TEST THREE SAPLING
In a hypothetical mouse species, brown fur (B) is completely dominant to white fur (b), and long fur (L) is completely dominant to short fur (l). If two mice heterozygous for both traits mate and produce a litter of pups, what is the probability that an individual pup will have brown, long fur? - 1/16 - 9/16 - 3/4 - 1/2 - 3/16
- 9/16
In certain breeds of chickens, black feathers (CB ) are codominant with white feathers (CW ). What is the genotype of a chicken of this breed with black feathers? - CBCB or CBCW - CWCW - CBCW - CBCB
- CBCB
Which describes a locus? - the number of alleles for a gene - the specific sequence of a gene - the specific position of a gene on a chromosome - the linkage of one gene to a nearby gene
- the specific position of a gene on a chromosome
What is visible light? - the blend of all the wavelengths of radiation in the electromagnetic spectrum - the ultraviolet and infrared wavelengths in the electromagnetic spectrum of radiation - the wavelengths of electromagnetic radiation living organisms most often use - the segment of the electromagnetic spectrum that cannot be used for photosynthesis
- the wavelengths of electromagnetic radiation living organisms most often use
Cell division by mitosis is a mechanism of asexual cell replication. Some single‑celled organisms reproduce by cell division, and cell division enables multicellular organisms to grow and to repair damaged cells. Which is a product of cell division by mitosis? - cells that have different forms of the same gene - four genetically similar daughter cells - two cells genetically identical to the original cell - daughter cells with half the number of chromosomes
- two cells genetically identical to the original cell
Arrange the events of the light‑dependent reactions of photosynthesis in the order that they occur. - H+ ions flow out of the thylakoid through an enzyme channel - hydrogen ions are pumped into the interior of the thylakoid - photons of light excite electrons on specific chlorophyll molecules - ATP and NADH are produced - chlorophyll molecules release electrons that travel down an electron transport chain
1) photons of light excite electrons on specific chlorophyll molecules 2) chlorophyll molecules release electrons that travel down an electron transport chain 3) hydrogen ions are pumped into the interior of the thylakoid 4) H+ ions flow out of the thylakoid through an enzyme channel 5) ATP and NADH are produced
Classify each description as applying to either autotrophs or heterotrophs. - use inorganic materials to produce energy - many use photosynthesis to produce organic compounds - producers - depend on other organisms for energy - synthesize their own food - unable to produce organic compounds from inorganic materials - obtain their food by consuming other organisms - consumers
AUTOTROPHS: - producers - many use photosynthesis to produce organic compounds - use inorganic materials to produce energy - synthesize their own food HETEROTROPHS: - consumers - unable to produce organic compounds from inorganic materials - obtain their food by consuming other organisms - depend on other organisms for energy
Zygote, gamete, and fertilization are key terms associated with sexual reproduction. Identify the definitions and examples of these three key terms. - sperm cell - a fertilized egg cell - diploid cell resulting from fertilization - a process fusing the nuclei of two gametes - haploid cell Zygote: Gamete: Fertilization:
Zygote: - diploid cell resulting from fertilization - a fertilized egg cell Gamete: - haploid cell - sperm cell Fertilization: -a process fusing the nuclei of two gametes
What is needed for the light‑dependent reactions of photosynthesis to take place? What is produced during the light‑dependent reactions? Not all of the answer choices will be placed. - energy-rich ATP and NADH - H2O molecules - chlorophyll - light energy - carbon dioxide
needed for light-dependent reactions: - light energy - H2O molecules - chlorophyll produced by light-dependent reactions: - energy-rich ATP and NADH
Which of the statements can be concluded from Gregor Mendel's experiments with pea plants? - A heterozygous phenotype is the same as a homozygous dominant phenotype. - The inheritance of alleles of one gene does not affect the inheritance of alleles of another gene. - The pair of alleles for each gene stay together during gamete production. - Parents with dominant phenotypes always have offspring with dominant phenotypes.
- A heterozygous phenotype is the same as a homozygous dominant phenotype. - The inheritance of alleles of one gene does not affect the inheritance of alleles of another gene.
