Chapters 10,12&14 Flashcards
(157 cards)
1
Q
What is photosynthesis?
A
A series of anabolic reactions that form carbohydrates. It takes in carbon dioxide and water to produce glucose.
2
Q
Carbon dioxide & water to glucose
A
6 CO2 + 12 H2O —-> C6H12O6 + 6H2O + 6O2
3
Q
Autotrophs
A
Make organic molecules themselves by photosynthesis
Ex green plants, algae
4
Q
Heterotrophs
A
Take in organic molecules themselves by photosynthesis
Ex. Animals (feeding) fungi (decomposing)
5
Q
Leaf structure
A
Water comes into the leaf through veins from the roots. CO2 enters the leaf through small holes called stomata. Chloroplasts are mainly on the top surface of the lead.
6
Q
What are stomata?
A
Small holes in leaf where CO2 enters.
7
Q
Where are chloroplasts mainly located?
A
On the top surface of the leaf.
8
Q
Two stages of photosynthesis
A
Light reactions: use light energy to form ATP and also split water into hydrogen (added to NADP to make NADPH) and oxygen (waste)
Calvin cycle: uses NADPH and ATP to form carbohydrate from carbon dioxide.
9
Q
Light
A
Different colors of light have different wavelengths. Red has a longer wavelength than blue light.
10
Q
Is red light wavelength or blue light wavelengths longer?
A
Red
11
Q
What does chlorophyll do with green light?
A
Reflects
12
Q
What does chlorophyll do with red and blue light?
A
Absorbs
13
Q
Electron acceptor molecules
A
Hold high energy electrons to stop them from wasting the energy as heat.
14
Q
What is a photosystem?
A
A chlorophyll molecule, electron acceptor, and other light gathering molecules like carotene.
15
Q
What is an idea to help search or life on other planets?
A
Look for characteristic wavelengths of light that are reflected by photosynthetic organisms.
16
Q
Where do light reactions take place?
A
In the grana of the chloroplast.
17
Q
Cyclic electron flow
A
Uses photosystem I
Produces ATP using a proton pump
18
Q
Non-cyclic electron flow
A
- uses photosystem I and II
- produces ATP and NADPH molecules
- splits water to get electrons from the hydrogen
19
Q
Where does the Calvin cycle take place?
A
In the stroma of the chloroplast
20
Q
How does the Calvin cycle work?
A
It takes CO2 and produces carbohydrate (glyceraldehyde phosphate). It uses the ATP and NADPH that were produced in the light reactions.
21
Q
Light in artificial photosynthesis
A
Is used to split water and produce hydrogen.
22
Q
Hydrogen powered cars
A
Have a range of over 300 miles and can be refueled in a few minutes.
23
Q
What is glyceraldehyde phosphate used to make?
A
Glucose (C6H12O6)
24
Q
Glucose can be stored in the plant as what?
A
Starch.
25
Other enzymes convert carbohydrates into what?
Lipids.
26
Plants can make proteins if they have what?
Nitrate (absorbed into roots from fertilizer)
27
Plants can make nucleic acids if they have
Phosphate.
28
Photosynthesis
A series of anabolic reactions that form carbohydrates
29
Three different types of plants:
C3 plants
C4 plants
CAM plants
30
C3 plants
typical plants that open their stomata during the day, and close their stomata at night. Common in cool areas, ex, Canada.
31
C4 plants
Open their stomata only briefly during the da. They wrote CO2 as the 4 carbon sugar: oxaloacetate. Mainly tropical plants.
Ex sugarcane.
32
CAM plants
Only open their stomata at night to conserve water. Desert plants
Ex cactus.
33
Why is cell division needed?
For growth, reproduction, and to replace dead cells.
34
Mitosis definition
A type of cell division that leaves two identical copies of a cell. The chromosome number is unchanged.
35
Examples of cells divided by mitosis
Skin, blood, kidney. Most cells divide by mitosis.
36
Why is nerve and brain damage usually permanent?
Because nerve and brain cells rarely divide after childhood.
37
What is interphase?
Where the cell grows and DNA replicates
38
What is interphase followed by?
Mitosis
39
Stages of mitosis
Prophase
Metaphase
Anaphase
Telophase
40
Stages of mitosis: Prophase
The spindle (made of microtubules) forms. The chromosomes are visible scattered at random.
