Final exam BIOL1406 part2

In plants, photosynthesis takes place inside the

chloroplasts

A stack of flattened sacs or thylakoids in a chloroplast where electron transport chains exist are called:

granum

Joseph Priestly in 1971 performed the mint and candle experiment to prove that plants add something to the air. What was the name of the gas added to the air by plants in his experiment?

Oxygen

The splitting of water and the generation of oxygen occur in

Light dependent reactions

Calvin cycle fixes one carbon dioxide molecule in a cycle. In order to generate a sucrose (12 carbon molecule), the Calvin cycle has to turn how many times?

12

As electrons travel from the primary electron accepter in photosystem ll, down the electron transport chain to photosystem I, they drive the movement of protons from the stroma into the thylakoid compartment. Why is the development of this chemical gradient useful to photosynthesis?

the proton gradient drives the production of ATP by ATP Synthase, which is needed for the light-independent reactions

In photosynthesis, carbon fixation occurs:

Calvin Cycle

For photosynthesis in green plants, the electron donor in the light dependent reaction is:

water

During the light dependent reactions, light energy is absorbed by the pigments to excite the electrons in reaction centers. Which wavelengths of the light are absorbed by the chlorophyll-a the most?

400-450 & 650-700 nm.

Light consists of units of energy called

photons

ATP during photosynthetic electron transport chain is produced by the enzyme called

ATP synthase

NADP+ during the light reaction is reduced to NADPH by

NADP reductase

What products of light reactions of photosynthesis are used in the Calvin cycle?

ATP and NADPH

Most atmospheric oxygen comes from photosynthesis. From which of the following molecules is the oxygen derived during photosynthesis?

water

Plants that open the stomata during the night and close during the day are called:

CAM

Fall leaf color on deciduous trees is a result of:

disintegration of chlorophyll pigments, which allows the accessory pigments to be revealed

Porphyrin ring of a chlorophyll molecule has_______
at the center.

Mg

You are working on a research project that involves a mutational analysis of the light harvesting complex Lhca1, which is an important light harvesting complex found in plants.
Your lab-mate asks where this complex is located. You say:

It is in the thylakoid membrane

CAM and C4 plants likely grow in what type of environment?

Hot and arid

During photorespiration

RuBP reacts with oxygen

In bacterial cell division, the cell divides into two nearly equal halves, This process is referred to as:

binary fission

The accommodation of the very long DNA strands that are part of a chromosome into the limited space of the nucleus is achieved by coiling the DNA around beads of 8 histones into repeating subunits. These DNA-wrapped histones are called:

Nucleosomes

A pair of identical chromosomes (maternal and paternal) found in normal somatic (body) cells in an organism, throughout the cell cycle, are called:

homologous chromosomes

Before cell division of somatic cells, each chromosome must be replicated. After replication, the resulting two parts of each chromosome are held together by cohesin at the centromere. These two parts are referred to as:

sister chromatids

If there are 92 sister chromatids in prophase-l in a cell undergoing meiosis, how many chromosomes each cell will have after telophase-ll (in gametes)?

23

What is the sequence of events in a typical eukaryotic cell cycle?

G1 to S to G2 to mitosis to cytokinesis

A duplicate copy of all of the hereditary information (DNA) contained in the nucleus of eukaryotic cells is made during what stage of the cell cycle?

S

If a cell has 32 chromosomes prior to S and undergoes mitosis followed by cytokinesis, each new daughter cell will have how many chromosomes?

32

The stage of mitosis characterized by the physical separation of sister chromatids is called:

anaphase

This stage of mitosis is characterized by the disassembly of spindle apparatus, and the restablishment of the nuclear membrane, and the decondensation of the chromosomes:

Telophase

During this stage of moles, the homologous chromosome separate and move to the
opposite poles.

Anaphase 1

Animal cells typically achieve cytokinesis by:

forming a cleavage furrow that pinches the cell in two

During mammalian sexual life cycle an egg and a sperm, each containing half the complement of chromosomes found in somatic cells, fuse to produce a single cell called a(n)

Zygote

Human sperm cells produced by meiosis are

haploid

In life cycles that alternate between haploid and diploid stages, fertilization doubles the number of chromosomes per cell while________
reduces it in half.

Meiosis

Compared to asexual reproduction, the main advantage of sexual reproduction is that it

increases the genetic diversity of the offspring

The fusion of a male gamete with a female gamele is called

Fertilization

Chromosomes exchange genetic information by

crossing over

The pairing of homologous chromosomes is called

synapsis

Which structures indicate where crossing over has occurred?

chiasmata

You are studying meiosis in an organism where 2n=24. How many chromosomes will each nucleus have after meiosis Il is complete?

12

Which of the following statements about crossing over is FALSE?

Crossing over takes place between sister chromatids.

Sister chromatids are separated during which phase of the meiosis?

anaphase II

As an error in meiosis, a human sperm may carry 22 chromosomes. This condition is

Aneuploid gametes

Which of the following is NOT true about meiosis cell division:

It produces two daughter cells after meiosis lI

Ovaries in a fertile female produce an egg every month. As you know, egg cells are the products of meiosis cell division. How many chromosomes do you expect in an egg cell produced in a woman?