What happens during anaphase I of meiosis? - Homologous chromosomes separate, but sister chromatids remain joined at their centromeres. - The nuclear membrane begins to form around haploid sets of chromosomes. - Homologous chromosomes form, and crossing over occurs between them. - Sister chromatids are distributed in a single layer across the center of the cell. - Homologous chromosomes are randomly arranged in the middle of the cell. - Sister chromatids separate from each other and migrate to opposite ends of the cell.
- Homologous chromosomes separate, but sister chromatids remain joined at their centromeres.
In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (A) is dominant over albinism (a). For this question, assume the phenotype is determined by a single gene with two alleles. If two people have normal pigmentation, what possible phenotypes may be observed in their offspring? - marbling of albino and normal pigmentation - normal pigmentation only - normal pigmentation or albinism - albinism only
- normal pigmentation or albinism
Which statements describe the light‑dependent reactions of photosynthesis, which describe the Calvin cycle (light‑independent reactions of photosynthesis), and which describe both? - synthesize ATP and NADPH - require water - use CO2 - happen inside chloroplasts in plants - produce sugars - generate oxygen gas - use chlorophyll to capture light energy - need ribulose bisphosphate Light‑dependent reactions: Calvin cycle: Both the light‑dependent reactions and the Calvin cycle:
Light‑dependent reactions: - require water - use chlorophyll to capture light energy - synthesize ATP and NADPH - generate oxygen gas Calvin cycle: - use CO2 - produce sugars - need ribulose bisphosphate Both the light‑dependent reactions and the Calvin cycle: - happen inside chloroplasts in plants
In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (A) is dominant over albino characteristics (a) . For this question, assume the phenotype is determined by a single gene with two alleles. If both parents have normal pigmentation, what are all of the possible genotypes that may be observed in their offspring? - AA, Aa, or aa - AA or Aa only - Aa only -aa only
- AA, Aa, or aa
Through a series of experiments on pea plants, Gregor Mendel observed that some traits followed particular rules of inheritance. Which of the statements are true about Mendelian inheritance? (multiple answers) - Alleles on separate chromosomes are always inherited together. - An organism with a Bb genotype will express the phenotype coded by the B allele. - An organism's set of genes is called a phenotype. - Offspring inherit one allele from each parent.
- An organism with a Bb genotype will express the phenotype coded by the B allele. - Offspring inherit one allele from each parent.
What is the difference between asexual reproduction and sexual reproduction? - Asexual reproduction produces genetically identical offspring, whereas sexual reproduction produces offspring that are genetically different from each other and from their parents. - Asexual reproduction produces genetically unique offspring, whereas sexual reproduction produces offspring that are genetically identical to each other and identical to their parents. - Asexual reproduction occurs only in prokaryotic organisms, whereas sexual reproduction occurs only in eukaryotic organisms. - Asexual reproduction involves both cell replication and fertilization, whereas sexual reproduction includes only cell replication.
- Asexual reproduction produces genetically identical offspring, whereas sexual reproduction produces offspring that are genetically different from each other and from their parents.
How did Mendel use self‑pollination and cross‑pollination techniques in his experiments with flower color to observe the basic patterns of inheritance? - By allowing a parental generation of plants to self‑pollinate and cross‑pollinating the F1 generation, Mendel observed the basic patterns of inheritance in the F2 generation. - By cross‑pollinating a parental generation of plants with different colored flowers, Mendel was able to observe the basic patterns of inheritance in the F1 generation. - By cross‑pollinating a parental generation of plants with different‑colored flowers and allowing the F1 generation to self‑pollinate, Mendel observed the basic patterns of inheritance in the F2 generation. - By cross‑pollinating a parental generation of plants with same‑colored flowers and allowing the F1 generation to self‑pollinate, Mendel observed the basic patterns of inheritance in the F2 generation.
- By cross‑pollinating a parental generation of plants with different‑colored flowers and allowing the F1 generation to self‑pollinate, Mendel observed the basic patterns of inheritance in the F2 generation.
In a particular species of octopus, long arm length is completely dominant over short arm length. If an octopus of this species has long arms, what is its genotype? - dd - DD or Dd - DD only - D
- DD or Dd
In meiosis, a diploid cell divides into reproductive cells called gametes. The provided diagram shows chromosome separation during gamete production. Using the diagram, select the statements that are true about Mendel's law of segregation. (multiple answers) - Each parent provides one allele for each gene. - Both chromosomes in a pair are identical. - All gametes carry the same alleles. - Each gamete carries one version of each gene.