41
What is the spindle in prophase made of?
Microtubules
42
Stages of mitosis: metaphase
Chromosomes line up in the center of the cell
43
Stages of mitosis: anaphase
Centromeres divide. The chromosomes move to the opposite ends of the cell. (V shape)
44
Stages of mitosis: telophase
Two nuclei form. The cytoplasm divides (cytokinesis). In plant, the cytoplasm separated from the center of the cell towards the outside by forming a cell plate. In animals the cell membrane pushes inwards from the outer edge making a cleavage furrow, so the center is the last part that divides.
45
Normal cells divide only if
a) the correct growth factor is present
| b) each cell is not completely surrounded by other cells
46
Proteins inside the cell control the cell cycle
👌🏼
47
Cyclins in the nucleus
Control the replication of DNA.
48
Who was the 2001 Nobel prize awarded to?
The people who discovered cyclins.
49
Protein kinases
Switch on proto-onco genes that start mitosis. A mutation in a proto-onco gene can turn it into an oncogene that causes cancer (uncontrolled cell division)
50
Tumor-suppressor genes
Prevent mitosis, & make abnormal cells kill themselves. Everyone has some of these, p53 for example.
51
Most cancers have mutations in tumor-suppressor genes.
🦀
52
Why does your chance of cancer increase as you get older?
Because chance of mutations in tumor-suppressor genes increases.
53
Cancer cells keep dividing
Even if surrounded by other cells.
54
Benign tumor
Limited to one site and cannot spread.
55
Malignant tumor
Have spread around the body in the blood.
56
Metastasis
Means that cancer has spread.
57
Causes of cancer
1) environment:
Carcinogens (chemicals which cause cancer)
Radiation
UV light causes skin cancer
Virus (HPV causes cancer of cervix)
2) genetics:
High risk: prostate, colon, breast, skin, ovary
Low risk: lung, pancreas, testicle, uterus
58
Cancer treatment
Surgery
Chemotherapy
Radiation
59
Cancer treatment: surgery
Removes cancer cells. Best for benign tumors.
60
Cancer treatment: chemotherapy
Chemicals that kill dividing cells. Standard for malignant tumors.
61
What are the problems with chemotherapy?
Causes many side effects, because the chemicals kill all cells that are dividing, cancer and regular cells like skin, blood, hair. Hair falls out, feel nausea. In 2001 a new chemotherapy was approved that targets only cancer cells.
62
Cancer treatments: radiation
Kills all the cells in one spot. Standard for malignant tumors.
63
What is the problem with radiation cancer treatment?
Radiation kills all cells in the area, cancerous or not, so causes side effects. Radiation itself can also cause new cancer to start.
64
Types of cancer
Prostate
Breast
Colon
Lung
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Prostate cancer stats
```
Annual deaths: 39,000
5 year survival: 93%
Early detection-
Exam: age 40+
Blood: age 50+
```
66
Breast cancer stats
```
Annual deaths: 44,000
5 year survival: 85%
Early detection-
Self exam: 20+
Mammogram: 40+
```
67
Colon cancer stats
```
Annual deaths: 57,000
5 year survival: 62%
Early detection-
Exam: 40+
Blood: 50+
```
68
Lung cancer stats
Annual deaths: 160,000
5 year survival: 14%
No tests for early detection
69
How is most cancer research done?
Using human cells grown in the lab called HeLa cells.
70
Where do HeLa cells come from?
Henrietta Lacks
71
What are HeLa cells?
Human cells grown in the lab, used for cancer research.
72
What is a telomerase?
An enzyme that repairs the telomeres on the ends of the chromosomes. Cancer cells have this.
73
What are cancer researchers developing?
A) inhibitors against telomerase
B) inhibitors that stop cancer cells from producing new blood vessels
C) medications that boost the immune system
74
Types of reproduction and meiosis
Asexual reproduction
Sexual reproduction
Diploid cells
Haploid cells
75
Asexual reproduction facts
Offspring are identical
Only one parent, cells divide by mitosis
Ex. Bacteria, banana
76
Sexual reproduction facts
Offspring vary
2 parents, sex cells have one set of chromosomes, compared to two sets in a normal cell.
