy: when a person has the wrong amount of chromosomes (resulting in non-disjusction in meiosis)
Monosomy: chromosome missing
Polysomy: additional chromosome
144
Effects of non-disjunction in anaphase 1 and 2?
When non-disjunction happens during anaphase 1, no normal gametes will be created. If in anaphase 2, half the gametes will have the correct chromosome number. IF the gamete with an abnormal chromosome number undergoes successful fertilization, that resulting individual
will have an extra or missing chromosome.
145
Disadvantages of errors in meiosis?
Have a dramatic impact on the development and survival of their offspring. In humans it can result in genetic disorders like down syndrome (polysomy) and Cri du Chat (deletion of chromosome 5). In both animals and plants with aneuploidy, they are infertile
146
Errors in Chromosome Sequence?
- Deletion: loss of chromosomal segment (example: cri du chat)
- Duplication: repeated segment (chromosome 1 gives x to chromosome 2 but chromosome 2 keeps their x so now it has 2) (example charcot-marie-tooth disease)
- Inversion: reversed segment (after separating, the chromosome changes the sequence of the alleles) (example FG syndrome)
- Translocation: 2 chromosomes that are not homologous pairs form a tetrad and switch alleles that shouldn't be switched (aren't from the same chromosome number) (example chronic myelogenous leukemia)
147
Examples of chromosome abnormalities in humans?
- Trisomy 21 (extra chromosome 21 causing down syndrome, effects: intellectual disabilities, short stature)
- XO Turner syndrome ( missing an X chromosome causing sterile females, can't produce eggs, underdeveloped female characteristics)
- Trisomy 18 Edward syndrome (life expectancy about 10 weeks, severe adnormalities)
148
What is aminocentesis?
A prenatal test that allows your healthcare practitioner to gather information about your baby's health from a sample of your amniotic fluid- this is the fluid that surrounds your baby in the uterus
149
What are problems with Fertillization?
- Problems with fertilization are more common than chromosomal abnormalities
- Causes include: poor or reduced egg or sperm quality/quantity
150
What is mutation and what causes it to occur?
Mutations are mistakes during cell division. Spontaneous mutations are mutations that happen naturally on accidents and can be the result of incorrect copying of DNA. Induced mutations happen when exposed to a physical or chemical agent like UV radiation, cigarette smoke, chemicals in processed foods, etc.
151
What are point mutations?
A point mutation is a failure in replicating cells to copy the genetic
information accurately causing base-pair substitution, insertion, or deletion
152
What are chromosome mutations?
Chromosome mutation involves a mutation of an entire chromosome or a large part of it. Nondisjunction is an example of chromosome mutation happening in meiosis which can result in genetic disorders if it happens in gametogenesis or early in development during mitosis.
153
How are mutations inherited?
Mutations that occur in somatic cells are not passed onto offspring so it does not affect future generations. However, mutations that occur in the formation of sex cells become part of the DNA of the zygote. This means the offspring will have a copy of every cell of its body, including its sex cells, so it will pass it on to future generations.
154
Example of inherited mutations?
- Lactose Intolerance: A common trait in which people are not able to digest lactose (common sugar in milk). Caused by a deficiency of the lactase enzyme. When consuming a lot of dairy products, the undigested lactose will metabolize by intestinal bacteria which causes bloating, cramping, and diarrhea
- Sickle-cell anemia: Both helpful and harmful caused by a single amino acid substitution making red blood cells into c shaped and less effective at moving oxygen around the body via blood. Increases risk of infection however, the parasite malaria, cannot survive in people with sickle-cell anemia since the cells aren’t doing their job, they are destroyed along with the malaria parasite
155
What is complete dominance?
When one allele is expressed in the phenotype even when there is another allele present. Basically, the dominant allele is expressed even if the genotype is heterozygous.
156
What is incomplete dominance?
When 2 alleles interact with one another and instead of one being dominant, they blend
157
What is codominance?
Both alleles mask each other and show up mixed in the phenotype, Example: shorthorn cattle
158
Codominances and dominance in blood types?
Blood types are inherited from 3 possible alleles: I^A, I^B, and i. Each of the alleles code for a different enzyme that places different sugars in the red blood cells surface. This indicates that I^A and I^B alleles are co-dominant to each other (they both show up on the red blood cell) However, I^A and I^B are completely dominant to i allele.
159
What is a Pedigree and it's use?
A Pedigree chart is a special type of family tree used to visually follow the inheritance. This chart traces the inheritance of a certain trait among members of a family. Pedigrees are used by plant and animal breeders to track desirable and undesirable traits.
160
What is a genetic counsellor?
Genetic counsellors construct and analyze pedigree charts to trace genotypes and phenotypes of a family. Can be used to determine if and how any particular trait runs in a family.
161
What is autosomal inheritance?