- Each parent provides one allele for each gene - Each gamete carries one version of each gene.
Choose all the events that occur during the light‑dependent reactions of photosynthesis. (multiple answers) - Energy from ATP and NADPH is incorporated into carbohydrate molecules. - Excited electrons help move H+ ions to create a concentration gradient. - H+ ions are used to help produce the energy carriers, ATP and NADPH. - Light energy is used to excite electrons on specific chlorophyll molecules.
- Excited electrons help move H+ ions to create a concentration gradient. - H+ ions are used to help produce the energy carriers, ATP and NADPH. - Light energy is used to excite electrons on specific chlorophyll molecules.
In fruit flies, gray bodies (G) are dominant over black bodies (g), and red eyes (R) are dominant over orange eyes (r). Each individual possesses two alleles for each trait. If a fly that is homozygous dominant for both traits is crossed with a fly that is homozygous recessive for both traits, what is the predicted genotype of the offspring? - black bodies and orange eyes - GgRr, ggRr, Ggrr, and ggrr - gray bodies and red eyes - GgRr - GGRR
- GgRr
Which of the statements about incomplete dominance are true? - Heterozygous individuals have the same phenotype as homozygous dominant individuals. - Heterozygous individuals have a phenotype intermediate to the homozygous dominant and homozygous recessive phenotypes. - If homozygous dominant mice have black fur, and homozygous recessive mice have white fur, then heterozygous mice have gray fur. - Heterozygous individuals express both the homozygous dominant and homozygous recessive phenotypes.
- Heterozygous individuals have a phenotype intermediate to the homozygous dominant and homozygous recessive phenotypes. - If homozygous dominant mice have black fur, and homozygous recessive mice have white fur, then heterozygous mice have gray fur.
What happens during metaphase I of meiosis? - The nuclear membrane begins to form around haploid sets of chromosomes. - Homologous chromosomes separate, but sister chromatids remain joined at their centromeres. - Sister chromatids separate from each other and migrate to opposite ends of the cell. - Sister chromatids are distributed in a single layer across the center of the cell. - Homologous chromosomes are randomly arranged in the middle of the cell. - Homologous chromosomes form, and crossing over occurs between them.
- Homologous chromosomes are randomly arranged in the middle of the cell.
What happens during prophase I of meiosis? - Sister chromatids separate from each other and migrate to opposite ends of the cell. - Homologous chromosomes separate, but sister chromatids remain joined at their centromeres. - Sister chromatids are distributed in a single layer across the center of the cell. - Homologous chromosomes form, and crossing over occurs between them. - The nuclear membrane begins to form around haploid sets of chromosomes. - Homologous chromosomes are randomly arranged in the middle of the cell.
- Homologous chromosomes form, and crossing over occurs between them.
Consider what happens to energy in photosynthesis. How does this differ from what happens to energy in cellular respiration? - Photosynthesis releases energy from storage molecules, whereas cellular respiration puts energy from light into these molecules. - Plants create energy using carbon dioxide and water in photosynthesis, whereas they gather extra energy from light during cellular respiration. - In photosynthesis, energy is captured from light, whereas in cellular respiration energy is transferred from storage molecules to ATP. - Energy is stored in both processes, but photosynthesis only happens in plants and cellular respiration only happens in animals.
- In photosynthesis, energy is captured from light, whereas in cellular respiration energy is transferred from storage molecules to ATP.
What happens during metaphase II of meiosis? - The nuclear membrane begins to form around haploid sets of chromosomes. - Homologous chromosomes separate, but sister chromatids remain joined at their centromeres. - Homologous chromosomes form, and crossing over occurs between them. - Sister chromatids are distributed in a single layer across the center of the cell. - Homologous chromosomes are randomly arranged in the middle of the cell. - Sister chromatids separate from each other and migrate to opposite ends of the cell.
- Sister chromatids are distributed in a single layer across the center of the cell.