Gametes are produced by meiosis
77
What are gametes and how are they produced?
Sex cells
| Meiosis
78
Diploid cell
Have two sets of chromosomes (2n)
Ex. Snin, stomach, liver. Aka somatic cells.
46 chromosomes in humans
79
What are skin, stomach, and lover cells called
Somatic cells
80
How many chromosomes do diploid cells have in humans?
46
81
Haploid cells
Have one set of chromosomes (n)
Ex. Sperm & egg (gametes)
In humans haploid cells have 23 chromosomes.
82
What are gametes
Sex cells
83
How many chromosomes do haploid cells have in humans?
23
84
Difference between mitosis and meiosis
Mitosis has 1 cell division, meiosis has 2
In mitosis 1 cell produces 2 cells, oh meiosis one cell produces 4 cells
No pairing in mitosis, in meiosis chromosomes pair up in prophase I
No crossing over in mitosis, in meiosis crossing over occurs
In mitosis the number of chromosomes doesn't change, in meiosis chromosomes number is halved in anaphase I
Mitosis produces diploid cells, meiosis produces haploid cells
85
Sources of genetic variation
A) independent assortment
B) crossing over
C) random fertilization
86
Genetic variation: independent assortment
Picking 23 chromosomes from 46 in humans.
| In species with 3 chromosomes in gametes it gives 8 genetic combinations. Roughly 8 million combinations in humans.
87
How many genetic combinations of chromosomes in humans with independent assortment?
Roughly 8 million
88
Genetic variation: crossing over
Changes the combinations of genes that are inherited. May give thousands of different combinations.
89
Genetic combinations of crossing over?
Thousands.
90
Genetic variation: random fertilization
The sperm that fertilizes the egg is chosen at random. In a sperm with 3 genetically different gametes it gives 9 combinations. At least 70 trillion combinations in humans.
91
Random fertilization combinations
At least 70 trillion
92
What is genetics?
The study of inheritance
93
When were genetics first studied and by who?
In 1850-1870 by Gregor Mendel using peas.
94
When did mendels genetic factors prove to be DNA?
In 1952
95
What is DNA divided into?
Genes. Each gene has the code for making one protein
96
How many proteins can one gene make?
One.
97
How many genes does human DNA have?
About 25,000
98
Genes can be several alternative types called what?
Alleles
99
Alleles definition
Alternative forms of a gene
100
Examples of alleles
Allele B for brown hair or b for blond hair.
101
How many alleles do you inherit?
Two, one from each parent
102
Dominant alleles
Have an effect whether they have one copy or two. Ex BB or Bb are both brown hair
103
A recessive allele
Only has an effect if you inherit two copies
| Ex bb is blond hair
104
What is the genotype?
The genetic makeup of an individual
| Ex. Bb
105
What is the phenotype?
The physical appearance
| Ex. Brown hair
106
Geno- & phenotype chart
```
Genotype Phenotype
TT homozygous tall plant
Dominant
Tt heterozygous tall plant
tt Homozygous Short plant
Recessive
```
107
Mendel's law of genetics
Different characteristics are caused by different alleles
An organism inherits two alleles for each trait
Each gamete only contains one allele for each trait
In a heterozygous individual, only the dominant allele affects the trait
108
Monohybrid cross
Only one trait is studied
| Ex. Black/brown fur
109
Dihybrid cross
Two traits are studied
| Ex. Black/brown fur and short/long hair
110
Mendel's results table
Contains trait, dominant, and recessive gene
111
What is a test cross?
It is used to work out an unknown genotype (dominant phenotype)
112
How does a test cross work?
The unknown genotype is crossed with a homozygous recessive individual. If all the offspring have the dominant phenotype, the unknown parent must be homozygous dominant. If some of the offspring have the recessive phenotype the unknown parent must be heterozygous.
113
Dihybrid cross
Each trait is inherited independently. There are four possible phenotype in the offspring.
114
If two heterozygous individuals are crossed (BbSs) the result is a ratio of
9:3:3:1
Black, black, brown, brown
Short hair, long hair, short hair, long hair
115
What do Punnett squares do?
Work out the probability of getting a particular offspring
116
What happens if two heterozygous individuals breed?