23

The point of constriction on chromosomes that contains certain repeated DNA sequences that bind specific proteins such as kinetochore and cohesin protein is called:

centromere

In modern terminology, Mendel's heredity "factors" are called

genes

The observable expression such as hair color, height, blood types, etc. of human is called their

phenotype

The Principle of _____ states that the 2 alleles present at each gene locus separate from one another during gamete formation and remain distinct.

segregation

A diploid organism that has two identical alleles for a given trait is called _____ for that trait

homozygous

Human blood type is determined by three alleles, I^A I^B and i, ABO blood grouping in human is an example of

multiple allele

During his experiments with pea plants, Mendel referred to the trait that was expressed in the Fl or first filial generation as

Dominant

In Mendel's experiments on seed color in pea plants, when a homozygous yellow seed-bearing plant was crossed with a homozygous green seed-bearing plant, he observed all yellow seed bearing plants in F, generation. He then self-fertilized F, plants. What was the approximate phenotypic ratio among the F2 generation?

3 yellow: 1 green

You were trying to find the genotypes of unknown pea seeds for the height. After you grow one of the seeds you found it is tall but you still did not know if it was heterozygous or homozygous tall. You performed a test cross for that plant with a short parent (homozygous recessive) plant and you confirmed the plant is heterozygous by observing ______ ratio of tall:short.

1:1

Let P = purple flowers and p = white, and T = tall plants and t = dwarf. If the upper case letters represent the
dominant alleles, what is the phenotype of a plant with the genotype PpTt?

purple flowers, tall

In a dihybrid cross, you crossed a genotype TtRr with genotype TtRr plant. What is the probability of getting
TTRR offspring?

1/16

11. A person who has lost a large amount of blood but is still alive is found in a wrecked automobile under a highway bridge. Several people are helping the paramedics load the victim into the ambulance. After the ambulance has departed for the hospital, you overhear the following conversation from the persons who helped the paramedics.
"I am certain that when that guy gets to the hospital, they will transfuse him with any blood that they have in the blood bank since he has lost so much blood." The other person says, "Yeah, I bet you're right!" Having had a biology course, what might be the victim's blood type who can receive any blood?

AB

In a cross between pea plants that are heterozygous for purple flower color (Pp), what is the probability of the offspring being a homozygous white (pp)?

1/4

If both parents have AB blood type, what is the probability of their first child's blood type being O?

0%

Let R = red pigment and r = no pigment. In carnations, RR offspring make a lot of red pigment, ir offspring make
no pigment and Rr offspring make a small amount of red pigment, thus appearing pink. Pink carnations are therefore an example of

Incomplete dominance

In the cross shown on the right, round seeds are RR and wrinkled seeds are rr for Parents (P). What is the phenotype and genotype of the F, offspring?

Round; Rr

Mendel used the garden pea plant for his studies on inheritance because .

- it can be self or cross fertilized.
- it is small and easy to grow.
- there were many varieties of pea plants available.

Nucleotides are monomers of nucleic acids. Nucleotides have a phosphate group attached at the carbon atom of the sugar.

5'

Watson and Crick developed a model of DNA in which the two strands twist into the shape of a

double helix

DNA consists of two antiparallel strands of nucleotides held together by

hydrogen bonds

The chemical bond connecting one nucleotide to the next along one strand of a DNA molecule is called a

phosphodiester bond

Chargaff's rules for the pairing of nitrogen bases in DNA is

A = T and G = C

If 15% of the nucleotides from a DNA molecule contain the base T, what percent will contain the base G?

35%

If one strand of DNA is 5' AATTGAGT 3', its complement strand is

3' TTAACTCA 5'.

During DNA replication, DNA polymerase III synthesizes the lagging strand in segments, these segments are called

Okazaki fragments

Who provided X-ray diffraction photographs of purified DNA fibers that suggested a helical structure with a consistent diameter of about 2 nm and a complete helical turn every 3.4 nm?

Franklin

You decide to repeat the Meselson-Stahl experiment, except this time you plan to grow the cells in light 14N medium for many generations and then transfer them to heavy 15N medium and allow them to grow for 2 additional generations (2 rounds of DNA replication) and analyzed the DNA running in gel. If the SEMICONSERVATIVE model of DNA replication is correct, what is the expected distribution of DNA in the density gradient after ONE round of replication?

One band of intermediate density

Genetic analysis indicates that you have a gene that codes for a defective form of photolyase. This puts you at increased risk for developing

skin cancer

Gene expression involves two phases,____ and translation

transcription

During______, a ribosome assembles a polypeptide whose amino acid sequence is specified by the nucleotide sequence in a molecule of mRNA.

Translation

During transcription of mRNA in eukaryotes, some sequences are cut out of the primary mRNA transcript and the remaining sequences are joined together. This modification of mRNA is called

splicing

An enzyme that synthesize mRNA is

RNA polymerase II

During translation, amino acids are carried to the ribosome by

tRNA

Which base in an anticodon of tRNA will pair with the base adenine in a codon on mRNA?

Uracil

A codon is composed of how many bases?

3

In eukaryotes, transcription takes place

inside the nucleus

Which of the following codons codes for a Methionine and also as a start codon?

AUG

If the bases on the template strand of DNA read ACTGAC, what codes will be copied on mRNA during

UGACUG

Codons that serve as "stop" signals for translation are recognized by

release factors

Eukaryotic mRNA molecules may contain non-coding sequences that must be removed before translation. These are called

introns

During translation, an empty tRNA molecule leaves the ribosome after it is attached to the ______ site.

E

The Central Dogma of biology can be stated as

DNA→ RNA→ proteins.

The template strand of a DNA segment that codes for mRNA has the sequence: ATGCGT. Which tRNA anticodons would pair with the mRNA that is coded for by this sequence?

AUG CGU

Eukaryotes have ___ types of RNA polymerase

three

During protein synthesis in eukaryotes, which molecule passes from the nucleus to the cytoplasm and specifies the sequence of amino acids in the new polypeptide?

mRNA

The type of point mutation responsible for Sickle cell anemia disease is a

missense mutation

Mutation may be good for an organism if

mutated gene makes a trait that adapts an organism in changing environment