What happens during anaphase II of meiosis? - The nuclear membrane begins to form around haploid sets of chromosomes. - Homologous chromosomes separate, but sister chromatids remain joined at their centromeres. - Homologous chromosomes are randomly arranged in the middle of the cell. - Homologous chromosomes form, and crossing over occurs between them. - Sister chromatids are distributed in a single layer across the center of the cell. - Sister chromatids separate from each other and migrate to opposite ends of the cell.
- Sister chromatids separate from each other and migrate to opposite ends of the cell.
In a species of flowers, having long thorns (TT) is incompletely dominant over not having thorns (TN) . What is the genotype of a flower of this species that has short, stubby thorns? - TTTT - TTTN - TNTN - TTTT or TNTN
- TTTN
Which statement accurately describes the Calvin cycle? - The Calvin cycle is the metabolic pathway during which pyruvate, derived from glucose, is completely broken down to carbon dioxide and water. - The Calvin cycle is a light‑dependent metabolic pathway occurring in the chloroplast thylakoid membrane that captures energy from sunlight with chlorophyll and converts it to ATP. - The Calvin cycle is a light‑independent metabolic pathway occurring in the chloroplast stroma that converts carbon from carbon dioxide into sugar. - The Calvin cycle is an anaerobic metabolic pathway of ATP formation during which glucose is converted to alcohol and two net ATP molecules.
- The Calvin cycle is a light‑independent metabolic pathway occurring in the chloroplast stroma that converts carbon from carbon dioxide into sugar.
Which of the given scenarios is a direct effect of the absence of carbon dioxide during photosynthesis? - The regeneration phase of the Calvin cycle would be unable to replenish the sugar RuBP. - The photosystem of the light‑dependent reactions would be unable to capture the energy from photons. - The electron transport chain of the light‑dependent reactions would be unable to synthesize ATP. - The carbon fixation stage of the Calvin cycle would be unable to synthesize the sugar 3‑PGA.
- The carbon fixation stage of the Calvin cycle would be unable to synthesize the sugar 3‑PGA.
What happens during telophase II of meiosis? - Sister chromatids separate from each other and migrate to opposite ends of the cell. - The nuclear membrane begins to form around haploid sets of chromosomes. - Homologous chromosomes form, and crossing over occurs between them. - Sister chromatids are distributed in a single layer across the center of the cell. - Homologous chromosomes separate, but sister chromatids remain joined at their centromeres. - Homologous chromosomes are randomly arranged in the middle of the cell.
- The nuclear membrane begins to form around haploid sets of chromosomes.
Select the descriptions that apply to the thylakoid. (multiple answers) - Thylakoids are arranged within the chloroplast into numerous membrane folds called cristae. - The thylakoid membrane is the site of the light‑dependent reactions of photosynthesis. - The thylakoid membrane is the site of the light‑independent reactions of photosynthesis. - Thylakoids are arranged within the chloroplast into stacks of coin‑shaped discs called grana. - The thylakoid membrane is the site of an electron transport chain that generates cellular energy from biochemical energy. - The thylakoid membrane is the site of an electron transport chain that generates cellular energy from light energy.
- The thylakoid membrane is the site of the light‑dependent reactions of photosynthesis. - Thylakoids are arranged within the chloroplast into stacks of coin‑shaped discs called grana. - The thylakoid membrane is the site of an electron transport chain that generates cellular energy from light energy.
Which statement describes the function of photosynthetic pigments in leaves? - They sequester nutrients in the leaves of green food plants. - They convert energy from sunlight to energy in simple sugars. - They allow carbon dioxide to enter the cell through the stomata. - They absorb light energy and trap high energy electrons. - They block light from sensitive energy‑generating areas of the cell.
- They absorb light energy and trap high energy electrons.
How is a true breeding yellow‑seeded pea plant different from a hybrid yellow‑seeded pea plant? - They have a different genotype and phenotype. - They have the same genotype but different phenotypes. - They have the same genotype and phenotype. - They have the same phenotype but different genotypes.
- They have the same phenotype but different genotypes.