If an allele is inherited on an autosome (non-sex chromosome) it is under the control of autosomal inheritance. It affects both sexes equally and is not affected by the inheritance of sex chromosomes
162
What is a discontinuous variation?
The gene for y is on a different section/chromosome than the gene for X. The gene for height is on a different chromosome than a gene for eye colour so the height couldn't tell you what eye colour they have.
163
What is continuous variation?
Traits are controlled by multiple genes for example skin or eye colour. It is not just one gene that affects it.
164
What is Mendel's Law of Independent Assortment?
Each allele is inherited independent of each other as long as they are on different chromosomes.
165
What is Mendel's law of segregation?
Allele pairs separate during gamete formation
166
How was cloning done on Dolly?
An adult cell was fused with an unfertilized egg cell and inserted into the uterus of another sheep.
167
Why do cells divide?
Reproduction, repair or tissue and organs, replace dead cells
168
What would be a test cross for gene R and gene r?
RRxrr
169
What is evolution?
Change in the gene pool of a population from generation to generation over time caused by mutations, natural selection, and genetic drift.
170
What did Leclerc de Buffon hypothesize?
He hypothesized that species were created perfect but over time they changed. He studied anatomy and questioned why animals have body parts they don't use.
171
What were the 2 principles Chevalier de Lamarck hypothesized?
- Use and Disuse: structures an individual used became larger and stronger where passed down while weaker ones that weren’t used were became weaker and smaller
- Inheritance of Acquired Characteristics: individuals could pass characteristics to their offspring what they gained overtime
172
What is the theory of evolution by natural selection?
Darwin described natural selection as a way that the environment favours the reproductive success of certain species over others.
Evolution was simply the result of natural selection occurring over many generations
173
What was Darwin's Theory?
He observed that all healthy populations produce far more offspring than can survive and all individuals exhibited heritable variability.
From this he concluded:
- Some individuals will have better chance of success than others
- Their traits are more likely to be passed onto the next generation
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What was Charles Darwin's adventure?
In December 1831, Charles Darwin set sail on a 5 year trip on the HMS Beagle where he helped survey the coast but used this as an opportunity to study plants and organisms.
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What did Charles Darwin notice at the Galapagos Islands?
- Noticed nesting babies had no fear of humans
- Iguanas that could dive underwater
- Giant land tortoise
He collected information from islands in close proximity to each other. When he studies these islands, there were variations within the species and some species were considered separate because they were so different (the finches).
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What is natural selection?
- Evolution occurs when natural selection acts on genetic variability of a population
- Benefit of the trait for survival and is passed on to the next generation
- Environment favours a certain trait
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What is directional selection?
Selection is favouring one extreme of the trait over another
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What is a stabilizing selection?
Majority of the population is taking on the middle of the 2 extreme ends of the trait
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What is disruptive selection?
Intermediate trait is not favoured but the 2 extreme ends of the trait is favoured
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What is sexual selection?
- Favouring a trait that enhances the mating success of the organism
- Allows for males or females within the population to evolve in their appearances or behaviours
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What is genetic drift?
- Change by chance with no selection influence
- No benefit or loss from the trait passing on
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What is a Genetic Bottleneck?
- No selective pressure but change in frequency of the population
- Loss in genetic diversity due to extreme reduction in the size of population
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What is Behavioural Isolation?
Different species use different courtship and other mating clues to find and attract a mate.
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What is temporal isolation?
Different species breed at different times of the year
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What is ecological isolation?
Very similar species may occupy different habitats within a region.
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What is mechanical isolation?
Differences in morphological features may make two species incompatible.
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What is gametic isolation?
Male gametes may not be able to recognize and fertilize an egg of a different species.
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What is zygotic mortality?
Mating and fertilization are possible, but genetic differences result in a zygote that is unable to develop properly.
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What is hybrid inviability?
The offspring is a hybrid of the two organisms but they die before birth or if they are born they cannot survive to maturity.
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What is hybrid infertility?
Hybrid offspring remain healthy and viable but are sterile (they cannot reproduce)
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What is gradualism?
a slow and continuous process of evolutionary change over long periods, with new species arising gradually from ancestral forms
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What is punctuated equilibrium?
Describes a process of evolution that suggests very short, rapid periods of change followed by long periods of stability (no change).
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What is divergence and convergence evolution?
- Divergence: When one single species is placed under selective pressures and evolves to occupy unique niches
- Convergent: Occurs when two different species evolve to occupy similar ecological niches in different geographic regions but similar environmental pressures (but no common ancestor)
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What are the types of mutation?
- Neutral mutations do nothing
- Harmful mutations reduce the reproductive success of the organism, Ex. turner’s syndrome
- Beneficial mutations produce changes that give the organism an advantage, Ex. drug resistant bacteria
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What is the importance of genetic variation?
Genetic variation allows for a species to adapt which results in evolution overtime. Often, mutations are the source of genetic variation
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What impact does mutations have on human health?
