Exam2 Flashcards
What is meiosis?
Cell division that leads to a halving of chromosome number and ultimately to the production of sperm and egg.
What are autosomes?
Non-sex chromosomes
What are pairs of chromosomes called?
homologous chromosomes are paired chomrosomes of similar size and shape. They also house the same genes
What is a karyotype?
The number and types of a chromosome present
What is the ploidy of organisms that have two sets of chromosomes?
2n
What information can be obtained from an individual’s karyotype?
The types of chromosomes present in the individual
The number of autosomes in the individual
The ploidy of the individual
If a cell has 24 chromosomes, how many chromosomes would each of its four daughter cells have after meiosis?
- Meiosis is a reduction division that reduces the number of chromosomes passed on to daughter cells by one-half.
What type of cell divides in meiosis II?
A haploid cell
How is Meiosis II similar to mitosis?
Both meiosis II and mitosis are cell divisions involving the separation of sister chromatids.
Which structure is directly correlated with the production of genetic variability in the daughter cells produced during meiosis?
Chiasma. The chiasma is an X-shaped structure formed from the crossing over of homologous chromosomes, which can then exchange segments at the crossover sites.
What are sister chromatids?
Two identical chromosomes connected at the centromere
Do replicated and unreplicated chromosomes contain the same number of chromosomes?
Yes, they do. While there are more copies of a given chromosome. The chromosomes are exactly the same, so the cell is considered to have the same number of chromosomes even after replication.
What is an autosome?
A non-sex chromosome
What does an unreplicated chromosomes look like?
A single strand of DNA
What does a replicated chromosome look like?
Two sister chromatids connected at the centromere
What is a tetrad?
Also called a bivalent. It is one pair of homologous chromosomes that are joined together during prophase I and metaphase I of meiosis.
What is the composition of a tetrad at the beginning of prophase I?
One pair of homologous chromosomes
What are chromatids?
They are replicated chromosomes. Only replicated chromosomes are referred to this way.
In the Na/K potassium pump what is pumped in and what is pumped out?
3 sodium out and 2 potassium in
What are the products of the light reaction?
ATP, NADPH
When does CO2 enter photosynthesis?
During the dark reactions or Calvin cycle
When the Na/K pumps are working what is the relationship of the charge on the inside verses the outside of the cell?
The charge is more negative inside
What is co-transport?
It is a combination of active transport and facilitated diffusion. Active transport is used to create a gradient. This gradient is then used to transport other molecules across the membrane via facilitated diffusion.
How do plants power co-transport?
H+ gradients.
How do animals power co-transport?
Na+ gradients
Describe the H+ sucrose co-tranport system.
The H+ pumps H+ out of the cell. This creates a high H+ gradient outside of the cell. This higher concentration gradient outside the cell allows for facilitated diffusion to power H+ and sucrose back into the cell.
Moreover, the active transport of H+ creates a concentration gradient that allows for facilitated diffusion of sucrose
What are ion channels?
Pores which selectively allow ions to enter the cell.
What are uniport channels?
Transport one substance in one direction
What are symport channels?
Transport two substances in one direction
What are antiport channels?
Transport two or more substances in opposite directions
What is the chloroplast? Describe its structure?
It is a highly structured membrane rich organelles. The innermost membrane of the chloroplast is called the thylakoid membrane. The thylakoid membrane is folded up upon itself forming many disks. These disks are called grand.
What is the space inside the thylakoid membrane called?
The thylakoid space.
What is the stoma?
The cytoplasm of the chloroplast
What is the goal of the light harvesting reactions?
To convert sunlight energy to the chemical energy of ATP and NADPH.
Where do the light harvesting reactions occur?
The thylakoids
What ranges of light are best absorbed by plant
Blue/violet and red
What colors are worst absorbed in photosynthesis?
Green/yellow
What is the goal of the light harvesting reactions
To trap light energy and store it as ATP and NADPH
Where do light harvesting reaction occur?
On the membranes of the thylakoids
Which photosystem absorbs the electron?
Photosystem II (P680)
What is photolysis?
The splitting off of H+ electrons from H2O. The H+ is kept inside the thylakoid space forming the proton gradient. The O2 is released and is the source of all of the Oxygen in our atmosphere.
What happens to the electrons from photosystem II?
They reach reach photosystem I (P700). Eventually it reduces NADP+ to NADPH
What happens to NADHP?
It is sort of an electron taxi. They are used in the Calvin cycle to reduce CO2 to make sugar
Where doe the O released in photosynthesis come from?
H2O
Do the light reactions requires CO2?
NO.
Describe what the light reactions do?
It produces O2 from H2O
What do the light independent reactions do?