Which statement describes a gene? - the pair of DNA sequences an organism has for a trait - a section of DNA in which the code for a protein is located - one variation of the code for a protein - the physical trait produced by an organism's genetic makeup
- a section of DNA in which the code for a protein is located
In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (A) is dominant over albino characteristics (a) . For this question, assume the phenotype is determined by a single gene with two alleles. If both parents display the albino phenotype, what are all of the possible genotypes that may be observed in their offspring? - AA only - AA and Aa - AA, Aa, and aa - aa only
- aa only
In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (A) is dominant over albinism (a). For this question, assume it is a single gene with two alleles. If both parents display the albino phenotype, what possible phenotypes may be observed in their offspring? - normal pigmentation only - normal pigmentation or albinism - albinism only - marbling of albino and normal pigmentation
- albinism only
During which phase of mitosis do spindle fibers shorten, pulling sister chromatids apart from one another and toward opposite ends of the cell? - telophase - metaphase - anaphase - cytokinesis - prophase
- anaphase
Which statement describes dominant alleles? - two alleles that blend to create an intermediate phenotype - any allele whose presence can be masked by another allele - any allele that can hide the presence of a different allele - two alleles that are expressed separately and equally
- any allele that can hide the presence of a different allele
Which statement describes recessive alleles? - two alleles that are expressed separately and equally - two alleles that blend to create an intermediate phenotype - any allele that can hide the presence of a different allele - any allele whose presence can be masked by another allele
- any allele whose presence can be masked by another allele
During one of the three phases of the Calvin cycle, the carbon atoms from three CO2 molecules are incorporated into three five‑carbon sugar molecules called ribulose bisphosphate (RuBP). This reaction forms an unstable six‑carbon intermediate which immediately splits into two three‑carbon sugar molecules called 3‑phosphoglyceric acid (3PGA). In which phase of the Calvin cycle does this occur? - reduction - carbon fixation - regeneration - light‑dependent reactions
- carbon fixation
As genetic material replicates, sister chromatids are linked in an X‑shaped structure. What is the term used to describe the area where the two chromatids are linked? - centrosome - centromere - centriole - chromatin
- centromere
Sickle‑cell anemia is a disease that affects the type of hemoglobin (Hb) a person makes in his or her red blood cells. Consider the case of Martin and Cindy, who are the parents of Mary. Martin has sickle‑cell anemia with abnormal hemoglobin, and his genotype is HbS/HbS. Cindy has normal hemoglobin, and her genotype is HbA/HbA. Their child Mary carries the sickle‑cell trait and produces both normal hemoglobin and abnormal hemoglobin. Mary's genotype is HbS/HbA. What type of dominance pattern would result in Mary's blood producing both normal and abnormal hemoglobin? - complete dominance - incomplete dominance - codominance - pseudodominance
- codominance
During which phase of mitosis does the cytoplasm of a cell divide, fully separating the two daughter cells? - metaphase - telophase - anaphase - prophase - cytokinesis
- cytokinesis
Which statements describe crossing over? (multiple answers) - increases genetic variation across gametes - occurs between homologous chromosomes - separates chromosome pairs into gametes - occurs between duplicated sister chromatids
- increases genetic variation across gametes - occurs between homologous chromosomes
During which phase of mitosis do chromosomes line up along the middle of a cell? - telophase - prophase - anaphase - cytokinesis - metaphase
- metaphase
Which statement describes an allele? - the physical trait produced by an organism's genetic makeup - a section of DNA in which the code for a protein is located - one variation of the code for a protein - the pair of DNA sequences an organism has for a trait
- one variation of the code for a protein
Plants synthesize their own food in the form of sugars during the process of photosynthesis. Which of the statements describe photosynthesis? (multiple answers) - is a cellular process that occurs in the mitochondria of plant cells - produces sugars for the plant using only the nutrients in soil - produces sugars for the plant using the energy from sunlight - uses sugars to generate cellular energy, releasing carbon dioxide - is a cellular process that occurs in the chloroplasts of plant cells - converts carbon dioxide to sugars, releasing oxygen
- produces sugars for the plant using the energy from sunlight - is a cellular process that occurs in the chloroplasts of plant cells - converts carbon dioxide to sugars, releasing oxygen
During which phase of mitosis does chromatin condense into chromosomes as the nuclear membrane breaks down? - anaphase - metaphase - cytokinesis - telophase - prophase