Since viruses carry genetic information even though they are not alive and are genetically variable and can change overtime, These mutations can increase the viruses ability to spread which is why every year we try to predict these changes and update vaccines
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What is selective breeding?
Selective breeding includes domestication which is the changing of members of a species to suit human needs through controlled captive breeding. (ex. domestication of dogs from wolves)
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How does selective breeding work?
When a trait is found favourable, that plant/organism is chosen to reproduce. This means that the trait is more likely to show up in the next generation
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What power does artificial selection have?
- Reduces genetic variation because we are choosing one trait over and over again
- Overtime they might not be suitable for their environment
- Can also produce organisms far beyond the natural variability within the original population
- Can make a species vulnerable to disease or extinction
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What is biogeography?
The scientific study of the geographic distribution of organisms based on both living species and fossils
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What is a homologous feature?
Similar structures but different functions. Closely related species share homologous features because they shared a common ancestor. Overtime, as species evolved the original structures were modified. Closely related species also share homologous developmental processes and patterns.
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What are analogous features?
A structure that performs the same function but is not similar in structure (bird wings and insect wings). Analogous features are evolved independently from each other
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What are vestigial features?
Features that no longer serve the function they do in similar species
(Ex. the extra toe pigs have but don’t use or goosebumps in humans). Can be explained as evolutionary baggage
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What is competition in populations caused by?
Populations are limited in size by their environment and food supply. Populations can't grow indefinitely since there isn’t enough food which leads to competition for survival within species.
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What is speciation?
- Speciation: the formation of a new species in the course of evolution
- If enough adaptation occurs over a period of time, two organisms can become two different species and they will no longer mate with each other
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What is reproductive isolation?
Reproductive isolation is when organisms are separated from each other and some mechanism is preventing them from mating.
Reproductive isolation mechanisms are factors that prevent two populations from interbreeding while in the same region.
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What is the difference between prezygotic and postzygotic?
- Prezygotic: something that is preventing the organisms from mating with each other
- Postzygotic: Organisms that can mate and form a zygote but the offspring either can’t or doesn’t reproduce
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What is Allopatric speciation?
Formation of a new species through the separation of the species into two geographically isolated populations.
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What is Sympatric speciation?
Formation of a new species within a large population without the need for geographical separation. Can result from mutation or change in the environment
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What are some patterns of evolution?
- Closely related species share many homologous features even if they don’t have the same function
- Species may have vestigial structures that once served a function in their ancestors
- Analogous features have similar functions but different features
- Remote islands are inhabited by unique species that are descended from a few individuals who were able to reach the island
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What is adaptive radiation?
- Occurs when a single species evolved into a number of distinct but closely related species (Ex. the finches)
- Occurs when a new variety of resources become available that are not being used by the other species
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What is coevolution?
- Organisms adapt and evolve with each other
- When a species evolutionary success is closely like another species
- Ex. predator-prey
- Symbiotic relationships start to occur due to this (in some cases, when one species gets wiped out so does the other)
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What caused extinction?
Changes in the environment and isolation that occurs too quickly for the organism to adapt
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What is uniformitarianism?
The theory that geological changes are slow and gradual and natural laws have not changed. Earth has been changed by the same processes in the past as it is right now.
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What is catastrophism?
The theory that the pattern of fossils could be connected to the series of global catastrophes that wiped out most species on earth.
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What does reading fossils tell us?
the discovery of fossils of unknown organisms, there being no fossils of living species, fossils being buried kilometres below earth's surface, and fossils being found in unexpected locations like desserts. Oldest fossil deposits contain only simple life forms while recent ones have complex organisms similar to the ones already existing.
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Why are bacteria that exhibit resistance to antibiotics becoming more widespread?
less-resistant strains of bacteria are being killed off by antibiotics
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Which scientists claimed that life may have evolved from a single source?
Erasmus Darwin
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What are tropisms?
growth responses from plants to stimulus such as:
- phototropism: light
- gravitropism: gravity
- thigmotropism: touch
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Characteristics of monocot and dicot stems and leaves?
Monocot:
- Narrow leaf and linear lines
- Scattered vascular bundles
- flowers in mutiples of 3
Dicot:
- Wider leaves with a network of lines
- Arranged vascular bundles
- flowers in mutiples of 4-5
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What is the sinoatrial node (SA node)?
small group of cells in the right atrium that sends out electrical signals to make your heart beat. These signals tell the heart muscles when to contract, keeping your heartbeat at the right speed.
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What is the atrioventricular node (AV node)?
small group of cells that receives signals from the SA nodes and delays them to allow the atrias to squeeze blood into the ventricles. Then it sends the signal down the septum. It is located between the atria and ventricles
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What do purkinje fibers do?
tiny fibers spread the signal throughout the ventricles, causing them to contract and pump blood out to the lungs and body.