They convert CO2 into sugars. These reactions are also called the Calvin Cycle
What is the Calvin Cycle?
It is the light independent reactions that turn CO2 into sugars
What are the three possibilities when a photon strikes and object?
It can be absorbed, transmitted or reflected.
What colors do green leaves reflect?
Green
What colors do green leaves absorb?
Red and blue
What colors to carotenoids absorb?
blue and green and they appear yellow, orange and red because that is what they reflect.
What color photons are most effective as absorbing photosynthesis?
Blue to violet and red
What is pumped into and out of the cell in Na/K pump?
3 Na out. 2 K in
What are the two configurations of the Na/K pump?
The Na+/K+ pump has two configurations, one which can bind to Na+ and the other which can bind to K+
What are the ways to change the configuration of the NA/K pump?
One way to change configuration of the Na+/K+ pump is to phosphorylate it with the phosphate group from ATP
Plants require CO2 from the atmosphere for photosynthesis. Do they also require O2?
B. Yes, plants perform aerobic respiration and, therefore, require O2.
About how long can the ATP reserves in your body be used to keep you alive?
Seven minutes
Which process produces the most ATP?
oxidative phosphorylation
What is the biological function of fermentation?
To reduce pyruvate, thus converting NADH to NAD+
How many of the four steps of aerobic respiration (glycolysis, oxidation of pyruvate, citric acid cycle, oxidative phosphorylation) actually produce ATP?
Three
When do sister chromatids separate during meiosis?
Anaphase II
During which stage of meiosis is a non-disjunction most like to occur in women?
Anaphase I
A fruit is a ripened
Ovary
Where does meiosis occur in a fern?
The sporangia
What is the function of a fruit?
To aid seed dispersal
Which grouping includes all of the vascular seed plants?
Angiosperms + conifers
You want to observe bee pollination in the field. You have two patches of flowers, one with larger red flowers and one with smaller blue flowers. Which patch is most likely to attract bees?
B. The patch with smaller blue flowers
Do fructose and glucose have identical metabolic pathways?
No
True or false?
You observe that a plant cell contains a chloroplast and can perform photosynthesis. This same cell will also contain a mitochondria and be able to perform aerobic respiration.
Everyone knows that plants have a net intake of CO2 and a net output of O2. What is molecular source of this O2 produced as a byproduct of photosynthesis?
H2O
n which state region would you expect to find the greatest concentration of C4 plants?
The grasslands of Kansas
True or false: The Rubisco enzyme in a C4 plant is the same as the Rubisco enzyme in a C3 plant.
True
Arrange the following colors of light in order of most readily absorbed by the chloroplast to least readily absorbed by the chloroplast.
Blue - Red - Green
How many molecules of CO2 must be input into the Calvin cycle to produce one molecule of glucose?
Six
Is photorespiration more common in C3 or C4 plants?
C3
What would you assume about a plant with Kranz anatomy?
It is a C4 plant
Do both photosynthesis and aerobic respiration utilize electron transport chains?
yes
Do both aerobic respiration and photosynthesis synthesize ATP through the generation of H+ gradients
Yes
Do both photosynthesis and aerobic respiration have a net production of ATP
Yes
Does photosynthesis consume Oxygen?
No
What is the effect of a high concentration of ATP on phosphofructokinase?
The enzyme will be allosterically modified and be temporarily turned off
Why would a muscle cell sometimes perform lactic acid fermentation if this fermentation produces so much less ATP and produces a poisonous byproduct?
Muscle cells under stress can be oxygen starved and must perform lactic acid fermentation to regenerate NAD+
What is the direct role of O2 in mitochondrial electron transport?
O2 functions as the final electron acceptor in the electron transport chain
How are ATP synthesized in glycolysis and the Krebs cycle?
Substrate-level phosphorylation
Which of the following processes produce NADH?
Glycolysis, Oxidation of Pyruvate, & Krebs Cycle
Is aerobic respiration endergonic or exergonic?
Exergonic
What is the main function of fermentation?
To oxidize NADH
During which stage of meiosis do homologous chromosomes separate?
Anaphase I
rocesses which increase genetic diversity in the daughter cells produced in meiosis occur during which stage(s)?
Prophase I and Metaphase I
I’m looking at a plant with distinct free-living sporophyte and gametophyte plants. The plant also has vascular tissue. This plant is a:
B. Fern (Pteridophyta)
I’m looking at another plant. This plant has vascular tissue and seeds. This plant is a:
Pine (Coniferophyta) or a Flowering plant (angiosperm)
Plants with naturally-occurring red flowers are typically pollinated by:
birds
In a moss, meiosis produces:
spores
What is pheophytin? What photosystem is it in?
It is the first electron acceptor in photosystem II.