- prophase
During one of the three phases of the Calvin cycle, six molecules of ATP and six molecules of NADPH transfer electrons to six three‑carbon sugars known as 3‑phosphoglyceric acid (3PGA). The transfer of electrons transforms the six 3PGA molecules into six molecules of a three‑carbon sugar called glyceraldehyde‑3‑phosphate (G3P). In which phase of the Calvin cycle does this occur? - carbon fixation - light‑dependent reactions - regeneration - reduction
- reduction
During one of the three phases of the Calvin cycle, three molecules of ATP are used to catalyze the rearrangement of five three‑carbon sugars, known as glyceraldehyde 3‑phosphate (G3P), into three five‑carbon sugars, known as ribulose bisphosphate (RuBP). One other molecule of G3P is exported to the cytoplasm to form glucose. In which phase of the Calvin cycle does this occur? - reduction - regeneration - light‑dependent reactions - carbon fixation
- regeneration
What is the function of the mitotic spindle? - replicating chromosomes - keeping sister chromatids connected - separating sister chromatids - pinching a cell into two daughter cells
- separating sister chromatids
In pea plants, the genes for plant height and flower color are located on different chromosomes and assort independently of one another. Consider that T=tall, t=short, P=purple flowers, and p=white flowers.According to the law of independent assortment, what are all the possible phenotypes for offspring of a self‑pollinated pea plant with a genotype of TtPp? - medium height with light purple flowers - only tall with purple flowers - tall with purple flowers, tall with white flowers, short with purple flowers, short with white flowers - tall with purple flowers and short with white flowers
- tall with purple flowers, tall with white flowers, short with purple flowers, short with white flowers
During which phase of mitosis do nuclear membranes reform around the separated copies of DNA? - prophase - cytokinesis - telophase - anaphase - metaphase
- telophase
Which phrase describes a sister chromatid? - the exact copy of a single chromosome - the second, noncoding strand of double‑stranded DNA - RNA that is copied directly from the original DNA template - the second copy of a homologous chromosome
- the exact copy of a single chromosome
Diploid organisms, such as humans and other mammals, have two copies of their genetic material in the form of homologous chromosomes. One copy of each homologous chromosome is passed to the organism from each of its parents during the process of fertilization. For many genetic traits, a diploid organism is said to be either homozygous or heterozygous at a particular locus, depending on whether its parents passed down two of the same or two different alleles for that specific sequence. Which describes a heterozygous locus? (multiple answers) - the presence of only a single allele for a particular trait in the gene pool - two different alleles are found in a particular position on homologous chromosomes - the alleles at a particular position on homologous chromosomes of an individual with two true‑breeding parents for different alleles two alleles that are positioned on the same chromosome - the alleles at a particular position on homologous chromosomes of an individual who expresses a recessive trait
- two different alleles are found in a particular position on homologous chromosomes - the alleles at a particular position on homologous chromosomes of an individual with two true‑breeding parents for different alleles two alleles that are positioned on the same chromosome
During the light‑dependent reactions of photosynthesis, energy excites electrons in chlorophyll molecules, transforming the energy into chemical energy. What provides the energy that excites the electrons in the chlorophyll molecules? - NADPH - carbon dioxide - light - H2O What is the source of the electrons that replace the excited electrons lost from chlorophyll? - light - H2O - carbon dioxide - NADPH
1)- light 2)- H2O
Place the steps of the prokaryotic cell cycle in order. - two genetically identical daughter cells are produced - plasma membrane and cell wall grow inward and divide the cell - prokaryotic chromosome replicates - prokaryotic chromosome attaches to the plasma membrane - cell elongates, pulling each chromosome to a different end of the cell
1)- prokaryotic chromosome attaches to the plasma membrane 2)- prokaryotic chromosome replicates 3)- cell elongates, pulling each chromosome to a different end of the cell 4)- plasma membrane and cell wall grow inward and divide the cell 5)- two genetically identical daughter cells are produced
Classify each of the characteristics as describing animal cell cytokinesis or plant cell cytokinesis. - Cleavage produces a furrow around the cell. - A cell wall forms between daughter cells. - A contractile ring pinches the cell in two. - Vesicles fuse to form a cell plate. Animal cell cytokinesis: Plant cell cytokinesis:
Animal cell cytokinesis: - A contractile ring pinches the cell in two. - Cleavage produces a furrow around the cell. Plant cell cytokinesis: - A cell wall forms between daughter cells. - Vesicles fuse to form a cell plate.