3/4 of the offspring will have the dominant trait and 1/4 will have the recessive trait.
117
If two heterozygous people have children, what chance does the child have of being blond?
1/4 chance because brown hair is dominant
118
For a dihybrid cross
You multiply the probabilities together.
119
Hair type probabilities for children with heterozygous parents w/ brown & curly hair
Brown/curly: 3/4 x 3/4 = 9/16
Brown/straight: 3/4 x 1/4 = 3/16
Blond/ curly: 1/4 x 3/4 = 3/16
Blond/straight: 1/4 x 1/4 = 1/16
120
Incomplete dominance
Both alleles affect the phenotype. So homozygous dominant (red) looks different from heterozygous (pink)
Both alleles have capital letters
C^R (red), C^W (white)
121
If two heterozygous individuals are crossed the offspring ratio:
1 : 2: 1
Homo Hetero Homo
Dom (Pink) Recessi
(Red) (White)
122
Polygenetic inheritance
Trait is affected by several genes
There is a range of variation in the population
Offspring of heterozygous can be dif from either parent
Ex average sized parents have very tall child
123
A graph of the expected offspring from heterozygous parents follows
A normal distribution curve (bell curve)
| Ex. Skin color, height
124
Where are genes located?
On chromosomes
125
Different species have different
Numbers of chromosomes but about the same amount of DNA.
126
How many genes does a typical human chromosome have on it?
About 1000 genes.
127
Linked genes
Genes that are on the same chromosome. They tend to be inherited tighter.
128
How are linked genes separated?
By crossing over in prophase I, which gives different results from the Punnett square prediction
129
A genetic map
Gives the location of genes, obtained by working out the frequency of crossing over.
130
How much of a chromosome is genes?
About 10%, the rest has an unknown function, and was originally called junk DNA, but 2012 study showed that 80% is active.
131
What does the 80% of the chromosome that is not genes consist of?
Switches that turn genes on and off.
132
How many genetic switches may be in human DNA?
As many as 4 million
133
How many pairs of autosomal (non-sex) chromosomes do human cells have?
22
134
How many pairs of sex chromosomes do human cells have?
1
135
Male and female non-sex (autosomal) chromosomes are
The same
136
Sex chromosomes in females are
XX
137
Sex chromosomes in males are
XY
138
Which is larger, X or Y chromosomes?
X (over 1000 genes)
139
How many genes do X chromosomes have?
Over 1000
140
How many genes do Y chromosomes have?
Less than 80
141
Human birth rates:
52% male, 48% female.
142
Why are male birth rates slightly higher?
Because sperm carrying Y chromosomes are light and swim faster than ones with the X chromosome
143
Why do sex-linked diseases mainly effect men?
Because they are caused by recessive genes in the X chromosome. Women have two copies of the X, while men only have 1
144
Sex-linked diseases are usually passed on from
A carrier female to her son.
Ex. Color blindness (8% of men are colorblind, .5% of women)
Hemophilia (blood does not clot) queen Victoria was a carrier
145
Sex-linked diseases in women
Genotype
X^NX^N- Normal
X^NX^n- carrier
X^nX^n- disease
146
Sex-linked diseases in men
X^NY - normal
| X^nY - disease
147
What is the Barr body?
A condensed non-active C chromosome
148
Only one X chromosome is active in women, what happens to the other?
It condenses to form the Barr body on the edge of the nucleus.
149
The genes in the Barr body are
Inactive
150
Heterozygous females can have different X chromosomes active in different parts of the body
🐱
| Ex. Calico cat
151
What are Barr bodies used for?
Testing for gender in sporting events like the Olympics
152
Imprinted genes
Genes whose expression is determined by which parent contributed them.
153
What happens if two sperm or two eggs join?
The embryo will not survive
154
In mice, embryos with mainly the fathers genes have
Small heads and large bodies.
155
In mice embryos with mainly the mothers genes have
Small bodies and large heads.
156
In mice, male imprinted genes affect what and female imprinted genes affect
Male: lower parts of the brain (feeding, reproduction, emotions)
Female: the higher brain (thinking, memory)
157
How does the gender imprinted genes affect size of baby?
Male imprinted genes increase the size of babies, female reduce the size.