The dominance pattern of a gene can be determined from the phenotypes of the parents and offspring. In the examples below, assume that each parent is homozygous for the specific allele and that the progeny are heterozygous. Classify each example as either complete dominance, incomplete dominance, or codominance. - A pea plant with smooth seeds and a pea plant with wrinkled seeds produce a pea plant with smooth seeds. - A mother with type A blood and a father with type B blood have a daughter with type AB blood. - A red snapdragon and a white snapdragon produce a pink snapdragon. - A white cow and a red bull have a calf that is white with red spots (roan colored). - A moth with red wings and a moth with yellow wings produce a moth with orange wings. Complete dominance: Incomplete dominance: Codominance:
Complete dominance: - A pea plant with smooth seeds and a pea plant with wrinkled seeds produce a pea plant with smooth seeds. Incomplete dominance: - A red snapdragon and a white snapdragon produce a pink snapdragon. - A moth with red wings and a moth with yellow wings produce a moth with orange wings. Codominance: - A mother with type A blood and a father with type B blood have a daughter with type AB blood. - A white cow and a red bull have a calf that is white with red spots (roan colored).
Cell division can occur by either of two distinct processes, mitosis or meiosis. However, each process has a unique function. Determine whether each phrase describes mitosis, meiosis, or both. Place each phrase in the correct category. - used for asexual reproduction - forms four haploid gametes - contributes to genetic diversity through crossing over - results in two diploid cells identical to the parent cell - duplication of chromosomes occurs before cell division Mitosis: Both mitosis and meiosis: Meiosis:
Mitosis: - results in two diploid cells identical to the parent cell - used for asexual reproduction Both mitosis and meiosis: - duplication of chromosomes occurs before cell division Meiosis: - forms four haploid gametes - contributes to genetic diversity through crossing over
Both mitosis and meiosis begin with a single diploid cell, but their end products are different. What are the end results of mitosis and meiosis? - haploid cells - two identical cells - four different cells - diploid cells Mitosis: Meiosis:
Mitosis: - two identical cells - diploid cells Meiosis: - four different cells - haploid cells
The light‑independent reactions of photosynthesis, also called the Calvin cycle, use and produce a variety of molecules. Sort the molecules into three categories: molecules brought in and used in the Calvin cycle, molecules produced during the Calvin cycle that leave the cycle, and molecules made in the cytoplasm from the products of the Calvin cycle. - energy‑carrier molecules that have lost some energy - energy‑carrier molecules formed in the light-dependent reactions - organic molecules such as glucose - carbon dioxide from the environment - 3‑carbon molecules that store energy Molecules brought in and used in the Calvin cycle: Molecules produced in the Calvin cycle that leave the cycle: Molecules made in the cytoplasm from the products of the Calvin cycle:
Molecules brought in and used in the Calvin cycle: - carbon dioxide from the environment - energy‑carrier molecules formed in the light-dependent reactions Molecules produced in the Calvin cycle that leave the cycle: - 3‑carbon molecules that store energy - energy‑carrier molecules that have lost some energy Molecules made in the cytoplasm from the products of the Calvin cycle: - organic molecules such as glucose
Classify each statement according to whether it describes similarities between the two photosystems in the light‑dependent reactions of photosynthesis or is unique to one of the photosystems. - The energized electrons are used to form NADPH after leaving this photosystem. - The bonds of water molecules are broken, producing H+, O2, and replacement electrons for chlorophyll molecules. - Light energy is used to excite an electron on specialized chlorophyll molecules. - Replacement electrons for chlorophyll molecules come from the electron transport chain. - Energy from electrons excited in this photosystem is used to help pump H+ ions into the thylakoid for ATP production. Similarities between the two photosystems: Unique to photosystem II: Unique to photosystem I:
Similarities between the two photosystems: - Light energy is used to excite an electron on specialized chlorophyll molecules. Unique to photosystem II: - The bonds of water molecules are broken, producing H+, O2, and replacement electrons for chlorophyll molecules. - Energy from electrons excited in this photosystem is used to help pump H+ ions into the thylakoid for ATP production. Unique to photosystem I: - The energized electrons are used to form NADPH after leaving this photosystem. - Replacement electrons for chlorophyll molecules come from the electron transport chain.